Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Gordian Knot on 13/08/2012 18:25:19
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Science seems to have a fairly good idea of how the Very Big works, with the foundation being Einstein's Theory of Relativity.
Science seems to have a fairly poor idea how how the Very Small works, that having been contributions by a host of folks we call Quantum Theory.
There seems to be a desire to bring these two very disparate systems together somehow. A single theory that explains both how the Very Big AND the Very Small works.
My question (finally) is does there HAVE to be such a unified theory? Is it not possible that things simply act differently; that there are entirely different laws for the Very Small and the Very Big???
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Hmm, who knows? Though I think it is right that an aim of science should be to try to find a unified theory. In any case, the big and the small are already unified to a large extent and relativity (normally associated with the "big") has to be taken into account to more precisely explain the "small"; e.g. The Klein-Gordon equation rather than the Schrödinger equation.
Anyway, it seems to me that there should be a unified set of "rules" on which the universe is built and it is up to science to find them. The idea that this should not be so would be a very negative view: rather like thinking (as may have been thought in the past) that chemistry, biology and physics are unrelated and subject to different laws that were independent.
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Science seems to have a fairly good idea of how the Very Big works, with the foundation being Einstein's Theory of Relativity.
General and Special relativity work very well and are highly tested. On the super large cosmological scale you will find that there are a number of fudges going on - dark energy and dark matter are unobservable influences that have been introduced to reconcile theory with observation. Personally I think we are correct to postulate unseen matter and an expanding energy rather than throw away our ideas - but there is a fair size group of physicists who are working on alternative cosmologies that fit observations as they are now.
Science seems to have a fairly poor idea how how the Very Small works, that having been contributions by a host of folks we call Quantum Theory.
Quantum mechanics, QFT - QED and QCD are incredibly successful and have been tested to a mind-boggling degree of accuracy.
There seems to be a desire to bring these two very disparate systems together somehow. A single theory that explains both how the Very Big AND the Very Small works.
Our theories tell us that at certain energies - much higher than experienced on earth (even at the LHC) the four fundamental "forces" start to merge; ie the strong nuclear force / colour force that holds protons neutrons and nuclei together, the weak force that deals with some radioactive decays, the electromagnetic force, and gravity. We already have the theory and the maths to unify the electromagnetic and the weak - unsurprisingly this theory is called the electro-weak. there is a strong feeling that there is one theory that at high energies gives one simple answer, but at our present energies resolves into 4 different forces.
My question (finally) is does there HAVE to be such a unified theory? Is it not possible that things simply act differently; that there are entirely different laws for the Very Small and the Very Big???
Yes - I think there does. One reason - what happens at the changeover point? When a phenomena is at the large side of the small and the small side of the large? there must be a cut off point - a discontinuity; and non-smooth functions like that are anathema.
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They should have some connections, somewhere, to work. If you decide that they are two different realities then reality becomes very tricky. Although you could take a middle path and question if causality chains always is what define reality? We have a lot of examples of observer dependencies (Relativity) on one hand, and on the other you in QM can find indeterminism and quantum fuzziness . Both seems, to me that is, to speak of other principles, although both seems to follow a intrinsic logic of their own?
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is it possible that no unified theory exists ?
I mean, suppose that matter just follows a different set of rules once it has "acquired" a certain level of mass, and it is as simple as that.
just the same way that mass comes about upon combinations, maybe this process in of itself, requires said mass of particles to now follow these new rules..
"something" holds matter together to get "mass",
maybe that something, requires matter to change the rules at that point.
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I used to subscribe to all sorts of crazy theories about reincarnation and how the entirity of the universe was an all powerful consciousness or some nonsense. Then I was introduced to the awesome stand-up musical comedy of Tim Minchin (don't worry, this IS going somewhere - sort of). I realised that there doesn't have to be a simple answer to life.
A lot of people who believe in hocus pocus think they are opened minded. I think they have yet to open their minds to the possibility that there may never be a simple answer and the world doesn't have to make sense.
I think it's important to try and keep looking for the answers and in the search for solutions to incredibly inaccessible problems, we will invariably find new and better ways to deal with the real things we can touch.
In terms of relativity and quantum mechanics, I've often pondered at the idea that both seem to be very dependant on an observer. Things change in both realms based on the observer. I've often wondered whether consciousness plays a part in these things, or maybe that's the hocus pocus creeping back in ;D
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String theory a development of quantum theory is based on a theory that there are more physical dimensions in the universe than the three of space and one of time that we experience.
It can be shown that large long lived universes can only exist in structures with this number of large dimensions. The remaining dimensions are probably very small.
Some of the unusual features of quantum mechanics indicate that the universe is simultaneously very large and very small so both ends are important.
All we can really observe is the middle however an important feature of a theory of everything is that it must go beyond just the basic physical laws it must show how our and any universe originated and how new universes are created, probably by other universes in a continuing fractal chain. We can see the possibility of this actually happening in our universe in the form of black holes and until we have followed this trail to the end and our current knowledge of the big and the small will allow a lot of this to be done.
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For a start, a theory doesn't have to be right so there can be any number of "theories of everything" but most of them are more or less wrong.
Also there are a finite (if rather big) number of particles in the observable universe. (Estimated as less than a googol).
