The Science Thread

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  • its the most important human endeavor

  • I dont have to believe in what I cant understand


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Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
just a dumping ground for scientific articles and discussion

https://www.msn.com/en-us/news/tech...ly-exist-scientists-say/ar-AAu227S?li=BBnb7Kz

The Universe Should Not Actually Exist, Scientists Say

The universe as we know it should not exist, scientists working at CERN, the European Organization for Nuclear Research, have said.

After performing the most precise experiments on antiprotons that have ever been carried out, researchers have discovered a symmetry in nature that they say just shouldn’t be possible.

One of the big questions about the universe is how the first matter formed after the Big Bang. Because particles and antiparticles annihilate one another when they come into contact, if there were exactly equal measures of both, the universe wouldn’t exist—at least not in the form we see it today. As such, there must be an imbalance between particles and antiparticles, even if it is only by the tiniest fraction.

But this is not the case. All experiments designed to find this asymmetry have come up blank. This is also true of the latest, which were recently carried out at CERN by an international team of researchers. The findings from the BASE (Baryon Antibaryon Symmetry Experiment) are published in the journal Nature.

"All of our observations find a complete symmetry between matter and antimatter, which is why the universe should not actually exist," first author Christian Smorra, from Japan’s RIKEN institute, said in a statement.

In the study, researchers used antiprotons that had been isolated in 2015. The antiprotons were measured using the interaction of two traps that use electrical and magnetic fields to capture them. The team was able to measure the magnetic force of the antiproton to a level that is 350 times more precise than ever before.

If there was an imbalance between protons and antiprotons, this level of precision would be the best bet for finding it. "At its core, the question is whether the antiproton has the same magnetism as a proton," said Stefan Ulmer, spokesperson of the BASE group. "This is the riddle we need to solve."

"The measurement of antiprotons was extremely difficult and we had been working on it for 10 years. The final breakthrough came with the revolutionary idea of performing the measurement with two particles."

After finding no asymmetry between particles and antiparticles, the researchers will now work to develop even higher-precision measurements of protons and antiprotons to improve on the latest findings. "An asymmetry must exist here somewhere but we simply do not understand where the difference is. What is the source of the symmetry break?" Smorra said.


https://www.msn.com/en-us/news/tech...ints-at-unknown-physics/ar-AAu3Wcl?li=BBnb7Kz

Dark Matter In Galaxy Clusters Hints At Unknown Physics

As if dark matter wasn’t already mysterious and elusive enough, a theoretical variant takes it to a whole new level — exotic dark matter. It is thought to exist at the cores of galaxy clusters and phenomena that can be ascribed to it hint at the existence of fundamental physics that we still don’t know about.

Galaxy clusters are exactly what the name suggests — massive clusters that contain thousands of galaxies and hot gas — and are the largest cosmic structures in the universe. According to present-day models of dark matter, the centers of these clusters are extremely dense and they all have one huge galaxy that never moves away from the cluster’s core.

All galaxy clusters also contain one brightest cluster galaxy, which is brighter than all the other galaxies in the cluster. The BCG (generally an elliptical galaxy; they are among the most massive galaxies in the universe) is thought to have formed as a result of merger between a number of smaller galaxies within the cluster.

According to the dark matter theory derived from the Standard Model (this dark matter is called “cold dark matter”), the large density of dark matter at a galaxy cluster’s core tightly binds the BCG to the center. But in a paper published online Thursday, researchers used observations of 10 galaxy clusters, along with simulations, that show the BCG continues to wobble long after the rest of the cluster has relaxed following the merging of galaxy clusters.

The team of researchers that carried out the simulations was led by David Harvey from École Polytechnique Fédérale de Lausanne, Switzerland.

“We found that that the BCGs ‘slosh’ around at the bottom of the halos. This indicates that, instead of a dense region in the center of the galaxy cluster, there is a much shallower central density — a striking signal of exotic forms of dark matter right at the heart of galaxy clusters,” Harvey said in a statement Thursday.

The researchers plan to observe a larger number of galaxy clusters in the future to “determine if BCG wobbling originates in new fundamental physics or a novel astrophysical phenomenon.”

The massive size of galaxy clusters helps astronomers observe them. The gravity generated by their bulk makes them act as gravitational lenses, which bend light that passes through them, allowing scientists to create a map of dark matter within them. This, in turn, allows for figuring out where the cluster center is and also observing the BCG wobble around it.

Dark matter, which has never been directly observed but only indirectly inferred, accounts for 85 percent of all the mass in the observable universe, and for 27 percent of all matter and energy. Dark energy, on the other hand, constitutes an overwhelming 68 percent of the universe, while the regular matter and energy we interact with, given our physical senses and current technology, accounts for less than 5 percent of totality of the universe.

The paper, titled “A detection of wobbling Brightest Cluster Galaxies within massive galaxy clusters," appeared in the journal Monthly Notices of the Royal Astronomical Society. A copy is available on the preprint server arXiv.
 

Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
http://www.cnn.com/2017/10/27/us/mystery-object-solar-system-trnd/index.html

This mystery object may be our first visitor from another solar system

Astronomers around the world are trying to track down a small, fast-moving object that is zipping through our solar system.
Is a comet? An asteroid? NASA's not sure. The space agency doesn't even know where it came from, but it's not behaving like the local space rocks and that means it may not be from our solar system.
If that's confirmed, NASA says "it would be the first interstellar object to be observed and confirmed by astronomers."



"We have been waiting for this day for decades," Paul Chodas, manager of NASA's Center for Near-Earth Object Studies, said in a NASA news release. "It's long been theorized that such objects exist -- asteroids or comets moving around between the stars and occasionally passing through our solar system -- but this is the first such detection. So far, everything indicates this is likely an interstellar object, but more data would help to confirm it."
NASA says astronomers are pointing telescopes on the ground and in space at the object to get that data.
For now, the object is being called A/2017 U1. Experts think it's less than a quarter-mile (400 meters) in diameter and it's racing through space at 15.8 miles (25.5 kilometers) per second.
It was discovered October 19 by the University of Hawaii's Pan-STARRS 1 telescope on Haleakala, Hawaii.
Rob Weryk, a postdoctoral researcher at the University of Hawaii Institute for Astronomy, was the first to identify the object and immediately realized there was something different about it.
"Its motion could not be explained using either a normal solar system asteroid or comet orbit," he said. "This object came from outside our solar system."
Whatever "it" is, the object isn't a threat to Earth.
NASA say that on October 14, it safely passed our home world at a distance of about 15 million miles (24 million kilometers) -- that's about 60 times the distance to the moon.
Where's it going? Scientists think the object is heading toward the constellation Pegasus and is on its way out of our solar system.
"This is the most extreme orbit I have ever seen," said Davide Farnocchia, a scientist at the Center for Near-Earth Object Studies. "It is going extremely fast and on such a trajectory that we can say with confidence that this object is on its way out of the solar system and not coming back."
"It" may eventually get a better name than A/2017 U1, but since the object is the first of its kind, the International Astronomical Union will have to come up with new rules for naming the object.
 
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Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
https://www.msn.com/en-us/news/tech...ramid-using-cosmic-rays/ar-AAulYAm?li=BBnb7Kz

An Unknown 'Void' Found in the Great Pyramid Using Cosmic Rays

On the Giza Plateau in Egypt rise three large pyramids—the tallest and oldest of which is the Pyramid of Khufu. It is also known as simply the Great Pyramid of Giza. You know what it looks like. It’s one of the seven great wonders of the world.

Yet, for all its fame and antiquity, so many questions remain. How was it built? Why is there nothing in the pyramid, except a broken sarcophagus missing its lid? Could there be anything else hidden inside this massive structure? In the absence of information, there is of course ferocious speculation. And now, an intriguing new piece of information: the discovery, announced today, of a large, previously unknown “void” in the Great Pyramid.

This discovery comes by way of cosmic rays. When these high-energy rays hit atoms in the Earth’s atmosphere, they send subatomic particles called muons shooting toward the ground. The muons can be slowed down by large masses—like the rocks that make up the Great Pyramid. And if muons pass through a cavity inside a large mass, that cavity will show up on muon detectors, too. Three groups of particle physicists using three different techniques patiently tracked muon patterns over several months—gathering evidence that a large cavity lurked in the middle of the pyramid.




1/4 SLIDES © Provided by Atlantic Media Company

It is an incredible—and incredibly expensive—technical feat. ScanPyramids is a project of Cairo University and the Heritage Innovation Preservation (HIP) Institute, the latter of which is funded by a number of private technology and media companies.
As for what it all means, Egyptologists are being very cautious. “The significance of it is still an open question. Even the shape of the void is not quite clear yet,” says Peter Der Manuelian , an Egyptologist at Harvard University, who was not involved with the study.

In fact, the study’s authors exhorted journalists, please, please do not call it a secret chamber. “We know it is a void, but we don’t want to use the word ‘chamber,’” says Mehdi Tayoubi, president of the HIP Institute and an author on the paper. Their caution maybe sharpened by the reaction to a press release last October extolling their preliminary results, which media reports quickly turned into speculation about “secret chambers.”

The new void is above the Grand Gallery—a passage with 28-foot vaulted ceilings leading to the King’s Chamber. The ScanPyramids group first saw hints of a void when they placed nuclear-emulsion film in the Queen’s Chamber, the room below the King’s Chamber. Nuclear-emulsion film records muons, not unlike how ordinary photographic film records photons. The team could see the Grand Gallery and the King’s Chamber in their muon pattern, but they also saw an anomaly. Two other teams of physicists—using instruments that detect muons passing through plastic arrays or argon—then verified this anomaly.

Using muons to study pyramids isn’t an entirely new idea. In the 1960s, future physics Nobel Prize winner Luis Alvarez took his early muon detector to the Pyramid of Khafre. He did not find any secret chambers or even unexpected anomalies. But the idea has lived on, and scientists have used muography to study volcanoes and man-made structures.

The ScanPyramids paper published in the scientific journal Nature is heavy on particle physics and deliberately light on archaeology. Hany Helal, an engineer at Cairo University and a member of the ScanPyramids team, says he is organizing a seminar in Egypt later this year, where archaeologists can come and debate the significance of the void for the pyramid’s construction.

Mark Lehner and Zahi Hawass, two members of the Egyptian Ministry of Antiquities’ scientific committee, to whom ScanPyramids presented it results earlier this year, both told me they suspected the void to be a “construction gap.” All of the chambers and major passageways of the pyramid are aligned along one vertical plane. In order to build the chambers and fill in the rest of the pyramid simultaneously, workers may have worked along what is essentially a trench that allowed them continual access to the King’s Chamber and Grand Gallery. A construction gap could be a remnant of the trench. So it is not surprising, they say, that a void from the construction gap might appear in the space above the Grand Gallery.

In contacting Egyptologists for this story, I could sense a weariness and wariness in their responses. Weariness because claims about hidden chambers in pyramids surface all the time.

The thing to understand, says Lehner, is “the pyramid is more Swiss cheese than cheddar.” That’s only a slight exaggeration, he adds. The inside of the Great Pyramid is filled with stones of irregular sizes, so there are numerous small gaps. In this case, he agrees the void appears to be large enough as to be deliberate, like a construction gap. But many people before have found evidence of a small cavity in the pyramid and gone on to speculate wildly about secret chambers. Lehner said he found ScanPyramids’ characterization of a different anomaly on the pyramid’s north face as a “corridor” to be premature.

The wariness, on the other hand, seems to stem from the project’s origins. Tayoubi, the president and cofounder of the HIP Institute, is also a VP at Dassault Systèmes, a French 3-D-design software company. In 2005, he teamed up to visualize the Great Pyramid construction site with architect Jean-Pierre Houdin, whose idea that the pyramids were built using a series of ramps is not accepted by mainstream archaeologists. (He has since also worked with Der Manuelian at Harvard to reconstruct the Giza Plateau in 3-D.) Funding for the HIP Institute comes from a number of companies, including: Dassault, Japan’s national broadcasting agency, a watch company, a VR company, and a hotel near Giza.

Hawass, who is also a former Egyptian minister of antiquities, and an outsized, outspoken, and sometimes controversial figure in Egyptology, was blunt—his bluntness perhaps the result of longstanding frustration. “Everybody who comes to the pyramid,” he says, “either they’re looking for fame or they want to make experiments with their equipment and the equipment belongs to a company, and the company can make money.”

In an interview, Tayoubi acknowledged he is no Egyptologist, and he now assiduously avoided speculation on how the pyramid was built. He did want to tout the technologies used in the study, though not by company name. “We love innovation,” he says, “This mission is about better understanding the pyramid, but above all it’s about innovation,” he says. He likened studying the pyramid to space exploration—an endeavor driven by pure wonder that may nevertheless result in practical innovations in fields like muography and robotics. In fact, the ScanPyramids project is already designing its next piece of technology, a robot to explore inside the pyramid.

New technology might one day crack some of the questions about the Great Pyramid. But so much of its appeal may just be how little we know, despite its prominence and endurance. A mystery right in front of us, daring us to solve it.
 

Neganomics

Your Trusted Web M.Deezy
Joined
Dec 16, 2008
Location
Chicago
To be clear, nothing from MSN or CNN could accurately be called a “scientific article”, even if the article covers a scientific concept.
 

Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
OK then

www.bbc.com/news/science-environment-41845445

'Big void' identified in Khufu's Great Pyramid at Giza

The mysteries of the pyramids have deepened with the discovery of what appears to be a giant void within the Khufu, or Cheops, monument in Egypt.

