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location Princeton, NJ
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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).


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
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
comment Is our universe an emulation?
@CountIblis That's a good thing to turn into an answer.
Aug
11
comment Why are objects opaque?
@NikosM. Sorry, but I can't let this slip unchallenged, off-topic though it may be. The existence of black holes is as well accepted in astrophysics as is the existence of other galaxies, or of planets around other stars, or of the asteroid belt. For just one of a multitude of solid pieces of evidence, see the dynamics of S2 around our own galaxy's central black hole.
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
10
comment Penetration and skin depth in 'metallic' magnetic induction tomography (classical electromagnetism)
Hi Brendan, and welcome to Physics Stackexchange! Note that we generally discourage salutations in posts (your name appears attached to it anyway).
Aug
9
comment Kinematics problem involving rocket
@user166748 I'm referring to the powered portion of its flight, where it starts out near the ground not moving. If you're near the ground not going fast and then you decide to accelerate downward, you're playing a dangerous game.
Aug
9
comment Kinematics problem involving rocket
@user166748 Yes, generally an upward-directed object coasts upward for a while even after its source of thrust has disappeared.
Aug
8
comment Does a 4-current J determine a unique maxwell-faraday F tensor up to isometry?
So then you're saying "no" to a situation where Wald said "yes"? I feel there's something subtle I'm missing still, perhaps in the particular way Wald actually formulates the question ($D_a E^a = D_a B^a = 0$ iirc), but I haven't fully thought this through.
Aug
8
comment How do crocodiles jump?
Are there really subfields of fluid mechanics that define a foil as something that provides thrust? Because otherwise the tail's classification as a hydrofoil (i.e. "a thing in the water") is really irrelevant.
Aug
8
comment Expansion of the Universe, will light from some galaxies never reach us?
Agreed that this is not a dupe at least of the indicated question (late-time acceleration vs. early-time inflation, for one).
Aug
8
comment Does a 4-current J determine a unique maxwell-faraday F tensor up to isometry?
I'm probably missing something obvious, but where did you use the hypothesis $J^b \neq 0$? Or does this hold without that assumption?
Aug
7
comment How do whitening toothbrushes work?
If you accept that whitening pastes (the ones that don't use paint) work by just being more abrasive, then sure a more abrasive brush would have the same effect. Then again, one should be skeptical of claims that some toothbrushes are magically better than others.
Aug
7
comment Is everything moving at c in a c unit circle
If analogies with circles worked, we wouldn't teach SR with hyperbolas. Things would be much better for the layman if hyperbolic trig got half the attention of "regular" trig in high school.
Aug
7
comment How do crocodiles jump?
+1 for the best stroke. Also a possibly more direct analogy is people doing vertical dolphin kick drills.
Aug
7
comment How to measure trajectory regularity?
This is an underspecified problem that cannot be objectively answered. You can look at fractal dimension, total path length, distributions of velocities, correlations between directions on some scale, or three dozen other metrics. My advice: step back, take a deep breath, and think about what you really want to measure about the system. Maybe you're interested in energetics, or cognitive simplicity, or emergent behavior, or obstacle pathing. It all depends.
Aug
7
comment Interesting Hamiltonian System
Also possibly of interest on MO: mathoverflow.net/q/35900
Aug
6
comment What exactly is a virtual displacement in classical mechanics?
I'm leave the work of a full answer to someone more comfortable in the field, but I quote Arnold: "In mechanics, tangent vectors to the configuration manifold are called virtual variations." So I'd say that's a pretty standard way of looking at things.
Aug
6
comment What's the point of NASA's impossible space engine? Wouldn't a mirror work better?
It's science fiction that makes any and all actual scientists laugh at how inept NASA is these days. It makes as much sense as an 8-year-old's superhero-based doodles, so trying to ascribe motive to the design is doomed to failure. Maybe their design has the benefit of squaring the circle and solving the halting problem. Who knows.