759 reputation
312
bio website keith-s-thompson.github.com
location San Diego, CA
age 55
visits member for 1 year, 4 months
seen 2 days ago

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

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


Jan
19
comment How would we detect an Earth doppelganger planet?
"As to planets the size of earth, we've never yet been able to find one, let alone a rocky one in the habitable zone of a star." -- This is out of date: en.wikipedia.org/wiki/Exoplanet#Earth-size_planets
Jan
10
comment Do Roche limits apply to black holes?
The idea of the Roche limit does apply to black holes if the secondary body isn't a black hole. For example, if an asteroid approaches a black hole too closely, it will be torn apart. The distance at which this happens is related to the radius of a body with the mass of the black hole and the density of the asteroid.
Jan
7
comment If an asteroid twice the size of Earth passed super close would half of the Earth be pulled towards it?
Something that big would be a planet, not an asteroid.
Jan
7
comment Do contracting objects show redshift?
I'm not sure how I can be clearer. If you have a question, you can post it as a question. If you're asking for clarification, it should be a comment (you'll need a few more reputation points to be able to post comments). And the question was about red shifts of contracting objects, not distant galaxies. Are you under the impression that galaxies contract?
Jan
6
answered Do contracting objects show redshift?
Jan
6
comment Do contracting objects show redshift?
You can ask a followup question by posting a new question. And I think you've misunderstood the OP's question. It doesn't imply anything in particular about distant galaxies; it's about contracting objects, and galaxies typically don't contract significantly.
Jan
6
comment Do contracting objects show redshift?
"To have any appreciable redshift, the speed of the object needs to be huge." The speed doesn't need to be huge for the redshift to be detectable.
Jan
4
comment landing on a comet is more important than landing on an asteroid?
@questionhang: No, Rosetta/Philae is not a sample return mission.
Jan
2
comment Why doesn't Earth's axis change during the year?
I think the answer boils down to conservation of angular momentum, but I'll leave it to someone else who knows the physics better than I do to post an answer.
Jan
2
comment Why doesn't Earth's axis change during the year?
Why would you expect it to change? Changing the direction of the Earth's axis would require a huge change of angular momentum. It does change over thousands of years, but there's no mechanism to change it over a single year.
Dec
30
comment Will Saturn's rings become a moon?
It's not primarily the tides of the moons that prevent the ring particles from coalescing. It's the tide exerted by Saturn itself. See Gerald's answer.
Dec
22
revised What is the exact mass of the Sun?
Render exponent correctly, use complete sentences
Dec
22
suggested approved edit on What is the exact mass of the Sun?
Dec
20
comment Likelihood of a stable system with a dwarf planet's orbit inside that of a gas giant
@HDE226868: That could be observational bias. Hot Jupiters are easy to find; since they're both massive and close to the parent star, they cause the star to move and are more likely to block some of its light.
Dec
18
comment What is the orbit of Earth around the Sun?
Hmm. We're currently close to perihelion (which will be on Jan 4), and the Sun is in or near Sagittarius, which is in the direction of the galactic core. So the second focus of the Earth's orbit around the sun is in the direction of the galactic core. I believe this is purely coincidental. Can you demonstrate that it's not? (The same effect should apply to the other planets.)
Dec
18
comment What is the orbit of Earth around the Sun?
I suggest you calculate (an order-of-magnitude estimate should suffice) the gravitational influence on Earth of the galactic core relative to the influence of the Sun. I think you'll find that the galactic core's influence is negligible compared to the Sun, or even to the other planets. Earth's orbit could be elliptical rather than circular even in the absence of any bodies other than the Earth and the Sun; external influences aren't necessary to explain the eccentricity. -1. (And your link says nothing about the influence of the Milky Way.)
Dec
12
answered Why isn't the star that created the black hole a black hole?
Dec
10
comment Do Pluto and Charon have unusual Langrange points?
Quibble: 25 times as massive, not more massive.
Dec
9
comment Lack of contact with Aliens
I wouldn't say the question is "incorrect". It's entirely possible that one of the three options listed in the question is the correct answer. The problem is that we simply don't have enough information to answer it.
Dec
8
comment Lack of contact with Aliens
I seriously doubt that anyone can answer this. Nobody knows.