theory of everything

[physicsx20]

Should physicists formulate a theory of everything? would you agree with formulating such a theory or would u prevent it from being formulated?

[ajb]

...or would you prevent it from being formulated?

 

 

Why should one want to stop such a theory being created, assuming it exists?

[JohnStu]

Yups, and they are doing so.

[Tres Juicy]

Yups, and they are doing so.

 

 

Why would anyone do that?

 

What a ridiculous assertion.

[Phi for All]

LOL Conspiracy Theory of Everything.

[PeterJ]

Sorry to be contentious, but physics cannot ever formulate a 'theory of everything'. Such a theory would have to be metaphysical to qualify. This is why I am so baffled by the rejection of metaphysics in physics. It appears to be the equivalent to shooting oneself in the foot. Physics cannot have a fundamental theory of anything at all while it avoids discussions of first principles. This is definitely not rocket science.

 

It may not even be possible for physics to define 'everything', let alone explain it, since the definition would raise metaphysical/mathematical issues connected with Russell's paradox, self-reference, incompleteness etc.

 

Paul Davies is very good on this topic, and seems to have a well-considered view on what physics can and cannot do.

[ajb]

Sorry to be contentious, but physics cannot ever formulate a 'theory of everything'.

 

It will depend on what you mean by a "theory of everything". I would take it to mean a theory that unifies gravity with the other forces of nature.

 

This does not necessarily mean that such a theory can exactly predict everything in the Universe.

 

Classically, we have chaotic behaviour of systems, which means large sensitivity to the initial conditions. Without knowing all the initial conditions (or the conditions at some specified time) infinitely precisely the theory is unlikely to make exact predictions of everything, even in principle. So, as we can never know everything exactly, or maybe more carefully we could never represent this knowledge, predictions of the evolution of everything in the Universe are bound to have some ambiguity.

 

In fact, this is even true of the N-body problem in Newtonian gravity.

 

And this is before we consider the effects of quantum theory with give probabilistic predictions anyway.

 

So, I would expect a "theory of everything" to make predictions when quantum effects of gravity are important, but it would not necessarily really predict "everything".

 

 

Such a theory would have to be metaphysical to qualify. This is why I am so baffled by the rejection of metaphysics in physics. It appears to be the equivalent to shooting oneself in the foot. Physics cannot have a fundamental theory of anything at all while it avoids discussions of first principles. This is definitely not rocket science.

 

Physics deals with mathematically modelling nature and comparing these models with nature. It deals with things that we can observe and measure.

 

Metaphysics is a branch of philosophy, asking questions about existence and what is. It is close to physics in some sense, but it cannot be regarded as a true science.

 

 

It may not even be possible for physics to define 'everything', let alone explain it, since the definition would raise metaphysical/mathematical issues connected with Russell's paradox, self-reference, incompleteness etc.

 

Maybe, though physics is not mathematics, and so fundamental mathematical issues may not necessarily be a problem. Also, this will depend on what we mean by a theory of everything as already stated.

Edited October 19, 2012 by ajb

[Ophiolite]

Yups, and they are doing so.

John are you replying to the opening post and stating that physicists are seeking a so-called theory of everything?

Or, are you replying to the next post and implying that physicists are trying to stop such a theory being evolved?

[PeterJ]

It will depend on what you mean by a "theory of everything". I would take it to mean a theory that unifies gravity with the other forces of nature.

I would not call this a theory of everything, but a theory of how to unify gravity with other forces.

 

So, I would expect a "theory of everything" to make predictions when quantum effects of gravity are important, but it would not necessarily really predict "everything".

For me such a theory would explain everything in principle, or by extension, or not qualify for the name.

 

Physics deals with mathematically modelling nature and comparing these models with nature. It deals with things that we can observe and measure.

Yes. This is why it cannot have a fundamental theory. To go beyond the observable means dipping into metaphysics.

 

Metaphysics is a branch of philosophy, asking questions about existence and what is. It is close to physics in some sense, but it cannot be regarded as a true science.

I disagree. Done properly it is a science of logic, as Hegel argues. But I'd agree that it rarely achieves this, and very rarely indeed in our universities at present, and so it may not appear to be this. I recently wrote a piece arguing that physicists have every right to insist that metaphysics should be scientific, in response to a philsopher who argues that to do this is the worst kind of 'scientism'. But to me metaphysics is either a science or a waste of time.

