Does physics win over everything?

[seriously disabled]

Do you think that physics is the most fundamental of the all the sciences?

 

And if yes, then do you think that physics will one day provide a complete theory (a theory of everything) of all the phenomena in existence including space, time, energy and matter?

Edited June 6, 2012 by seriously disabled

[immortal]

Do you think that physics is the most fundamental of the all the sciences?

 

Yes, Physics is an exact science, its experiments are normally like + or - error_rate_of and such small changes in the precision of those values determines whether a model is accepted or not.

 

And if yes, then do you think that physics will one day provide a complete theory (a theory of everything) of all the phenomena in existence including space, time, energy and matter?

 

 

According to many Physicists QM is one of the most intellectual theories mankind has ever achieved. There will always be new problems in physics and physicists will work towards to clearing up that mess.

Edited June 6, 2012 by immortal

[juanrga]

Do you think that physics is the most fundamental of the all the sciences?

 

What do you mean by "fundamental"? Contrary to "applied"? Reductionist?

 

And if yes, then do you think that physics will one day provide a complete theory (a theory of everything) of all the phenomena in existence including space, time, energy and matter?

 

By definition Science cannot provide a theory of everything.

[John Cuthber]

 

By definition Science cannot provide a theory of everything.

Why not, and in particular, what part of the definition prevents it?

[juanrga]

Why not, and in particular, what part of the definition prevents it?

 

The part that defines its scope and methods.

 

Even if we admit that someone was able to formulate a TOE tomorrow, its testing would use the universe as a whole and this only could be made by the so-called "supernatural observers", which are not real.

Edited June 6, 2012 by juanrga

[John Cuthber]

As far as I can see that's only true in the sense that testing the idea that electrons repel each-other would take the whole universe. You would need to test it with all possible pairs of electrons.

 

However most people would accept, a theory that had been tested on quite a bit of the universe and found to work, as a potential ToE.

[D H]

A theory of everything would cover both general relativity and quantum mechanics. Biologists don't use Newtonian mechanics, relativity theory, or quantum mechanics to describe predator-prey relationships, and they would be even less likely to use this theory of everything. The same goes for sociologists and their descriptions of group dynamics. Different sciences operate at different levels of abstraction. The very detailed level at which physicists work is inappropriate for most aspects of the life sciences and is completely inappropriate for the soft sciences. We physicists tend to look down on the soft sciences as being less scientific, but then again, those in the softer sciences tend to look down on physics as being unimportant to humanity. IMO, both of those viewpoints are wrong.

[Bill Angel]

A theory of everything would cover both general relativity and quantum mechanics. Biologists don't use Newtonian mechanics, relativity theory, or quantum mechanics to describe predator-prey relationships, and they would be even less likely to use this theory of everything. The same goes for sociologists and their descriptions of group dynamics. Different sciences operate at different levels of abstraction....

I agree. Physicists have explained quite well the ground state of the hydrogen atom, the thesis being that all hydrogen atoms in their ground state are identical. But there is no equivalent "ground state" description for a human being, let alone one that would allow scientific assertions to be made that assumed that all humans in such a "ground state" were identical.

[John Cuthber]

I could ask this question two ways.

Either where does the cut-off occur? i.e. where is the point where the complexity becomes too much for physics and we end up with collections of atoms behaving in unpredictable ways. It must happen somewhere between hydrogen atoms which we can calculates quite well and humans which we can't.

 

Or I could ask if the physicists have solved the 3 body problem yet?

i.e even for some incredibly simple systems like a single helium atom, we are not able to solve the equations analytically. We can write then down and we can get pretty good answers, but strictly speaking these equations can not be solved.

 

The physicists look down on the other sciences as being "inexact", but the fact is that they are not, philosophically speaking, any better off themselves.

The difference is in what level of approximation you choose to put up with.

 

You can't solve Schroedinger's equation for a human, but then again, you can't really solve it for a helium atom.

[D H]

Or I could ask if the physicists have solved the 3 body problem yet?

Yes, they have. People misread "not solvable in the elementary functions" as "not solvable". That is wrong.

[doG]

Or I could ask if the physicists have solved the 3 body problem yet?

This one?

[juanrga]

As far as I can see that's only true in the sense that testing the idea that electrons repel each-other would take the whole universe. You would need to test it with all possible pairs of electrons.

 

However most people would accept, a theory that had been tested on quite a bit of the universe and found to work, as a potential ToE.

 

And the history of physics is full of misguided assertions assuring that a "potential ToE" was already available. E.g. Laplace claiming that Newtonian mechanics plus gravity was a ToE. Some years after it was shown that Newtonian gravity could not even explain fully the motion of Mercury. And now we know that Newtonian mechanics plus gravity is very very far from being a ToE.

 

Recent assertions that string theory or Garret Lisi's theory would become physicists' dreamed ToE were fatally flawed as well. In fact, critics of string theory like to call it now a ToN: Theory of Nothing.

