Controversial physics theory says reality around us behaves like a computer neural network.
- Physicist proposes that the universe behaves like an artificial neural network.
- The scientist's new paper seeks to reconcile classical physics and quantum mechanics.
- The theory claims that natural selection produces both atoms and "observers".
Does the reality around us work like a neural network, a Matrix-like computer system that operates similar to a human brain? A new physics paper argues that looking at the universe that way can provide the elusive "theory of everything".
This controversial proposal is the brainchild of the University of Minnesota Duluth physics professor Vitaly Vanchurin. In an interview with Futurism, Vanchurin conceded that "the idea is definitely crazy, but if it is crazy enough to be true?"
The scientist developed the theory while exploring the workings of machine learning using statistical mechanics. He found that mechanisms involved in the computer learning were similar in some instances to the dynamics of quantum mechanics.
A computer neural network works via nodes, which mimic biological neurons, processing and passing on signals. As the network learns new information, it changes, giving certain nodes more priority, allowing it to connect bits of information in such a way that next time in will know, for example, what are they key traits of a "zebra".
"We are not just saying that the artificial neural networks can be useful for analyzing physical systems or for discovering physical laws, we are saying that this is how the world around us actually works," writes Vanchurin in the paper. "With this respect it could be considered as a proposal for the theory of everything, and as such it should be easy to prove it wrong."
How do you prove his theory wrong? Vanchurin proposes a way. All you have to do is "find a phenomenon which cannot be modeled with a neural network." That, of course, isn't actually so easy to pull off, as Vanchurin himself points out. We don't fully understand how neural network and machine learning work and need to grasp those processes first.
Vanchurin thinks his idea can accomplish another purpose that has been the goal of modern physics – to reconcile classical physics, which describes how the universe works on a large scale, and quantum mechanics, the study of the atomic and subatomic level of existence. The physicist thinks that if you view the universe as working essentially as a neural network, its behavior under certain conditions can be explained by both the quirky equations of quantum mechanics and the laws of classical physics like the theory of general relativity devised by Albert Einstein.
"The learning dynamics of a neural network can indeed exhibit approximate behaviors described by both quantum mechanics and general relativity," writes Vanchurin in his study.
Diving deeper into his theory, Vanchurin thinks it supports such apparent mechanisms of our world as natural selection. He suggests that in a neural network, particles and atoms, but even us, the "observers" would emerge from a natural-selection-like process. On the microscopic level of the network, some structures would become more stable while some would be less so. The stable ones would survive the evolutionary process, while the less stable ones would not.
'On the smallest scales I expect that the natural selection should produce some very low complexity structures such as chains of neurons, but on larger scales the structures would be more complicated," he shared with Futurism.
He sees little reason why this kind of process would only work on just the small scale, writing in the paper:
"If correct, then what we now call atoms and particles might actually be the outcomes of a long evolution starting from some very low complexity structures and what we now call macroscopic observers and biological cells might be the outcome of an even longer evolution."
While he posits the neural network explanation, Vanchurin doesn't necessarily mean we all live in a computer simulation, like proposed by philosopher Nick Bostrom, adding the caveat that even if we did, "we might never know the difference."
Vanchurin's idea has so far been received with skepticism by other physicists but he is undeterred. You can check out his paper for yourself on ArXiv.
Vanchurin on “Hidden Phenomena”:Vitaly Vanchurin speaking at the 6th International FQXi Conference, "Mind Matters: Intelligence and Agency in the Physical World." The Foundational Questions...
A new conception of quantum mechanics rests on the idea that parallel universes exist, and that they interact with our own to create weird and wonderful quantum phenomena.
Quantum mechanics is hard to do. The great physicist Richard Feynman once remarked “It is safe to say that nobody understands quantum mechanics” and that statement was regarded as correct. The problem isn’t in the math, even an undergraduate can use Schrödinger’s equation, it is in what the math means.
We are all familiar with several interpretations of what the math could mean, from cats that are both dead and alive to an infinite multiverse where every possible history does happen. How to prove which of these interpretations is correct is another problem; as parallel universes are postulated to not interact with one another and scientists don’t quite have the stomach to put cats in quantum booby traps. With no ability to experiment, the math is all we know for sure.
But, a radical new interpretation might hold the answer, and in a manner that could be tested.
The idea is called the Many Interacting Worlds hypothesis, the or MIW. The core concept is that a plethora of universes have always existed side by side, and that they subtly influence the ones near them to differ from themselves. The bizarre effects of quantum mechanics that we observe and are confused by, such as quantum tunneling and the double slit experiment, are really caused by the interactions between these universes.
