What is The Theory of Everything?

[JonF]

Hello. I’ve been reading this site for a pretty good while now. I haven’t taken very many physics classes so a lot of what is posted is over my head. I see the Theory of Everything mentioned quite often. Can someone explain to me what it is, without going to far out the realm of what I understand about physics?

 

[arildno]

It's about everything, I guess (personally, I think it's nothing, really)

 

[chroot]

The "Theory of Everything" refers to a single cohesive model that explains every physical phenomenon known. Currently, we have two theories, quantum mechanics and general relativity, that seem to do a good job of modelling the universe at small and large scales, respectively, but they are not compatible -- they give different predictions for the same conditions, like those inside black holes. A theory of everything would unite QM & GR as special cases of a more general theory in such a way that they no longer are in conflict.

There are also many open questions in physics, such as the nature of the mechanism that gives particles the particular masses they have. A theory of everything would answer all those questions, as well.

- Warren

 

[BasketDaN]

Theory of Everything = God.

 

[Tree Penguin]

Theory of Everything = God.

Nothing more than an easy 'answer' (/escape) to all the questions you don't know the answer to. People tend like it because it's so easy.

 

[ZapperZ]

I resisted throwing a wrench into all this, but I just can't help myself! :)

The "Theory of Everything" (TOE) is a reductionist point of view that the unification of gravity with quantum field theory would then lead to, in principle, our knowledge of every known phenomena.

Notice that there are two separate parts to that above statement: (i) unification of gravity and QFT (some called that as GUT=Grand Unified Theory); (ii) GUT implies TOE.

By knowing all the interaction at the simplest, fundamental level (i.e. at the fundamental particles), we then would have known all the basic interactions that govern all the phenomena that we observed and will observe. The macroscopic phenomena are simply "added complexities" to the fundamental interactions. This point of view is championed by most field theorists, particle physicists, etc., such as Steven Weinberg.

It is, however, not shared by most condensed matter physicists. Prominent figures such as Phil Anderson, Bob Laughlin, (both Nobel laureates), Dave Pines, etc., point out something that is known as "emergent" phenomena in which, as Anderson points out, "More is Different". Laughlin showed that in superconductivity, for example, the phenomena simply disappears as one tries to break it up into its individual constituents.[1] Superconductivity, magnetism, fractional quantum hall effect, etc. are all collective, emergent phenomena that cannot be described by knowing all the interactions at the single-particle domain.[2,3]

In fact, such emergent phenomena may even be as fundamental as any other fundamental interaction, considering, for example, that one can get fractional charges of 1/3 e under such conditions. It has been argued that such observation may in fact be the explanation for the fractional quark charges and other observations of particle physics and fundamental interactons.[4]

The point here being that there are a large group of physicists that do NOT share the idea that Unification = TOE. Unification is unification. It may be the TOE of reductionism. But it is certainly far from being the TOE of physics.

Zz.

[1] R. B. Laughlin, Rev. Mod. Phys. 71, 863-874 (1999).
[2] http://www.pnas.org/cgi/reprint/97/1/28.pdf
[3] http://www.pnas.org/cgi/reprint/97/1/32.pdf
[4] http://arxiv.org/abs/hep-th/0210162

 

[Nenad]

I don't think TOE will ever be acheved or found out.

 

[bettysfetish]

Well, - - you seek to speak with God. Just kidding, I'm not that religious. As most here may agree, T.O.E. won't happen in our lifetime. The "Theory Of Everything" will even have to explain how nothing exsisted before there was something; that's a problem, as well as a few other things. But it is what it is. It will need to combine everything we will ever learn to figure it out; because once we figure it out there won't be any unanswered questions.
L8R
---------"After all is said and done, Gravity Rules."--------