567 reputation
111
bio website keith-s-thompson.github.com
location San Diego, CA
age 55
visits member for 11 months
seen yesterday

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


Aug
22
comment Multiple apparent lunar eclipses last night
So something was blocking the moon as seen from your location. How sharp was the edge of the blockage? Was the edge straight or curved? (I can just about guarantee it wasn't a true eclipse; almost certainly something close to you, within a few miles, was blocking your view.)
Aug
12
comment How to polar align an equatorial mounted telescope when you are close to the equator?
Sounds like you need to figure out where due north is and aim about 4° below the top of the mountains. If I knew a good way to do that I'd post an answer, but a compass, a level, and a protractor might help. (Polaris is about 1° off the celestial north pole anyway.)
Aug
12
comment How to polar align an equatorial mounted telescope when you are close to the equator?
Polaris should be 16° above the northern horizon.
Aug
11
comment Connection between Earth, Moon, Theia, and astroid belt?
I'm saying that if a body the size of Ceres were deformed into some non-spherical shape, it would re-form itself into a sphere over time. Any significant irregularities would not hold up against gravity. We have at least one Hubble photo showing it to be close to spherical; this is not a coincidence. I don't suggest that it's plausible that Ceres is a remnant of the Theia/Earth collision, but its shape doesn't argue against it.
Aug
11
comment Connection between Earth, Moon, Theia, and astroid belt?
I don't think the shape of Ceres is an issue. It's big enough for its own gravity to pull it into a sphere.
Aug
7
comment What would the effects be on Earth if Jupiter was turned into a star?
And I'm pretty sure Lucifer's energy output was far less than the Sun's, so the increase would be even smaller.
Aug
7
comment What would the effects be on Earth if Jupiter was turned into a star?
@HDE226868: I believe the monoliths compressed Jupiter; they didn't appear to add mass (that's certainly what it looked like in the movie). The Sun supports fusion because its core is sufficiently dense, because it has all that mass compressing it gravitationally. Assuming Jupiter's core is mostly hydrogen, it should also support fusion given enough density/pressure, whether that pressure is applied by gravity or by "sufficiently advanced technology" (a.k.a. magic). I don't know whether continuing intervention would be needed to keep it from re-expanding.
Jul
11
comment What is the farthest point of light that is emitted by a torch?
In US English, a handheld battery-powered light is called a "flashlight"; the word "torch" usually refers to a more primitive burning light source.
Jul
11
comment What would happen if an ice cube is left in space?
In the Oort cloud, I don't think there's a whole lot of gas and other objects for it to pick up (though we probably don't have a good estimate for its density).
Jul
7
comment What's the likelihood of the existence of unknown elements in the Solar System?
Elements in the "island of stability" are expected to be relatively stable, compared to their neighbors. Quoting the Wikipedia article, "Specifically, they are expected to have radioactive decay half-lives of minutes or days, with "some optimists" expecting half-lives of millions of years." Even with half lives in the millions of years, there could still have gone through hundreds or thousands of half-lives over the history of the Solar System. Unless the optimists are underestimating their stability, there should be practically nothing left of them.
Jun
17
revised One year on the sun
Spelling, cleanup
Jun
16
suggested suggested edit on One year on the sun
Jun
16
revised One year on the sun
added 11 characters in body
Jun
16
answered One year on the sun
Jun
13
comment In 2016, the summer solstice will coincide with a full moon. How often does this happen?
@Bishop: The solstice is a single moment. For example, this year's summer solstice occurs at about 10:51 UTC on June 21.
Jun
13
comment In 2016, the summer solstice will coincide with a full moon. How often does this happen?
If you're talking about an exact coincidence, it virtually never happens. If you're willing to accept a two-week margin of error, it happens almost every year. The 400-year cycle is an artifact of the Gregorian calendar, which has no effect on when or how closely the solstice and the full moon coincide.
Jun
12
comment Using the Sun as a Gravitational Lens
That confirms the phenomenon (gravitational bending of light) that makes gravitational lensing possible, but it doesn't confirm that the Sun can be used as a gravitational lens to achieve better telescopic viewing. Eddington didn't get a better view of those stars than he would have gotten at night.
Jun
11
comment Using the Sun as a Gravitational Lens
You don't see stars during the day because the atmosphere scatters sunlight. To use the Sun as a gravitational lens, you'd have to be in deep space, about 50 billion miles away according to MycrofD's answer. Since that is, to put it mildly, well beyond the atmosphere, an observer at that point could mask out the Sun's light. Light from a distant object could be bent around the Sun and focused on the observer, appearing as a ring surrounding the Sun.
Jun
10
comment Which is really larger, Big Dipper or Small Dipper, in 3D
@Marc: That's debatable, but with a little more specificity (as I discussed in my comment) the question could have an unambiguous answer. You might not find it a particularly interesting question, but that's different from being meaningless.
Jun
9
awarded  Citizen Patrol