Can there ever be a Theory of Everything?

[Gort]

I thought it was rather obvious.

The standard model and an effective field theory of gravity.

It has a number of ugly issues eg the already alluded to large number parameters and the Landau pole in the Electroweak theory.

Thanks
Bill

But that's my point! Those are two ToS's. And it is quite naive to think that they cover it all. A few questions they don't attempt to answer: Why do fundamental constants have the value they do? Planck's constant, Gravitational constant, charge on the electron, ...etc.
And why do particles have the mass they do? Frank Wilczek (Lightness of Being) says "Although it's accurate to say that the Higgs field allows us to reconcile the existence of certain kinds of mass with details of how the weak interactions work, that's a far cry from explaining the origin of mass or why the different masses have the values they do. ...We really don't understand the masses of neutrinos...and a welter of other particles..."
No, we haven't unified the four "fundamental" forces or the potentially large number of yet undiscovered fundamental forces (per Gell-Mann). So we have no ToE.

 

[friend]

I don't believe you can get a ToE that explains everything unless you derive your physical model starting solely from the principles of logic. Otherwise, you will have some parameters without explanation that are inserted by hand because there is no explanation for them. But it seems the only way to explain "everything" is to start from reason to begin with. The alternative seems to be to be satisfied with some curve-fitting, engineering equations that are used only because they so far predict outcomes. That may be the best we can do. But it by no means is an explanation for why things obey these equations. As I understand it, the only complete system of language is propositional logic. So if you want a "complete" explanation, you need to start with logic. Just my opinion.

 

[DevilsAvocado]

Of course a ToE doesn't mean we'll know "absolutely everything about everything", but it DOES imply that about the physical world. That's what a ToE is. By definition.

Have you really thought that claim through??

By your personal definition of ToE, it must include the tools for analyzing Mona Lisa (i.e. the data/measurement) and thereby construct a set of equations that explains/predicts the emotions that went through Leonardo da Vinci while painting her...

This is definitely not physics definition of ToE.

 

[Gort]

I give up. I will define all terms used. Didn't think it was necessary in a QM forum.

Physical world - 3rd definition from the Oxford Dictionary - "Relating to http://www.oxforddictionaries.com/definition/english/physics#physics__3 or the http://www.oxforddictionaries.com/definition/english/operation#operation__3 of natural forces generally".

 

[Gort]

...thereby construct a set of equations that explains/predicts the emotions that went through Leonardo da Vinci while painting her...
This is definitely not physics definition of ToE.

Perhaps you need some background on the Physical World, such as offered by the Open University - http://physicalworld.org/index.html

 

[ZapperZ]

I read all of this with a bit of amusement, considering that Vanesh and I already went through the debate of ToE (or lack thereof) and emergent phenomenon way back in 2005!

https://www.physicsforums.com/threads/whats-wrong-with-qm.68265/page-9#post-514756

These 5 references will get you up to speed on why many prominent condensed matter physicists think that the so-called "Theory of Everything" is really a ToE for reductionism.

1. http://www.pnas.org/cgi/reprint/97/1/28.pdf
2. http://www.pnas.org/cgi/reprint/97/1/32.pdf
3. http://arXiv.org/abs/hep-th/0210162
4. R.B. Laughlin, Rev. Mod. Phys., v.71, p.863 (1999).
5. http://www.sciencemag.org/content/177/4047/393.extract

Zz.

 

[atyy]

I read all of this with a bit of amusement, considering that Vanesh and I already went through the debate of ToE (or lack thereof) and emergent phenomenon way back in 2005!

https://www.physicsforums.com/threads/whats-wrong-with-qm.68265/page-9#post-514756

These 5 references will get you up to speed on why many prominent condensed matter physicists think that the so-called "Theory of Everything" is really a ToE for reductionism.

1. http://www.pnas.org/cgi/reprint/97/1/28.pdf
2. http://www.pnas.org/cgi/reprint/97/1/32.pdf
3. http://arXiv.org/abs/hep-th/0210162
4. R.B. Laughlin, Rev. Mod. Phys., v.71, p.863 (1999).
5. http://www.sciencemag.org/content/177/4047/393.extract

Zz.

Condensed matter physicists are the worst, they claim to have a ToE: everything is emergent, even the ToE!

 

[lucas_]

It's possible the Theory of Everything is dangerous. For example. If we were living in a false vacuum, and future scientists keep experimenting on the TOE, what if they caused a phase transition of the false vacuum then everything vanishes in an instance.

Maybe there are times when "Ignorance is just Bliss".. at least we get to keep everything..

 

[Gort]

I read all of this with a bit of amusement, considering that Vanesh and I already went through the debate of ToE (or lack thereof) and emergent phenomenon way back in 2005!

Thanks! So much for the Forum's search function (or my inability to use it).

I think this was only resurrected because Hawking apparently argued (in 2010) that there would never be a ToE (this point was argumentative by several contributors - whether Hawking really said that, and if he did, what it meant). Fair enough. There were some good arguments and points made.

Although you quoted some interesting sources, I don't think any tackled the question Hawking (apparently) answered.

 

[bhobba]

And it is quite naive to think that they cover it all.

I specifically stated they had problems and don't answer tons of questions. We want a TOE to do that and more. We also want it to be 'beautiful'. Just as an example think about the Landau pole. It doesn't interfere with predicting anything we can actually measure but it's very ugly. Evidently Weinberg and Feynman had a debate about it - Feynman thought it a real issue - Weinberg not so much - what it boiled down to is what you are willing to accept in a theory. If it was there in a final theory most would say it wasn't achieved. Whether such will ever come about is another matter.

This all started from when you wrote:

Of course a ToE doesn't mean we'll know "absolutely everything about everything", but it DOES imply that about the physical world.

Indeed with a TOE we will need to know everything about the physical world. But it's more than that - colloquially it can't look like a kludge eg it should not have things like tons of constants put in by hand and Landau poles.

Thanks
Bill

 

[Gort]

Certainly agree with that. But the question is - can it (ever) be done?

Indeed with a TOE we will need to know everything about the physical world.

Can we ever know "everything about the physical world" (which implies an objective reality), or, as Hawking (apparently) said "it doesn't matter what is actually real and what isn't, all that matters is what we experience as reality".

Sorry to bring up "reality" again. I think its tied up with any ToE. Just MHO.

 

[bhobba]

Can we ever know "everything about the physical world" (which implies an objective reality),

I think your idea of knowing everything about the physical world and mine may differ.

For me its simply being able to predict anything we can actually observe - for you it seems to require this 'reality' thing which doesn't worry me in the least.

What really worries me is it must not be 'kludgy' - it must be beautiful in the sense of Gell-Mann.

Thanks
Bill

 

[Dale]

This has gotten silly.