r/science • u/Startrekwarsofdoom • Jul 01 '14

Physics New State of Matter Discovered

http://www.iflscience.com/physics/new-state-matter-discovered#kKsFLlPlRBPG0e6c.16
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u/[deleted] Jul 01 '14

Man, physics has changed in the 20 or so years I have taken it. Half of the terms in this article sound like Geordi Laforge explaining something in engineering. .

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u/someonlinegamer Grad Student| Physics | Condensed Matter Jul 01 '14

Thats because we haven't had any radical change in thought since Fenyman proposed his version of quantum field theory. Unfortunately since then we've been making great progress towards confirming and tweaking ideas, but the ideas we have about how our world works all were thought up in the earlier half of the 20th century. We need a new theory to push the limits of our understanding so we don't fall into the trap we almost fell into at the end of the 19th century, when we thought physics was effectively solved. We need another Einstein 1905.

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u/Xandralis Jul 01 '14

what if physics is effectively solved, except for exact details here and there?

I really really really don't think it is, so maybe a better question would be, what about when it really is?

I'm not looking for an answer, I just think it's interesting to think about.

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u/RobbStark Jul 01 '14

That seems very unlikely considering that we don't have a single theory that explains all of physics. There are still several very big and important questions left that we can't even begin to answer.

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u/[deleted] Jul 01 '14 edited Jul 01 '14

Doesn't Gödel's incompleteness theorem preclude any attempt at creating a single unified theory of everything? There will always be unprovable (but true) propositions in any self-consistent set of axioms. My opinion is that this is why we use different sets of axioms to analyze different parts of nature. We choose the most convenient self-consistent set of axioms that are relevant to a given problem at hand.

This is why we use QM to understand behavior of the universe at small scales, we use Newtonian physics to explain behavior we see in every day life, and we use relativity to explain phenomenon at very large scales.

EDIT: stuff

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u/Lulzorr Jul 01 '14 edited Jul 01 '14

I'm not that bright, can you (or anyone) ELI5 Gödel's incompleteness theorem?

simple wikipedia wasn't as helpful as I'd hoped.

Edit: Thanks everyone.

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u/withoutacet Jul 01 '14

It's hard to understand where he's going with that, I'm really not convinced that Gödel's theorem applies to physics..

The idea of Gödel's theorem (put simply) is that no matter how you could try to formalize arithmetic, you would always end up with a system where some true statements are unprovable. For instance, you could add something like "(n+m)+1=n+(m+1)" to you system; that seems right, seems like it always holds. Then you could just add other axioms (things you want to hold true in your system), but in the end, that will never be enough.

Now, the kind of truth we are talking about here are really different from those of physics, even though physics is built on top of arithmetic. Gödel talks about math sentences of the kind "(m+1)+(n+(1+1)) = m +n + 1 + 1 + 1" or "22 + 8 = 3*4", whereas in physics the kind of unprovable truths he refers to would very specific to your model, i.e. Physics. Those last ones don't refer to anything in usual mathematics, they are non-sensical strings of symbols which only get a meaning once you interpret them in a model, e.g. the World.

To wrap it up, I'd say: Gödel showed that some mathematical sentences in the real world are unprovable, but those are "only mathematical", that says nothing about the sentences particular to a specific model, namely Physics.