Starship Asterisk*

Since the US does not use, nor are children taught in schools, the metric system, most of America (over 7 billion people) would have no idea how many deciliters it is. That is what doesn't make sense. This is argument is reminiscent of a situation when I was a student at a US high school. While the...

I only just noticed that (at least in this image) the dust and gas is streaming roughly towards the Sun and perhaps even vaguely in the direction of the comet's orbital motion, indicating that the stream is being expelled with a certain oomph, from pockets of sublimating ice. But I suppose the forc...

Maybe they're caused by some type of high energy particle impacting the upper layers of the atmosphere? Also I'd be very happy if Chris Peterson responded to my post, that guy's awesome! :D I am not Chris, but I try answer anyhow :) High energy particles don't cause lightning but extensive air show...

Arborist wrote:Looks like something out of Tolkien’s Lord of the Rings. Simply fantastic, and non-fiction, too.

Exactly what I was thinking!

This image shows very well how dust reddens starlight that passes through it. Notice how in the upper left and lower right corners there are dust free areas where most all of the stars appear blue. You can discern the boundary of the dust cloud by how it reddens the light form background stars. Whe...

This APOD did inspire me and my colleagues to write this paper published in the peer-reviewed Modern Physics Letters A . We even included the APOD in the references. Us not being astronomers, it is maybe no surprise that this was an APOD not showing a field of stars or nebulae. Therefore, I support...

Also, please, I would like to know if we see just a cutting plane or a projection on a plane ? From this link (also given in the APOD caption and mentioned by Indigo_Sunrise), I think that it's the equatorial plane. They define this plane as an imaginary plane containing many of the most massive cl...

I am confused ... "everyone" tells me that the universe is expanding (Einstein, Hubble, etc.) ... yet this "contraction" of the Supercluster seems to refute that ... and if all the other galaxies outside the orange line are "contracting" toward their own supercluster c...

I don't quite understand the color code. The captions says that "green areas are rich with white-dot galaxies". There are no white dots at about 9 o' clock, which implies to me that the cyan represents "empty". What does, then, the dark blue next to the image center stand for? Bu...

Interesting that "The Sorcerer's Apprentice", which I had to memorize in school, shows up here :) Now, I wonder how the wizard has done the trick, i.e. how did he remove the stars? My naive guess is that you first use some kind of peak finder and then subtract it from the image. But that w...

As with yesterday's APOD, a lovely and inspiring picture!

There is the implication that this image owes much to the altitude of the site. But the sky would look identical to a camera at sea level, assuming dark, dry skies. And almost identical visually, as well. The altitude has very little effect on the limiting magnitude. What is important for submillim...

As to the phenomenon itself, on a gut level I feel like it might have something special to say about Dark Matter, too. I can't help but try to picture how the Dark Matter halos of the galaxies are merging and molding the "bridge" of stars. Or maybe not, but when I look at the image and th...

I'm not sure I agree with Art's comments, either his calculated timing or the issue of Cherenkov radiation. But that issue aside, it's not clear to me why photons traveling at very slightly less than c changes much about our observations. How does light arriving slightly later than we have assumed ...

I only had a quick glance at their paper, but somehow they don't seem to mention that their wormholes require negative energy density. But no substance or mechanism is known to provide enough negative energy density for a supermassive wormhole. Also, we have not observed any "white holes",...

After looking at the picture and reading the text I wonder if the citizens of Alderaan felt the same.

I really like the idea Unfortunately, all I have seen so far is the gray screen. Hope to see some real pictures soon!

Since we can study the effects of black holes on their surroundings, we are, in a sense, close enough to study it. For instance, we can measure the mass of the black hole at the center of the Milky Way. But if an experimenter close to the event horizon would send the data via electromagnetic radiati...

Just asking you people who seem to have a better overall knowledge of the flow of current investigations: Is the idea of multiple universes still too far-out to be incorporated into serious theoretical work ? I have thought that it's possible that all the hoopla about the search for dark matter may...

Would these be around the CMBH of the Milky Way? Would they be drawn to it, and thus start hitting or interacting with other WIMPS? Are they observed in other galactic centers? If they are so pervasive, why do we not see them in other places, interacting and giving off Gamma Rays? A common density ...

Indigo_Sunrise wrote:Now, can someone point out the invisible cat that is supposed to be in the last link of the description? The one in the 'disappeared' link..?

Spoiler warning!

Looks like a UFO lifting off

How a teaspoon of anything can weigh ten tons or more and what infinite density would even be like / A teaspoon of matter being ???? A million tons???? I live for this stuff, I just love reading about it The matter density inside the nucleus of an atom is about a billion tons per teaspoon (~10^9 T/...

This is below the melting point of carbon dioxide. Very cold indeed.

I'm not certain that the interior of a black hole will remain forever hidden from us, except in the most literal way. Theories that describe the interior are likely to have observable ramifications outside the interior. Much of nature is directly hidden from us, which hasn't stopped us from achievi...