Hawking: No 'Theory of Everything'

Flash Modin writes "In a Scientific American essay based on their new book A Grand Design, Stephen Hawking and Leonard Mlodinow are now claiming physicists may never find a theory of everything. Instead, they propose a 'family of interconnected theories' might emerge, with each describing a certain reality under specific conditions. The claim is a reversal for Hawking, who claimed in 1980 that there would be a unified theory by the turn of the century."

Comments

Re:Celebrity physicist troll train

[Anonymous Coward]

What sort of people do you think predict the as yet unobserved particles that Fermi and LHC people are looking for? Though I doubt Hawking is right on this one, not many besides you would say he was on the sidelines anyway.

Past His Prime

[Wannabe Code Monkey]

I certainly hate to say it. And I certainly don't think I'm any smarter. But, Hawking is past his prime. It seems like he's been saying stuff recently just to say stuff. Maybe it's for attention, maybe it's because he knows extraordinary claims will sell headlines and his books/documentaries, or maybe it's because he actually believes in them. However, after his comments on active SETI being dangerous and now this... I don't know, it's like watching an amazing baseball player, past his prime, coaching a crappy minor league team. It's hard to criticize because I was never as good as he, and even now I couldn't manage a Denny's, but I don't really want to watch him either.

Re:Past His Prime

[interkin3tic]

It happens. James Watson, who was part of the team that discovered the structure of DNA, has been saying crazier things for years.

My favorite was his presentation on why men liked butts. Certainly funnier than his comments on race.

Scientists sometimes don't age well. We probably age better on average than rock stars, but then again people pay don't take what rock stars say as seriously as scientists.

Re:Past His Prime

[deodiaus2]

The comment about Hawkins being past his prime is really ugly, especially coming from you. I think Hawkins is honest enough to say that he does not know or understand something if he doesn't. Hawkins refered to himself as being lazy in his early years in college, so he does admit some of his shortcomings. Ronnie Reagan was often ignorant of the facts, but he said them with such conviction that even people who knew had to go back to check their references before retorting. We survived Ronnie, so I'm more inclined to trust Hawkins.
It might be that it takes a lifetime to learn enough physics in order to make a statement like that. Also, as someone said, the theory of everything might fall into Godel's incompleteness type of problem. Quantum physics is a patchwork of knowledge without enough theory to explain itself. Or the theory could be beyond Human understanding.

Re:Past His Prime

[oldhack]

You're conflating blings with accomplishment. Should have listed his papers instead of awards given to him.

Wisdom from DS9

[MBGMorden]

I'm reminded of a scene from DS9. Sure it's fiction, but it always held some sway with me:

Bashir: "Trevean was right. There is no cure. The Dominion made sure of that. But I was so arrogant, I thought I could find one in a week!"
Jadzia: "Maybe it was arrogant to think that. But it's even more arrogant to think there isn't a cure just because you couldn't find it."

Hawking a smart guy, but he by no means knows everything. Throwing in the towel and declaring that there is no right answer simply because he hasn't found it just doesn't hold much water with me. We might not figure it out for 100 years. We might figure it out tomorrow. We might NEVER figure it out, but simple logic says that there is a unified equation. It might not be simple or pretty, but if the universe operates on a consistent set of physical laws, it's out there.

Re:Wisdom from DS9

[electron sponge]

"The universe is not required to be in perfect harmony with human ambition." - Carl Sagan

Re:Wisdom from DS9

[guyminuslife]

Simple logic says a lot of things, some of which it turns out are not true.

Re:Wisdom from DS9

[MortimerGraves]

I wonder if it may be an example of Clarke's First Law:

"When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is probably wrong."

Re:The hand of Godel?

[abigor]

Godel used the term "formal system" to specifically mean a recursive axiomatic system that can do arithmetic. I don't think it really applies here.

Re:The hand of Godel?