 

Maybe, though physics is not mathematics, and so fundamental mathematical issues may not necessarily be a problem. Also, this will depend on what we mean by a theory of everything as already stated.

Thinking is mathematical, so the problems arise whenever we examine these issues and whatever the angle we approach them from. The same foundational mathematical problems arise in physics and metaphysics. We see this whenever yet another person starts a post about whether the universe 'begins' with something or nothing. The problem is mathematical, or at least set-theoretic, and also metaphysical. It is not a question physics can address by referring to observations and measurements, while any theory of everything would have to answer it.

 

I should add that I'm not being critical of physics, just recognising its limits. There's nothing to stop a physicist from formulating a theory of everything, but the result will be a metaphysical theory. Physics does not deal with the world as a whole, or not since we defined the study of absolutes and first principles as metaphysics.

 

I'm assuming that 'everything' here means what it says. I appreciate that it usually has a more limited meaning within physics.

[ajb]

I would not call this a theory of everything, but a theory of how to unify gravity with other forces.

 

That is how most physicists would understand a "theory of everything", which is synonymous with unified "theory".

 

To go beyond the observable means dipping into metaphysics.

 

There are plenty accepted scientific theories that have non-observable aspects. This does not by itself imply metaphysics.

 

But to me metaphysics is either a science or a waste of time.

 

As is philosophy as a whole?

 

 

Thinking is mathematical, so the problems arise whenever we examine these issues and whatever the angle we approach them from. The same foundational mathematical problems arise in physics and metaphysics. We see this whenever yet another person starts a post about whether the universe 'begins' with something or nothing. The problem is mathematical, or at least set-theoretic, and also metaphysical. It is not a question physics can address by referring to observations and measurements, while any theory of everything would have to answer it.

 

We can think mathematically, that I agree with.

 

 

 

There's nothing to stop a physicist from formulating a theory of everything, but the result will be a metaphysical theory.

 

What is a metaphysical theory?

 

I'm assuming that 'everything' here means what it says. I appreciate that it usually has a more limited meaning within physics.

 

What does everything mean?

[Nobrainer]

A proposed physical theory of everything.

 

Here is a proposed solution of what Einstein missed and everyone else has also.

The universe is dissolving in total useful energy creating space itself. There is a hidden process of mass and energy decaying into continuously synchronizing gravitational waves creating the actions of forward time, expanding space, gravity and dark matter. The gravitational wave, consisting of the essence matter, irreversibility bound is the singularity's substance in it's least potential energy form. A version if this Ghost Wave Theory is a three dimensional overview of the basis for actions of the universe.

 

Once energy is exhausted in the universe, the lone 100% space that is left is finally at Absolute Zero and time has run it's course... Then the wave folds onto itself, it becomes condensed, rushing in on itself, the ultimate implosion until a new singularity... to be continued without metaphysics...

Edited October 19, 2012 by Nobrainer

[Ophiolite]

That's a little unclear. Could you post the math for that please.

[ACG52]

That's a little unclear.

 

You have a definite talent for understatement.

[Ophiolite]

You have a definite talent for understatement.

It's what I do.

[PeterJ]

That is how most physicists would understand a "theory of everything", which is synonymous with unified "theory".

Yes. But obviously this would not be a theory of everything.

 

 

There are plenty accepted scientific theories that have non-observable aspects. This does not by itself imply metaphysics.

Do you have an example that we can dissect?

 

 

As is philosophy as a whole?

I would say so.

 

 

We can think mathematically, that I agree with.

We have no choice in the matter.

 

 

What is a metaphysical theory?

A theory of the world as a whole.

 

 

What does everything mean?

To me it means all phenomena.

Edited October 20, 2012 by PeterJ

[ajb]

Do you have an example that we can dissect?

 

A great example that springs to my mind are FP ghosts in gauge theory. They appear only in internal loops in Feynman diagrams. They are essential (well, in covariant gauges) to unitarity of perturbative gauge theories.

 

or what about the electron field? That is not directly observable in any way, yet it is fundamental in QED. And so on...

 

 

A theory of the world as a whole.

 

To me it means all phenomena.

 

This is quite obscure. You would need to carefully explain what you mean by "world as a whole" and "phenomena". If you are taking about things we can measure then you are talking physics, if not then it is probably philosophy.

[futuretech1281]

there is a theory of everything. it is pretty simple. everything in this planet and in the universe are created by energy, different types. from weak to strong. gravity it self is an energy pulling down on other energy.

