A problem has turned out to be impossible for the brightest minds in physics.
Albert Einstein & Stephen Hawking – the most famous physicists of the 12th century – have spent decades trying to find a single law that could explain how the world works on an atom scale & on a galaxies scale. In short, the Standard Model describes the physics of the very small. General relativity describes physics of the very large. The problem? The two theories tell different stories about the basic nature of reality. Einstein described the problem nearly a century ago in his 1923 Nobel Lecture, telling audience that a physicist in search of “an integrated theory cannot be satisfied with the assumption that there are two distinct fields exist which are completely independent of each other by nature. Even on his deathbed, Einstein worked on a way to unite all laws of physics under one unifying theory.
Hawking eventually gave up.
Now, Stephon Alexander, professor of physics at Brown University, takes up the challenge. In a pre-publication that has yet to be peer-reviewed, Alexander & several collaborators, including technologist Jaron Lanier & physicist Lee Smolin, expressed a slightly different spin on problem. Instead of focusing on laws of physics, they wonder why the physical world is ruled by some laws & not by others. They write that although physicists have not “finished the task” of discovering laws of physics, “it seems that we know enough to take a few steps towards the answer to a deeper question.
The Standard Model and General Relativity really have a lot in common
What physicists know is that 2 theories – Standard Model & Einstein General Theory of Relativity – offer powerful, empirically sound explanations of physics on the scales they are designed to explain. It turns out that theories also share some basic mathematical qualities too.
According to Alexander, both are based on gauge theories & principles of symmetry, which use mathematics to describe how objects can move & interact. Researchers working in tradition of string theory have relied on these similarities in their efforts to unify the 2 theories by re-imagining some particles into one-dimensional objects called strings. But there is a catch. This approach results in “a vast rich-ness of laws” which are mathematically possible. This “multiverse of theories,” as Alexander calls it, includes the Standard Model & General Relativity – and many other theories that could apparently describe our physical world, although they exist on a scale too small to be tested.
According to string theory, physical characteristics, such as mass or electric charge of a product, are the result of how the string vibrates in many dimensions, including many hypothetical dimensions that exist on a very small scale. , wrote Brain Greene in Smithsonian. . Determining shape of these dimensions would be the key to understanding how these strings constitute physical reality, but mathematics does not offer a clear answer. As early string theorists identified a handful of possible shapes for these tiny extra dimensions, the list of mathematically possible shapes grew in-to millions, then in-to billions, & finally into “numbers so big they don’t have been named.” , ”according to Greene.
“String theory does not answer the question of why,” Alexander told New Scientist in September. “It lack a mechanism to select which of slot machines of 10,500 possible universes is our universe.
His idea is that physical world as we know it today is not the only real reality, it is the result of many iterations of universe attempting an arrangement of laws that did not work. In Alexander’s story, our universe probably took on the characteristics of many possible universes. Eventually it “found itself in a configuration … which was stable” and allowed it to “build out in a consistent way.”
He Compare this process of trying, failing, & trying again to play an arcade game with a ver big-bag-of-quarters. “If you have endless lives, you play, you die, you play, you keep playing, you die, but you can keep playing, right? I think it’s kind of like the idea, ”he said.
The universe is always able to “keep trying”. In this regard, the universe “learns” what works and what does not as it evolves. Since the universe has no teacher but learns its lessons as it goes, researchers call it “autodidactic”.
The answer could be a primordial “Metalaw”
How could this be possible? Alexander’s answer is elegant: a “meta law” that existed long before laws of physics, which we know as the Standard Model & General Relativity. It is this meta law that contains ability to try things & learn. Con-fusingly metalaw is the universe itself, at least in some ways.
“The thing that strange here is that hardware is the software & the software is the hardware,” says Alexander. General relativity & Standard Model emerged later, once the universe found the stability it was looking for. He Compare idea to Darwin’s theory of evolution.
“In biology, there was a ‘Why these species?’ Problem. : This explains why there are cats and dogs exist while unicorns & werewolves don’t, “the researchers wrote in the prepress. They explain that Darwin introduced a handful of principles governing life in general that make it possible to understand how a specific species was born. For example, the idea that species emerge because individuals who adapt well to their environment have a better chance of passing on valuable characteristics to their offspring. Finding that first glimpse of these underlying principles was a mammoth achievement, but it wasn’t the end of the story. It took 160 years for researchers to fill in the details, and they’re not finish yet.
Alexander & his colleagues do not claim to have discovered the physics equivalent of evolution. They describe their contribution as “small, small steps” towards a complete theory. For Alexander, it was important to come up with a formal version of theory to see if it withstood the scrutiny of other theoretical physicists & the empirical work of experimenters.
“We have to engage in something so that we can play & try to do math calculation and explore the idea,” he said.
How would a self-taught universe work?
The idea that the universe evolved according to other rules is not entirely new. Philosopher Charles Sanders Pierce applied the principles of natural selection to cosmology in 1893, less than 4 decades after published On The Origin of Species. Alexander & his colleagues inspired by advances in theoretical physics, computer science, and the philosophy of science to make a much bolder claim that the universe learns its laws, and not simply that it evolves to achieve a better physical form in its environment. .
The argument-rests on 3 fundamental elements: matrix models, quantum gauge theories & learning machines.
The team began with the intuition that the theories of physics could be understood as models of matrix. That is, theories could be written as equations or they could be sub-stantiated as tables of numbers with perhaps billions of columns & rows. Such a vast matrix could contain all the possible laws that could govern the universe. In-sights from computer-science- light way from there.
“The mathematics of matrix theory seems to have some of ingredients of a particular type of neural network,” Alexander said in an interview with New Scientist.
“Maybe there is a little input & output and universe adjust-ing the weights in this way that it ends up learning the standard model & gravity,” said science atom. “That’s the basic idea.” Here, “weights” refer to specific mathematical relationships that determine how the inputs entering into a neural network are transformed to generate its outputs.
If Alexander is right, we humans are almost certainly not able to see everything the universe has learned. “There may be other corners of the universe, where other interesting things have happened that completely radical from our point of view,” he said, pointing-out that there is no reason to think that the universe had a preference to learn the laws that made it possible to get out of life & consciousness to emerge.
“As far as I’m concerned, that was part of the evolution,” he said. “We’re the ones that claim thats’s great.
Confirming the self-study (autodidactic) of the universe theory wouldn’t necessarily rule out the possibility of a theory like Einstein or Hawking might have imagined, but it would certainly underscore Alexander’s belief that physicists should explore. ideas that go far beyond the limits of traditional boundaries. The answers to these questions may not be found in what we currently think of as “physics.”
Greene says, direct observation of the strings would require a particle accelerator “the size of galaxy”. Alexander’s hope, which he describes in his new book, Fear of a Black Universe: An outsider’s guide to the future of physics, is more modest, but far from guaranteed. “Experts should engage in exploration with people in other fields.