Philosophy Of The Cosmos - Gravity And Star Clusters
After hearing that Halley showed the relation between the movements of stars and the Sun, I made the assumption that clusters were formed due to gravitational pull: "This was the first evidence that a star could move to other stars due to their combined gravitational attraction." (His. of Astronomy II, slide 17)
So, if gravitational forces are the cause of particular star clusters and the formation of galaxies, is it fair to assume that there can be a shift in the positions of other stars as the cluster moves (assuming it has either a blue or red shift) and that it can almost gather other stars as it travels, due to its gravitational pull?
Jordan U4847190
Yes. Jason
Oh. Well, alright then! I just won a $5 bet! Jordan
So if the stars are being attracted to each other, what's stopping them from colliding? Or do they collide? (Tim - u 4311243)
They would collide, in the long run, but they would be in very complex orbits with each other. This would be like our solar system, in which the sun and planets are close together but do not collide. (Ben - u 4868271)
So have we had much observation of these collisions, or is it purely theoretical? And following from what you said, Ben, is it possible that stars in our own system will collide, or is there some sense of stability in their complex orbits of each other that would prevent this? (Jordan u 4847190)
What Ben says is right. Stars are very small compared to the distances between them, so they don't come close to each other very often, except near the centres of galaxies. When they do come near each other, their velocities are sufficiently large compared to the gravitational force that they often sail right on past, or go into orbit around each other. But sometimes they collide. Jason
For more information, read http://www.popsci.com.au/military-aviation-amp-space/article/2009-09/i-one-welcome-our-new-andromedan-overlords <— It provides some information on the union of Andromeda and the Triangulum Galaxy. Take special note because we're next in Andromeda's path. It's only 3 billion years until 'collision'! While Andromeda contains more stars, the Milky Way has a greater mass due to its Dark Matter content, so the resulting union will most likely be very different. (Sunny - u 4746830)
Cool! Thanks. Jason
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That our galaxy is in the path of a collision course with Andromeda has fascinated me for years, some of the photos taken of colliding galaxies are some of the most beautifully terrifying images i've ever seen - such as:>
and
http://apod.nasa.gov/apod/image/0804/arp272_hst_full.jpg
This simple fact poses also some major questions though regarding the pursuit of physics, the purpose of existence and naturally religion. Saving some deus ex machina, it certainly was a clumsy god we'd have to agree! (-though I'd suppose that this would merely be cited as proof of revelations blah blah blah blah).
jason.a
Beautiful pic. Thanks. Jason