Starship Asterisk*

. . . some of it may have to do with gravity and stellar winds. Probably the rotation of the galaxy and and nearby galaxies. . . On the scale of dust-clouds, I would expect gravitational influences of embedded/nearby stars to be "smooth" rather than "chaotic" in appearance, even...

The features of the gas clouds remind me of cloud shapes and small features of cyclones, etc. on Earth. On Earth, these features are influenced by small localized atmospheric pressure variations, winds, moisture content differences, among other things. It seems to me that if "empty space" ...

. . . The core's gravity would have caused the matter to curve inwards behind the core, the amount of deflection depending on the distance from the core. Even at the very high speed of the blast front, there would still be deflection of matter, and over the period of a thousand years, the deflected...

. . . The arms of the galaxy are not objects to discover, rather associations among great numbers of objects and looser materials. So not only do we have to observe the objects and other materials that make up the arms, but we have to find evidence that they are associated in a mappable arm. That m...

I have the same opinion on this as Case.

Even if we're wrong, what's the worst that can happen? You will have to return, or sign over to Chandra/Harvard, the millions you will make for posting your results on the APOD forum.

. . . As she continues to watch, she will see it get closer and closer to the event horizon, slowing down because of the time-stretching effects of gravity in general relativity. :: What Qev called red shift:: However, she will never see it cross the horizon. Instead she sees it stop just short, wh...

Qev wrote: (. . . 'snail's head' explanation . . .)

Thanks for the reference and explanation.

Another example of how looks can be deceiving in many of these APOD pix.

. . . Have we (the proverbial we) actually seen a black hole disappear? . . . I don't believe we have . . . yet. However, in response to questions (lawsuits, even) about the safety of the CERN LHC near Geneva, it is asserted by physicists that the possible creation of microscopic black holes is ben...

re: http://antwrp.gsfc.nasa.gov/apod/ap080630.html In the picture at about 10 o'clock from the central star and near the edge of the blue color, there is a feature that looks like the head of a snail which includes the two eye stalks. In my view, these two "stalks" appear to be trails of t...

. . . Is there a cosmologist among you who doesn't believe that time goes only forward? I'm kind of surprised we haven't heard from any fans of negative time yet. Ah, ye of little faith! Once the "Unified Theory of Everything" is perfected, someone will undoubtedly be able to figure out h...

. . . I couldn't begin to suggest a simple model of how the spiral arms of a spiral galaxy maintain themselves. . . Is it well-established fact that a spiral galaxy will maintain its spiral arms in a stable "end-state"? Is it not possible that the time-constants are such that the time nec...

apodman wrote:(lots of info and recommended reading)

Thanks again for your posts. Google and other research it is.

It's also quite frustrating to me that my 35 year old math and physics texts have become much less intelligible than they were when new.

Since we're talking nonsense .. My 2 cents on "nonsense". Pejorative labels are unhelpful in any discussion. I believe that the consensus is that there exists a mechanism to account for the streams and that mechanism is a companion galaxy. Manifestations of similar streams around other ga...

http://www.fas.org/irp/imint/docs/rst/Sect20/A8.html . . . Thank for the fas.org link - mostly understandable and helpful stuff. From the text: ". . . the Milky Way . . . is not near any center ( expansion models do not allow for a discoverable center ) - a positional state that may not even b...

. . . A 3-D sphere has a 3-D center, but its 2-D surface has no preferred 2-D center point on that surface. Likewise, a 4-D supersphere has a 4-D center, but its 3-D supersurface has no preferred 3-D center point on/in that supersurface. . . Thanks, that makes sense to me; I can even comprehend a &...

. . . The centre isn't *miles* away, it's thirteen milliard *years* away, in that direction, the direction of "past". . . OK, more conceptualization/visualization problems!! It seems to me that the "center" of the universe at the time of the big bang (EDIT: actually just after t...

My thoughts from a layman's perspective: The shape of the galaxy under discussion in this thread suggests that the angular momentum (AM) vector is pretty much perpendicular to the galactic plane. Since the galaxy is not a single solid object, for it to be "tumbling" (i.e., a non-trivial co...

. . . The Magellanic Stream was detected in the 1970s. http://apod.nasa.gov/apod/ap980826.html http://en.wikipedia.org/wiki/Magellanic_Stream The caption for the APOD indicates that this stream is a gas cloud, while the wiki article could be interpreted to imply, but does not explicitly state, the ...

. . . the companion galaxy completely has disappeared. So it is more 'astronomical forensics' to find out what might have happened. . . Disappeared from our view, certainly, but there is an awfully large volume of space in that galaxy that we can't see. Again, things like timing, could be important...

. . . Next, ask yourself the question why not all -or a large percentage of- galaxies show these faint trails like NGC 5907, perpendicular to the main rotational plane. While I'm not a proponent of the "tumbling" hypothesis, let me proffer the following (in the spirit of Billy Ockham). It...

. . . So I'm sorry I'm no help. . . Quite the contrary, the references are great. While they may not explicitly answer my question, I had not seen either the Cambridge site or the sukidog site before and I expect to spend some time reading and following some of the links they provide. Thank you ver...

Is there any "real" (whatever the definition of real is) evidence of the existence of dimensions greater than the number that we as humans actually experience, or is all of this just the result of playing with mathematics? . . . the four dimensions of space, space, space, and time were al...

To question these dimensional analogies further: I remember way back when, we had problems of the type "John has x apples. If Mary takes . . . , etc., etc. How many apples does John have left?" In many cases involving quadratic solutions, there were two answers, one positive, one negative....

re: http://antwrp.gsfc.nasa.gov/apod/image/0806/M51HST-GendlerM.jpg In the picture of these interacting galaxies, NGC5195 seems to have little or no detail. (A quick look elsewhere on the internet yielded no "better" images of this galaxy - not saying they're not out there, but I couldn't ...

http://antwrp.gsfc.nasa.gov/apod/image/0806/scoop_phoenix_big.jpg If one looks at the front end of the scoop containing the martian soil, there seems to be a strange-looking adhesion effect. What it reminds me of is the appearance of the residue that might be left in a crepe pan when removing a cre...