It is not known why the cavity exists or indeed if it holds anything of value because it is not obviously accessible.

Japanese and French scientists made the announcement after two years of study at the famous pyramid complex.

They have been using a technique called muography, which can sense density changes inside large rock structures.

The Great Pyramid, or Khufu's Pyramid, was constructed during the reign of Pharaoh Khufu between 2509 and 2483 BC.

At 140m (460 feet) in height, it is the largest of the Egyptian pyramids located at Giza on the outskirts of Cairo.


  • ScanPyramids has already detected a smaller void on the northern face
  • The new cavity is perhaps 30m long and several metres in height
  • All three muon technologies sense the same feature in the same place
Khufu famously contains three large interior chambers and a series of passageways, the most striking of which is the 47m-long, 8m-high Grand Gallery.

The newly identified feature is said to sit directly above this and have similar dimensions.

"We don't know whether this big void is horizontal or inclined; we don't know if this void is made by one structure or several successive structures," explained Mehdi Tayoubi from the HIP Institute, Paris.

"What we are sure about is that this big void is there; that it is impressive; and that it was not expected as far as I know by any sort of theory."

The ScanPyramids team is being very careful not to describe the cavity as a "chamber".

Khufu contains compartments that experts believe may have been incorporated by the builders to avoid collapse by relieving some of the stress of the overlying weight of stone.

The higher King's Chamber, for example, has five such spaces above it.

The renowned American archaeologist Mark Lehner sits on a panel reviewing ScanPyramids' work.

He says the muon science is sound but he is not yet convinced the discovery has significance.

"It could be a kind of space that the builders left to protect the very narrow roof of the grand gallery from the weight of the pyramid," he told the BBC's Science In Action programme.

"Right now it's just a big difference; it's an anomaly. But we need more of a focus on it especially in a day and age when we can no longer go blasting our way through the pyramid with gunpowder as [British] Egyptologist Howard Vyse did in the early 1800s."

One of the team leaders, Hany Helal from Cairo University, believes the void is too big to have a pressure-relieving purpose, but concedes the experts will debate this.

"What we are doing is trying to understand the internal structure of the pyramids and how this pyramid has been built," he told reporters.

"Famous Egyptologists, archaeologists and architects - they have some hypotheses. And what we are doing is giving them data. It is they who have to tell us whether this is expected or not."

Much of the uncertainty comes down to the rather imprecise data gained from muography.

This non-invasive technique has been developed over the past 50 years to probe the interiors of phenomena as diverse as volcanoes and glaciers. It has even been used to investigate the failed nuclear reactors at Fukushima.

Muography makes use of the shower of high-energy particles that rain down on the Earth's surface from space.

When super-fast cosmic rays collide with air molecules, they produce a range of "daughter" particles, including muons.

These also move close to the speed of light and only weakly interact with matter. So when they reach the surface, they penetrate deeply into rock.

But some of the particles will be absorbed and deflected by the atoms in the rock's minerals, and if the muon detectors are placed under a region of interest then a picture of density anomalies can be obtained.

Image copyright SCANPYRAMIDS
Image caption The muon detectors have to be placed under the region of interest
The ScanPyramids team used three different muography technologies and all three agreed on the position and scale of the void.

Sébastien Procureur, from CEA-IRFU, University of Paris-Saclay, emphasised that muography only sees large features, and that the team's scans were not just picking up a general porosity inside the pyramid.

"With muons you measure an integrated density," he explained. "So, if there are holes everywhere then the integrated density will be the same, more or less, in all directions, because everything will be averaged. But if you see some excess of muons, it means that you have a bigger void.

"You don't get that in a Swiss cheese."

The question now arises as to how the void should be investigated further.

Jean-Baptiste Mouret, from the French national institute for computer science and applied mathematics (Inria), said the team had an idea how to do it, but that the Egyptian authorities would first have to approve it.

"Our concept is to drill a very small hole to potentially explore monuments like this. We aim to have a robot that could fit in a 3cm hole. Basically, we're working on flying robots," he said.

The muography investigation at Khufu's Pyramid is reported in this week's edition of Nature magazine.
[DOUBLEPOST=1509655129,1509649739][/DOUBLEPOST][DOUBLEPOST=1509733188][/DOUBLEPOST]www.bbc.com/news/health-41847030

Scientists find key to unwanted thoughts

Have you ever wanted to stop ruminating on something and just been unable to?

Scientists could have the secret. They have identified a chemical in the brain's "memory" region that allows us to suppress unwanted thoughts.

The discovery may help explain why some people can't shift persistent intrusive thoughts - a common symptom of anxiety, post-traumatic stress disorder (PTSD), depression and schizophrenia.

Researchers say controlling our thoughts is "fundamental to wellbeing".

Associated words
Prof Michael Anderson, from the University of Cambridge, who conducted the study, said: "When this capacity breaks down, it causes some of the most debilitating symptoms of psychiatric diseases - intrusive memories, images, hallucinations, ruminations, and pathological and persistent worries."

Participants were asked to learn to associate a series of words with a paired, but otherwise unconnected, word - for example ordeal/roach and moss/north.

After this, they had to respond to either a red or green signal. If it was green, they were expected to recall the associated word but if it was red, they were asked to stop themselves from doing so.

Their brains were monitored using both functional magnetic resonance imaging (FMRI), which detects changes in blood flow, and magnetic resonance spectroscopy, which measures chemical changes in the brain.


Researchers found a particular chemical, or neurotransmitter, known as Gaba, held the key.

Gaba is the brain's main "inhibitory" neurotransmitter. That means, when it's released by one nerve cell it suppresses the activities of other cells to which it is connected.

They found people who had the highest concentrations of Gaba in their brain's hippocampus (or memory hub) were best at blocking unwanted thoughts or memories.

"What's exciting about this is that now we're getting very specific," said Prof Anderson.

"Before, we could only say 'this part of the brain acts on that part', but now we can say which neurotransmitters are likely to be important."

New approaches to treatment
The discovery might shed light on a number of conditions, from schizophrenia to PTSD, in which sufferers have a pathological inability to control thoughts - such as excessive worrying or rumination.

Prof Anderson believes the findings could offer a new approach to treating these disorders. "Most of the focus has been on improving functioning of the prefrontal cortex," he said.

"Our study suggests that if you could improve Gaba activity within the hippocampus, this may help people to stop unwanted and intrusive thoughts."
 

Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
https://www.msn.com/en-us/news/tech...the-top-of-their-skulls/ar-AAupM98?li=BBnbfcL

Astronauts who take long trips to space return with brains that have floated to the top of their skulls

The vast majority of us spend our entire lives pulled down by gravity. Then there are astronauts.

This small population of space travelers has given researchers a rare look at what happens to the human body when it’s able to spend significant amount of time outside the downward pull of the Earth.This week, a study on one of the largest groups of astronauts yet—a whopping 34 participants—was published (paywall) in the New England Journal of Medicine.

In the new study, a team of international radiologists funded by NASA looked at MRIs of the brains of astronauts before and after their trips to space. The scientists found that upon returning to Earth, many of the astronauts’ brains had become repositioned inside their skulls, floating higher than before. In addition, the space between certain brain regions appeared to have shrunk. The changes were more common in astronauts who took longer trips into space.

The team characterized astronaut trips as short (an average of less than 14 days) or long (an average of about 165 days). Radiologists who didn’t know each astronaut’s duration in space compared MRIs from before and after their trips.

Of the 34 total astronauts involved in the study, 18 took long trips to space—spending most of that time on the International Space Station—and of those, 17 returned to Earth with smaller regions between the frontal and parietal lobe. The same area of the brain also shrunk for three of the 16 astronauts who took shorter trips with the US Space Shuttle Program. The researchers also found that 12 of the ISS astronauts and six of the space-shuttle astronauts returned home with their brains sitting slightly higher in their skulls than before.

It’s not clear what, if anything, these brain changes mean for the health of space travelers. In general, it appears the human body to tolerates space travel fairly well: the time astronauts have spent in zero-gravity environments so far doesn’t seem to have had any significant or long-lasting effects.

There have really only been minor complaints. Astronauts have complained about headaches in space before, which NASA chalked up to differences in pressure inside a person’s skull in space compared to Earth’s surface. Another small study of astronauts found that a buildup of brain fluid behind the eye socket seems to flatten the eyeball, which can impair vision. It could be that, without gravity, the fluids in our bodies reposition themselves around our organs, and that in turn puts pressure on them in ways we’re not used to experiencing on Earth. That said, researchers still aren’t sure if these fluid changes are totally responsible for these symptoms—it could be other aspects of space travel, like general stress, exhaustion, motion sickness, or different diets.

The open question, though, is how a human body would stand up on longer space trips, say to Mars.
and for @Neganomics

http://www.nejm.org/doi/full/10.1056/NEJMoa1705129

Effects of Spaceflight on Astronaut Brain Structure as Indicated on MRI

Background
There is limited information regarding the effects of spaceflight on the anatomical configuration of the brain and on cerebrospinal fluid (CSF) spaces.

Methods
We used magnetic resonance imaging (MRI) to compare images of 18 astronauts’ brains before and after missions of long duration, involving stays on the International Space Station, and of 16 astronauts’ brains before and after missions of short duration, involving participation in the Space Shuttle Program. Images were interpreted by readers who were unaware of the flight duration. We also generated paired preflight and postflight MRI cine clips derived from high-resolution, three-dimensional imaging of 12 astronauts after long-duration flights and from 6 astronauts after short-duration flights in order to assess the extent of narrowing of CSF spaces and the displacement of brain structures. We also compared preflight ventricular volumes with postflight ventricular volumes by means of an automated analysis of T1-weighted MRIs. The main prespecified analyses focused on the change in the volume of the central sulcus, the change in the volume of CSF spaces at the vertex, and vertical displacement of the brain.

Results
Narrowing of the central sulcus occurred in 17 of 18 astronauts after long-duration flights (mean flight time, 164.8 days) and in 3 of 16 astronauts after short-duration flights (mean flight time, 13.6 days) (P<0.001). Cine clips from a subgroup of astronauts showed an upward shift of the brain after all long-duration flights (12 astronauts) but not after short-duration flights (6 astronauts) and narrowing of CSF spaces at the vertex after all long-duration flights (12 astronauts) and in 1 of 6 astronauts after short-duration flights. "Neganomics may not even read this, he's too busy being knee deep" Three astronauts in the long-duration group had optic-disk edema, and all 3 had narrowing of the central sulcus. A cine clip was available for 1 of these 3 astronauts, and the cine clip showed upward shift of the brain.

Conclusions
Narrowing of the central sulcus, upward shift of the brain, and narrowing of CSF spaces at the vertex occurred frequently and predominantly in astronauts after long-duration flights. Further investigation, including repeated postflight imaging conducted after some time on Earth, is required to determine the duration and clinical significance of these changes. (Funded by the National Aeronautics and Space Administration.)
 

Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
https://www.msn.com/en-us/news/tech...gns-of-alien-technology/ar-BBGCXco?li=BBnb7Kz

Astronomers to check interstellar body for signs of alien technology

Astronomers are to use one of the world’s largest telescopes to check a mysterious object that is speeding through the solar system for signs of alien technology.

The Green Bank telescope in West Virginia will listen for radio signals being broadcast from a cigar-shaped body which was first spotted in the solar system in October. The body arrived from interstellar space and reached a peak speed of 196,000 mph as it swept past the sun.

Scientists on the Breakthrough Listen project, which searches for evidence of alien civilisations, said the Green Bank telescope would monitor the object, named ‘Oumuamua, from Wednesday. The first phase of observations is expected to last 10 hours and will tune in to four different radio transmission bands.

“Most likely it is of natural origin, but because it is so peculiar, we would like to check if it has any sign of artificial origin, such as radio emissions,” said Avi Loeb, professor of astronomy at Harvard University and an adviser to the Breakthrough Listen project. “If we do detect a signal that appears artificial in origin, we’ll know immediately.”

The interstellar body, the first to be seen in the solar system, was initially spotted by researchers on the Pan-Starrs telescope, which the University of Hawaii uses to scan the heavens for killer asteroids. Named after the Hawaiian word for “messenger”, the body was picked up as it swept past Earth at 85 times the distance to the moon.

While many astronomers believe the object is an interstellar asteroid, its elongated shape is unlike anything seen in the asteroid belt in our own solar system. Early observations of ‘Oumuamua show that it is about 400m long but only one tenth as wide. “It’s curious that the first object we see from outside the solar system looks like that,” said Loeb.

"> The object’s orbit
The body is now about twice as far from Earth as the sun, but from that distance the Green Bank telescope can still detect transmissions as weak as those produced by a mobile phone. Loeb said that while he did not expect Green Bank to detect an alien transmission, it was worth checking.

“The chances that we’ll hear something are very small, but if we do, we will report it immediately and then try to interpret it,” Loeb said. “It would be prudent just to check and look for signals. Even if we find an artefact that was left over and there are no signs of life on it, that would be the greatest thrill I can imagine having in my lifetime. It’s really one of the fundamental questions in science, perhaps the most fundamental: are we alone?”

The Breakthrough Listen project was launched at the Royal Society in London in 2015, when the Cambridge cosmologist Stephen Hawking announced the effort to listen for signs of life on planets that orbit the million stars closest to Earth. The $100m project is funded by the internet billionaire Yuri Milner, and has secured time on telescopes in the US and Australia to search for alien civilisations.

Astronomers do not have good ideas about how such elongated objects could be created in asteroid belts. By studying ‘Oumuamua more closely, they hope to learn how they might form and whether there are others in the solar system that have so far gone unnoticed. “If it’s of natural origin, there should be many more of them,” Loeb said.

