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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).


Jun
17
comment What is the deal with heat capacity?
Another awesome exposition! Just one thing: I'm getting $P = (NkT)^{n/(n-1)} / X^{1/(n-1)}$ rather than what you wrote?
Jun
17
comment Mars just collided with Earth! A question of eccentricity
@JohnRennie Well, I was looking at the plot in this part of a wiki article at the time. If you believe it (which I'm not saying I do), it seems planet-planet effects can be significant. I suppose the magnitude of the Earth-Sun tidal dissipation could be another whole question, but I guess I was assuming without proof that it fell off too steeply with $r$ to matter.
Jun
17
comment What is 656 Beagle?
I nominate for reopening based on astronomy being on-topic now. (And besides, astronomy has been physics since before physics was physics by several millennia ;) But if people think it is still too localized, then don't bother reopening.
Jun
17
comment What is the deal with heat capacity?
@DepeHb Also, as this may very well be deemed a duplicate, but that other post doesn't seem to lend itself to getting the answers you want, perhaps edit this to the specific case of an arbitrary polytropic process. If someone writes up a thorough enough solution for that case, it should be easy enough to generalize to other paths in P-V space.
Jun
17
comment What is the deal with heat capacity?
@DepeHb I've been searching for such a text ever since my first thermo course 4 years ago. To this day thermo/stat mech remain subjects where I cannot recommend even a single halfway decent textbook. Such a thing may very well not exist. Asking questions like this is probably the best thing you can do for your education.
Jun
17
comment Why aren't there more than three generations of the leptons and quarks?
The stackexchange internal search feature is pretty bad; I don't know why. I always search for things via google with the site:physics.stackexchange.com restriction. In any event, no harm done - hopefully the answers there work for you (though the theory side of those answers is not as fleshed out as the experimental side...).
Jun
17
comment Energy in a wind instrument?
Agreed that sounds hard to believe. I'm pretty sure that calculation is off by, oh, 10 orders of magnitude or so.
Jun
17
comment Why aren't there more than three generations of the leptons and quarks?
possible duplicate of Why do we think there are only three generations of fundamental particles?
Jun
17
comment What is the equation for Lin-Shu density wave theory?
Hmmm I don't know that I've ever seen any one set of equations described as the density wave equations. The theory is a mix of fluid dynamics, self-gravitation, perturbation theory, and a little WKB for flavor. Chapter 6 of Galactic Dynamics by Binney and Tremaine covers the theory in detail, using no fewer than 102 equations (plus another 25 from the appendices).
Jun
16
comment Two orbiting planets in perpendicular planes
It's a shame that after more than 2 years this question hasn't been answered. Also a shame that for some reason everyone resorted to simulations to test stability, which is a nonsensical thing to do. An analytic inquiry such as this can basically never be solved by a finite-precision, finite-runtime simulation.
Jun
16
comment Why are some of the biggest stars known blue?
Note: We actually have directly seen a few exoplanets, just not too many and not necessarily in many wavebands. That said, people are working very hard to even get spectra of planets' atmospheres in cases where they transit in front of their stars, which would very much get you a color if the atmosphere is anything but clear.
Jun
16
comment How big of a telescope to view Gliese 581g in great detail?
BTW, it's not clear that Gliese 581g even exists. When it comes to exoplanets, the more "habitable" they are, the greater the chance their very existence is a false positive, given that astronomers too can be over-enthusiastic at times.
Jun
16
comment Electricity directly from heating a material
possible duplicate of Understanding the Seebeck effect
Jun
16
comment Why can't some light ever reach earth?
@bjwalls In particular, these subtleties are summarized here. (Yes, that is a plug for my own answer. ;) But I think it's worth a read.)
Jun
16
comment Why can't some light ever reach earth?
Also possible duplicate of physics.stackexchange.com/q/41058
Jun
16
comment Why can't some light ever reach earth?
@bjwalls That paper is technical, but we cite it around here a lot because it lists out many such misconceptions. In your case, you are equating the Hubble sphere (recession velocity = speed of light) with the event horizon (surface beyond which we cannot get information, ever). There is indeed an event horizon, but it is outside the Hubble sphere - any galaxy receding at less than $c$ can be seen, and even some receding faster (up to about $3c$ in our universe as it turns out) can also be seen. Search site:physics.stackexchange.com davis lineweaver for more posts that explain this.
Jun
16
comment what happens to the angular velocity of star in star-black hole system?
What is losing mass? The star? How? A stellar wind? A Roche lobe overflow onto an accretion disk? A tidal tail of particles set to escape the system? An AGB-phase, proto-planetary nebula sort of thing?
Jun
16
comment If time standard clocks and any memories about the time standard are destroyed, can we recover the time standard again?
The phase could not be recovered from pulsars. How would you know how many pulses passed? 1000? 1001? Even knowing the spin-down rates, pulsars have glitches, so unless they are being continuously monitored (which means you are simply watching a clock the whole time anyway), phase information is lost.
Jun
16
comment Can the axis of rotation of a celestial body point in any arbitrary direction?
Well, I'd say the jury is still out on how Uranus and Venus ended up rotating the way they are. It is difficult to torque a planet that much via a collision without obliterating it. But these are just details.
Jun
16
comment How to predict Iridium Flare?
Just to be clear, you do know there are websites and apps that do this down to the second already, right? So you're interested in how they accomplish this?