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programming numerical algorithms for astrophysical applications.


Oct
6
revised Is there any way a meteor can hit at less than escape velocity?
added 290 characters in body
Oct
5
answered Is there any way a meteor can hit at less than escape velocity?
Oct
5
comment What causes jets from newly born stars?
be honest upfront: "I/we don't know"
Oct
5
comment What are the current observational limits on the existence of Dyson spheres/swarms/rings?
No serious astronomer does. Those who do, do only because they can market that well with the public and hence get some funding.
Oct
4
comment What causes jets from newly born stars?
It's not clear from your answer why the magnetic field would create jets.
Oct
4
comment What are the current observational limits on the existence of Dyson spheres/swarms/rings?
I think a Dyson sphere is impossible, because nothing can stabilise it against gravitational collapse into the star. A ring rotating at the right rate is better, but a completely different type of thing and can only capture a tiny fraction of the stars energy.
Oct
4
answered If the expansion of the universe is speeding up, how long until everything nears the speed of light, and what would happen?
Sep
24
awarded  Autobiographer
Sep
18
revised How fast is a comet moving when it crosses Earth's orbit?
added 162 characters in body
Sep
18
comment How fast is a comet moving when it crosses Earth's orbit?
who is Wolfram?
Sep
18
answered Did cosmological inflation occur at speeds greater than $c$?
Sep
18
answered How fast is a comet moving when it crosses Earth's orbit?
Sep
16
comment What are the biggest problems about the numerical, finite-element GR models?
Perhaps, this sort of calculation is not so interesting (compared to QCD). What has been done is the merging of two BHs (including the gravitational radiation and the resulting anisotropic effects)
Sep
15
comment What is the difference between Sphere of Influence and Hill sphere?
@HDE226868 Excellent spot! Unfortunately, this is on another stack exchange site, so we cannot close this as a duplicate. However, duplicating the answer is clearly not worth the effort.
Sep
15
reviewed Approve suggested edit on Time-density and time-temperature functions of the Universe since the Big Bang
Sep
15
revised Are there stars that don't emit visible light?
elaborated the answer
Sep
15
comment Are there stars that don't emit visible light?
@jwenting Jupiter is not a star, but a planet. Stars are defined to undergo (or have undergone) hydrogen burning (H$\to$He fusion). This requires a minimum mass of about 0.08M$_\odot$. Objects smaller than that, but massive enough to have some fusion (Li) early on are brown dwarves. The mass limit here is about 10M$_{\mathrm{Jupiter}}$.
Sep
13
comment Are there sufficient observational data to measure non-Newtonian perihelion advances of any Asteroid and Comet orbits?
Use ADS to search for publications (via author names, title words, keywords, or words from the abstract) and even read their abstract for free. Almost all astronomy papers are also published on the arXiv (linked from ADS), where you can obtain (a preprint version) for free.
Sep
12
revised the metal distribution in our solar system
added 346 characters in body
Sep
12
revised the metal distribution in our solar system
added 346 characters in body