Is there a GUT?

[Moontanman]

In a recent issue of Discover magazine they suggested that there might not be a Grand Unification Theory. The reason our science cannot accurately bring about a GUT is that there might not only not be a GUT but that the laws of the universe change as time passes. In other words the laws that brought about or were ruling how the universe "was" at the beginning were different than now and will be different in the far future, slowly evolving toward complexity in much the same way biology has been evolving toward complexity. Any thoughts on this?

[Buffy]

Well, the key question is, why is there any reason to think one might exist? Is it necessary to have one?

 

The usual excuse I hear when they're pressed is that physicists are basically mathematicians and that they just want all the equations to work together for truth-beauty reasons.

 

Of course this is being in denial about all the ugliness that there is in pure mathematics, as anyone who's taken Differential Equations will tell you! :phones: ;)

 

It is of course a full-employment act for physicists!

 

In physics, you don't have to go around making trouble for yourself - nature does it for you,

Buffy

[Jay-qu]

You are right, we may never know either way - if there is or isnt a GUT. But as a physicist I believe that the universe is fundamentally understandable and describable. This stems from first my hand experience in seeing the successes of new theories elucidating order where others could only see chaos. If the universe was fundamentally illogical I find it very hard to believe that such beautiful and elegant order could arise and proliferate for billions of years.

 

Saying that the laws change over time is not so much a road block for GUT's, it would just become a necessary part of the description.

[Buffy]

...But as a physicist I believe that the universe is fundamentally understandable and describable.

I agree. I just don't think you need one single theory that describes it all. I'm quite fine if the equations for gravity and electroweak are similar but never quite the same! :)

If the universe was fundamentally illogical I find it very hard to believe that such beautiful and elegant order could arise and proliferate for billions of years.

See? It's always the truth-beauty response!

 

Isn't the beauty excuse a justification for the existence of God? (My woman-who-pressed-the-start-button of course, not one of those silly meddling-jealous-wrathful ones!)

 

Saying that the laws change over time is not so much a road block for GUT's, it would just become a necessary part of the description.

:phones:

 

Nothing wrong with making the theory more complex, just so long as you don't violate Occam... ;)

 

In physics, your solution should convince a reasonable person. In math, you have to convince a person who's trying to make trouble. Ultimately, in physics, you're hoping to convince Nature. And I've found Nature to be pretty reasonable,

Buffy

[Little Bang]

My opinion, if we ever learn enough about the electron and proton to describe them using the spoken word we will be able to produce the GUT.

[modest]

See? It's always the truth-beauty response! :rolleyes:

 

Isn't the beauty excuse a justification for the existence of God? (My woman-who-pressed-the-start-button of course, not one of those silly meddling-jealous-wrathful ones!) :evil:

 

I object! Your GOD is nowhere near as beautiful as my GUT... or my TOE for that matter. Well... ok, that might be subjective. Let's just agree that they're all acceptable words in scrabble.

 

Unfair scrabble word point distributions aside, I agree—Einstein figured that God didn't play dice with the universe and Niels Bohr told Einstein not to tell God what to do. I think Bohr was right. However we think the universe might be most beautiful, hedging our bets on those expectations has no guarantee of success.

 

That said, physical laws should describe the physical world, and in the physical world gravity gets along just fine with the other forces of nature. We should at least expect two compatible theories, if not one all-encompassing one.

 

~modest

[Jay-qu]

There is a distinction to make, in that a beautiful universe doesnt mean a beautiful theory - ideally it would be, but so far the reality is that quantum field theory is a mess of careful and sneaky tricks.

 

Also I completely agree that there may not be one theory, and if not then I hope there should at least be a bunch of theories that can cover all of the useful energy scales. For example finding a theory of quantum gravity that may not reduce perfectly to GR in the classical limit - but does at least give meaningful results at the high energies and short distances of QFT.

[Moontanman]

In other words the laws that brought about or were ruling how the universe "was" at the beginning were different than now and will be different in the far future, slowly evolving toward complexity in much the same way biology has been evolving toward complexity. Any thoughts on this?

 

While two theories might be just as good as one unified theory this does not address the premise of the Discover magazine article that asserts that there is no theory nor can their be one because the laws of nature are not static and the results of the evolution of those laws toward complexity cannot be predicted specifically anymore than the results of evolution can be predicted specifically.