Starship Asterisk*

I found this link from slashdot.org about black hole simulation at http://www.newscientist.com/article/dn1 ... r-data.htm. The app can be downloaded from http://www.vis.uni-stuttgart.de/~muelleta/IntBH/.

I watched the embedded video but have a question about whether the simulation is accurate. If a real black hole were to pass thru Orion as shown in the video (first link), would it come out in tact?

Thanks,
Smita

smita wrote:I watched the embedded video but have a question about whether the simulation is accurate. If a real black hole were to pass thru Orion as shown in the video (first link), would it come out in tact?

In the video, the black hole isn't near Orion. It shows a black hole somewhere between our solar system and Orion, and how Orion would appear if you passed very close to that black hole (or it passed by you). The black hole is just acting as a kind of lens, distorting light rays, not any physical material.

That said, there is no physical object "Orion". It is a constellation made up of stars at all different distances; a coincidence of layout visible as it is only from here. So there's really nothing for a black hole to pass through. But a black hole could pass through some compact area of Orion, such as the Great Nebula, and have almost no physical effect. A black hole has almost the same effect on its surroundings as a star. So a black hole inside the Orion Nebula would do the same thing that adding a star would do... not much.

Thanks Chris for the clarification.

Here is a diagram with the constellation Orion on the left and lines showing the true distances to the individual stars. Not a very good example but it does the job. I think I have a better diagram somewhere, I will take a look.

Actually, this is an area in which I did some work a while ago. Here is a link to another online black hole (and neutron star) movie simulation that I did in the 1990s:
http://antwrp.gsfc.nasa.gov/htmltest/rjn_bht.html .

Near the top of that link is an accompanying paper that explains many of the effects seen in some detail. Here is a link to that paper:
http://adsabs.harvard.edu/abs/1993AmJPh..61..619N

The specific simulation of a black hole moving in front of Orion can be found at this link:
http://antwrp.gsfc.nasa.gov/htmltest/gi ... ircbh.html

An MPG file link that directly play this simulation is here:
http://antwrp.gsfc.nasa.gov/htmltest/gifcity/circbh.mpg

- RJN

Thanks, I asked the question because I thought that a passing black hole would affect the characteristics of a nearby constellation due to the gravity of that black hole. Of course, that also depends on size of the black hole.

smita wrote:Thanks, I asked the question because I thought that a passing black hole would affect the characteristics of a nearby constellation due to the gravity of that black hole. Of course, that also depends on size of the black hole.

In case my previous explanation was too brief, just let me point out that unless you're talking about the supermassive black holes at the center of galaxies, black holes are practically all stellar mass. As such, they have the same gravitational influence on their surrounding as stars of similar mass. It is only when you are very close to a black hole that you start experiencing their peculiar gravitational (and tidal) effects. The Sun could become a black hole today, and the rest of the Solar System would continue without a hiccup (although it would get very cold).

Thanks Chris, that clarifies it.