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353111
bio website arcsecond.wordpress.com
location Baltimore, MD
age 29
visits member for 3 years, 10 months
seen 17 hours ago

I'm a physics graduate student.


Aug
23
awarded  Nice Answer
Jul
28
awarded  Nice Question
Jul
14
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Jul
12
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Jul
11
revised What is the optimal weight for a golf ball?
edited body
Jul
2
awarded  Inquisitive
Jul
2
awarded  Curious
Jun
30
comment How quickly should a fluid come to hydrostatic equilibrium?
Hi Graviton, thanks for your comments. I don't think I understand very well, yet, though. Where does the 4-6 microseconds come from, and why do viscosity and surface tension come into play?
Jun
30
asked How quickly should a fluid come to hydrostatic equilibrium?
Jun
26
awarded  Good Answer
Jun
22
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Jun
19
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Jun
19
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May
23
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May
23
awarded  Notable Question
May
11
comment Intuitively, why does removing solutes cost $k_B T$ of free energy per molecule?
These are equivalent way of saying the same thing. If we believe that entropy is extensive, then the entropy per ion must be intensive. That means it can only be a function of the concentration, not the volume. That is why it is not necessary to go through an argument about the volume of the tank and N!, etc. You just need to believe in extensivity of entropy.
May
11
comment Intuitively, why does removing solutes cost $k_B T$ of free energy per molecule?
momentum is unimportant because it doesn't change between the two reservoirs. I'm expecting the reader to use some discretion. This lets me avoid unnecessary lists of caveats and assumptions.
May
11
comment Intuitively, why does removing solutes cost $k_B T$ of free energy per molecule?
$e$ is the base of the natural logarithm. My expression for the entropy is obvious from extensivity. The problem with what you have is that the ions are indistinguisable, so you're missing a factor 1/N!. You can confirm that modifying your expression in this way is equivalent to what I said.
May
11
asked Intuitively, why does removing solutes cost $k_B T$ of free energy per molecule?
Apr
26
awarded  Nice Answer