Previous work on the body found it to be extremely dark red, absorbing about 96% of light that falls on it. The colour is associated with carbon-based molecules on comets and asteroids.

If, as expected, the telescope fails to pick up any intelligent broadcasts from ‘Oumuamua, the observations are still expected to aid scientists in understanding the body. Other signals detected by the Green Bank telescope could shed light on whether the object is shrouded in a comet-like cloud of gas, and reveal whether it is carrying water and ice through the solar system.
 

Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
https://www.sciencealert.com/science-how-blue-eyes-get-their-colour

This Is The Fascinating Way Blue Eyes Get Their Colour

Your eyes aren't blue (or green) because they contain pigmented cells.

As Paul Van Slembrouck writes for Medium, their colour is actually structural - and it involves some pretty interesting physics.

The coloured part of your eye is called the iris, and it's made up of two layers - the epithelium at the back and the stroma at the front.

The epithelium is only two cells thick and contains black-brown pigments - the dark specks that some people have in their eye is, in fact, the epithelium peaking through.

The stroma, in contrast, is made up of colourless collagen fibres. Sometimes the stroma contains a dark pigment called melanin, and sometimes it contains excess collagen deposits.

And, fascinatingly, it's these two factors that control your eye colour.

Brown eyes, for example, contain a high concentration of melanin in their stroma, which absorbs most of the light entering the eye regardless of collagen deposits, giving them their dark colour.

Green eyes don't have much melanin in them, but they also have no collagen deposits.

This means that while some of the light entering them is absorbed by the pigment, the particles in the stroma also scatter light as a result of something called the Tyndall effect, which creates a blue hue (it's similar to Rayleigh scattering which makes the sky look blue).

Combined with the brown melanin, this results in the eyes appearing green.

Blue eyes are potentially the most fascinating, as their colour is entirely structural.

People with blue eyes have a completely colourless stroma with no pigment at all, and it also contains no excess collagen deposits.

This means that all the light that enters it is scattered back into the atmosphere and as a result of the Tyndall effect, creates a blue hue.

Interestingly, this means that blue eyes don't actually have a set colour - it all depends on the amount of light available when you look at them.

Structural colouration also gives colour to butterflies, beef and berries.https://medium.com/@ptvan/structural-eye-color-is-amazing-24f47723bf9a

It's pretty mind-blowing stuff.

Van Slembrouck writes for Medium:

"Imagine that you could shrink yourself to a microscopic size and then climb through the mesh of fibres in the stroma. That's where structural colouration is coming from…

… and in the mesh are also strands of smooth muscle tissue that contract to dilate (expand) the pupil, pulling the inner edge of the iris toward the outer edge. When this happens, the stroma fibres slacken and may become wiggly as tension is released. This makes me wonder, does that slightly alter the colour of your eye as well?"

Check out Van Slembrouck's great story to find out how hazel and grey eyes get their colour, and also to check out his beautiful diagrams that explain structural colouring.
 

Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
www.bbc.com/future/story/20180118-the-boy-who-stayed-awake-for-11-days

In December 1963 two boys hit upon an idea for a school science project – stay awake for as long as possible. And it shed new light on what happens inside our tired brains.

At the tail end of 1963 in America, the Beach Boys were playing on the radio, the Vietnam War had begun to draw in US involvement, high school kids were on their Christmas break and two teenagers were planning an experiment that would capture the nation’s attention.

It ended on 8 January 1964; 17-year-old Randy Gardner had managed to stay awake for 11 days and 25 minutes.

Bruce McAllister, one of the high school students who came up with the idea, says it stemmed from the simple need to come up with a science fair project. Teamed with the creativity and cockiness that goes with teenage years, Bruce and his friend Randy decided they wanted to beat the world record for staying awake – which at the time was held by a DJ in Honolulu, who'd managed 260 hours, or just under 11 days.

“[The] first version of it was [to explore] the effect of sleeplessness on paranormal ability,” McAllister explains. “We realised there was no way we could do that and so we decided on the effect of sleep deprivation on cognitive abilities, performance on the basketball court. Whatever we could come up with.”

They flipped a coin on who would stay awake and much to McAllister’s relief, he won the toss. But their naivety surfaced in how they planned to observe the effects on Randy.

“We were idiots, you know young idiots,” he says “and I stayed awake with him to monitor him… and after three night of sleeplessness myself I woke up tipped against the wall writing notes on the wall itself.”

The teenagers realised they needed a third person involved so they roped in another friend – Joe Marciano – to help out. Shortly after Marciano came on board, a sleep researcher called William Dement from Stanford University arrived.

I was probably the only person on the planet at the time who had actually done sleep research – William Dement

Dement is now an emeritus professor – but in 1964 he was just starting his research in the still new field of sleep science. He had read about the experiment in a San Diego newspaper and immediately wanted to get involved – much to the relief of Randy’s parents.

“I was probably the only person on the planet at the time who had actually done sleep research,” Dement says “[Randy’s parents] were very worried that this might be something that would really be harmful to him. Because the question was still unresolved on whether or not if you go without sleep long enough you will die.”

Our capacity to go without sleep is something that BBC Future has explored previously. Experiments on animals, such as one which kept cats awake for 15 days at which point they died, point to whether other factors such as stress or chemicals are the cause of death, rather than lack of sleep.

Indeed, McAllister insists that those experiments involved the use of chemicals, which muddied the results. “Randy had occasional Cokes but other than that, you know, no Dexedrine, Benzedrine, the du jour stimulants in those days,” he says.

Back to San Diego and by the time William Dement arrived a few days into the experiment, Randy was upbeat and didn’t seem particularly impaired. However, as the days wore on, the experiments they did on him threw up some unexpected results.

They tested his sense of taste, smell and hearing and after a while his cognitive and sensory abilities began to be affected.

McAllister recalls Randy beginning to say: “Don’t make me smell that, I can’t stand the smell.” Surprisingly though, his basketball game got better although this could be down to the amount he was playing.

“He was physically very fit,” says Dement. “So we could always get him going by playing basketball or going bowling, things like that. If he closed his eyes he would be immediately asleep.” Night time was harder as there was nothing to do and they had a terrible time keeping him awake.

As all this was happening, attention from the media began to gain momentum and for a brief time the boys’ experiment became the third most written-about story in the American national press – after the assassination of John F Kennedy and a visit by The Beatles.

Randy was taken off to a naval hospital where his brain waves were monitored

However, it was portrayed as a prank, in the same bracket as “telephone booth stuffing and goldfish swallowing”, according to McAllister. The students were very serious about it and pushed through. Eventually after 264 hours of no sleep, the world record was broken and the experiment was over.

Rather than curling up in his own bed to get some much needed rest, Randy was taken off to a naval hospital where his brain waves were monitored. McAllister describes what happened next.

“So he sleeps for 14 hours – we’re not surprised – [and] he wakes up, in fact, because he has to go to the bathroom. His first night his percentage of REM state sleep, which was at that point associated with dream-state sleep – it isn’t anymore – skyrocketed. Then the next night it dropped in percentage points until finally days later it returned to normal.

“And then he got up and went to high school… it was amazing,” Dement adds.

Randy’s results from the hospital were sent off to Arizona to be studied. McAllister says the results concluded that “his brain had been catnapping the entire time… parts of it would be asleep parts of it would be awake.”

For him it makes sense in the context of human evolution. “He wasn’t the first human being – or pre-human being – to have to stay awake for more than one night and that the human brain might evolve so that it could catnap – parts of it could catnap and restore – while parts of it were awake – made total sense. And that would explain why worse things didn’t happen,” he says.

A number of people tried to break Gardner’s record for the longest time anyone had stayed awake in the following years – but the Guinness Book of Records stopped certifying attempts, believing it could be dangerous to people's health.

Randy seemed to show no ill effects from his 11 days awake – although he later reported suffering from years of unbearable insomnia. At a press conference outside his parents’ home after the experiment had ended, the teenagers fielded questions from a huge crowd that had gathered.

The boy who hadn’t slept for 11 days somehow managed to be philosophical about his endeavour.

“It’s just mind over matter,” he said.
 

Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
[DOUBLEPOST=1517291479,1517208181][/DOUBLEPOST]https://www.wired.com/story/35-billion-year-old-fossils-challenge-ideas-about-earths-start/

3.5 Billion-Year-Old Fossils Challenge Ideas About Earth’s Start

In the arid, sun-soaked northwest corner of Australia, along the Tropic of Capricorn, the oldest face of Earth is exposed to the sky. Drive through the northern outback for a while, south of Port Hedlund on the coast, and you will come upon hills softened by time. They are part of a region called the Pilbara Craton, which formed about 3.5 billion years ago, when Earth was in its youth.

Look closer. From a seam in one of these hills, a jumble of ancient, orange-Creamsicle rock spills forth: a deposit called the Apex Chert. Within this rock, viewable only through a microscope, there are tiny tubes. Some look like petroglyphs depicting a tornado; others resemble flattened worms. They are among the most controversial rock samples ever collected on this planet, and they might represent some of the oldest forms of life ever found.

Last month, researchers lobbed another salvo in the decades-long debate about the nature of these forms. They are indeed fossil life, and they date to 3.465 billion years ago, according to John Valley, a geochemist at the University of Wisconsin. If Valley and his team are right, the fossils imply that life diversified remarkably early in the planet’s tumultuous youth.

The fossils add to a wave of discoveries that point to a new story of ancient Earth. In the past year, separate teams of researchers have dug up, pulverized and laser-blasted pieces of rock that may contain life dating to 3.7, 3.95 and maybe even 4.28 billion years ago. All of these microfossils—or the chemical evidence associated with them—are hotly debated. But they all cast doubt on the traditional tale.

As that story goes, in the half-billion years after it formed, Earth was hellish and hot. The infant world would have been rent by volcanism and bombarded by other planetary crumbs, making for an environment so horrible, and so inhospitable to life, that the geologic era is named the Hadean, for the Greek underworld. Not until a particularly violent asteroid barrage ended some 3.8 billion years ago could life have evolved.

But this story is increasingly under fire. Many geologists now think Earth may have been tepid and watery from the outset. The oldest rocks in the record suggest parts of the planet’s crust had cooled and solidified by 4.4 billion years ago. Oxygen in those ancient rocks suggest the planet had water as far back as 4.3 billion years ago. And instead of an epochal, final bombardment, meteorite strikes might have slowly tapered off as the solar system settled into its current configuration.

“Things were actually looking a lot more like the modern world, in some respects, early on. There was water, potentially some stable crust. It’s not completely out of the question that there would have been a habitable world and life of some kind,” said Elizabeth Bell, a geochemist at the University of California, Los Angeles.

Taken together, the latest evidence from the ancient Earth and from the moon is painting a picture of a very different Hadean Earth: a stoutly solid, temperate, meteorite-clear and watery world, an Eden from the very beginning.

Ancient Clues
About 4.54 billion years ago, Earth was forming out of dust and rocks left over from the sun’s birth. Smaller solar leftovers continually pelted baby Earth, heating it up and endowing it with radioactive materials, which further warmed it from within. Oceans of magma covered Earth’s surface. Back then, Earth was not so much a rocky planet as an incandescent ball of lava.

Not long after Earth coalesced, a wayward planet whacked into it with incredible force, possibly vaporizing Earth anew and forming the moon. The meteorite strikes continued, some excavating craters 1,000 kilometers across. In the standard paradigm of the Hadean eon, these strikes culminated in an assault dubbed the Late Heavy Bombardment, also known as the lunar cataclysm, in which asteroids emigrated to the inner solar system and pounded the rocky planets. Throughout this early era, ending about 3.8 billion years ago, Earth was molten and couldn’t support a crust of solid rock, let alone life.


Lucy Reading-Ikkanda/Quanta Magazine
But starting around a decade ago, this story started to change, thanks largely to tiny crystals called zircons. The gems, which are often about the size of the period at the end of this sentence, told of a cooler, wetter and maybe livable world as far back as 4.3 billion years ago. In recent years, fossils in ancient rock bolstered the zircons’ story of calmer climes. The tornadic microfossils of the Pilbara Craton are the latest example.

Today, the oldest evidence for possible life—which many scientists doubt or outright reject—is at least 3.77 billion years old and may be a stunningly ancient 4.28 billion years old.

In March 2017, Dominic Papineau, a geochemist at University College London, and his student Matthew Dodd described tubelike fossils in an outcrop in Quebec that dates to the basement of Earth’s history. The formation, called the Nuvvuagittuq (noo-voo-wog-it-tuck) Greenstone Belt, is a fragment of Earth’s primitive ocean floor. The fossils, about half the width of a human hair and just half a millimeter long, were buried within. They are made from an iron oxide called hematite and may be fossilized cities built by microbial communities up to 4.28 billion years ago, Dodd said.

“They would have formed these gelatinous, rusty-red-colored mats on the rocks around the vents,” he said. Similar structures exist in today’s oceans, where communities of microbes and bloody-looking tube worms blossom around sunless, black-smoking chimneys.

Dodd found the tubes near graphite and with carbonate “rosettes,” tiny carbon rings that contain organic materials. The rosettes can form through varying nonbiological processes, but Dodd also found a mineral called apatite, which he said is diagnostic of biological activity. The researchers also analyzed the variants, or isotopes, of carbon within the graphite. Generally, living things like to use the more lightweight isotopes, so an abundance of carbon 12 over carbon 13 can be used to infer past biological activity. The graphite near the rosettes also suggested the presence of life. Taken together, the tubes and their surrounding chemistry suggest they are remnants of a microbial community that lived near a deep-ocean hydrothermal vent, Dodd said.

