5,136 reputation
1127
bio website keith-s-thompson.github.com
location San Diego, CA
age 54
visits member for 2 years, 6 months
seen Apr 11 at 0:37

I'm a programmer and all-around nerd living in San Diego, California and working at JetHead Development Inc.

E-mail: Keith.S.Thompson@gmail.com


Oct
1
comment Theoretically, can a black hole collapse until it gets smaller than its Schwarzschild radius?
I see someone recently downvoted this answer. I don't doubt that it was deserved, but an explanation would be helpful to everyone.
Sep
28
comment Age of the Earth and the star that preceded the Sun
That assumes that there was one such star, something that's not at all obvious.
Sep
28
comment Age of the Earth and the star that preceded the Sun
In what sense is it "unheralded"?
Sep
26
comment Magnitude of New Comet C/2012 S1 (ISON)
This doesn't answer your question about dust and ice, but here's an article about it in Astronomy Now. It suggests that it might reach a magnitude of -16; compare that to -12.92, the maximum brightness of the full Moon. (As with Kohoutek, prepare to be disappointed.)
Sep
23
comment Since radioactive material decays how is it possible that there is any left after 4.5 billion years?
Yes, but the creation of heavy elements in stars doesn't significantly affect the abundance of such elements on Earth.
Sep
16
comment How does space affect the human body (no space suit, no space craft)
@CraigFeinstein: Nope. Your skin itself provides enough pressure to hold you together.
Sep
13
comment Would you be weightless at the center of the Earth?
@Nick: So an object released at the geocenter would fall away from the point of zero acceleration? That seems counterintuitive.
Sep
12
comment Does juggling balls reduce the total weight of the juggler and balls?
If the man juggles vigorously for long enough, he'll lose weight because of the exercise; there will also be some wear on the balls.
Sep
12
comment sun-moon-earth anomaly
I don't see how the phase of the Moon would affect this, unless perhaps it's easier to judge the direction when it's a thin crescent.
Sep
12
comment Would you be weightless at the center of the Earth?
This question and my answer are closely related, though I don't think this question is an exact duplicate.
Sep
12
comment Would you be weightless at the center of the Earth?
What does "pgal" mean (Google was unhelpful)? And if the acceleration is non-zero at the center of mass, due to the non-uniformity of the Earth's shape, am I correct in assuming there's a point where the acceleration is zero? How far from the geometric center is that point, and in what direction?
Aug
21
comment Turning Jupiter into a star
"Jupiter is big, and Jupiter is cold" -- Big, yes. Cold, not so much. The interior is believed to be very hot, about 36,000 Kelvins at the core boundary.
Aug
18
comment black hole event horizon
Possibly relevant (and possibly wrong).
Aug
14
comment Can an electric motor force angular momentum not to be conserved in an isolated system?
Angular momentum is still conserved in the system consisting of the skater, the motor, and whatever the motor is attached to (probably the planet). Why do you think the skater will weigh less?
Aug
10
comment Can fusion and fission happen at the same time, in the same place?
@GustavoBandeira: References for what? The composition of the Sun is, I think, fairly common knowledge, and I provided a references for "About 67 elements have been detected in the solar spectrum" and for "spontaneous fission". My answer is a (reasonable, I think) extrapolation from that information.
Aug
10
comment What is the escape velocity of a Black Hole?
Where the "surface" is the event horizon. There isn't necessarily any material surface there.
Aug
7
comment Why are planetary systems so rare?
Not yet, but New Horizons is on its way with the bad news.
Aug
7
comment Why are planetary systems so rare?
xkcd.com/1071
Aug
7
comment Why are planetary systems so rare?
Yeah, but Pluto isn't a planet anyway. 8-)}
Aug
3
comment Is it possible to lift yourself off from the ground?
@Argus: Well, not for me. 8-)}