[Hatta]

Aren't the laws of physics axioms for the universe? Isn't the idea behind a grand unified theory to find one or two simple mathematical expressions (axioms) from which the rest of the universe can be derived? The universe is clearly Turing complete, so I really don't see how it wouldn't apply.

Clarke said it best

[MpVpRb]

When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong

Re:The hand of Godel?

[tomhudson]

First problem ( of many ) - a representation of something is not that something. This is something that programmers forget all the time. There is no such thing as objects, methods, function calls, etc. Those are just representations. At a higher level, ordering a pizza online, and them sending you a fax of that pizza, is not going to work either. Even them sending you a complete description of the state of every single atom in a pizza is not going to work. Information, contrary to popular belief, is not equivalent to the thing being described.

In other words, even if you had a machine that was able to represent every single state of the universe, it is not equivalent to the universe. Any description of something, no matter how detailed, is not that thing, no matter how many times people chant "information theory says otherwise." It's like the pastor who preaches against same-sex marriage, saying it's unnatural and that same-sex behaviour doesn't occur in nature, but completely ignores the male dog humping his leg.

However, what you offer is not proof by contradiction. It buys into the idea that there's the possibility that the universe might be represented by a Turing machine. That's the flawed premise (but try to get people to see it when they've got their precious theories on the line).

Also, the halting problem is trivially solved by allowing the arrow of time to reverse at the end of each calculation (say once a second), so that even a near-infinite solution must, by definition, complete in 1 second of "real" time. In other words, either the Turing machine continues to exist after one second, or it disappears - stuck in an infinite time loop. This lets you know that the problem is either solvable, or not.

As for the "dude" bit, please see my profile thx bye!

Re:The hand of Godel?

[John Hasler]

The universe contains complete, formal, logical systems (e.g. computers).

Real computers are not complete, formal, logical systems.

Are they not governed by the laws of physics?

Real computers are, yes. And they are, therefor, not complete, formal, logical systems. The future state of a real computer is not entirely determined by its current state.

Re:The hand of Godel?

[Goldsmith]

I don't know Godel as well as some other people here, but I do know physics and you're making a lot of assumptions there, starting with that the universe can be "derived" from a theory of everything. The name is a little unfortunate, but the goal of a theory of everything is to create a unified description of the fundamental forces, not a program to simulate the entire universe. If you wanted to simply say "the theory of everything won't be able to tell you absolutely everything about every particle in the universe," you'd be right, and probably that's where you're going with your incompleteness thing.

More fundamentally though, you're assuming the universe is a logical system. From a physicists point of view, it is a happy coincidence that rigorous mathematics is useful in describing the universe, but there is nothing that demands that this is the case (more practically: we're happy in physics to have assumptions about things like causality and time invariance, where needed).

This may sound crazy to most people, but why exactly mathematics has been so successful in physics is still a subject of debate among physicists: whether mathematics approximates an ultimately imperfect physical reality or mathematics *is* physical reality. I don't think it will be settled soon.

Re:The hand of Godel?

[PenguiN42]

However, the halting problem (and all other semi-decidable and undecidable problems) exists in the Universe.

This is a HUGE assumption on which your entire argument hinges, so I think you need to define it more precisely, and provide some evidence that it is true.

Your argument seems to fall apart due to equivocation -- at the beginning you define a set of "problems" that the universe turing machine has to solve. For example, one of those "problems" might be "if you arrange mass in a certain configuration, in which direction will it accelerate?"

However, you then include "the halting problem" in this set. Bzzzt, full stop. This is a decidedly different sense of the word "problem." In this case, we're talking about an abstract idea that only exists as definitions on paper and in peoples' minds, but doesn't actually physically exist in the universe. In other words, our universe can talk about and consider and represent undecidable problems, but that doesn't mean it can actually solve them.

If you disagree, please describe a phyisical system that is "the halting problem" or some other undecidable problem and show that the universe can indeed resolve it.