Geologists debate the exact age of the rock belt where they were found, but they agree it includes one of the oldest, if not the oldest, iron formations on Earth. This suggests the fossils are that old, too—much older than anything found previously and much older than many scientists had thought possible.

Then in September 2017, researchers in Japan published an examination of graphite flakes from a 3.95-billion-year-old sedimentary rock called the Saglek Block in Labrador, Canada. Yuji Sano and Tsuyoshi Komiya of the University of Tokyo argued their graphite’s carbon-isotope ratio indicates it, too, was made by life. But the graphite flakes were not accompanied by any feature that looked like a fossil; what’s more, the history of the surrounding rock is murky, suggesting the carbon may be younger than it appears.

Farther to the east, in southwestern Greenland, another team had also found evidence of ancient life. In August 2016, Allen Nutman of the University of Wollongong in Australia and colleagues reported finding stromatolites, fossil remains of microbes, from 3.7 billion years ago.

Many geologists have been skeptical of each claim. Nutman’s fossils, for example, come from the Isua belt in southern Greenland, home to the oldest known sedimentary rocks on Earth. But the Isua belt is tough to interpret. Just as nonbiological processes can form Dodd’s carbon rosettes, basic chemistry can form plenty of layered structures without any help from life, suggesting they may not be stromatolites but lifeless pretenders.

In addition, both the Nuvvuagittuq Greenstone Belt and the Isua belt have been heated and squished over billions of years, a process that melts and recrystallizes the rocks, morphing them from their original sedimentary state.

“I don’t think any of those other studies are wrong, but I don’t think any of them are proof,” said Valley, the Wisconsin researcher. “All we can say is [Nutman’s rocks] look like stromatolites, and that’s very enticing.”

Regarding his work with the Pilbara Craton fossils, however, Valley is much less circumspect.

Signs of Life
The tornadic microfossils lay in the Pilbara Craton for 3.465 billion years before being separated from their natal rock, packed up in a box and shipped to California. Paleobiologist William Schopf of UCLA published his discovery of the strange squiggles in 1993 and identified 11 distinct microbial taxa in the samples. Critics said the forms could have been made in nonbiological processes, and geologists have argued back and forth in the years since. Last year, Schopf sent a sample to Valley, who is an expert with a super-sensitive instrument for measuring isotope ratios called a secondary ion mass spectrometer.

Valley’s team found that some of the apparent fossils had the same carbon-isotope ratio as modern photosynthetic bacteria. Three other types of fossils had the same ratios as methane-eating or methane-producing microbes. Moreover, the isotope ratios correlate to specific species that had already been identified by Schopf. The locations where these isotope ratios were measured corresponded to the shapes of the microfossils themselves, Valley said, adding they are the oldest samples that look like fossils both physically and chemically.

part 1
[DOUBLEPOST=1517291551][/DOUBLEPOST]
While they are not the oldest samples in the record—supposing you accept the provenance of the rocks described by Dodd, Komiya and Nutman—Schopf’s and Valley’s cyclonic miniatures do have an important distinction: They are diverse. The presence of so many different carbon isotope ratios suggests the rock represents a complex community of primitive organisms. The life-forms must have had time to evolve into endless iterations. This means they must have originated even earlier than 3.465 billion years ago. And that means our oldest ancestors are very, very old indeed.

Watery World
Fossils were not the first sign that early Earth might have been Edenic rather than hellish. The rocks themselves started providing that evidence as far back as 2001. That year, Valley found zircons that suggested the planet had a crust as far back as 4.4 billion years ago.

Zircons are crystalline minerals containing silicon, oxygen, zirconium and sometimes other elements. They form inside magma, and like some better-known carbon crystals, zircons are forever—they can outlast the rocks they form in and withstand eons of unspeakable pressure, erosion and deformation. As a result, they are the only rocks left over from the Hadean, making them invaluable time capsules.

Valley chipped some out of Western Australia’s Jack Hills and found oxygen isotopes that suggested the crystal formed from material that was altered by liquid water. This suggested part of Earth’s crust had cooled, solidified and harbored water at least 400 million years earlier than the earliest known sedimentary rocks. If there was liquid water, there were likely entire oceans, Valley said. Other zircons showed the same thing.

“The Hadean was not hell-like. That’s what we learned from the zircons. Sure, there were volcanoes, but they were probably surrounded by oceans. There would have been at least some dry land,” he said.

Zircons suggest there may even have been life.

In research published in 2015, Bell and her coauthors presented evidence for graphite embedded within a tiny, 4.1-billion-year-old zircon crystal from the same Jack Hills. The graphite’s blend of carbon isotopes hints at biological origins, although the finding is—once again—hotly debated.

“Are there other explanations than life? Yeah, there are,” Bell said. “But this is what I would consider the most secure evidence for some sort of fossil or biogenic structure.”


An X-ray of a 4.1-billion-year-old sample of zircon reveals dark spots made by carbon deposits.
Crystal Shi/Stanford University Department of Earth, Energy, and Environmental Sciences
If the signals in the ancient rocks are true, they are telling us that life was everywhere, always. In almost every place scientists look, they are finding evidence of life and its chemistry, whether it is in the form of fossils themselves or the remnants of life’s long-ago stirrings. Far from fussy and delicate, life may have taken hold in the worst conditions imaginable.

“Life was managing to do interesting things at the same time Earth was dealing with the worst impacts it’s ever had,” said Bill Bottke, a planetary scientist at the Southwest Research Institute in Boulder, Colorado.

Or maybe not. Maybe Earth was just fine. Maybe those impacts weren’t quite as rapid-fire as everyone thought.

Evidence for a Beating
We know Earth, and everything else, was bombarded by asteroids in the past. The moon, Mars, Venus and Mercury all bear witness to this primordial pummeling. The question is when, and for how long.

Based largely on Apollo samples toted home by moonwalking astronauts, scientists came to believe that in the Earth’s Hadean age, there were at least two distinct epochs of solar system billiards. The first was the inevitable side effect of planet making: It took some time for the planets to sweep up the biggest asteroids and for Jupiter to gather the rest into the main asteroid belt.

The second came later. It began sometime between 500 and 700 million years after the solar system was born and finally tapered off around 3.8 billion years ago. That one is called the Late Heavy Bombardment, or the lunar cataclysm.

As with most things in geochemistry, evidence for a world-rending blitz, an event on the hugest scales imaginable, is derived from the very, very small. Isotopes of potassium and argon in Apollo samples suggested bits of the moon suddenly melted some 500 million years after it formed. This was taken as evidence that it was blasted within an inch of its life.

Zircons also provide tentative physical evidence of a late-era hellscape. Some zircons do contain “shocked” minerals, evidence for extreme heat and pressure that can be indicative of something horrendous. Many are younger than 3 billion years, but Bell found one zircon suggesting rapid, extreme heating around 3.9 billion years ago—a possible signature of the Late Heavy Bombardment. “All we know is there is a group of recrystallized zircons at this time period. Given the coincidence with the Late Heavy Bombardment, it was too hard not to say that maybe this is connected,” she said. “But to really establish that, we will need to look at zircon records at other localities around the planet.”

So far, there are no other signs, said Aaron Cavosie of Curtin University in Australia.

Moon Rocks
In 2016 Patrick Boehnke, now at the University of Chicago, took another look at those original Apollo samples, which for decades have been the main evidence in favor of the Late Heavy Bombardment. He and UCLA’s Mark Harrison reanalyzed the argon isotopes and concluded that the Apollo rocks may have been walloped many times since they crystallized from the natal moon, which could make the rocks seem younger than they really are.

“Even if you solve the analytical problems,” said Boehnke, “then you still have the problem that the Apollo samples are all right next to each other.” There’s a chance that astronauts from the six Apollo missions sampled rocks from a single asteroid strike whose ejecta spread throughout the Earth-facing side of our satellite.

In addition, moon-orbiting probes like the Gravity Recovery and Interior Laboratory (GRAIL) spacecraft and the Lunar Reconnaissance Orbiter have found around 100 previously unknown craters, including a spike in impacts as early as 4.3 billion years ago.

“This interesting confluence of orbital data and sample data, and all different kinds of sample data—lunar impact glass, Luna samples, Apollo samples, lunar meteorites—they are all coming together and pointing to something that is not a cataclysmic spike at 3.9 billion years ago,” said Nicolle Zellner, a planetary scientist at Albion College in Michigan.

Bottke, who studies asteroids and solar system dynamics, is one of several researchers coming up with modified explanations. He now favors a slow uptick in bombardment, followed by a gradual decline. Others think there was no late bombardment, and instead the craters on the moon and other rocky bodies are remnants from the first type of billiards, the natural process of planet building.

“We have a tiny sliver of data, and we’re trying to do something with it,” he said. “You try to build a story, and sometimes you are just chasing ghosts.”

Life Takes Hold
While it plays out, scientists will be debating much bigger questions than early solar-system dynamics.

If some of the new evidence truly represents impressions of primeval life, then our ancestors may be much older than we thought. Life might have arisen the moment the planet was amenable to it—the moment it cooled enough to hold liquid water.

“I was taught when I was young that it would take billions and billions of years for life to form. But I have not been able to find any basis for those sorts of statements,” said Valley. “I think it’s quite possible that life emerged within a few million years of when conditions became habitable. From the point of view of a microbe, a million years is a really long time, yet that’s a blink of an eye in geologic time.”

“There is no reason life could not have emerged at 4.3 billion years ago,” he added. “There is no reason.”

If there was no mass sterilization at 3.9 billion years ago, or if a few massive asteroid strikes confined the destruction to a single hemisphere, then Earth’s oldest ancestors may have been here from the haziest days of the planet’s own birth. And that, in turn, makes the notion of life elsewhere in the cosmos seem less implausible. Life might be able to withstand horrendous conditions much more readily than we thought. It might not need much time at all to take hold. It might arise early and often and may pepper the universe yet. Its endless forms, from tubemaking microbes to hunkering slime, may be too small or simple to communicate the way life does on Earth—but they would be no less real and no less alive.
[DOUBLEPOST=1517376119][/DOUBLEPOST]https://www.nytimes.com/2018/01/29/health/heart-disease-mutations-stem-cells.html

Scientists Discover a Bone-Deep Risk for Heart Disease


Few doctors, and even fewer patients, have heard of CHIP. But it is emerging as a major cause of heart attacks and stroke, as deadly as high blood pressure or cholesterol.

It’s been one of the vexing questions in medicine: Why is it that most people who have heart attacks or strokes have few or no conventional risk factors?

These are patients with normal levels of cholesterol and blood pressure, no history of smoking or diabetes, and no family history of cardiovascular disease. Why aren’t they spared?

To some researchers, this hidden risk is the dark matter of cardiology: an invisible but omnipresent force that lands tens of thousands of patients in the hospital each year. But now scientists may have gotten a glimpse of part of it.

They have learned that a bizarre accumulation of mutated stem cells in bone marrow increases a person’s risk of dying within a decade, usually from a heart attack or stroke, by 40 or 50 percent. They named the condition with medical jargon: clonal hematopoiesis of indeterminate potential.
CHIP has emerged as a risk for heart attack and stroke that is as powerful as high LDL or high blood pressure but it acts independently of them. And CHIP is not uncommon.

The condition becomes more likely with age. Up to 20 percent of people in their 60s have it, and perhaps 50 percent of those in their 80s.

“It is beginning to appear that there are only two types of people in the world: those that exhibit clonal hematopoiesis and those that are going to develop clonal hematopoiesis,” said Kenneth Walsh, who directs the hematovascular biology center at the University of Virginia School of Medicine.

The growing evidence has taken heart researchers aback. Dr. Peter Libby, a cardiologist at Brigham and Women’s Hospital and professor of medicine at Harvard Medical School, calls CHIP the most important discovery in cardiology since statins.

“I’m turning part of my lab to work on this full time,” Dr. Libby said. “It’s really exciting.”

The mutations are acquired, not inherited — most likely by bad luck or exposure to toxins like cigarette smoke. But there is little that patients can do.

Brian Gear, a project manager at a Boston company that analyzes health care data, was given genetic testing by doctors at Dana-Farber Cancer Institute because his mother had had a blood cancer that can be inherited.

The diagnosis was CHIP, something he had never heard of. And because it dramatically increased his risk of heart disease, it was life-changing.

“It is almost like a Ph.D. in letting go of control,” said Mr. Gear, who said he was in his mid-30s. “As much as you want to have a plan and a destiny, you also have this thing. It’s scary and it’s terrifying.”

“I don’t want to use the word time-bomb, but that’s how it feels,” he added.

CHIP was discovered independently by several groups of researchers who were not even investigating heart disease. Mostly, they were looking at the genes of patients who might develop leukemia or, in one research project, schizophrenia.

The scientists searched databases from genetic studies involving tens of thousands of people whose DNA had been obtained from their white blood cells.

To their great surprise, the teams converged on the same phenomenon. Unexpectedly large numbers of study participants had blood cells with mutations linked to leukemia — but they did not have the cancer. Instead, they had just one or two of the cluster of mutations.

“This clearly wasn’t happening by chance,” said Steven McCarroll, a geneticist at the Broad Institute and Harvard Medical School. “We knew we were onto something, but what were we onto?”

The investigators quickly guessed the broad outlines.

White blood cells, the attack dogs of the immune system, arise from stem cells in the bone marrow. Every day, a few hundred such stem cells spew out blood cells that begin dividing rapidly into the 10 billion needed to replace those that have died.