There are, therefore a finite number of interactions between those particles. (I'm assuming the number of fundamental forces is finite, even if it's more than 4)
So if you have a theory that calculates the effects of all those interactions it is a theory of everything.
There must be such a theory.
It's never going to be possible to record it (the universe won't be big enough).
It's also pretty useless.
What people are hoping to find is a theory that codes all that information into a few relatively simple rules.
That theory may or may not exists.
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Nature abhors a vacuum and science abhors a contradiction.
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Logically and philosophically there is no necessity for a simple unified grand theory of everything, and no contradiction if there is not one.
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Logically and philosophically there is no necessity for a simple unified grand theory of everything, and no contradiction if there is not one.
I completely agree. But looking for one has been quite productive for physics!
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a theory of everything, includes everything.
and mankind is so far from finding out everything..
maybe one day................
maybe never................
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I think there is one, but it's not as we measure, and use other principles that those we observe. Not meaning that it isn't fruitful to follow causality chains, but the puzzle we lay by them is like a facet on something 'more', or maybe 'less' :) But when we try to build the sciences we have observations, theory, and experiments testing those, that leads us. Any other way and we are talking philosophy, but maybe we some day will have enough experimental evidence to peek behind the curtain.
But i doubt that will allow us to 'live' there though. We're here, not there.
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I love how we all (( me included )) like to decide the best way for mother nature to set out her laws.
there only has to be a unified theory, because it makes it all easier, and because one makes sense.
quantum mechanics, consciousness, emergence, and complexity to name a few, should show everyone,
nature does not always make sense......or always follow "our" expectations..
I do not believe a unified theory exists, but then again, there is only one truth, it does or it does not..
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Thanks as always for the great responses. A few comments. Someone early on mentioned that it would be wrong not to "try" to find a unified theory of everything.
I agree. Wasn't suggesting otherwise. What I was suggesting is that it is not the only course to follow. Is anyone testing the possibility that there are two sets of physics, that of Relativity, and that of Quantum Mechanics? It seems incomplete to test for but one of these two possibilities.
Imatfaal asked a really interesting question about what would happen if there are indeed two sets of physics. Namely what happens at the changeover point?
Some queries first.
Is the smallest observable thing 10 to the minus 10 meters? (An electron microscope).
Lengths smaller than 10 to the minus 15 meters cannot be confirmed (Roughly the size of protons and neutrons).
Is it correct that most define the beginning of the Quantum Level at 10 to the minus 14 meters?
If these statements are all true, then it seems to me we can almost observe that zone where the Quantum Level is said to begin. So what is indeed happening in that zone? Do we know anything at all?
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yes, in time, either 10, 50, 100, or 1000 years, humanity will hopefully unlock the laws of the universe, and know all particles on all levels, or maybe, they will always elude us.....if we don't all kills each other first...
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A nice Q Gordian, and one I'm wondering about too. How and where do we limit uncertainty?
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it's just wanting to understand things at a deeper level, which is always a good thing i think.
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The power of science is not simply in that it can provide generalizations, but that a small number of points in a theory can produce explanations of many quite separate and apparently unrelated phenomena. For example (and I always feel most comfortable with chemical examples) the fact that the water molecule has its two bonds at an angle rather than in a straight line explains
• why water is a good solvent for ionic lattices
• why water has a higher boiling temperature than other substances with similar molecular weight and composition
• why water has a wide liquid range
• why ice is (unusually) less dense than liquid water
• why water forms co-ordination complexes with metal ions.
The search for a theory of everything is, in essence, an attempt to extend this sort of power of science -- to be able to absorb a very large number of very diverse observations into a very small number of principles. It is clearly a valuable exercise, and although the goal has not yet been reached, the journey has provided valuable insights and many powerful generalizations.
The unfortunate thing, though, is that while recent physics has provided us with a lot of the framework for principles that will probably one day, and possibly soon, give us a complete "in principle" mathematical model that will purport to underpin the whole of science, it will not provide us with an "explanation" for all observed phenomena. Too much of the mathematics is intractable. Even when the mathematics can provide a solution, that is often all it can do. It can reassure us that the scientific principles are in accord with our observations, but it often, perhaps usually, cannot give us a satisfactory explanation in the form of a causal chain, or even a consequential chain. And these are the only sorts of things that will provide any sort of satisfaction as explanations, and that can point to creative exploitations of scientific knowledge or solutions to the problems that arise in the world.
The issue is that as more sophisticated and accurate mathematical treatments become available, concepts like "cold fronts" or "upper atmosphere troughs" or "chemical bonds" or "single electron wave functions" start to disappear, and with them the whole explanatory lexicon of meteorology or chemistry.
I thoroughly recommend that physicists read and deeply consider articles in
http://books.google.com.au/books/about/Of_Minds_and_Molecules.html?id=eKhy2SCmGNAC&redir_esc=y (http://books.google.com.au/books/about/Of_Minds_and_Molecules.html?id=eKhy2SCmGNAC&redir_esc=y)
I must declare an interest (as a chapter co-author), but not a vested interest.
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yes, it is true, that even if a theory of everything is never fund, many other questions will be answered along the way, and many new questions will be found.
just because Human beings will never find all of the answers is no reason not to try !!!!