This is the best scientific argument that your brain isn’t a computer
Rafi Letzter, Tech Insider
One of the most intriguing speculative arguments in physics and computer science isn’t really about physics or computer science at all. It’s about the brain — or more precisely, about consciousness — and it’s been going on for decades. The central question: Is the brain fundamentally like a computer?
The side that says no relies on some seriously outlandish thinking.
On the more conservative side, there are researchers like Scott Aaronson, a respected theoretical computer scientist at MIT. His view, which is more widely accepted, is that because the brain exists inside the universe, and because computers can simulate the entire universe given enough power, your entire brain can be simulated in a computer. And because it can be simulated in a computer, its structure and functions, including your consciousness, must be entirely logical and computational.
In other words, all evidence suggests that your mind is a computer. (There is, of course, a great deal more nuance to his ideas than this, but that is the crux of his view.)
But there’s a dissenting view, advanced most forcefully by the mathematical physicist Roger Penrose: That your consciousness emerges from mysterious, exotic physics acting inside your neurons.
Penrose (who, at 84, is responsible for a substantial chunk of our understanding of the shape of the universe) has argued since the 1980s that conventional computer science and physics can not explain the human mind. He laid out his argument in a pair of books published in the late ’80s and early ’90s, and more recently in a debate with Aaronson at a conference in Minnesota. (Unfortunately, no complete transcript of that debate exists, but Aaronson summarizes it thoroughly on his blog.)
In essence, Penrose argues that human consciousness has certain features and abilities that conventional computers can not replicate. The nature of computers is algorithmic and logical, and the human mind (in Penrose’s view) transcends algorithms and logic. The most salient evidence he points to is the capacity of large groups of mathematicians to move toward true solutions for computationally unsolvable problems. (Aaronson disputes this evidence.)
To explain: Computers as we conceive of them rely on and are bound by the physical and logical rules of our universe. They conduct tasks and solve problems through the logic of algorithms. There are certain problems, however, that conventional computers and mathematical logic cannot solve (like whether a given program will stop or simply run forever). And there’s another set of problems that computers can theoretically solve, but would require eons to actually return answers for in practice (like finding all the prime number roots of extremely large numbers). This isn’t due to power limitations, but rather the fundamental properties of logic and physics in our universe.
If, as Penrose suggests, humans demonstrate the ability to circumvent some of these basic limits on computation, the brain must interact with systems that exist outside the logical, algorithmic universe. And the quantum world is the most likely candidate.
Penrose speculates that there might exist quantum mechanical processes that can turn up answers to questions in ways no current model of a computer (classical or quantum) would allow, and that the human brain might be able to engage with them through tiny structures, or “microtubules,” inside neurons. Michael Shermer, a Scientific American columnist, called this idea pure conjecture.
If anyone thinks [a brain is nothing like a computer], the burden is on them to articulate what it is about the brain that could possibly make it relevantly different from a digital computer. It’s their job! …
… One of the many reasons I admire Roger is that, out of all the AI skeptics on earth, he’s virtually the only one who’s actually tried to meet this burden, as I understand it! He, nearly alone, did what I think all AI skeptics should do, which is: suggest some actual physical property of the brain that, if present, would make it qualitatively different from all existing computers, in the sense of violating the Church-Turing Thesis. Indeed, he’s one of the few AI skeptics who even understands what meeting this burden would entail: that you can’t do it with the physics we already know, that some new ingredient is necessary.
So there it is: Either the brain is basically a computer, or there’s a whole new world of neuroscience and physics out there that we have not yet even begun to discover.
You can read Aaronson’s full write-up of their debate here.
Proving Einstein Wrong with ‘Spooky’ Quantum Experiment
by Jesse Emspak, Live Science Contributor | March 26, 2015 07:21am ET
Quantum mechanics is one of the best-tested theories in science, and it’s one of the few where physicists get to do experiments proving that Einstein was wrong.
That’s what a team at Griffith University and the University of Tokyo in Japan did this week, showing that a weird phenomenon — in which the measurement of a particle actually affects its location — is real.
Back in the 1920s and 1930s, Albert Einstein said he couldn’t support this idea, which he called “spooky action at a distance,” in which a particle can be in two places at once and it’s not until one measures the state of that particle that it takes a definite position, seemingly with no signal transmitted to it and at a speed faster than light. When the particle takes its definite position, physicists refer to this as its wave function collapsing.
