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location Princeton, NJ
age 25
visits member for 2 years, 9 months
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I am a graduate student studying astrophysics at Princeton. I received my bachelor's in physics and mathematics from Caltech (2011).

My primary interest is in general relativistic magnetohydrodynamics simulations of black hole accretion.


Aug
14
answered A common definition of a scalar
Aug
14
comment Wouldn't the presence of dark matter slow the expansion of the universe?
@allanemery be careful about jumping to hypotheses like that. The "dark" in both is a complete coincidence of naming. And moreover the ratio of dark matter to dark energy changes with the scale of the universe.
Aug
14
comment Why are cgs units the norm in astrophysics?
And this is why the IAU is a worthless organization. The audacity of professional bureaucrats to go up to scientists and say "these are the units you should be using." There may be reasons to prefer one unit system over another, but "we should go along with some long-dead French engineers because completely different fields do so" is definitely not one of them.
Aug
14
comment What is the physical meaning of commutators in quantum mechanics?
Maybe I'm underthinking this (certainly compared to the given answers), but exactly is wrong with "this expresses how much applying A then B is different from applying B then A"? Commutators of operators are important whenever operators don't commute. I suppose I realized this better when I learned about the commutator of covariant derivatives in GR (better known as the Riemann tensor of course).
Aug
14
awarded  general-relativity
Aug
13
comment Does extreme cold make **everything** extremely brittle?
Note that most things you see shattered in movies have lots of water in them, and we all know that ice tends to shatter. So, at least in principle, most movies can be sort of right even if other objects aren't so affected. In fact, answers should distinguish between "shattering because it turned into ice" and "shattering because it was a solid that became brittle."
Aug
13
comment Thermal superconductivity
In light of your characterization, would it be fair to say superconductivity is the prevention of gradients from building up, rather than the prevention of losses in flows? That is, it is only coincidental that nonzero electrical gradients imply nonzero ohmic losses?
Aug
13
answered Why does pitch in a helicopter take effect 90 degrees later?
Aug
13
comment What's the biggest cube you could have before gravity rounded it?
The easy observational way, no first principles required: larger than oddly shaped asteroids, smaller than round moons.
Aug
13
answered How does a spatial covariant derivative act on tensors that are not purely spatial?
Aug
13
reviewed Leave Open How to test that a flat metric represents a global three-torus geometry
Aug
13
reviewed No Action Needed Put a bullet into orbit around the moon
Aug
13
reviewed No Action Needed Can I tune a magnetic field to conduct heat from a rotating object?
Aug
13
comment Is our universe an emulation?
@CountIblis That's a good thing to turn into an answer.
Aug
11
comment Is interstellar flight possible in near future in a way that would keep our civilization alive?
@HostileFork That comment displays a remarkable lack of understanding of physics. FTL travel to a physicist is as nonsensical as "a positive integer less than 0" to a mathematician. There is not a single practicing physicist who believes FTL is possible.
Aug
11
comment Is 'amp' a technically invalid term?
@baharini It's entirely up to you (no pressure), but alemi's answer is now far more official and complete than mine so you may consider changing the accepted answer.
Aug
11
awarded  Nice Answer
Aug
10
answered Is 'amp' a technically invalid term?
Aug
10
reviewed Edit and Reopen Is “now” the bounding edge of the universe in the time dimension?
Aug
10
revised Is “now” the bounding edge of the universe in the time dimension?
replaced pdf link with arxiv abstract