The hypothesis says the probabilistic nature we ascribe to certain events is really uncertainty caused by our not knowing which universe we are in, and that if we knew where we were physics would again be deterministic. The authors of the study say as little as two existent universes would be enough to assure quantum effects take place. They show they can account for basic quantum phenomena using their ideas.
What makes this model different from the others?
Firstly, it “contains nothing that corresponds to the mysterious quantum wave function,” except when the number of modeled universes is infinite. When the model contains only one universe, it simplifies to a classical, Newtonian system. Quantum physicist and author of the hypothesis Michael Hall called this element “surprising” and said that it means that their hypothesis “incorporates both classical and quantum theory”. A vital step for any interpretation that wants to make headway.
Another key difference is that the proposed words in this hypothesis interact with one another. Because of this, scientists could devise an experiment to show if the predicted interaction was taking place; supporting or disproving the hypothesis. Since science typically holds falsifiability to be a gold standard, this is a great leap forward for quantum theory.
So, is this model going to be of any use?
At the moment, the model is still speculative and unlikely to become the new standard interpretation anytime soon. The authors of the hypothesis hope that their concept “will be useful in planning experiments to test and exploit quantum phenomena such as entanglement. Our findings include new algorithms for simulating such phenomena and may even suggest new ways to extend standard quantum mechanics.”
Even if the ideas are proven false, or never catch on as a paradigm for interpreting quantum phenomena, the researchers hope to advance our understanding of science anyway. As they say in their press release, “while Richard Feynman may have had a point when he said ‘I think I can safely say that nobody understands quantum mechanics,’ there is still much to be gained by trying to do so”.
Theoretical physicist and cosmologist Lawrence M. Krauss spoke at CSICon 2016 about scientists' attempt to look back in time to the beginning of our universe.
At a 2016 convention hosted by the Committee for Skeptical Inquiry, theoretical physicist Lawrence M. Krauss spoke about scientists' attempts to look back to when the universe was just fractions of a second old. A few highlights from Krauss' talk are listed below, and his full presentation can be seen at the bottom of this article.
Inflation and the Universe’s “Baby Picture”
The Cosmic Microwave Background radiation (CMB) is the oldest visible light in the universe. According to Inflationary Cosmology, the CMB is essentially the afterglow radiation that was produced when the nascent universe rapidly inflated when it was some 380,000 years old.
“[The universe] went from the size of an atom to the size of a basketball in a billionth of a billionth of a billionth of a billionth of a second,” Krauss said.
Before inflation, the universe was extremely small, hot and dense. It was governed by quantum mechanics, and everything was in flux.
“When Inflation happens, all those quantum fluctuations get frozen in,” Krauss said, noting that there were tiny variations, or “lumps,” in temperature across the CMB that became the spots where galaxies and other matter formed. “[Those fluctuations] later manifest themselves in density, in matter.”
The CMB effectively confirms the Big Bang Theory — the radiation pattern looks exactly like what scientists in the mid-20th century predicted when they first theorized that the universe was once a very small, dense place.
Scientists are now trying to look farther back in time, well beyond the CMB.
“We can never see back earlier than [the CMB], and by ‘see’ I mean look with light,” Krauss said. “We have to use something that interacts much more weakly than light.”
Instead of light, scientists are using gravity to look back on the early universe.
Albert Einstein’s general theory of relativity first predicted the existence of gravitational waves, which, in simplified terms, are ripples in the fabric of spacetime caused by the acceleration of objects.
The theory of inflation predicts that the early universe would have produced certain kinds of gravitational waves. If scientists one day find evidence of these particular gravitational waves, we’d be able to ‘see’ the universe when it was just a fraction of a second old – “essentially at the Big Bang,” Krauss said.
In September 2015, scientists first detected gravitational waves disrupting spacetime. The waves came from the collision of two black holes some 1.3 billion light years away, but they were extremely hard to detect – the spacetime “wobbling” generated by the waves was so subtle that it was thousands of times smaller than the nucleus of an atom.
The video below describes how scientists at the Laser Interferometer Gravitational Wave Observatory (LIGO) first directly detected the waves in 2015.
Eternal Inflation and Multiple Universes
“If we can show that inflation happened, and we can measure the characteristics of inflation, then we know something very interesting,” Krauss said, referring to the idea of eternal inflation.
Eternal inflation suggests that, in extremely simplified terms, inflation caused the universe to expand at different rates in different places, and this gave rise to an infinite number of bubble universes. This process, according to some theorists, could go on forever.
