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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).


Sep
5
comment How can interstellar space have a temperature of 2-3K?
@Phaptitude There are hundreds of millions of CMB photons per cubic meter. As for how they have a temperature, that deserves a longer answer (which I'll bet has been asked here before). The key phrase to look up is "blackbody radiation."
Sep
5
comment How can interstellar space have a temperature of 2-3K?
@BowlOfRed For an ideal gas of particles with no (or no excited) internal degrees of freedom, temperature is identical to average kinetic energy.
Sep
4
comment Motorbike with parachute vs normal skydive
@Johan "it is not lethal to glide on the tarmac at 200km/h" - citation very much needed.
Sep
3
comment Why group velocity represents energy or information transmission? What relation between phase velocity and special relativity
It is a common misconception that group velocity represents information transmission. It does not. It is perfectly reasonable to have superluminal group velocities.
Sep
2
comment Gravitational binding energy of a white dwarf at Chandrasekhar limit?
@akrasia I don't know where they get that number from, because every supernova researcher has a different opinion on Type Ia progenitors. It may be that most are double degenerate, it may be that none are. A lot more work needs to be done.
Sep
2
comment Einstein and the existence of Black Holes
Note that other big names in the field were also hesitant to accept black holes. See Wikipedia's history of the Chandrasekhar limit for how Eddington convinced everyone Chandrasekhar's argument must somehow be wrong.
Sep
2
comment Gravitational binding energy of a white dwarf at Chandrasekhar limit?
Very good question. Clearly one needs a better theory than the basic Chandrasekhar arguments. Kippenhahn and Weigert mention that pycnonuclear reactions and inverse $\beta$ decay become important at the high-mass end, and they refer to Hamada and Salpeter for more details. Perhaps someone can pick up here and make a full answer...
Sep
2
comment Mass of small fluctuation around vacuum
Hi milli, and welcome to Physics Stackexchange! Just so you know, we support MathJax for LaTeX-like formatting so you don't have to include equations as images. Most basic stuff is supported, as covered in this extensive guide.
Sep
1
comment Dark matter a medium for light propagation
Things can only propagate stuff they interact with. Dark matter's sole reason for existing is that we see evidence of stuff that interacts via gravity and essentially nothing else. So it can have gravitational effects, but e.g. gravitational waves, like light, don't need a medium to propagate in.
Aug
31
comment What does the notation $\Psi_k/(\Psi_k,\Psi_k)^{1/2} $ mean?
In math, $(\cdot, \cdot)$ is linear in the first argument and conjugate linear in the second, whereas in modern physics $\langle \cdot | \cdot \rangle$ is linear in the second argument. I wonder which one Weinberg (and Karolyhazy) use.
Aug
30
comment Solar stills with Wine
@namehere that's a good question I would hope an actual chemist or chemical engineer would calculate for me, but I'll think about it...
Aug
30
comment What is the meaning of this “let there be light” joke?
Related: physics.stackexchange.com/q/51753
Aug
30
comment Scientists observe the laws of the physics but, Where do they come from?
For the record, I don't think this is a bad question per se, nor that scientists shouldn't give it some thought now and again. It's just that, for better or for worse, physics proper decoupled from metaphysics 250 years ago, and this question certainly belongs in the latter category. Have a look at Philosophy.
Aug
29
comment Aftermath of Plasma Arc
Are you thinking of chemical changes (i.e. formation of molecules, as opposed to nuclear transformations), for instance as occurred in the Miller–Urey experiment?
Aug
29
comment Perceiving travel speeds from different view points
@gj255 I worded that confusingly. I mean that even scenery passing by at a full 200 km/h doesn't look to be moving so fast.
Aug
29
comment Best Research Documentation Habit for Computational Physics Research
I'm weakly in favor of this being on-topic as far as the coding/documentation angle is concerned (we allow computational stuff already), especially if the focus is on physics-specific techniques. If this is off-topic, IMO it should be because it solicits opinions. Perhaps we can take this to meta?
Aug
29
comment Why do we use time-dependent regions in this derivation?
This might not be needed to answer the question, but what are $\mathbf{b}$ and $\mathbf{S}$ here?
Aug
28
comment A force opposing Gravity
I feel like I've seen that Einstein-like fellow before... ;)
Aug
28
comment Gravity doesn't seem to work the way it is supposed to
@Dal No - spinning only pushes you off the surface. The faster the surface is spinning, the greater this effect.
Aug
27
comment Justification for new theories of Particle Physics and General Relativity
I got to page 3 of the GR paper, and at that point I lost count of the number of crackpot indicators I saw (over a dozen). "EFEs failed to explain the dark matter and dark energy" (of course they fail there - they are equations of motion, and they say nothing about what exists in the universe); no solution for CMB in spherical symmetry (so hundreds of cosmologists all missed this fact for the last century?); looking to the EFEs to explain inhomogeneity; the list goes on.