Question???

[johnkirkpatrick]

now we know the moon circles us and we circle the sun but what does all the star in our galaxy circle?? forgive me for being silly but I honestly dont know, I know our milkyway rotates but round what? lol

[LukeSkywatcher]

All the stars in our galaxy and indeed most other galaxies all rotate around a blackhole that is situated in the centre of the galaxies.

So i have heard.

[Paxo]

A supermassive blackhole.

Steve..

[richbyers]

unless its an elliptical galaxy where stars move in a rather chaotic fashion, the stars rotate around a black hole usually a the centre

rich

[johnkirkpatrick]

thanks I thought that but was to afraid to say, so at some point a black hole would devour a whole galaxy?, now they say nothing travels faster than light but with a black hole nothing can escape not even light so does that mean a black hole "eats/swallows" matter faster than the speed of light??

[Starblazer]

Only thing that is apparently faster than the speed of light is the expansion of the universe

We are nothing more than organic soup in a cosmic waltz. Hehe.

[hunterknox]

thanks I thought that but was to afraid to say, so at some point a black hole would devour a whole galaxy?, now they say nothing travels faster than light but with a black hole nothing can escape not even light so does that mean a black hole "eats/swallows" matter faster than the speed of light??

Black holes are quite well behaved and act, gravitationally, like any other object. They're not like hoovers, sucking everything up, so unless you're heading in their general direction anyway you can carry on rotating around them care free.

[Talitha]

Only thing that is apparently faster than the speed of light is the expansion of the universe

And cloud-cover.

[Starblazer]

As I have just witnessed Talitha, oh well, bed time it is lol.

[mark7331]

Everything rotates due to an effect called "the conservation of angular momentum".

When the gas in a nebula starts to coallesce into more dense areas (i.e. clump together) they start to rotate (rather like the water going down the plughole). So by the time the gas has become dense enough to form a large body like a star, the body is spinning quite quickly as are more clumps of material that form planets etc.

"But why?" you say - well the circular motion is the product of two opposing forces - gravity (pulling in) and radiation (pushing out) from the excited gas - so everything spins.

Like cosmic spinning tops - or something like that.

At least that's the way I understand it.

[sbooder]

I have always believed that the universe revolves around me!...not that I am spoilt or anything.

[peeceeTal2M]

Perhaps this might answer your question John

[barkis]

I always enjoy watching that, and I agree entirely with the last line of the song .

Ron.

[simon84]

Classic.

[fo0]

this is a good video of the effects of the black hole at the center of our galaxy on near by stars

[FraserClarke]

The stars in the galaxy orbit around their common centre of mass (as do the Earth/Sun). They'd do so whether there was a black hole in the middle or not. Only in the very central regions of the galaxy does the BH affect the orbits of the stars. As hunterknox says, black holes are pretty inconsequential gravitationally; unless you're really close to them.

Black holes in the centre of galaxies do seem somehow to be related to galaxy evolution; but exactly how isn't clear yet.