What’s more, the laws of physics could be unique in each bubble universe. Some universes might not even have galaxies at all.
“You’ll never see these universes because they’re expanding away from us faster than light,” Krauss said. “It sounds like it’s metaphysics. But if we could measure the properties of inflation, we might be able to measure grand unification and understand particle physics, and understand those properties and prove that inflation was eternal. And if that’s the case, we will know that there must be other universes out there.”
Although we’ll never be able to see these other universes, scientists would theoretically be able to confirm their existence through indirect experiments.
“It will be like being in 1905 when Einstein first showed that atoms existed in his Ph.D. thesis,” Krauss said. “No one ever thought you’d see an atom. So we’ll turn this metaphysical explanation into physics. And that’s the beauty of science.”
A study on the strange Cold Spot in space may prove that we live in a multiverse.
A new study about one of the most inexplicable places in the cosmos may offer the first proof that we are living in a multiverse.
The idea of a “multiverse" proposes that an infinite amount of universes, including the one we are living in, exist in parallel to each other. These universes differ in a variety of physical properties, featuring multiple Big Bangs, space bubbles and maybe even an alternate version of you who is reading this article in a world run by slugs. The “multiverse" hypothesis has been so far been impossible to test but has supporters among such scientists as Stephen Hawking, Michio Kaku, Neil deGrasse Tyson and Leonard Susskind.
The study by British astronomers focuses on what's known as the “Cold Spot" - an especially cold area of space that has been observed in the microwave background radiation coming from the early Universe 13 billion years ago. Usually temperatures of the radiation vary throughout the universe, but this area of coolness is much larger than others (about 0.00015 degrees Celsius colder than its surroundings).
The map of the cosmic microwave background (CMB) sky produced by the Planck satellite. Red represents slightly warmer regions, and blue slightly cooler regions. Credit: ESA and Durham University.
The Cold Spot, first found by NASA in 2004, is a strange place 1.8 billion light years across that doesn't comfortably gel with existing cosmological models. One explanation is that it simply doesn't exist, being just an illusion created by the expansion of the universe. Spaces with lower amount of galaxies or “voids" form as the expansion accelerates. With 10,000 fewer galaxies, the Cold Spot would be a “supervoid".
But the study, published in UK's Royal Astronomical Society, claims to prove that the supervoid is not a valid solution to the Cold Spot's mystery. The researchers think that instead of one giant emptiness in that area, there are galaxy clusters gathered around smaller bubble-like voids. And, significantly, these would be too small to be responsible for lowering the temperature in the Cold Spot.
In fact, other answers must be sought. The scientists, led by postgraduate student Ruari Mackenzie and Professor Tom Shanks in Durham University's Centre for Extragalactic Astronomy, think one possible hypothesis is that the Cold Spot resulted from a collision between our universe during its early days and another universe. The energy release of such an impact would have created the Cold Spot.
"We can't entirely rule out that the Spot is caused by an unlikely fluctuation explained by the standard model. But if that isn't the answer, then there are more exotic explanations. Perhaps the most exciting of these is that the Cold Spot was caused by a collision between our universe and another bubble universe. If further, more detailed, analysis of CMB [Cosmic Microwave Background] data proves this to be the case then the Cold Spot might be taken as the first evidence for the multiverse – and billions of other universes may exist like our own," said Professor Tom Shanks.
The multiverse, while an exciting idea, has its detractors. Some physicists feel since it's not something observable or provable, then a discussion of it is pointless or even unscientific. But when more ordinary solutions come up empty, the doors of science open wider.
Check out this video by Michio Kaku for more ideas on multiverses:
The Many Worlds Interpretation is just one of a few multiverse hypotheses—but is there a glaring paradox in this popular idea?
The idea of a multiverse as we conceive of it was first mentioned by Nobel Prize-winning Austrian physicist Erwin Schrödinger in 1952, who warned a lecture hall full of people that this may "seem lunatic", but perhaps his equations did not show mere alternative versions of history, but alternatives all happening simultaneously. For this week's question, Austin wants to know about the multiverses paradox: if every alternate timeline happens, and anything that can happen does—somewhere—then wouldn't there be a universe that could not support the idea of any other universe existing? All multiverse hypothesis are as yet unverified by experiments, so it's all up in the air. But if we ever want to find out, the way to do it is by supporting space exploration, because the more we find out about the cosmos, the closer we get to knowledge about our own origins and the greater our capacity grows for multiverse experimentation. Bill Nye's most recent book is Unstoppable: Harnessing Science to Change the World.