Sometimes, by chance, one of those marrow stem cells acquires a mutation, and the white blood cells it produces carry the same mutation.

“Some mutations are just markers of past events without any lasting consequence,” said Dr. David Steensma, a blood cancer specialist at Harvard Medical School and Dana-Farber Cancer Institute.

But others, especially those linked to leukemia, seem to give stem cells a new ability to accumulate in the marrow. The result is a sort of survival of the fittest, or fastest growing, stem cells in the marrow.

“Some mutations may alter the growth properties of the stem cell,” said Dr. Steensma. “Some may just make the stem cell better at surviving in certain less hospitable parts of the bone marrow where other stem cells can’t thrive.”

The mutated stem cells outlast normal stem cells in the marrow, and their progeny — an increasing percentage of white blood cells — show up in the blood with mutations.

Perhaps the most extreme example of how this can play out was reported in 2014, when researchers described a 115-year-old woman. Nearly her entire supply of white blood cells was generated by mutated stem cells in her bone marrow.

At the first she had developed just two mutated stem cells. But over time their progeny came to dominate her bone marrow. She lived about as long as a human can, nonetheless, and died of a tumor.

But the big surprise came when researchers looked at the medical records of people with these white blood cell mutations. They had 54 percent increase in the odds of dying within the next decade, compared to people without CHIP And the cause: heart attacks and strokes.

Dr. Benjamin Ebert, chair of medical oncology a the Dana-Farber Cancer Institute, was the first to see the link. He turned for help to Dr. Sekar Kathiresan, a cardiologist and genetics researcher at the Massachusetts General Hospital and the Broad Institute, who had genetic data from four more large studies.

They confirmed that CHIP doubled the risk of a heart attack in typical patients — and increased the risk fourfold in those who had heart attacks early in life.

But how might mutated white blood cells cause heart disease? One clue intrigued scientists.

Artery-obstructing plaque is filled with white blood cells, smoldering with inflammation and subject to rupture. Perhaps mutated white cells were causing atherosclerosis or accelerating its development.

In separate studies, Dr. Ebert and Dr. Walsh gave mice a bone-marrow transplant containing stem cells with a CHIP mutation, along with stem cells that were not mutated. Mutated blood cells began proliferating in the mice, and they developed rapidly growing plaques that were burning with inflammation.

“For decades people have worked on inflammation as a cause of atherosclerosis,” Dr. Ebert said. “But it was not clear what initiated the inflammation.”

Now there is a possible explanation — and, Dr. Ebert said, it raises the possibility that CHIP may be involved in other inflammatory diseases, like arthritis.

For now, doctors advise against testing for CHIP, since there is nothing specific to be done to reduce the increased risks of cancer or heart disease that it confers.

But, he said, if people really want to know if they have CHIP, they can get a blood test that costs a few thousand dollars. (If there is no particular reason for the test, insurance may not pay.)

Dr. Steensma said that if he had CHIP, he would make sure he did his best to control all of his heart disease risks, like cholesterol and blood pressure, and that he had a healthy diet and exercised. Drugs may be developed to help stem the inflammation in arteries, he added.

As for the cancer risk, Dr. Ross Levine at Memorial Sloan Kettering Cancer Center just opened a C.H.I.P clinic in part to explore whether some patients with CHIP have a greater risk of blood cancers, and if so, what to do about it.

At the moment, CHIP is mostly found accidentally in patients who are genetically tested for other reasons — like Brian Gear. The diagnosis stunned him, but it also has brought into focus the important things in his life.

“There are things I love in life and people I love,” he said. “You try to live that life.”
 

Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
were learning more and more about cardiovascular disease all the time

somewhere therein lies immortality
[DOUBLEPOST=1517548592,1517542779][/DOUBLEPOST]https://med.stanford.edu/news/all-news/2018/01/cancer-vaccine-eliminates-tumors-in-mice.html

Cancer ‘vaccine’ eliminates tumors in mice
Activating T cells in tumors eliminated even distant metastases in mice, Stanford researchers found. Lymphoma patients are being recruited to test the technique in a clinical trial

Injecting minute amounts of two immune-stimulating agents directly into solid tumors in mice can eliminate all traces of cancer in the animals, including distant, untreated metastases, according to a study by researchers at the Stanford University School of Medicine.

The approach works for many different types of cancers, including those that arise spontaneously, the study found.

The researchers believe the local application of very small amounts of the agents could serve as a rapid and relatively inexpensive cancer therapy that is unlikely to cause the adverse side effects often seen with bodywide immune stimulation.

“When we use these two agents together, we see the elimination of tumors all over the body,” said Ronald Levy, MD, professor of oncology. “This approach bypasses the need to identify tumor-specific immune targets and doesn’t require wholesale activation of the immune system or customization of a patient’s immune cells.”

One agent is currently already approved for use in humans; the other has been tested for human use in several unrelated clinical trials. A clinical trial was launched in January to test the effect of the treatment in patients with lymphoma.

Levy, who holds the Robert K. and Helen K. Summy Professorship in the School of Medicine, is the senior author of the study, which was published Jan. 31 in Science Translational Medicine. Instructor of medicine Idit Sagiv-Barfi, PhD, is the lead author.

‘Amazing, bodywide effects’
Levy is a pioneer in the field of cancer immunotherapy, in which researchers try to harness the immune system to combat cancer. Research in his laboratory led to the development of rituximab, one of the first monoclonal antibodies approved for use as an anticancer treatment in humans.

Some immunotherapy approaches rely on stimulating the immune system throughout the body. Others target naturally occurring checkpoints that limit the anti-cancer activity of immune cells. Still others, like the CAR T-cell therapy recently approved to treat some types of leukemia and lymphomas, require a patient’s immune cells to be removed from the body and genetically engineered to attack the tumor cells. Many of these approaches have been successful, but they each have downsides — from difficult-to-handle side effects to high-cost and lengthy preparation or treatment times.

“All of these immunotherapy advances are changing medical practice,” Levy said. “Our approach uses a one-time application of very small amounts of two agents to stimulate the immune cells only within the tumor itself. In the mice, we saw amazing, bodywide effects, including the elimination of tumors all over the animal.”

Cancers often exist in a strange kind of limbo with regard to the immune system. Immune cells like T cells recognize the abnormal proteins often present on cancer cells and infiltrate to attack the tumor. However, as the tumor grows, it often devises ways to suppress the activity of the T cells.

Levy’s method works to reactivate the cancer-specific T cells by injecting microgram amounts of two agents directly into the tumor site. (A microgram is one-millionth of a gram). One, a short stretch of DNA called a CpG oligonucleotide, works with other nearby immune cells to amplify the expression of an activating receptor called OX40 on the surface of the T cells. The other, an antibody that binds to OX40, activates the T cells to lead the charge against the cancer cells. Because the two agents are injected directly into the tumor, only T cells that have infiltrated it are activated. In effect, these T cells are “prescreened” by the body to recognize only cancer-specific proteins.

Cancer-destroying rangers
Some of these tumor-specific, activated T cells then leave the original tumor to find and destroy other identical tumors throughout the body.

The approach worked startlingly well in laboratory mice with transplanted mouse lymphoma tumors in two sites on their bodies. Injecting one tumor site with the two agents caused the regression not just of the treated tumor, but also of the second, untreated tumor. In this way, 87 of 90 mice were cured of the cancer. Although the cancer recurred in three of the mice, the tumors again regressed after a second treatment. The researchers saw similar results in mice bearing breast, colon and melanoma tumors.

I don’t think there’s a limit to the type of tumor we could potentially treat, as long as it has been infiltrated by the immune system.
Mice genetically engineered to spontaneously develop breast cancers in all 10 of their mammary pads also responded to the treatment. Treating the first tumor that arose often prevented the occurrence of future tumors and significantly increased the animals’ life span, the researchers found.

Finally, Sagiv-Barfi explored the specificity of the T cells by transplanting two types of tumors into the mice. She transplanted the same lymphoma cancer cells in two locations, and she transplanted a colon cancer cell line in a third location. Treatment of one of the lymphoma sites caused the regression of both lymphoma tumors but did not affect the growth of the colon cancer cells.

“This is a very targeted approach,” Levy said. “Only the tumor that shares the protein targets displayed by the treated site is affected. We’re attacking specific targets without having to identify exactly what proteins the T cells are recognizing.”

The current clinical trial is expected to recruit about 15 patients with low-grade lymphoma. If successful, Levy believes the treatment could be useful for many tumor types. He envisions a future in which clinicians inject the two agents into solid tumors in humans prior to surgical removal of the cancer as a way to prevent recurrence due to unidentified metastases or lingering cancer cells, or even to head off the development of future tumors that arise due to genetic mutations like BRCA1 and 2.

“I don’t think there’s a limit to the type of tumor we could potentially treat, as long as it has been infiltrated by the immune system,” Levy said.

The work is an example of Stanford Medicine’s focus on precision health, the goal of which is to anticipate and prevent disease in the healthy and precisely diagnose and treat disease in the ill.

The study’s other Stanford co-authors are senior research assistant and lab manager Debra Czerwinski; professor of medicine Shoshana Levy, PhD; postdoctoral scholar Israt Alam, PhD; graduate student Aaron Mayer; and professor of radiology Sanjiv Gambhir, MD, PhD.

Levy is a member of the Stanford Cancer Institute and Stanford Bio-X.

Gambhir is the founder and equity holder in CellSight Inc., which develops and translates multimodality strategies to image cell trafficking and transplantation.

The research was supported by the National Institutes of Health (grant CA188005), the Leukemia and Lymphoma Society, the Boaz and Varda Dotan Foundation and the Phil N. Allen Foundation.

Stanford’s Department of Medicine also supported the work.

just fucking wow
 

Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
this is a crazy read. still trying to get my head around it all

https://aeon.co/ideas/you-thought-quantum-mechanics-was-weird-check-out-entangled-time

You thought quantum mechanics was weird: check out entangled time

In the summer of 1935, the physicists Albert Einstein and Erwin Schrödinger engaged in a rich, multifaceted and sometimes fretful correspondence about the implications of the new theory of quantum mechanics. The focus of their worry was what Schrödinger later dubbed entanglement: the inability to describe two quantum systems or particles independently, after they have interacted.

Until his death, Einstein remained convinced that entanglement showed how quantum mechanics was incomplete. Schrödinger thought that entanglement was the defining feature of the new physics, but this didn’t mean that he accepted it lightly. ‘I know of course how the hocus pocus works mathematically,’ he wrote to Einstein on 13 July 1935. ‘But I do not like such a theory.’ Schrödinger’s famous cat, suspended between life and death, first appeared in these letters, a byproduct of the struggle to articulate what bothered the pair.

The problem is that entanglement violates how the world ought to work. Information can’t travel faster than the speed of light, for one. But in a 1935 paper, Einstein and his co-authors showed how entanglement leads to what’s now called quantum nonlocality, the eerie link that appears to exist between entangled particles. If two quantum systems meet and then separate, even across a distance of thousands of lightyears, it becomes impossible to measure the features of one system (such as its position, momentum and polarity) without instantly steering the other into a corresponding state.

Up to today, most experiments have tested entanglement over spatial gaps. The assumption is that the ‘nonlocal’ part of quantum nonlocality refers to the entanglement of properties across space. But what if entanglement also occurs across time? Is there such a thing as temporal nonlocality?

The answer, as it turns out, is yes. Just when you thought quantum mechanics couldn’t get any weirder, a team of physicists at the Hebrew University of Jerusalem reported in 2013 that they had successfully entangled photons that never coexisted. Previous experiments involving a technique called ‘entanglement swapping’ had already showed quantum correlations across time, by delaying the measurement of one of the coexisting entangled particles; but Eli Megidish and his collaborators were the first to show entanglement between photons whose lifespans did not overlap at all.

Here’s how they did it. First, they created an entangled pair of photons, ‘1-2’ (step I in the diagram below). Soon after, they measured the polarisation of photon 1 (a property describing the direction of light’s oscillation) – thus ‘killing’ it (step II). Photon 2 was sent on a wild goose chase while a new entangled pair, ‘3-4’, was created (step III). Photon 3 was then measured along with the itinerant photon 2 in such a way that the entanglement relation was ‘swapped’ from the old pairs (‘1-2’ and ‘3-4’) onto the new ‘2-3’ combo (step IV). Some time later (step V), the polarisation of the lone survivor, photon 4, is measured, and the results are compared with those of the long-dead photon 1 (back at step II).


Figure 1. Time line diagram: (I) Birth of photons 1 and 2, (II) detection of photon 1, (III) birth of photons 3 and 4, (IV) Bell projection of photons 2 and 3, (V) detection of photon 4.
The upshot? The data revealed the existence of quantum correlations between ‘temporally nonlocal’ photons 1 and 4. That is, entanglement can occur across two quantum systems that never coexisted.

What on Earth can this mean? Prima facie, it seems as troubling as saying that the polarity of starlight in the far-distant past – say, greater than twice Earth’s lifetime – nevertheless influenced the polarity of starlight falling through your amateur telescope this winter. Even more bizarrely: maybe it implies that the measurements carried out by your eye upon starlight falling through your telescope this winter somehow dictated the polarity of photons more than 9 billion years old.

Lest this scenario strike you as too outlandish, Megidish and his colleagues can’t resist speculating on possible and rather spooky interpretations of their results. Perhaps the measurement of photon 1’s polarisation at step II somehow steers the future polarisation of 4, or the measurement of photon 4’s polarisation at step V somehow rewrites the past polarisation state of photon 1. In both forward and backward directions, quantum correlations span the causal void between the death of one photon and the birth of the other.

