Starship Asterisk*

Hawking is just speculating. Wildly. There is no physical theory that describes the interior of a black hole. The interior of a black hole, excluding the "center", is described by general relativity. Of course, since the interior is hidden by the event horizon, it will be forever hidden f...

This photo reminds me of Independence Day.

They take in 3d material, and convert it to dark energy and dark matter, that is the reason for universe expansion. If initial condition are right, matter can fall into the black hole. But then it will never come out of it. Or matter can circulate around the black hole, just as the Earth orbits the...

Yet if gravity has been figured out, the physicists have done a remarkably poor job of transferring that knowledge to the public (the interested, educated public). There are plenty of books that explain gravity to an interested reader. To mention just two of them: "A Brief History of Time"...

Why are the diffraction spikes of the red stars different in size than the ones from the blue stars? Are there separate cameras mounted differently, or is it due to the different wavelengths?

Couldn't everyone have just crammed into the cockpit? The trip was planed with some preparation and is not just a simple snapshot. You probably don't want to setup your camera equipment in the cockpit and interfere with the pilot during the flight. I guess it's easier to mount the camera on a passe...

Ok two bodies moving apart (relative to each other ) could be traveling faster than C etc, etc I don’t have a problem with that it makes perfect sense. First, shine a laser pointer to the east. Then shine it to the west. The light pulses each move away from you with c, but in opposite directions. H...

Nitpicker wrote:That's just beautiful. Thank you APOD.

I second that!

Neufer you stated no the object could not be seen if it were traveling above C. No one is going to rebut this ? Well It doesn't seem right but I’ll take it as fact then. If an object travels faster than light, all light it emits cannot catch up with it, so you can only see it after it has passed yo...

( Traveling towards us ) What would an object with mass look like when viewed from earth if it were moving towards us at just under C Here is a simulated flight through the Brandenburg gate . One is with 0.9c the other with 0.99c . In the latter video, towards the end, you can actually see the back...

Unified theory :?: Wouldn't that be called "Life" :?: In this context unified theory refers to nothing more and nothing less than a unified treatment of gravity and the other three forces of nature. This unification is similar to electromagnetism, which allowed for a single unified treatm...

Seems neutrons may carry more Higgs bosons? The Higgs mechanism gives mass to elementary particles. The elementary particles the neutron is composed of are the up- and down-quarks. In the standard model of particle physics, they get their mass via the Higgs mechanism. However, the masses of the thr...

If galaxies are all being flung to the far-flung 'horizons' of the Universe, the outermost going fastest (?), how would they come to be on collision courses at all ? The distance between galaxies is increasing, they are not "flung around". Though difficult to imagine this is something dif...

However, the numbers quoted in the caption do not appear to add up (to me). The nebula (NGC 7635) is said to be both (absolutely) smaller and further away than the cluster (M52), yet the cluster appears smaller than the nebula. I had the same issue. However, the caption says the "Bubble Nebula...

Is that Conservation of Angular Momentum? It is. The process is similar to that of a spinning ice skater who pulls in her arms to increase her spin. During a supernova the outer region of the star is shaken off and the inner region contracts, which leads to an increase in angular speed of the neutr...

Are we to assume that the arrows are vector quantities, i.e., they have magnitude as well as direction? Or are they simply scalar quantities? From the IBEX homepage "the direction of motion of the various gas clouds are depicted by arrows". The arrows are thus vectors, not pointers to par...

The authors of the original paper (not the Nature article) refer to a "3-brane in 5D Minkowski space", whatever that is. There's no need to suspect that anything other than that is implied in this case by the use of the term brane -- a term which has been in use in mathematics, physics an...

But such astronomical ignorance is not suitable for an APOD picture. As it is, this picture is merely another photoshop wallpaper, and belongs here as much as ponies in morning mist. Yes, today's APOD is more art than science. However, keep in mind that most APODs, in particular those from Hubble (...

E.E. geek wrote:Does this and http://apod.nasa.gov/apod/ap130728.html hint that there might be a saturation point for a black hole? Curious..

There is no limit on how much mass a black hole can acquire and no saturation point.

So I’m wondering if these objects can, in effect, recycle entire solar systems, shredding them and then ejecting much of the material far out into space where, given enough time, the gas can cool off and eventually form new stars and planets. That’s what I mean by likening SMBHs to recycling engine...

Fascinating visual. Very ingenious. No matter how many times I see the Hubble Deep Fields, I am always impressed and deeply moved by them. And 2) In the observable Universe today (I realize there is debate on the estimated total size of the Universe), roughly where is the location of our Milkyway G...

My spontaneous association:

Hello,

does anyone know what the four red dots are that appear in the lower right from 2:15 to 2:29?

As goes the idea of all black holes possibly being the gateway’s / beginning point’s of another universe whereas material inside it may be being ejected much like what we would call the big bang that happened in our own universe. This was just one of the many, many possibilities put forth on the la...

RJN wrote:Today's APOD has been updated due to a better image being released during the day.
- RJN

This solves my question. Thanks!