[PeterJ]

A great example that springs to my mind are FP ghosts in gauge theory. They appear only in internal loops in Feynman diagrams. They are essential (well, in covariant gauges) to unitarity of perturbative gauge theories. or what about the electron field? That is not directly observable in any way, yet it is fundamental in QED. And so on...

The first one I cannot comment on, as you would expect, but it's not what I would call a profound theory so may have no metaphysical implications. The behaviour of electrons, on the other hand, has immediate implications. Metaphysics should have been rocked by the move from the Newtonian universe to quantum mechanics etc.. It wasn't, and hasn't been yet, and in fact physics seems to have largely ignored in philosophy since Eddington, Schrodinger and the rest passed on, just a philsophy is largely ignored in physics. But any talk of infinitely extended fields takes us straight into metaphysics.

 

This is quite obscure. You would need to carefully explain what you mean by "world as a whole" and "phenomena". If you are taking about things we can measure then you are talking physics, if not then it is probably philosophy.

I think you've made my point. Physics cannot include everything in its theories because the existence of things that can be measured must depend on something that cannot be measured. This is what logic concludes, and it is why physics cannot have a fundamental theory. Logic takes us further than measurement alone, just as it is supposed to do. A theory that includes only things that can be measured is not fundamental, or, if it is supposed be fundmental then it will give rise to problems of self-reference, contradictions etc. To put it another way, metaphysics does not endorse materialism or idealism. If a fundamental theory could be made only out of things that are measureable then philosophy would be a doddle. But it cannot be, and physics cannot make it happen because it does not deal with the world as a whole or with the final nature of phenomena. It is not its job, or not since we created the divide between physics and metaphysics.

 

there is a theory of everything. it is pretty simple. everything in this planet and in the universe are created by energy, different types. from weak to strong. gravity it self is an energy pulling down on other energy.

 

A theory of everything should surely explain energy, not just pluck it out of thin air. Or it will be a theory of everything except energy and time and space, which wouldn't be much use.

Edited October 21, 2012 by PeterJ

[ajb]

I think you've made my point. Physics cannot include everything in its theories because the existence of things that can be measured must depend on something that cannot be measured.

 

It is the word "existence" that I always find difficult to deal with. My pragmatic view is that, although I am very happy with mathematics and making calculations, the only things that "exist" are those that I can measure. However, this is philosophy and maybe be utterly useless.

[PeterJ]

It is the word "existence" that I always find difficult to deal with. My pragmatic view is that, although I am very happy with mathematics and making calculations, the only things that "exist" are those that I can measure. However, this is philosophy and maybe be utterly useless.

Yes. Existence is the central problem for metaphysics. The problem is that in logic it does not work to say that everything that exists can be measured. Or, not unless we posit a phenomenon that is prior to the distinction between existing and not-existing. This was Kant and Hegel's solution, and many others. Russell endorsed this idea as a solution to his set-theoretic paradox, and it's a short step from there to seeing it as a metaphysical solution.

 

This is where there seems to be a real disconnect between physics and philosophy. By 'philosophy' I mean just thinking about the issues. Existence is paradoxical if we say that it starts with something that exists already. It's a major problem and very ancient. It has a solution, as Russell saw, but the solution probably seems unnecessarily drastic unless we see the profundity of the problem. It's a problem not usually studied in physics, and it can be avoided by settling for a non-reductive theory. But we can't do that in philosophy. (Albeit that David Chalmers has argued that this is what we must do.)

 

It's a topic I'd like to discuss more since I'd like to explore what this solution would mean for physics, but I'm not sure it wouldn't get the thread closed.

[imatfaal]

!

Moderator Note

It won't be closed - although it might be moved to philosophy

[PeterJ]

Fair enough. But please leave it here. It's the physics that interests me, how it is to be related to the philosophy. Besides, it's not my thread and the OP shouldn't have to suffer from my intervention. I'll try to behave.

[Moontanman]

I have to ask... What is a "first principal"?

[PeterJ]

An axiom or postulate. For a physical or mathematical theory it can be any axiom or postulate that suits us. For a metaphysical theory it must allow us to derive the world as whole in a systematic way, and be first in the sense of not implying a previous principle. Most times a first principle would be just a first principle for some particular theory about some particular phenomenon, but in metaphysics it would have to be the first principle for a fundamental theory of all phenomena.

Edited October 22, 2012 by PeterJ