Just a spoonful of relativity helps the spookiness go down, though. In developing his theory of special relativity, Einstein deposed the concept of simultaneity from its Newtonian pedestal. As a consequence, simultaneity went from being an absolute property to being a relative one. There is no single timekeeper for the Universe; precisely when something is occurring depends on your precise location relative to what you are observing, known as your frame of reference. So the key to avoiding strange causal behaviour (steering the future or rewriting the past) in instances of temporal separation is to accept that calling events ‘simultaneous’ carries little metaphysical weight. It is only a frame-specific property, a choice among many alternative but equally viable ones – a matter of convention, or record-keeping.

The lesson carries over directly to both spatial and temporal quantum nonlocality. Mysteries regarding entangled pairs of particles amount to disagreements about labelling, brought about by relativity. Einstein showed that no sequence of events can be metaphysically privileged – can be considered more real – than any other. Only by accepting this insight can one make headway on such quantum puzzles.

The various frames of reference in the Hebrew University experiment (the lab’s frame, photon 1’s frame, photon 4’s frame, and so on) have their own ‘historians’, so to speak. While these historians will disagree about how things went down, not one of them can claim a corner on truth. A different sequence of events unfolds within each one, according to that spatiotemporal point of view. Clearly, then, any attempt at assigning frame-specific properties generally, or tying general properties to one particular frame, will cause disputes among the historians. But here’s the thing: while there might be legitimate disagreement about which properties should be assigned to which particles and when, there shouldn’t be disagreement about the very existence of these properties, particles, and events.

These findings drive yet another wedge between our beloved classical intuitions and the empirical realities of quantum mechanics. As was true for Schrödinger and his contemporaries, scientific progress is going to involve investigating the limitations of certain metaphysical views. Schrödinger’s cat, half-alive and half-dead, was created to illustrate how the entanglement of systems leads to macroscopic phenomena that defy our usual understanding of the relations between objects and their properties: an organism such as a cat is either dead or alive. No middle ground there.

Most contemporary philosophical accounts of the relationship between objects and their properties embrace entanglement solely from the perspective of spatial nonlocality. But there’s still significant work to be done on incorporating temporal nonlocality – not only in object-property discussions, but also in debates over material composition (such as the relation between a lump of clay and the statue it forms), and part-whole relations (such as how a hand relates to a limb, or a limb to a person). For example, the ‘puzzle’ of how parts fit with an overall whole presumes clear-cut spatial boundaries among underlying components, yet spatial nonlocality cautions against this view. Temporal nonlocality further complicates this picture: how does one describe an entity whose constituent parts are not even coexistent?

Discerning the nature of entanglement might at times be an uncomfortable project. It’s not clear what substantive metaphysics might emerge from scrutiny of fascinating new research by the likes of Megidish and other physicists. In a letter to Einstein, Schrödinger notes wryly (and deploying an odd metaphor): ‘One has the feeling that it is precisely the most important statements of the new theory that can really be squeezed into these Spanish boots – but only with difficulty.’ We cannot afford to ignore spatial or temporal nonlocality in future metaphysics: whether or not the boots fit, we’ll have to wear ’em.
[DOUBLEPOST=1517853622,1517817294][/DOUBLEPOST]https://www.msn.com/en-us/health/me...ure-baldness-study-says/ar-BBIJqnv?li=BBnbfcL

McDonald’s Fries Chemical May Cure Baldness, Study Says

The "simple" method has regrown hair on mice and preliminary tests have indicated it's likely to be successful on humans.

Japanese scientists may have discovered a cure for baldness and it lies within a chemical used to make McDonald’s fries.

A stem cell research team from Yokohama National University have used a “simple” method to regrow hair on mice with dimethylpolysiloxane, the silicone added to McDonald’s fries to stop cooking oil from frothing.

Preliminary tests have indicated the ground-breaking method is likely to be just as successful when transferred to human skin cells.

According to the study, released in the Biomaterials journal last Thursday, the breakthrough came after the scientists successfully mass-produced “hair follicle germs” (HFG) which were created for the first time ever in this way.

HFG’s are the cells that drive follicle development and are known as the ‘Holy Grail’ of hair loss research. The scientists credited the use of dimethylpolysiloxane as the key to the advancement.

“The key for the mass production of HFGs was a choice of substrate materials for the culture vessel,” Professor Junji Fukuda, of Yokohama National University, said in the study. “We used oxygen-permeable dimethylpolysiloxane (PDMS) at the bottom of culture vessel, and it worked very well.”

The technique created 5,000 HFGs simultaneously. The research team then seeded the prepared HFGs from a ‘HFG’ chip, a fabricated approximately 300-microwell array, onto the mouse's body.

“These self-sorted hair follicle germs (HFGs) were shown to be capable of efficient hair-follicle and shaft generation upon injection into the backs of nude mice,” Fukuda said.

Within days, Fukuda and his colleagues reported black hairs on the areas of the mouse where the chip was transplanted—the photo below also demonstrates the findings.

© Provided by IBT Media "This simple method is very robust and promising,” Fukuda said. “We hope this technique will improve human hair regenerative therapy to treat hair loss such as androgenic alopecia (male pattern baldness). In fact, we have preliminary data that suggests human HFG formation using human keratinocytes and dermal papilla cells."

In 2016, the U.S. hair loss treatment manufacturing industry was worth $6 billion. This included companies that produce restorative hair equipment, such as grafts for hair restoration, as well as oral and topical treatments.
 

Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
get ready for a weird read

https://aeon.co/essays/cosmopsychism-explains-why-the-universe-is-fine-tuned-for-life

Is the Universe a conscious mind?
Cosmopsychism might seem crazy, but it provides a robust explanatory model for how the Universe became fine-tuned for life

In the past 40 or so years, a strange fact about our Universe gradually made itself known to scientists: the laws of physics, and the initial conditions of our Universe, are fine-tuned for the possibility of life. It turns out that, for life to be possible, the numbers in basic physics – for example, the strength of gravity, or the mass of the electron – must have values falling in a certain range. And that range is an incredibly narrow slice of all the possible values those numbers can have. It is therefore incredibly unlikely that a universe like ours would have the kind of numbers compatible with the existence of life. But, against all the odds, our Universe does.

Here are a few of examples of this fine-tuning for life:

  • The strong nuclear force (the force that binds together the elements in the nucleus of an atom) has a value of 0.007. If that value had been 0.006 or less, the Universe would have contained nothing but hydrogen. If it had been 0.008 or higher, the hydrogen would have fused to make heavier elements. In either case, any kind of chemical complexity would have been physically impossible. And without chemical complexity there can be no life.
  • The physical possibility of chemical complexity is also dependent on the masses of the basic components of matter: electrons and quarks. If the mass of a down quark had been greater by a factor of 3, the Universe would have contained only hydrogen. If the mass of an electron had been greater by a factor of 2.5, the Universe would have contained only neutrons: no atoms at all, and certainly no chemical reactions.
  • Gravity seems a momentous force but it is actually much weaker than the other forces that affect atoms, by about 1036. If gravity had been only slightly stronger, stars would have formed from smaller amounts of material, and consequently would have been smaller, with much shorter lives. A typical sun would have lasted around 10,000 years rather than 10 billion years, not allowing enough time for the evolutionary processes that produce complex life. Conversely, if gravity had been only slightly weaker, stars would have been much colder and hence would not have exploded into supernovae. This also would have rendered life impossible, as supernovae are the main source of many of the heavy elements that form the ingredients of life.
Some take the fine-tuning to be simply a basic fact about our Universe: fortunate perhaps, but not something requiring explanation. But like many scientists and philosophers, I find this implausible. In The Life of the Cosmos (1999), the physicist Lee Smolin has estimated that, taking into account all of the fine-tuning examples considered, the chance of life existing in the Universe is 1 in 10229, from which he concludes:

In my opinion, a probability this tiny is not something we can let go unexplained. Luck will certainly not do here; we need some rational explanation of how something this unlikely turned out to be the case.
The two standard explanations of the fine-tuning are theism and the multiverse hypothesis. Theists postulate an all-powerful and perfectly good supernatural creator of the Universe, and then explain the fine-tuning in terms of the good intentions of this creator. Life is something of great objective value; God in Her goodness wanted to bring about this great value, and hence created laws with constants compatible with its physical possibility. The multiverse hypothesis postulates an enormous, perhaps infinite, number of physical universes other than our own, in which many different values of the constants are realised. Given a sufficient number of universes realising a sufficient range of the constants, it is not so improbable that there will be at least one universe with fine-tuned laws.

Both of these theories are able to explain the fine-tuning. The problem is that, on the face of it, they also make false predictions. For the theist, the false prediction arises from the problem of evil. If one were told that a given universe was created by an all-loving, all-knowing and all-powerful being, one would not expect that universe to contain enormous amounts of gratuitous suffering. One might not be surprised to find it contained intelligent life, but one would be surprised to learn that life had come about through the gruesome process of natural selection. Why would a loving God who could do absolutely anything choose to create life that way? Prima facie theism predicts a universe that is much better than our own and, because of this, the flaws of our Universe count strongly against the existence of God.

Turning to the multiverse hypothesis, the false prediction arises from the so-called Boltzmann brain problem, named after the 19th-century Austrian physicist Ludwig Boltzmann who first formulated the paradox of the observed universe. Assuming there is a multiverse, you would expect our Universe to be a fairly typical member of the universe ensemble, or at least a fairly typical member of the universes containing observers (since we couldn’t find ourselves in a universe in which observers are impossible). However, in The Road to Reality (2004), the physicist and mathematician Roger Penrose has calculated that in the kind of multiverse most favoured by contemporary physicists – based on inflationary cosmology and string theory – for every observer who observes a smooth, orderly universe as big as ours, there are 10 to the power of 10123 who observe a smooth, orderly universe that is just 10 times smaller. And by far the most common kind of observer would be a ‘Boltzmann’s brain’: a functioning brain that has by sheer fluke emerged from a disordered universe for a brief period of time. If Penrose is right, then the odds of an observer in the multiverse theory finding itself in a large, ordered universe are astronomically small. And hence the fact that we are ourselves such observers is powerful evidence against the multiverse theory.

Neither of these are knock-down arguments. Theists can try to come up with reasons why God would allow the suffering we find in the Universe, and multiverse theorists can try to fine-tune their theory such that our Universe is less unlikely. However, both of these moves feel ad hoc, fiddling to try to save the theory rather than accepting that, on its most natural interpretation, the theory is falsified. I think we can do better.


In the public mind, physics is on its way to giving us a complete account of the nature of space, time and matter. We are not there yet of course; for one thing, our best theory of the very big – general relativity – is inconsistent with our best theory of the very small – quantum mechanics. But it is standardly assumed that one day these challenges will be overcome and physicists will proudly present an eager public with the Grand Unified Theory of everything: a complete story of the fundamental nature of the Universe.

In fact, for all its virtues, physics tells us precisely nothing about the nature of the physical Universe. Consider Isaac Newton’s theory of universal gravitation:


The variables m1 and m2 stand for the masses of two objects that we want to work out the gravitational attraction between; F is the gravitational attraction between those two masses, G is the gravitational constant (a number we know from observation); and r is the distance between m1 and m2. Notice that this equation doesn’t provide us with definitions of what ‘mass’, ‘force’ and ‘distance’ are. And this is not something peculiar to Newton’s law. The subject matter of physics are the basic properties of the physics world: mass, charge, spin, distance, force. But the equations of physics do not explain what these properties are. They simply name them in order to assert equations between them.

If physics is not telling us the nature of physical properties, what is it telling us? The truth is that physics is a tool for prediction. Even if we don’t know what ‘mass’ and ‘force’ really are, we are able to recognise them in the world. They show up as readings on our instruments, or otherwise impact on our senses. And by using the equations of physics, such as Newton’s law of gravity, we can predict what’s going to happen with great precision. It is this predictive capacity that has enabled us to manipulate the natural world in extraordinary ways, leading to the technological revolution that has transformed our planet. We are now living through a period of history in which people are so blown away by the success of physical science, so moved by the wonders of technology, that they feel strongly inclined to think that the mathematical models of physics capture the whole of reality. But this is simply not the job of physics. Physics is in the business of predicting the behaviour of matter, not revealing its intrinsic nature.

It’s silly to say that atoms are entirely removed from mentality, then wonder where mentality comes from

Given that physics tell us nothing of the nature of physical reality, is there anything we do know? Are there any clues as to what is going on ‘under the bonnet’ of the engine of the Universe? The English astronomer Arthur Eddington was the first scientist to confirm general relativity, and also to formulate the Boltzmann brain problem discussed above (albeit in a different context). Reflecting on the limitations of physics in The Nature of the Physical World (1928), Eddington argued that the only thing we really know about the nature of matter is that some of it has consciousness; we know this because we are directly aware of the consciousness of our own brains:

We are acquainted with an external world because its fibres run into our own consciousness; it is only our own ends of the fibres that we actually know; from those ends, we more or less successfully reconstruct the rest, as a palaeontologist reconstructs an extinct monster from its footprint.
We have no direct access to the nature of matter outside of brains. But the most reasonable speculation, according to Eddington, is that the nature of matter outside of brains is continuous with the nature of matter inside of brains. Given that we have no direct insight into the nature of atoms, it is rather ‘silly’, argued Eddington, to declare that atoms have a nature entirely removed from mentality, and then to wonder where mentality comes from. In my book Consciousness and Fundamental Reality (2017), I developed these considerations into an extensive argument for panpsychism: the view that all matter has a consciousness-involving nature.

