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Feb2313 08:38 AM
ZapperZ

1 
35,536 
Hi, there
Today, a friend came to me and asked the following questions and they made me confused.
If the source is...

Jun814 09:17 PM
Robert_G

5 
339 
Why is quantum physics needed to explain photosynthesis?
In what aspect does the corresponding classical theories...

Jun814 11:23 AM
HeavyMetal

2 
265 
Hey!
I did an quantum mechanical analysis of a Hydrogen Atom in a homogeneous magnetic vector potential (I know...

Jun814 11:00 AM
Vanadium 50

6 
305 
I'm a bit of a nonclassical physics newbie here, so let me check my (rudimentary) understanding of some things first....

Jun814 10:10 AM
mfb

6 
383 
Hello and apologies if the title of the question is not very precise.
Question: I am reading the document talking...

Jun814 09:07 AM
UltrafastPED

1 
141 
This is a question about The Computational Capacity of the Universe by Seth Lloyd.
It seems to me that arbitrary...

Jun714 11:57 PM
bhobba

3 
239 
I am referring to an experiment mentioned in Quantum Entanglement lecture:...

Jun714 10:51 AM
RobikShrestha

6 
290 
this might be a dumb question, but, if spacetime isn't a field and gravity is a property of spacetime. then gravity...

Jun714 03:35 AM
bloby

7 
454 
Sometimes it happens that hamiltonian has degenerate eigenvalue. This degeneracy can be removed by modifying the...

Jun714 03:32 AM
Jano L.

8 
316 
If I understand it, Hilbert spaces can be finite (e.g., for spin of a particle), countably infinite (e.g., for a...

Jun614 02:11 PM
samalkhaiat

35 
1,132 
Two entangled photons from a samepolarization source have their polarization measured at 120 deg difference from each...

Jun614 09:17 AM
DrChinese

1 
240 
This post is my reply to a blog comment by billschnieder, since I do not think it is wise to start a discussion in the...

Jun614 06:54 AM
georgir

0 
270 
I have a question: can the mechanism behind Pauli's exclusion principle be considered a fundamental force, like...

Jun614 06:35 AM
tom.stoer

9 
415 
Hello everyone. I was yesterday asked in an interview to draw a gaussian curve. I drew. And then they asked in what...

Jun614 06:18 AM
suvendu

8 
285 
Hi. I am very much interested in physics but my locality lacks good college for undergraduate physics but has good...

Jun514 11:41 PM
bhobba

1 
412 
Hi, everybody:
I encountered a problem when I am reading a book.
It's about the atomphoton interaction.
Let the...

Jun514 04:18 AM
strangerep

1 
241 
If I define a state ket in the traditional way, Say:
$$\Psi \rangle =\sum _{ i }^{ }{ a_{ i }\varphi _{ i...

Jun414 02:39 PM
atyy

5 
337 
is equal to the amplitude squared in quantum mechanics.
Why?

Jun414 08:01 AM
naima

17 
759 
What is the coherence time for a pair of entangled photons produced in a nonlinear crystal? Is it related to coherence...

Jun414 05:51 AM
Cthugha

4 
329 
Is the trace of an outer product of a normalized state eq. (psi) equal to 1?
Thanks,
Chris Maness

Jun314 09:50 PM
dextercioby

4 
244 
I was watching Richard Feynman's lectures on quantum electrodynamics where he concerned the probability of photon to...

Jun314 07:33 PM
UltrafastPED

1 
234 
This oftreferenced picture depicts a simulation of virtual particles popping into and out of existence in the empty...

Jun314 12:07 AM
tom.stoer

2 
311 
It is available for free from this source.
If someone can explain what has really been done here in simple English,...

Jun214 10:57 PM
gelatin

2 
262 
If spherical harmonics are simultaneous eigenfunctions of \hat{L} and \hat{L}_{z}, then that means for a state at...

Jun214 03:53 PM
siddharth5129

2 
220 
I learnt about the E<V(bound) and E>V cases. But what if V=E? Can we at all conclude V=E due to uncertainty...

Jun214 02:17 PM
suvendu

0 
228 
Hey, i hear about quantum teleportation on the news today. They said that they successfully teleported information....

Jun214 12:43 PM
Thinkor

19 
749 
A friend is a quantum chemist. He is in agreement that climate change is bad (he feels the primary problems with CO2...

Jun214 06:27 AM
D H

1 
283 
I have some questions regarding the Heisenberg picture of QM.
1. How does one calculate probabilities for measuring...

Jun214 12:13 AM
atyy

1 
347 
I am going through James Binney's course on Quantum Mechanics. I love all of the little misconceptions he points out...

Jun114 06:30 PM
Matterwave

13 
371 
Hello look at (3.24). Above it, it states "We make the same switch to polar coordinates (x, φ) in the (x, y) plane,...

Jun114 06:14 PM
epislon58

2 
227 
Do individual photons have some attributes which relate to EM wave frequency? In other words, is there any difference...

Jun114 12:28 PM
Nugatory

7 
368 
Quantum Mechanics using Index notation. Is it possible to do it?
I really don't get the Dirac Notation, and...

Jun114 09:00 AM
atyy

105 
2,587 
Is it true that there always exist a unitary matrix that can take a state vector of an arbitrary pure state to another...

Jun114 03:19 AM
tom.stoer

7 
522 
The eigenstates of a hydrogen atom are stationary states with definite values of energy. Now, as I understand it, the...

May3114 05:33 PM
dextercioby

4 
280 
A new type of energy storage described which uses quantum way to store energy.
''Battenice''.
...

May3114 09:08 AM
mfb

1 
462 
I am able calculate the solution for the TISE relating to the interval to the right of a step potential; however, I am...

May3114 02:52 AM
Simon Bridge

27 
1,061 
Is Timespace a literal real thing? or is it an abstract idea?
and what makes physisists so sure that gravity is a...

May3014 07:44 PM
bhobba

3 
425 
I am looking around for some sort of equation regarding optical power dissipation of light (ultraviolet light in...

May3014 12:53 PM
Jano L.

1 
253 
Hello,
I need help understanding how to apply the formula for converting a Lagrangian to an equation of motion in...

May3014 09:14 AM
sloneranger

8 
275 
Hi everybody,
Is it possible to obtain an expression equivalent to fermi golden rule within the framework of Green...

May3014 08:08 AM
Arthas85

0 
215 