Starship Asterisk*

Re: lunar ranging. Can someone provide a calculated or estimated value for how much higher the intensity of the light received would be (per unit surface) if the detector were near the center of the returning beam ? Just estimating, but I'd say there's little difference. The beam has lost coherency...

Hi all, Just a complaint about the text under the APOD for today. It says that " Today is an equinox, a date when day and night are equal. ". This is NOT correct. If the Earth did not have an atmosphere, it would be correct. It would be wrong even in the absence of an atmosphere, because ...

http://arxiv.org/abs/astro-ph/0702671 Do Black Holes End up as Quark Stars ? What part really is non scientific? My assessment of the paper is that the author is not a crackpot (quite a few self-published cosmologists are), but that the paper is weak. That's because some important arguments are bas...

Gee, I guess if someone has a good idea they have to give it to someone else to write-up, as they are excluded from being considered due to lack of membership within the clique of acceptable people. Science is a process of consensus. Radical new ideas occasionally alter mainstream thinking, but for...

I came across this link: http://arxiv.org/abs/astro-ph/0702671 How to evaluate a paper like this: It is self-published, with no peer review; The author has no peer reviewed publication history; The author self-published, in close succession, three papers covering nearly identical subject matter; Th...

I am curious… Does anybody know why the moon is situated the way it is? By that I mean that its orbit is tilted about 5 degrees from the ecliptic with the earth tilted roughly 23 degrees in its rotation to the ecliptic. Everything in the Solar System (inside the Oort Cloud) is largely on the plane ...

Black holes are only visible when they're eating. That's not really true. Black holes only produce photons when something falls into them, so if you limit "visible" to that, I'd agree. But they also have the same sort of properties that normal matter has, in that they can be charged or ha...

Could dark matter possibly be clouds of extremely small black holes? Atomic particle sized black holes would not interact with normal matter except for gravity. Furthermore, the cloud should be invisible. Why do you say this? Black holes interact normally with matter: they can have an electric char...

Just looked at the uncropped photo . There are two more stars at the top, and one at the extreme top right, that form an arc with Mercury and Mars. Curious about them, too. Here is a chart showing the visible stars. Forming a triangle with Mercury and Venus is Zaniah, eta Virgo. All the visible sta...

But in terms of reference there isn't a proper east or west portion of a continent that covers the south pole only the half (+/-) that lies in the eastern hemisphere and the half that lies in the western hemisphere. Exactly. And that's how the continent is divided. As noted previously, there are tw...

Yeah, It seems to me like from the South Pole all directions are North. And so they are. But there's an awful lot of the continent of Antarctica that is nowhere near the South Pole. In terms of distance to the Pole, most of Antarctica is similar to Siberia, northern Canada, or Greenland. People in ...

Chris, what precisely are hot pixel defects? I heared about pixel defects, single pixels, which do not work. Do hot poixel defects occur in groups of about 10 adjacent circular or square elements? Every pixel on a CCD has a slightly different dark current rate. So if you were simply to make an expo...

Some may be other arcs and it looks like some may be scratches in the film. I'm referring to the dark up and down streaks that are just barely noticeable. Nothing about this image has even remotely involved film. And data doesn't scratch <g>. There seem to be three types of background objects. The ...

I am in Cincinnati(east side) and caught this sequence early morning Labor Day... It may be something on your sensor, or on the optics close to the sensor, or it may be something floating not far above you. Whatever it is, it isn't above the atmosphere, since it is clearly a shadow against the skyg...

Did some googling and found a light curve of March 11th 2006, in stead of August 20th 2008 in the Uwe Keller press conference . It shows the same double periodicity and the plateau, although the plateau is less striking as in the August 20th light curve. Looking more closely at the published curves...

Thought experiment. Take a cylinder (soda can), paint it white and let it rotate around an axis, perpendicular to the symmetry axis. Let some light shine on it, e.g. from the back side of the observer. (Full moon idea). The light curve will show a double period, since the cylinder has a rotation by...

This is probably why we don't see 2867 Šteins ROTATING . However, TUMBLING implies a more chaotic motion... In the case of asteroids, tumbling can't be taken as implying chaotic motion. Tumbling means that there is rotation about more than one axis, which is not typically chaotic. The actual motion...

Did you see the presentation of H. Uwe keller ? On page/sheet 5 a light curve is drawn. The horizontal scale is in Modified Julian Date and the vertical scale is the "magnitude". There is a fluctuation in magnitude in length about 0.1 MJD visible, so roughly 2.5 hours, which could be inte...

If it is tumbling; the rate may have been too negligent for the photo to capture. :? I couldn't find much on not tumbling on google; as most sites suggested that asteroids do tumble. Most asteroids do not tumble, but simply rotate about their principal axis. Tumbling means the asteroid rotates abou...

Hey, I only said strange ... not offended, nor outraged, nor feeling the need to replace any terminology. I didn't take it wrong, but was serious if you had an alternate terminology in mind. The 2D coordinate system we find generally convenient to describe our position on the surface of a sphere do...

But East Antarctica still seems like a strange term to me. Do you have another suggestion? Seems to me that reasonable cardinal directions for Antarctica are east, west, central/south, and coastal/north. Even though its coast is deeply dented, Antarctica surrounds the South Pole. If I pick a spot a...

It is not my intention to be rude, but the phrase "It is simple to see" is synonymous with "the author did not bother to elaborate, after three weeks of intensive calculations the result can be found". I simply meant that if you made a simple drawing of the 2D case, it should be...

In the wiki i can read that it differs from a plane mirror. It is a constellation of three perpendicular perfectly flat reflecting planes. The reason (proof or explanation) why for any incident angle the light is reflected in the same direction, is missing. I guess its a matter of repetative applic...

Why is the laser light relefected so preceisely back to earth and not somewhere near the earth? The reflectors are arrays of corner prisms, aka retroreflectors . These cannot help but to send reflected light back along the same path it entered on. How does the ever changing path (different heights ...

The moon probably has a liquid core of about 20% of the Moon's radius. I can only guess that they must see it wobbling or something to infer this. To be fair, this is not established. There are various well regarded theories about the Moon's core, including little iron or a small, solid iron region...