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seen Apr 10 at 13:13

Mar
18
comment Double double-slit experiment
As for the photon that you do measure, it loses the entanglement with the other photon after the measurement. And you lose the interference pattern after determining the slit through which it went.
Mar
18
comment Double double-slit experiment
I don't understand your argument. Why you say that the spatial superposition is built up during the evolution of the photons, and why this loses the entanglement? The fact that there's an uncertainty $\Delta x$ means that the second photon (the one you didn't measure) is in a superposition of states spreading through some spatial region on the order of $\Delta x$. If this spatial region is large enough as to include both slits, you have an interference pattern.
Mar
18
comment Double double-slit experiment
+1 Good point. But I think that in the first case there should be only one interference pattern, not both. After determining through which slit the measured photon went, I'll still be ignorant as to the slit used by the second photon. So in this case I destroy the interference pattern of the measured photon (because I know which slit it used), but I still see the other interference pattern (because $\Delta x$ doesn't let me determine the slit of the non-measured photon from the slit of the measured photon).
Mar
13
comment Double double-slit experiment
@CarlWitthoft "see recent experiments which seem to show that a particle's quantum state can be "found" in one slit while the particle is "seen" in the other." .... can you provide some references?
Jan
15
comment Consequences of the new theorem in QM?
What is GRW? Thanks.
Dec
16
comment Does an electric field create a pH gradient?
Let's also hope someone provides a more thorough physical analysis... :)
Dec
9
comment Why the dissolution of hydrophobic compounds decreases the entropy of water molecules in the vicinity of the solute?
@ManishEarth Can you migrate this question to Physics.SE now? It's been almost a week. The current answer by Nicolau is helpful but it doesn't explain the physical mechanism behind the entropy decrease.
Dec
4
comment Why the dissolution of hydrophobic compounds decreases the entropy of water molecules in the vicinity of the solute?
@ManishEarth agreed
Dec
3
comment Why the dissolution of hydrophobic compounds decreases the entropy of water molecules in the vicinity of the solute?
So you're saying that some very strongly polar hydrophiles can decrease the entropy of water molecules in their vicinity even more than hydrophobic compounds? That's more in accordance with my intuition...
Dec
3
comment Why the dissolution of hydrophobic compounds decreases the entropy of water molecules in the vicinity of the solute?
I want to understand the physical mechanism behind the entropy increase of dissolving a nonpolar compound in water. I think that's more suited to Physics.SE.
Dec
2
comment Why the dissolution of hydrophobic compounds decreases the entropy of water molecules in the vicinity of the solute?
@SatwikPasani I read it. Thanks for pointing it out, but it is not a duplicate. Actually, if you read the answer given there, it seems to support my intuition that hydrophilic compounds attach to water molecules, reducing their freedom and thus decreasing entropy. However, my question is why the decrease in entropy associated with the water molecules in the vicinity of an hydrophobic compound is greater.
Nov
26
comment What is the “direction” of the transition dipole moment? (Understanding Eq. 9.29, Charge and Energy Transfer 3rd Ed, May & Kuhn)
+1 Thanks! Very thorough answer.
Oct
31
comment How long does it take for a chemostat to reach equilibrium?
@ColinMcFaul It's a simple set of equations describing an aspect of the real world. I'm not interested in any rigorous mathematics. You can see the chemostat as a complex system, which can be seen as a topic inside physics. Many universities have a complex systems group inside their physics departments. Also, Szilard, one of the creators of the chemostat, was a physisist. That's why I don't think this question is off-topic here.
Sep
8
comment Definition of “localized state”
I suppose there's no "hard", precise definition?
Aug
26
comment What properties are used to quantify the odds of a star harboring earth-like life?
Without a star, where does the planet get the energy necessary to sustain life? On the Earth, almost all the energy used by higher forms of life originates in photosynthesis, which depends on the sun light.
May
31
comment Google interview riddle and scaling arguments
This question comes from Google? They do this in their interviews to new applicants?
May
30
comment Uniqueness of Helmholtz decomposition?
cross-post: math.stackexchange.com/q/41844/10063
May
30
comment Uniqueness of Helmholtz decomposition?
@Qmechanic the question you link is about existence. This question is about uniqueness.
May
28
comment Why isn't the Earth's core temperature the average of its surface temperatures?
The question says: "the core is hotter than all but a few spots on the surface." Are there spots on the surface of the Earth that are as hot as the core?
May
25
comment Is every quantum measurement reducible to measurements of position and time?
It is interesting that this question has 14 votes, while all 4 answers have 0 votes...