The phenomenon was outside of contemporary experience in physics and seemed to violate the theory of relativity, which posits that the speed of light is an absolute limit on how fast any information can travel. Einstein proposed that the particle isn’t in a superposition state, or two places at once; but rather it always has a “true” location, and people just couldn’t see it. [How Quantum Entanglement Works (Infographic)]
Using a single photon (particle of light), the Australian and Japanese researchers ran an experiment showing that measuring a property of a quantum particle in one place will affect what one sees in another place. That is, they showed that superposition and collapsing wave function are real phenomena.
Alice and Bob
The phenomenon is demonstrated with a thought experiment in which a light beam is split, with one half going to Alice and the other to Bob. Alice then indicates if she detected a photon and if so what state it is in — it might be the phase of the wave packet that describes the photon. Mathematically, though, the photon is in a state of “superposition,” meaning it is in two (or more) places at once. Its wave function, a mathematical formula that describes the particle, seems to show the photon has no definite position.
“Alice’s measurement collapses the superposition,” meaning the photons are in one place or another, but not both, Howard Wiseman, director of Griffith University’s Center for Quantum Dynamics, who led the experiment, told Live Science. If Alice sees a photon, that means the quantum state of the light particle in Bob’s lab collapses to a so-called zero-photon state, meaning no photon. But if she doesn’t see a photon, Bob’s particle collapses to a one-photon state, he said.
“Does this seem reasonable to you? I hope not, because Einstein certainly didn’t think it was reasonable. He thought it was crazy,” he added, referring to the fact that Alice’s measurement looked like it was dictating Bob’s.
The paradox was partially resolved years later, when experiments showed that even though the interaction between two quantum particles happens faster than light (it appears instantaneous), there is no way to use that phenomenon to send information, so there’s no possibility of faster-than-light signals.
The team at Griffith, though, wanted to go a step further and show that the collapsing wave function — the process of Alice “choosing” a measurement and affecting Bob’s detection — is actually happening. And while other experiments have shown entanglement with two particles, the new study entangles a photon with itself.
To do this they fired a beam of photons at a splitter, so half of the light was transmitted and half was reflected. The transmitted light went to one lab and the reflected light went to the other. (These were “Alice” and “Bob” of the thought experiment.)
The light was transmitted as a single photon at a time, so the photon was split in two. Before the photon was measured, it existed in a superposition state.
One lab (Alice) used a laser as a reference, to measure the phase of the photon. If one thinks of light as a repeating sine wave, phase is the angle one is measuring, from 0 to 180 degrees. When Alice changed the angle of her reference laser, she got varying measurements of the photon: Either her photon was in a certain phase or it wasn’t present at all.
Then the other lab (or Bob) looked at their photons and found the photons were anti-correlated with Alice — if she saw a photon he did not, and vice versa. The state of Bob’s photon depended on what Alice measured. But in classic physics that shouldn’t happen; rather, the two particles should be independent of one another.
Akira Furusawa, professor of applied physics at the University of Tokyo and one of the co-authors on the study, said the experiment helps explore different kinds of quantum information processing — and with it, communications and computing.
“Usually there are two types of quantum information processing,” he said. “There’s the qubit type, the digital information processing, and there’s continuous variable, a sort of analog type of quantum information. We are trying to combine them.” Conventional processing often relies on counting photons, but this kind of measurement of single photons is more efficient, he said.
Wiseman said one application is in the security of communications.
“Our experiment is a more rigorous test of the properties of such states than has ever been done before, in the sense that we don’t have to trust anything that is happening in Alice’s laboratory. This could be useful for communicating secrets when not all the parties are trusted.”
The experiment is described in the March 24 issue of the journal Nature Communications.
Over 2,000 years ago, gold and silversmiths developed a variety of techniques, including using mercury like a glue, to apply thin films of metals to statues and other objects.
They developed thin-film coating technology that is unrivalled by today’s process for producing DVDs, solar cells, electronic devices and other products and used it on jewels, statues, amulets and more common objects.
Workmen managed to make precious metal coatings as thin and adherent as possible, which not only saved expensive metals but improved resistance to wear caused from continued use and circulation.
Scientists today say understanding these sophisticated metal-plating techniques could help preserve priceless artistic and other treasures from the past.
British scientists say Elizabethan craftsmen developed advanced manufacturing technology that could match that of the 21st century.
