Far out cosmology: laws of physics don't exist (Introduction)

by David Turell , Friday, December 09, 2022, 20:50 (713 days ago) @ David Turell

How contrary:

https://www.newscientist.com/article/2349359-why-the-laws-of-physics-dont-actually-exist/

"First things first. What we often call laws of physics are really just consistent mathematical theories that seem to match some parts of nature. This is as true for Newton’s laws of motion as it is for Einstein’s theories of relativity, Schrödinger’s and Dirac’s equations in quantum physics or even string theory. So these aren’t really laws as such, but instead precise and consistent ways of describing the reality we see. This should be obvious from the fact that these laws are not static; they evolve as our empirical knowledge of the universe improves.

***

"There are around 86 billion neurons in the human brain. This is less than the number of stars in the Milky Way which is just a miniscule part of the known universe. The universe seems almost infinite in comparison to the finite capacity of the human brain, leaving us perhaps little chance of figuring out ultimate laws. What is amazing is that we can make sense of some aspects of the universe through the laws of physics. It may have been Richard Feynman who first said that the issue is not how clever we humans are in figuring out how nature works, it is how clever nature is in following our laws!

***

"Take string theory as an example. It is a theory that is very mathematically tight and rather magical in the way that it treats gravity and quantum mechanics equivalently, matching many of our observations of the universe. It holds a lot of promise, but so far has struggled to provide any testable concrete predictions beyond our current understanding.

"It also has a rather thorny stumbling block known as the landscape problem, where literally zillions of universes (around 10500, the number is so large that it seems obscene) are acceptable solutions of the theory. If string theory is correct one can declare victory as one of those zillions of universes must be our universe, and all one needs to do is to somehow find that particular solution to figure out what the laws of physics are for us. Of course, this is an impossible task because of the exceptionally large number of possible universes existing in the landscape, and all with their own distinct laws.

"This scenario is often called the multiverse. All possible laws, conceivable and inconceivable, are allowed in some possible universe, and laws of physics are no longer meaningful or unique from a fundamental sense, since they depend entirely on where in the multiverse landscape one is looking. It is ironic that the theory of everything turned out to imply an everything which is exponentially larger than any everything anybody could have imagined before.

***

"As a theoretical condensed matter physicist I do not find this scenario discouraging at all – quite the opposite. The fact that there is an essentially infinite number of possible laws only makes doing science more exhilarating because exploring the landscape will remain an active and creative activity forever. Theoretical physics can never end because the landscape is simply too vast.

"I know from my 40 years of experience in working on real-life physical phenomena that the whole idea of an ultimate law based on an equation using just the building blocks and fundamental forces is unworkable and essentially a fantasy. We never know precisely which equation describes a particular laboratory situation. Instead, we always have to build models and approximations to describe each phenomenon even when we know that the equation controlling it is ultimately some form of the Schrödinger equation!

***

"For example, the standard model of particle physics, the theory of superconductivity and the theory of atomic spectra are all built using the rules of quantum mechanics, but they have little to do with each other. In addition, space and time are variables that have to be put in by hand into the theory, when space and time should come out naturally from any ultimate law of physics. This has remained perhaps the greatest mystery in fundamental physics with no solution in sight.

***

"Newton’s laws were extraordinarily successful for 300 years, but we had to go beyond them as we learned more about the universe, and the same should happen with quantum laws some day in the future.

"Any such unknown new theory of the future must build on and incorporate the physics of quantum mechanics, just as quantum mechanics built on and incorporated classical mechanics. Our understanding of the physical world must continue indefinitely, unimpeded by the search for ultimate laws. Laws of physics continuously evolve – they will never be ultimate."

Comment: the thermodynamic law of entropy is so general it will always survive. On the other hand, he is right. Most other equations are simply descriptive of or current knowledge. Interesting to note, he is down the rabbit hole of string theory, because of its math beauty, which runs into the mess of multiverse requirements. Never to be solved.