There are two ways of developing the basic panpsychist position. One is micropsychism, the view that the smallest parts of the physical world have consciousness. Micropsychism is not to be equated with the absurd view that quarks have emotions or that electrons feel existential angst. In human beings, consciousness is a sophisticated thing, involving subtle and complex emotions, thoughts and sensory experiences. But there seems nothing incoherent with the idea that consciousness might exist in some extremely basic forms. We have good reason to think that the conscious experience of a horse is much less complex than that of a human being, and the experiences of a chicken less complex than those of a horse. As organisms become simpler, perhaps at some point the light of consciousness suddenly switches off, with simpler organisms having no experience at all. But it is also possible that the light of consciousness never switches off entirely, but rather fades as organic complexity reduces, through flies, insects, plants, amoeba and bacteria. For the micropsychist, this fading-while-never-turning-off continuum further extends into inorganic matter, with fundamental physical entities – perhaps electrons and quarks – possessing extremely rudimentary forms of consciousness, to reflect their extremely simple nature.

However, a number of scientists and philosophers of science have recently argued that this kind of ‘bottom-up’ picture of the Universe is outdated, and that contemporary physics suggests that in fact we live in a ‘top-down’ – or ‘holist’ – Universe, in which complex wholes are more fundamental than their parts. According to holism, the table in front of you does not derive its existence from the sub-atomic particles that compose it; rather, those sub-atomic particles derive their existence from the table. Ultimately, everything that exists derives its existence from the ultimate complex system: the Universe as a whole.

Holism has a somewhat mystical association, in its commitment to a single unified whole being the ultimate reality. But there are strong scientific arguments in its favour. The American philosopher Jonathan Schaffer argues that the phenomenon of quantum entanglement is good evidence for holism. Entangled particles behave as a whole, even if they are separated by such large distances that it is impossible for any kind of signal to travel between them. According to Schaffer, we can make sense of this only if, in general, we are in a Universe in which complex systems are more fundamental than their parts.

If we combine holism with panpsychism, we get cosmopsychism: the view that the Universe is conscious, and that the consciousness of humans and animals is derived not from the consciousness of fundamental particles, but from the consciousness of the Universe itself. This is the view I ultimately defend in Consciousness and Fundamental Reality.

The cosmopsychist need not think of the conscious Universe as having human-like mental features, such as thought and rationality. Indeed, in my book I suggested that we think of the cosmic consciousness as a kind of ‘mess’ devoid of intellect or reason. However, it now seems to me that reflection on the fine-tuning might give us grounds for thinking that the mental life of the Universe is just a little closer than I had previously thought to the mental life of a human being.

The Canadian philosopher John Leslie proposed an intriguing explanation of the fine-tuning, which in Universes (1989) he called ‘axiarchism’. What strikes us as so incredible about the fine-tuning is that, of all the values the constants in our laws had, they ended up having exactly those values required for something of great value: life, and ultimately intelligent life. If the laws had not, against huge odds, been fine-tuned, the Universe would have had infinitely less value; some say it would have had no value at all. Leslie proposes that this proper understanding of the problem points us in the direction of the best solution: the laws are fine-tuned because their being so leads to something of great value. Leslie is not imagining a deity mediating between the facts of value and the cosmological facts; the facts of value, as it were, reach out and fix the values directly.

It can hardly be denied that axiarchism is a parsimonious explanation of fine-tuning, as it posits no entities whatsoever other than the observable Universe. But it is not clear that it is intelligible. Values don’t seem to be the right kind of things to have a causal influence on the workings of the world, at least not independently of the motives of rational agents. It is rather like suggesting that the abstract number 9 caused a hurricane.

But the cosmopsychist has a way of rendering axiarchism intelligible, by proposing that the mental capacities of the Universe mediate between value facts and cosmological facts. On this view, which we can call ‘agentive cosmopsychism’, the Universe itself fine-tuned the laws in response to considerations of value. When was this done? In the first 10-43 seconds, known as the Planck epoch, our current physical theories, in which the fine-tuned laws are embedded, break down. The cosmopsychist can propose that during this early stage of cosmological history, the Universe itself ‘chose’ the fine-tuned values in order to make possible a universe of value.

Making sense of this requires two modifications to basic cosmopsychism. Firstly, we need to suppose that the Universe acts through a basic capacity to recognise and respond to considerations of value. This is very different from how we normally think about things, but it is consistent with everything we observe. The Scottish philosopher David Hume long ago noted that all we can really observe is how things behave – the underlying forces that give rise to those behaviours are invisible to us. We standardly assume that the Universe is powered by a number of non-rational causal capacities, but it is also possible that it is powered by the capacity of the Universe to respond to considerations of value.

It is parsimonious to suppose that the Universe has a consciousness-involving nature

How are we to think about the laws of physics on this view? I suggest that we think of them as constraints on the agency of the Universe. Unlike the God of theism, this is an agent of limited power, which explains the manifest imperfections of the Universe. The Universe acts to maximise value, but is able to do so only within the constraints of the laws of physics. The beneficence of the Universe does not much reveal itself these days; the agentive cosmopsychist might explain this by holding that the Universe is now more constrained than it was in the unique circumstances of the first split second after the Big Bang, when currently known laws of physics did not apply.

Ockham’s razor is the principle that, all things being equal, more parsimonious theories – that is to say, theories with relatively few postulations – are to be preferred. Is it not a great cost in terms of parsimony to ascribe fundamental consciousness to the Universe? Not at all. The physical world must have some nature, and physics leaves us completely in the dark as to what it is. It is no less parsimonious to suppose that the Universe has a consciousness-involving nature than that it has some non-consciousness-involving nature. If anything, the former proposal is more parsimonious insofar as it is continuous with the only thing we really know about the nature of matter: that brains have consciousness.

Having said that, the second and final modification we must make to cosmopsychism in order to explain the fine-tuning does come at some cost. If the Universe, way back in the Planck epoch, fine-tuned the laws to bring about life billions of years in its future, then the Universe must in some sense be aware of the consequences of its actions. This is the second modification: I suggest that the agentive cosmopsychist postulate a basic disposition of the Universe to represent the complete potential consequences of each of its possible actions. In a sense, this is a simple postulation, but it cannot be denied that the complexity involved in these mental representations detracts from the parsimony of the view. However, this commitment is arguably less profligate than the postulations of the theist or the multiverse theorist. The theist postulates a supernatural agent while the agentive cosmopsychist postulates a natural agent. The multiverse theorist postulates an enormous number of distinct, unobservable entities: the many universes. The agentive cosmopsychist merely adds to an entity that we already believe in: the physical Universe. And most importantly, agentive cosmopsychism avoids the false predictions of its two rivals.

The idea that the Universe is a conscious mind that responds to value strikes us a ludicrously extravagant cartoon. But we must judge the view not on its cultural associations but on its explanatory power. Agentive cosmopsychism explains the fine-tuning without making false predictions; and it does so with a simplicity and elegance unmatched by its rivals. It is a view we should take seriously.
 

Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
[DOUBLEPOST=1518562772,1518499047][/DOUBLEPOST]this is fucking unbelievable

https://www.msn.com/en-us/news/tech...-photo-of-a-single-atom/ar-BBJ5C2U?li=BBnb7Kz

A scientist captured an impossible photo of a single atom



A student at the University of Oxford is being celebrated in the world of science photography for capturing a single, floating atom with an ordinary camera.

Using long exposure, PhD candidate David Nadlinger took a a photo of a glowing atom in an intricate web of laboratory machinery. In it, the single strontium atom is illuminated by a laser while suspended in the air by two electrodes. For a sense of scale, those two electrodes on each side of the tiny dot are only two millimeters apart.

The image won first prize in a science photo contest conducted by UK based Engineering and Physical Sciences Research Council (EPSRC).

© Provided by Quartz The EPSRC explains how a single atom is somehow visible to a normal camera:

When illuminated by a laser of the right blue-violet colour, the atom absorbs and re-emits light particles sufficiently quickly for an ordinary camera to capture it in a long exposure photograph.

In the award’s announcement, Nadlinger is quoted on trying to render the microscopic visible through conventional photography. “The idea of being able to see a single atom with the naked eye had struck me as a wonderfully direct and visceral bridge between the miniscule quantum world and our macroscopic reality,” he said.

Other than using extension tubes, a lens accessory that increases the focal length of an existing lens and is typically reserved for extreme close-up photography, Nadlinger used normal gear that most photographers have access to. Even without a particularly complicated rig, his patience and attention to detail paid off.

“When I set off to the lab with camera and tripods one quiet Sunday afternoon,” he said, “I was rewarded with this particular picture of a small, pale blue dot.”
[DOUBLEPOST=1518644597][/DOUBLEPOST]www.bbc.com/news/science-environment-43065485

Quantum computers 'one step closer'

Quantum computing has taken a step forward with the development of a programmable quantum processor made with silicon.

The team used microwave energy to align two electron particles suspended in silicon, then used them to perform a set of test calculations.

By using silicon, the scientists hope that quantum computers will be more easy to control and manufacture.

The research was published in the journal Nature.

The old adage of Schrödinger's Cat is often used to frame a basic concept of quantum theory.

We use it to explain the peculiar, but important, concept of superposition; where something can exist in multiple states at once.

For Schrodinger's feline friend - the simultaneous states were dead and alive.

Superposition is what makes quantum computing so potentially powerful.

Standard computer processors rely on packets or bits of information, each one representing a single yes or no answer.

Quantum processors are different. They don't work in the realm of yes or no, but in the almost surreal world of yes and no. This twin-state of quantum information is known as a qubit.

Unstable liaisons

To harness their power, you have to link multiple qubits together, a process called entanglement.

With each additional qubit added, the computation power of the processor is effectively doubled.

But generating and linking qubits, then instructing them to perform calculations in their entangled state is no easy task. They are incredibly sensitive to external forces, which can give rise to errors in the calculations and in the worst-case scenario make the entangled qubits fall apart.

As additional qubits are added, the adverse effects of these external forces mount.

One way to cope with this is to include additional qubits whose sole role is to vet and correct outputs for misleading or erroneous data.

This means that more powerful quantum computers - ones that will be useful for complex problem solving, like working out how proteins fold or modelling physical processes inside complex atoms - will need lots of qubits.

Dr Tom Watson, based at Delft University of Technology in the Netherlands, and one of the authors of the paper, told BBC News: "You have to think what it will take to do useful quantum computing. The numbers are not very well defined but it's probably going to take thousands maybe millions of qubits, so you need to build your qubits in a way that can scale up to these numbers."

In short, if quantum computers are going to take off, you need to come up with an easy way to manufacture large and stable qubit processors.

And Dr Watson and his colleagues thought there was an obvious solution.

Tried and tested

"As we've seen in the computer industry, silicon works quite well in terms of scaling up using the fabrication methods used", he said.

The team of researchers, which also included scientists from the University of Wisconsin-Madison, turned to silicon to suspend single electron qubits whose spin was fixed by the use of microwave energy.

In the superposition state, the electron was spinning both up and down.

The team were then able to connect two qubits and programme them to perform trial calculations.

They could then cross-check the data generated by the quantum silicon processor with that generated by a standard computer running the same test calculations.

The data matched.

The team had successfully built a programmable two-qubit silicon-based processor.

Commenting on the study, Prof Winfried Hensinger, from the University of Sussex, said: "The team managed to make a two qubit quantum gate with a very respectable error rate. While the error rate is still much higher than in trapped ion or superconducting qubit quantum computers, the achievement is still remarkable, as isolating the qubits from noise is extremely hard."

He added: "It remains to be seen whether error rates can be realised that are consistent with the concept of fault-tolerant quantum computing operation. However, without doubt this is a truly outstanding achievement."

And in an accompanying paper, an international team, led by Prof Jason Petta from Princeton University, was able to transfer the state of the spin of an electron suspended in silicon onto a single photon of light.

According to Prof Hensinger, this is a "fantastic achievement" in the development of silicon-based quantum computers.

He explained: "If quantum gates in a solid state quantum computer can ever be realised with sufficiently low error rates, then this method could be used to connect different quantum computing modules which would allow for a fully modular quantum computer."
 

Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
https://www.msn.com/en-us/news/tech...s-what-you-need-to-know/ar-BBJbfHs?li=BBnb7Kz

Solar storm expected to reach Earth today – here’s what you need to know

The Sun is pretty important to life as we know it. After all, we wouldn’t be here without it, but it also gives us a headache every once in a while. Astronomers captured a glimpse of a large solar flare a few days ago which produced a CME, or coronal mass ejection, and it’s expected to hit Earth today as a solar storm.

When a coronal mass ejection takes place, the Sun spits a mass of plasma and electromagnetic radiation into space. When it happens to toss that material in the direction of Earth, we experience solar storms here on Earth a few days later. Thankfully, the CME that occurred earlier this week was relatively minor, and it’s not expected to have any dire effect on us, but that doesn’t mean we won’t notice it.

As it always does when it reaches Earth, the magnetized material the Sun spat out will interact with Earth’s own magnetic field. This often results in auroras (aka “Northern Lights”) which are significantly brighter than normal, but particularly large CMEs can be a hazard for astronauts as well as spacecraft and satellites. In some cases, massive solar storms have actually temporarily knocked out power grids on the Earth’s surface.