In Italy, Gabriel Maria Ingo, senior scientist at the Institute for the Study of Nanostructured Materials of the National Research Council, says that while scientists have made good progress in understanding the chemistry, big gaps in knowledge remain about how gilders in the Dark Ages and other periods applied such lustrous, impressively uniform films of gold or silver to intricate objects.
Ingo’s team set out to apply the newest analytical techniques to uncover the ancients’ artistic secrets. Using surface analytical methods, such as selected area X-ray photoelectron spectroscopy and scanning electron microscopy combined with energy-dispersive spectroscopy on Dark Ages objects such as St. Ambrogios altar from 825 AD, they say that their findings confirm “the high level of competence reached by the artists and craftsmen of these ancient periods who produced objects of an artistic quality that could not be bettered in ancient times and has not yet been reached in modern ones.”
In Britain, scientists studying a 400-year-old hoard of jewelry have found that Elizabethan craftsmen developed advanced manufacturing technology that could match that of the 21st century.
The team from Birmingham City University have analyzed the craftwork behind the famous Cheapside Hoard, the world’s largest collection of Elizabethan and Jacobean jewelry, discovered in a London cellar in 1912.
Among the historic find, which is being showcased by the Museum of London, is a Ferlite watch that dates back to the 1600s and is so technologically advanced it has been described as the “iPod of its day.”
Dr Ann-Marie Carey, a research fellow at Birmingham City University, and her colleagues have used modern technology to discover how these beautiful items were created – and have been stunned at the advanced technologies used.
“Our forensic analysis has revealed the amazing technologies which craftsman of this period were using, and we f ear some of these 400-year-old processes may now be lost to us,” she said.
“It is has been a fascinating investigation. We think of our own time as one of impressive technological advances, but we must look at the Elizabethan and Jacobean age as being just as advanced in some ways.”
Selected items of the Hoard are set to be revealed to the world at a major exhibition at the Museum of London from this October to next April.
The university experts combined their own background in craft with CAD-technology to investigate the Hoard in an attempt to discover what kind of manufacturing methods could have been used to create the jewelry, which includes brooches, pendants and delicate gemstone rings.
Dr Carey said: “When we received photographs of the Hoard we were fascinated with the level of detail in the jewelry.
“We wanted to know how such pieces were made and to understand the story behind them. Until now there had been little research into the craftsmanship involved so we feel we are making a unique contribution to the forthcoming exhibition.”
Dr Carey, with the help of senior technologist Keith Adcock, have used 21st century digital technologies to recreate pieces from the Hoard, including a ‘Pearl Dropper’ an egg-shaped item that originally featured ribbons of pearls and was possible worn on as a hairpiece.
The university team has created a bronze version of this item which will be used as part of the exhibition, as well as ‘augmented reality’ displays of the jewelry items.
“This will create tangible items which will be ideal for visually-impaired visitors who will be handle items directly,” added Dr Carey.
Scientists create levitation system with sound waves
By Tia Ghose
Published July 16, 2013
Hold on to your wand, Harry Potter: Science has outdone even your best “Leviosa!” levitation spell.
Researchers report that they have levitated objects with sound waves, and moved those objects around in midair, according to a new study.
Scientists have used sound waves to suspend objects in midair for decades, but the new method, described Monday, July 15, in the journal Proceedings of the National Academy of Sciences, goes a step further by allowing people to manipulate suspended objects without touching them.
‘If you have some dogs around, they are not going to like it at all.’
– Daniele Foresti, a mechanical engineer at the ETH Zürich in Switzerland
This levitation technique could help create ultrapure chemical mixtures, without contamination, which could be useful for making stem cells or other biological materials.
For more than a century, scientists have proposed the idea of using the pressure of sound waves to make objects float in the air. As sound waves travel, they produce changes in the air pressure — squishing some air molecules together and pushing others apart.
By placing an object at a certain point within a sound wave, it’s possible to perfectly counteract the force of gravity with the force exerted by the sound wave, allowing an object to float in that spot.
In previous work on levitation systems, researchers had used transducers to produce sound waves, and reflectors to reflect the waves back, thus creating standing waves.
“A standing wave is like when you pluck the string of a guitar,” said study co-author Daniele Foresti, a mechanical engineer at the ETH Zürich in Switzerland. “The string is moving up and down, but there are two points where it’s fixed.”
Using these standing waves, scientists levitated mice and small drops of liquid.
But then, the research got stuck.
