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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).


Jul
4
comment What would be walking speed in low gravity?
@Wouter I think the idea is if you kept the same force and duration then in low enough gravity that would no longer be "walking" but rather something more like skipping. The authors' definition of walking is based on body dimensions, not muscle exertion.
Jul
4
comment How does the research in theoretical physics differ from mathematics
Related: physics.stackexchange.com/q/56293
Jul
3
comment Why must a singularity form inside a black hole?
@RBarryYoung The singularity theorems are pure GR, no quantum effects. Stability is structural, in the hydrostatic equilibrium sense of pressure counterbalancing gravity.
Jul
3
comment Why must a singularity form inside a black hole?
GR tells us how long someone just inside the horizon has before, according to their watch, they reach the singularity. It is a short wait, and you can no more avoid that fate than you can avoid moving forward in time.
Jul
3
comment How does the research in theoretical physics differ from mathematics
If there were no problems that could be solved in the span of a PhD, how would theoretical physicists get their degrees? Also note that the vast majority of physicists work on nuanced particulars in fields that are not as sexy or publicly advertised as e.g. string theory.
Jul
3
comment Time dilation derivation of special relativity
It is possible to derive the Lorentz transformations using just the first postulate: Can the first postulate, without any other physical laws (e.g. without any velocities), really exclude Galilean invariance in favor of Lorentz invariance? Or are we counting Galilean as $c\to\infty$ Lorentz here?
Jul
3
comment Is the body's exposure to an x-ray equal to an airplane trip across the country?
@TracyCramer Yes, barring the possibility that the effective dose -> committed dose conversion introduces a factor greater than 2 (e.g. if your chest tissue were for some reason really susceptible to cancer per unit DNA damage, or if all the damage being done in 1 second is worse than being done over 6 hours).
Jul
2
comment Could Legolas actually see that far?
And if the Legolas Binocular Array knows how to do intensity interferometry, he doesn't need a wavefront sensor or any such thing to detect phases. This was, after all, the technique developed to measure the sizes of several stars. As for seeing... biological AO? Using sunlight reflected off the hobbits' elven brooches as guide stars?
Jul
2
comment Is the body's exposure to an x-ray equal to an airplane trip across the country?
The problem is, equivalent dose ("actual" dose weighted by type of radiation, with particles worse than photons) and effective dose (equivalent dose weighted by how much of the body is exposed) are both measured in sieverts (or rems), as is committed dose (which takes more nuances into account). So just knowing the unit doesn't tell you how many dimensionless weighting factors were included.
Jul
2
comment Pressure and Density Using a General Lagrangian
btw, the upper/lower split indices on the metric are always $g^\mu_\nu = \delta^\mu_\nu$ by definition (no negative signs, no matter your sign convention)
Jul
1
comment Why does adding red light with blue light give purple light?
If you want to move it, use a moderator flag (a custom one probably works best) - they can migrate the question. That said, I make no guarantees about how questions are received on sites I don't frequent. There's also the possibility others here will disagree with my judgment about physics suitability - I don't want to be accused of single-handedly bullying new users :)
Jul
1
comment Why does adding red light with blue light give purple light?
Way back when I had elementary school art class, all the teachers made a big fuss about how purple was not the same as violet. In any event, I'm not sure physics is the right place to ask about color perception as such. This is probably better for Biology or Cognitive Science.
Jul
1
comment Protect drone from lightning
Asking for specific design recommendations may fall afoul of our engineering policy. In any event, it might be better to ask a more fundamental question of "will my airship be more likely to be struck by lightning, and will that lightning damage it?" After all, airplanes certainly aren't often destroyed or melted by an errant bolt of lightning...
Jul
1
comment light color and refraction
Your first question is a duplicate of What determines color — wavelength or frequency? and the questions linked to it. I'd suggest removing that and just focusing on the other main question: Is it wavelength or frequency that determines refraction?
Jul
1
comment How do objects outside a spacecraft fall “around” the earth?
"knowing micro-gravity is still enough gravity to pull objects towards earth": I might be misreading, but is your understanding that microgravity pulls things out of orbit? Because "microgravity" is just a synonym for "zero-g" or "weightless," and an orbit by definition is the path you follow accounting for the force of gravity on you.
Jun
30
comment Why does the speed of the propellant limit the speed of a space ship in open space?
@this If you created photons, I assure you you had a source of fuel that lost mass in the process. Also, for all intents and purposes, antimatter-powered anything is science fiction.
Jun
30
comment Why aren't all photons virtual particles even in the “vacuum” of empty space?
Possible duplicate of Does radio use virtual photons? Or at least the title and last sentence are. The whole middle paragraph seems to be on a completely separate topic, which is a duplicate of John Rennie's link.
Jun
29
comment Driving car with (almost) the speed of the light and switch the headlights on
possible duplicate of Double light speed
Jun
28
comment What does the size of an object have to do with it's color?
Hi Arul, could you specify whether you asking "how does an object's size relate to color in the normal sense?" or "how does an object's size relate to color in the quark sense?" or "what's the difference between normal color and quark color?"
Jun
28
comment When we look in different directions in the universe how do we know we're not seeing the same thing?
Your impression of the Big Bang has problems. There is no point at which it occurred. Really. Seriously. But I don't see what that has to do with your main question anyway.