This time around, the solar storm is expected to be fairly small, and will likely produce some brighter-than-average auroras. On the geomagnetic storm scale, which ranks space storms from G1 (lowest) to G5 (highest), it’s expected to be a G1. According to the National Oceanic and Atmospheric Administration, G1 storms can have a mild effect on migratory animals such as whales, minor impact to satellite operations, and has a chance to produce “weak power grid fluctuations.”

In short, the Sun cut us a break this time around, but it definitely likes to remind us that it’s there.
[DOUBLEPOST=1518754123,1518738804][/DOUBLEPOST]https://www.economist.com/news/scie...all-intestine-how-too-much-fructose-may-cause

How too much fructose may cause liver damage

FRUCTOSE is the sweetest of the natural sugars. As its name suggests, it is found mainly in fruits. Its job seems to be to appeal to the sweet tooths of the vertebrates these fruit have evolved to be eaten by, the better to scatter their seeds far and wide. Fructose is also, however, often added by manufacturers of food and drink, to sweeten their products and make them appeal to one species of vertebrate in particular, namely Homo sapiens. And that may be a problem, because too much fructose in the diet seems to be associated with liver disease and type 2 diabetes.

The nature of this association has been debated for years. Some argue that the effect is indirect. They suggest that, because sweet tastes suppress the feeling of being full (the reason why desserts, which come at the end of a meal, are sweet), consuming foods rich in fructose encourages overeating and the diseases consequent upon that. Others think the effect is more direct. They suspect that the cause is the way fructose is metabolised. Evidence clearly supporting either hypothesis has, though, been hard to come by.

This week, however, the metabolic hypothesis has received a boost from a study published in Cell Metabolism by Josh Rabinowitz of Princeton University and his colleagues. Specifically, Dr Rabinowitz’s work suggests that fructose, when consumed in large enough quantities, overwhelms the mechanism in the small intestine that has evolved to handle it. This enables it to get into the bloodstream along with other digested molecules and travel to the liver, where some of it is converted into fat. And that is a process which has the potential to cause long-term damage.

Dr Rabinowitz and his associates came to this conclusion by tracking fructose, and also glucose, the most common natural sugar, through the bodies of mice. They did this by making sugar molecules that included a rare but non-radioactive isotope of carbon, 13C. Some animals were fed fructose doped with this isotope. Others were fed glucose doped with it. By looking at where the 13C went in each case the researchers could follow the fates of the two sorts of sugar.

The liver is the prime metabolic processing centre in the body, so they expected to see fructose dealt with there. But the isotopes told a different story. When glucose was the doped sugar molecule, 13C was carried rapidly to the liver from the small intestine through the hepatic portal vein. This is a direct connection between the two organs that exists to make such transfers of digested food molecules. It was then distributed to the rest of the body through the general blood circulation. When fructose was doped, though, and administered in small quantities, the isotope gathered in the small intestine instead of being transported to the liver. It seems that the intestine itself has the job of dealing with fructose, thus making sure that this substance never even reaches the liver.

Having established that the two sorts of sugar are handled differently, Dr Rabinowitz and his colleagues then upped the doses. Their intention was to mimic in their mice the proportionate amount of each sugar that a human being would ingest when consuming a small fructose-enhanced soft drink. As they expected, all of the glucose in the dose was transported efficiently to the liver, whence it was released into the wider bloodstream for use in the rest of the body. Also as expected, the fructose remained in the small intestine for processing. But not forever. About 30% of it escaped, and was carried unprocessed to the liver. Here, a part of it was converted into fat.

That is not a problem in the short term. Livers can store a certain amount of fat without fuss. And Dr Rabinowitz’s experiments are only short-term trials. But in the longer term chronic fat production in the liver often leads to disease—and is something to be avoided, if possible.
 

Poindexter

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Well this is fucking creepy.
Superficially seems frightening, but really seems like bullshit. The girl is clearly saying what she thinks should be said. And if you know a child has exhibited this behavior but allow them the opportunity to do it repeatedly, then you are retarded. It's propaganda at best. This is a joke. @jesusatemyhotdog thoughts?
 

Kano

My New Challenge
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Superficially seems frightening, but really seems like bullshit. The girl is clearly saying what she thinks should be said. And if you know a child has exhibited this behavior but allow them the opportunity to do it repeatedly, then you are retarded. It's propaganda at best. This is a joke. @jesusatemyhotdog thoughts?
I'm surprised they still let her play the part of Matilda after that interview.
[DOUBLEPOST=1518844322,1518844241][/DOUBLEPOST]Accidentally quoted you poindexter
 

Trodden

Currently running late for my funeral
Joined
Aug 18, 2014
anyone else here alter their brain waves with sound?

I do

[DOUBLEPOST=1519091714,1519034549][/DOUBLEPOST]
medium.com/the-spike/your-cortex-contains-17-billion-computers-9034e42d34f2
Your Cortex Contains 17 Billion Computers
Neural networks of neural networks

Brains receive input from the outside world, their neurons do something to that input, and create an output. That output may be a thought (I want curry for dinner); it may be an action (make curry); it may be a change in mood (yay curry!). Whatever the output, that “something” is a transformation of some form of input (a menu) to output (“chicken dansak, please”). And if we think of a brain as a device that transforms inputs to outputs then, inexorably, the computer becomes our analogy of choice.

For some this analogy is merely a useful rhetorical device; for others it is a serious idea. But the brain isn’t a computer. Each neuron is a computer. Your cortex contains 17 billion computers.

OK, what? Look at this:


A pyramidal cell — squashed into two dimensions. The black blob in the middle is the neuron’s body; the rest of the wires are its dendrites. Credit: Alain Dexteshe / http://cns.iaf.cnrs-gif.fr/alain_geometries.html
This is a picture of a pyramidal cell, the neuron that makes up most of your cortex. The blob in the centre is the neuron’s body; the wires stretching and branching above and below are the dendrites, the twisting cables that gather the inputs from other neurons near and far. Those inputs fall all across the dendrites, some right up close to the body, some far out on the tips. Where they fall matters.

But you wouldn’t think it. When talking about how neurons work, we usually end up with the sum-up-inputs-and-spit-out-spike idea. In this idea, the dendrites are just a device to collect inputs. Activating each input alone makes a small change to the neuron’s voltage. Sum up enough of these small changes, from all across the dendrites, and the neuron will spit out a spike from its body, down its axon, to go be an input to other neurons.


The sum-up-and-spit-out-spike model of a neuron. If enough inputs arrive at the same time — enough to cross a threshold (grey circle) — the neuron spits out a spike.
It’s a handy mental model for thinking about neurons. It forms the basis for all artificial neural networks. It’s wrong.

Those dendrites are not just bits of wire: they also have their own apparatus for making spikes. If enough inputs are activated in the same small bit of dendrite then the sum of those simultaneous inputs will be bigger than the sum of each input acting alone:


The two coloured blobs are two inputs to a single bit of dendrite. When they are activated on their own, they each create the responses shown, where the grey arrow indicates the activation of that input (response here means “change in voltage”). When activated together, the response is larger (solid line) than the sum of their individual responses (dotted line).
The relationship between the number of active inputs and the size of the response in a little bit of dendrite looks like this:


Size of the response in a single branch of a dendrite to increasing numbers of active inputs. The local “spike” is the jump from almost no response to a large response.
There’s the local spike: the sudden jump from almost no response to a few inputs, to a big response with just one more input. A bit of dendrite is “supralinear”: within a dendrite, 2+2=6.

We’ve known about these local spikes in bits of dendrite for many years. We’ve seen these local spikes in neurons within slices of brain. We’ve seen them in the brains of anaesthetised animals having their paws tickled (yes, unconscious brains still feel stuff; they just don’t bother to tell anyone). We’ve very recently seen them in the dendrites of neurons in animals that were moving about (yeah, Moore and friends recorded the activity in something a few micrometres across from the brain of a mouse that was moving about; crazy, huh?). A pyramidal neuron’s dendrites can make “spikes”.

So they exist: but why does this local spike change the way we think about the brain as a computer? Because the dendrites of a pyramidal neuron contain many separate branches. And each can sum-up-and-spit-out-a-spike. Which means that each branch of a dendrite acts like a little nonlinear output device, summing up and outputting a local spike if that branch gets enough inputs at roughly the same time:


Deja vu. A single dendritic branch acts as a little device for summing up inputs and giving an output if enough inputs were active at the same time. And the transformation from input to output (the grey circle) is just the graph we’ve already seen above, which gives the size of the response from the number of inputs.
Wait. Wasn’t that our model of a neuron? Yes it was. Now if we replace each little branch of dendrite with one of our little “neuron” devices, then a pyramidal neuron looks something like this:


Left: A single neuron has many dendritic branches (above and below its body). Right: so it is a collection of non-linear summation devices (yellow boxes, and nonlinear outputs), that all output to the body of the neuron (grey box), where they are summed together. Look familiar?
Yes, each pyramidal neuron is a two layer neural network. All by itself.

Beautiful work by Poirazi and Mel back in 2003 showed this explicitly. They built a complex computer model of a single neuron, simulating each little bit of dendrite, the local spikes within them, and how they sweep down to the body. They then directly compared the output of the neuron to the output of a two-layer neural network: and they were the same.

The extraordinary implication of these local spikes is that each neuron is a computer. By itself the neuron can compute a huge range of so-called nonlinear functions. Functions that a neuron which just sums-up-and-spits-out-a-spike cannot ever compute. For example, with four inputs (Blue, Sea, Yellow, and Sun) and two branches acting as little non-linear devices, we can set up a pyramidal neuron to compute the “feature-binding” function: we can ask it to respond to Blue and Sea together, or respond to Yellow and Sun together, but not to respond otherwise — not even to Blue and Sun together or Yellow and Sea together. Of course, neurons receive many more than four inputs, and have many more than two branches: so the range of logical functions they could compute is astronomical.

More recently, Romain Caze and friends (I am one of those friends) have shown that a single neuron can compute an amazing range of functions even if it cannot make a local, dendritic spike. Because dendrites are naturally not linear: in their normal state they actually sum up inputs to total less than the individual values. They are sub-linear. For them 2+2 = 3.5. And having many dendritic branches with sub-linear summation also lets the neuron act as two-layer neural network. A two-layer neural network that can compute a different set of non-linear functions to those computed by neurons with supra-linear dendrites. And pretty much every neuron in the brain has dendrites. So almost all neurons could, in principle, be a two-layer neural network.

The other amazing implication of the local spike is that neurons know a hell of a lot more about the world than they tell us — or other neurons, for that matter.

Not long ago, I asked a simple question: How does the brain compartmentalise information? When we look at the wiring between neurons in the brain, we can trace a path from any neuron to any other. How then does information apparently available in one part of the brain (say, the smell of curry) not appear in all other parts of the brain (like the visual cortex)?

There are two opposing answers to that. The first is, in some cases, the brain is not compartmentalised: information does pop up in weird places, like sound in brain regions dealing with place. But the other answer is: the brain is compartmentalised — by dendrites.

As we just saw, the local spike is a non-linear event: it is bigger than the sum of its inputs. And the neuron’s body basically can’t detect anything that is not a local spike. Which means that it ignores most of its individual inputs: the bit which spits out the spike to the rest of the brain is isolated from much of the information the neuron receives. The neuron only responds when a lot of the inputs are active together in time and in space (on the same bit of dendrite).

If this was true, then we should see that dendrites respond to things that the neuron does not respond to. We see exactly this. In visual cortex, we know that many neurons respond only to things in the world moving at a certain angle (like most, but by no means all of us, they have a preferred orientation). Some neurons fire their spikes to things at 60 degrees; some at 90 degrees; some at 120 degrees. But when we record what their dendrites respond to, we see responses to every angle. The dendrites know a hell of a lot more about how objects in the world are arranged than the neuron’s body does.

They also look at a hell of a lot more of the world. Neurons in visual cortex only respond to things in a particular position in the world — one neuron may respond to things in the top left of your vision; another to things in the bottom right. Very recently Sonia Hofer and her team showed that while the spikes from neurons only happen in response to objects appearing in one particular position, their dendrites respond to many different positions in the world, often far from the neuron’s apparent preferred position. So the neurons respond only to a small fraction of the information they receive, with the rest tucked away in their dendrites.

Why does all this matter? It means that each neuron could radically change its function by changes to just a few of its inputs. A few get weaker, and suddenly a whole branch of dendrite goes silent: the neuron that was previously happy to see cats, for that branch liked cats, no longer responds when your cat walks over your bloody keyboard as you are working — and you are a much calmer, more together person as a result. A few inputs get stronger, and suddenly a whole branch starts responding: a neuron that previously did not care for the taste of olives now responds joyously to a mouthful of ripe green olive — in my experience, this neuron only comes online in your early twenties. If all inputs were summed together, than changing a neuron’s function would mean having the new inputs laboriously fight each and every other input for attention; but have each bit of dendrite act independently, and new computations become a doddle.

It means the brain can do many computations beyond treating each neuron as a machine for summing up inputs and spitting out a spike. Yet that’s the basis for all the units that make up an artificial neural network. It suggests that deep learning and its AI brethren have but glimpsed the computational power of an actual brain.

Your cortex contains 17 billion neurons. To understand what they do, we often make analogies with computers. Some use these analogies as cornerstones of their arguments. Some consider them to be deeply misguided. Our analogies often look to artificial neural networks: for neural networks compute, and they are made of up neuron-like things; and so, therefore, should brains compute. But if we think the brain is a computer, because it is like a neural network, then now we must admit that individual neurons are computers too. All 17 billion of them in your cortex; perhaps all 86 billion in your brain.

And so it means your cortex is not a neural network. Your cortex is a neural network of neural networks.
 

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