Edited June 7, 2012 by juanrga

[John Cuthber]

This one?

 

Strictly speaking, no. I was after the QM version but I think the data you have provided will show what I mean.

Is it possible to actually calculate the position of a (general) classical particle in this system as a well defined function of time?

x=f(t)

y=g(t)

z=h(t)

Can the equations be calculated exactly in a finite time?

OK, that last one is a bit harsh since square roots generally take forever and anything more complicated is a non-starter, but is it possible to express f,g and h as polynomials rather than some horrible transcendentals?

 

Juanrga,

The thing about theories is that they are expected to fail. The issue is not that we only have a Newton like theory (i.e one that works quite well, but not for very small or very fast things) but that we don't have a theory at all.

Newtonian mechanics got men to the moon.

I tend to agree that, at least so far, string theory has produced lots of bad pop. science programs and rather fewer results.

[studiot]

Has anyone read Godel or studied fuzzy logic or the colouring problem with cellular automata lately?

[juanrga]

Juanrga,

The thing about theories is that they are expected to fail. The issue is not that we only have a Newton like theory (i.e one that works quite well, but not for very small or very fast things) but that we don't have a theory at all.

Newtonian mechanics got men to the moon.

I tend to agree that, at least so far, string theory has produced lots of bad pop. science programs and rather fewer results.

 

The point here is that a true ToE is not "expected to fail". Otherwise, it cannot be a ToE.

[John Cuthber]

Nope, that would make it a Law of everything.

[D H]

Nope, that would make it a Law of everything.

Nah. It would make it a theorem of everything. Law is just another term for theory, maybe even less than that.

 

In any case, all of this is tangential to the topic of this thread. Even if there was a "theory of everything" that explained all four fundamental interactions, it still wouldn't be applicable to describing (for example) predator-prey relationships. Different sciences attack rather different problems. There is no one size fits all in the sciences. If anything, it's the other way around. Sciences are getting more and more specialized as time passes.

 

Saying that one science pwns all the others is just silly.

[John Cuthber]

Nah. It would make it a theorem of everything. Law is just another term for theory, maybe even less than that.

 

Even if there was a "theory of everything" that explained all four fundamental interactions, it still wouldn't be applicable to describing (for example) predator-prey relationships.

Saying that one science pwns all the others is just silly.

Oops! Fair enough.

If (big if) you could calculate the interactions in each and every atom in the prey and the predator why would you not be able to work out the relation between them?

In principle, it's physics.

That was my point. Where do you draw the line?

Or does the fact that some of these are, in principle, incalculable mean that physics really couldn't explain the predator prey relation?

 

In any event I agree it's silly to talk of any branch of science "winning".

[juanrga]

Why some people want to extend the concept of "physics" doing it equivalent to the concept of "science"?

 

Why some people still believes in reductionism when emergence, non-deterministic chaos, and other recent developments have falsified it?

[Aethelwulf]

Do you think that physics is the most fundamental of the all the sciences?

 

 

Oh yes, defo. Physics is the mother of all sciences, the science which attempts to reason why anything is.

[D H]

Oh yes, defo. Physics is the mother of all sciences, the science which attempts to reason why anything is.

You aren't going to explain predator prey relationships with physics; it's a case of TMI. Reductionism runs afoul of TMI, chaos, the uncertainty principle, and quantum indeterminism. Take reductionism too far and you can't see the forest for the trees. Auguste Comte argued that it was sociology that was the queen of all sciences, with mathematics, astronomy, and physics at the low (and least interesting) end of the scale.

 

Arguing which science pwns all the others is silly.

[Aethelwulf]

I guess which science pawns what is a matter of personal belief. Personally, physics is the science... the only science rather capable of explaining the origins of any other science.

[PeterJ]

This is odd. Has nobody heard of metaphysics?

 

For a science to be fundamental it would have to address first principles.

Edited June 12, 2012 by PeterJ

[StringJunky]

I guess which science pawns what is a matter of personal belief. Personally, physics is the science... the only science rather capable of explaining the origins of any other science.

 

Philosophy is really the root of all science because you have to start from premises, but I don't think anybody can really do it effectively now, that is also pertinent to math's and physics, from what I have gathered over the years reading these boards and others.

[PeterJ]

Yes. On these boards and in the sciences it is difficult to find anbody doing it effectively, and I can see that this must lead to the idea that physics must go it alone. It's quite easy to find them elsewhere though. and I would not like to think I was unable to do it effectively. Whether we do it effectively seems to me more a choice than a skill, as long as we can think reasonably well.

 

Physics is defined in such a way that it cannot go it alone. Theoretical physics becomes metaphysics at the limit and we have to start testing theories by logic alone.

 

Paul Davies is very good on this stuff, actually quite effective, and his view of the relationship between physics and metaphysics seems correct to me.