Pertains to any question concerning the ideas that are formulated, whether mathematically or not, to explain or describe physical phenomena.
3
votes
1answer
89 views
Are there microscopic theories, which work, but which wrongly predict macroscopic behaviour?
Motivated by this question (and the P. W. Anderson article linked in that question, which I came across here somewhere today and just read) I wonder about something, which is somewhat bordering an ...
4
votes
0answers
235 views
Relating the variance of the current operator to measurements
(EDIT: Thanks to Nathaniel's comments, I have altered the question to reflect the bits that I am still confused about.)
This is a general conceptual question, but for definiteness' sake, imagine a ...
2
votes
0answers
186 views
How is the “negative dispersion” derived?
I'm looking at Kopfermann H., Ladenburg R., Nature, 122, 338-339 (1928) and it appears Ladenburg in Ladenburg R., Z.Physik, 4, 451-468 (1921) was the first to discover the phenomenon of "negative ...
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vote
0answers
89 views
What is the origin of the many-body expansion?
I'm looking for the original introduction of the many-body expansion (MBE) in the scientific literature. More specifically, I'm interested in a theoretical justification of the rapid convergence of ...
1
vote
0answers
47 views
four boson quantum system contact interaction
I have to solve this problem. Four bosons moving in 1d harmonic potential(their spin is 0) and interacting through contact interaction defined via delta function.
Now, methods that I have to use: a) ...
0
votes
0answers
178 views
Calculating the number of turns and thickness of an electromagnet
I want to calculate the number of turns of an electromagnet and the thickness of the wire.
But i have tried to search arround in books, and can't really find any thing.
I know my wire is 0,114mm and ...