Acoustic levitation seemed to be more of a parlor trick than a useful tool: It was only powerful enough to levitate relatively small objects; it couldn’t levitate liquids without splitting them apart, and the objects couldn’t be moved.
Foresti and his colleagues designed tiny transducers powerful enough to levitate objects but small enough to be packed closely together.
By slowly turning off one transducer just as its neighbor is ramping up, the new method creates a moving sweet spot for levitation, enabling the scientists to move an object in midair. Long, skinny objects can also be levitated.
The new system can lift heavy objects, and also provides enough control so that liquids can be mixed together without splitting into many tiny droplets, Foresti said. Everything can be controlled automatically.
The system blasts sounds waves at what would be an ear-splitting noise level of 160 decibels, about as loud as a jet taking off. Fortunately, the sound waves in the experiment operated at 24 kilohertz, just above the normal hearing range for humans.
However, “if you have some dogs around, they are not going to like it at all,” Foresti told LiveScience.
Right now, the objects can only be moved along in one dimension, but the researchers hope to develop a system that can move objects in two dimensions, Foresti said.
The new system is a major advance, both theoretically and in terms of its practical applications, said Yiannis Ventikos, a fluids researcher at the University College London who was not involved in the study.
The new method could be an alternative to using a pipette to mix fluids in instances when contamination is an issue, he added. For instance, acoustic levitation could enable researchers to marinate stem cells in certain precise chemical mixtures, without worrying about contamination from the pipette or the well tray used.
“The level of control you get is quite astounding,” Ventikos said.
Though only about dozen potentially habitable exoplanets have been detected so far, scientists say the universe should be teeming with alien worlds that could support life. The Milky Way alone may host 60 billion such planets around faint red dwarf stars, a new estimate suggests.
Based on data from NASA’s planet-hunting Kepler spacecraft, scientists have predicted that there should be one Earth-size planet in the habitable zone of each red dwarf, the most common type of star. But a group of researchers has now doubled that estimate after considering how cloud cover might help an alien planet support life.
“Clouds cause warming, and they cause cooling on Earth,” study researcher Dorian Abbot, an assistant professor in geophysical sciences at the University of Chicago, said in a statement. “They reflect sunlight to cool things off, and they absorb infrared radiation from the surface to make a greenhouse effect. That’s part of what keeps the planet warm enough to sustain life.” [9 Alien Planets That Could Support Life]
Cloud Cover Exoplanet
Cloud Cover Exoplanet
This illustration shows simulated cloud coverage (white) on a tidally locked planet (blue) that would be orbiting a red dwarf star.
CREDIT: Jun Yang
View full size image
The habitable zone is defined as the region where a planet has the right temperature to keep liquid water on its surface, thought to be a requirement for life as we know it. If a planet is too far from its star, its water freezes; too close, water vaporizes. Since red dwarfs are dimmer and cooler than our sun, their habitable zone is much cozier than our solar system’s.
“If you’re orbiting around a low-mass or dwarf star, you have to orbit about once a month, once every two months to receive the same amount of sunlight that we receive from the sun,” explained another study author, Nicolas Cowan, a postdoctoral fellow at Northwestern University.
With such a snug orbit, a habitable planet around a red dwarf would become tidally locked, meaning it would always have one side facing its star, much like the moon faces Earth. This side would see eternal daylight.
In the new study, the researchers used 3D simulations to model the way air and moisture would move over a planet tidally locked around a red dwarf. The team found that any surface water would result in water clouds. What’s more, highly reflective clouds would build at the point of the star-facing side where it’s always high noon. This would have a cooling effect in the inner ring of the habitable zone, meaning the planets there would be able to sustain water on their surfaces much closer to their star, the researchers say.
The findings could give scientists a new way to confirm the presence of liquid water on the surface of alien planets with the James Webb Space Telescope (JWST), a new space-based observatory scheduled for launch in 2018, the researchers say.
“If you look at Brazil or Indonesia with an infrared telescope from space, it can look cold, and that’s because you’re seeing the cloud deck,” Cowan said. “The cloud deck is at high altitude, and it’s extremely cold up there.”
The same could be true of a habitable exoplanet with a highly reflective cloud cover, the researchers say. If JWST detects a similar cold signal over the dayside of an alien world, Abbot said, “it’s almost definitely from clouds, and it’s a confirmation that you do have surface liquid water.”
The research was detailed June 27 in the journal Astrophysical Journal Letters.
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