In "The Theory of Everything" paper, they mention the following: " The crystalline state is the simplest known example of a quantum protectorate, a stable state of matter whose generic low-energy properties are determined by a higher organizing principle and nothing else. " Is that related to why we observed the singlet state in the two electron system? And is the singlet at all related to the bands that form in a crystal?
The "More is Different"-paper was great reading, especially since we have been talking a lot about symmetry in class and I did not really understand it previously!
This means, in practice, that if you are locked in a room with the system Hamiltonian, you can’t figure the rules out in the absence of experiment, and hand-shaking between theory and experiment.
This seems kind of unsettling to me. It seems to me that when we make models we are just trying to match our math with experimental results. We do this by making convenient approximations which makes me wonder if our models have a base in any fundamental legitimacy. I guess it kind of makes me feel as if we will never come up with a complete theory for solid state physics like we did for electromagnetism.
That makes sense to me. I think maybe both perspectives can coexist.
It is unsettling in a sense that it represents a change from the absolutist reductionism that characterized a lot of thinking about science for most of the 20th century. (For example, Steven Weinberg has been a very quotable proponent of reductionism.)
I agree! I really enjoyed being given an explanation of how science progresses. And found it reassuring that we can know specific areas without having to have a full understanding of the whole. I think Krish was talking about this too. And yes this is unlike any other class we have taken, which was a bit unsettling to start with but also great!
In "The Theory of Everything" paper, they mention the following:
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The crystalline state is the simplest known example of a quantum protectorate, a stable state of matter whose generic low-energy properties are determined by a higher organizing principle and nothing else.
"
Is that related to why we observed the singlet state in the two electron system? And is the singlet at all related to the bands that form in a crystal?
Fascinating reads, by the way.
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DeleteThe "More is Different"-paper was great reading, especially since we have been talking a lot about symmetry in class and I did not really understand it previously!
ReplyDeleteI agree. and symmetry is really important but we rarely get to focus on it much. There is an interesting broken symmetry in anti-ferromagnetism.
DeleteThis means, in practice, that if you are locked in a room with the system Hamiltonian, you can’t figure the rules out in the absence of experiment, and hand-shaking between theory and experiment.
ReplyDeleteThis seems kind of unsettling to me. It seems to me that when we make models we are just trying to match our math with experimental results. We do this by making convenient approximations which makes me wonder if our models have a base in any fundamental legitimacy. I guess it kind of makes me feel as if we will never come up with a complete theory for solid state physics like we did for electromagnetism.
Both those articles were very interesting! Thanks for the link.
DeleteI agree. It is unsettling. This may be the most feared and unsettling paper in the last 60 years.
DeleteThat makes sense to me. I think maybe both perspectives can coexist.
DeleteIt is unsettling in a sense that it represents a change from the absolutist reductionism that characterized a lot of thinking about science for most of the 20th century. (For example, Steven Weinberg has been a very quotable proponent of reductionism.)
I agree! I really enjoyed being given an explanation of how science progresses. And found it reassuring that we can know specific areas without having to have a full understanding of the whole. I think Krish was talking about this too. And yes this is unlike any other class we have taken, which was a bit unsettling to start with but also great!
ReplyDeleteGlad you like it!
DeleteGood points.
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