21,418 reputation
44785
bio website
location Princeton, NJ
age 25
visits member for 2 years, 4 months
seen 1 hour ago

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.


Oct
19
answered Really quick question about the order of operations in the Lorentz force
Oct
19
comment How Earth protected from the gamma rays generated by Sun?
@sugunan Space suits are not capable of stopping gamma rays. Nothing can stop gamma rays except by being very thick.
Oct
18
reviewed Reject suggested edit on What causes a Phase-Transition?
Oct
18
comment How Earth protected from the gamma rays generated by Sun?
Minor correction to your logic: Many high-energy photons (in the regime where their interaction with matter is dominated by Compton scattering off electrons) basically only care about the column density along their path. And the full atmosphere has the same column density as 1 meter of lead (or 10 meters of water). That is, we only like dense materials because they make shielding more compact.
Oct
18
comment How Earth protected from the gamma rays generated by Sun?
@HDE226868 actually that page has a good image, since the Sun does produce some gamma rays. Its corona is millions of kelvin, so there is a (small) source other than the core.
Oct
18
comment How Earth protected from the gamma rays generated by Sun?
I think what NASA was trying to say (not too clearly) is that charged cosmic rays (not gamma rays of course) hit the upper atmosphere all the time, and this then produces gamma rays, so you want to point your gamma ray telescope away from Earth to avoid contamination.
Oct
18
comment Verifying radiation measurement smart phone applications
"highpass-filters every individual pixel and all three color channel": just to be sure, you're not filtering each image independently, right? When a cosmic ray, for instance, strikes a CCD, the most common outcome is a hot pixel. The only hot pixels you should remove are those that persist from one image to another. Also, I don't know the details of consumer cameras, but I've heard and fully believe they do similar filtering before saving the data (because no one wants grainy images reminiscent of 1990s-era digital cameras).
Oct
15
comment What does the “size of the universe” mean if the Universe is infinite?
@Goodies The observable universe can be made arbitrarily small as you go back closer to the big bang, but see the last few sentences I added. If you scale your coordinates with the expansion of space, there is just as much volume then as now. The "point" you envision is the whole observable universe, not a part of it.
Oct
15
answered What does the “size of the universe” mean if the Universe is infinite?
Oct
14
comment What experiments compete with BICEP 2, and when are their results expected?
There is also Spider.
Oct
14
comment How did Newton establish his famous third law of motion?
Re "We can prove 2nd law using calculus": see physics.stackexchange.com/questions/2644/…
Oct
14
revised What's wrong with my derivation for the spring constant?
tex and grammar
Oct
14
reviewed Edit suggested edit on How to calculate scalar neutron flux
Oct
14
revised How to calculate scalar neutron flux
Adding variables in latex and some minor style corrections
Oct
11
comment How big can a cube-shaped planet be?
@DavidHammen Interesting too that Lineweaver cites Dave Stevenson's notes, which predict numbers closer to what you are saying.
Oct
11
reviewed Close How big can a cube-shaped planet be?
Oct
11
reviewed Close why does a change in velocity cause length contraction, mass gain and the slow down of time?
Oct
11
answered Why we take two focuses in concave and convex lenses before the lens and behind the lens
Oct
11
reviewed Leave Open Why we take two focuses in concave and convex lenses before the lens and behind the lens
Oct
11
revised Is the E-Cat by Andrea Rossi et al. proof that cold fusion can work?
edited tags