Astronomy / Space Does our universe have a supermassive black hole directly at it's center?
- Thread starter creamgirL
- Start date
Sagittarius A* is the supermassive black hole in the center of our galaxy.
Most galaxies will have one as it makes sense that all those stars are orbiting something. The Universe is everything in existence (so every galaxy) - it may well have a black hole at the centre of it, though the Universe might not even have a centre...
The observable universe is the universe that we know of, ie all the galaxies we can currently detect.
Most galaxies will have one as it makes sense that all those stars are orbiting something. The Universe is everything in existence (so every galaxy) - it may well have a black hole at the centre of it, though the Universe might not even have a centre...
The observable universe is the universe that we know of, ie all the galaxies we can currently detect.
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The black hole would seem to be an inevitability of any galaxy, eventually.
Current thinking suggests that the 4th era of the universe will be the Black Home Era when all there will be will be Black Holes and their evaporates.
http://en.wikipedia.org/wiki/The_Five_Ages_of_the_Universe
Current thinking suggests that the 4th era of the universe will be the Black Home Era when all there will be will be Black Holes and their evaporates.
http://en.wikipedia.org/wiki/The_Five_Ages_of_the_Universe
As current thinking goes, there isn't a centre to the universe. Everywhere looks pretty much the same as everywhere else on large enough scales.
Pretty much all major galaxies have supermassive black holes (but that's not demonstrated by 'all those stars are orbiting something' - the central black hole doesn't have a major impact on the wider dynamics of the galaxy through its gravity). Smaller galaxies may not. I don't recall any evidence for the Magellanic Clouds having one for example. Essentially any big spiral or elliptical will though (I think there's some debate about possible exceptions).
Agree that there is not exact centre to the universe, not that can be identified anyway. Therefore there will not be any black hole there, but if there were it would not be caused by the physics of the universe maybe by coincidence.
edd raises an interesting point on rotation. Agree that with what we know at the moment the actual galactic rotation in unlikely to be driven by Sgt A*, local stars to the singularity though are indeed heavily influenced by its presence and display this with highly eccentric orbits. I do wonder if the actual galactic rotation is driven by dark matter and that the universe is a far stranger place than we can even contemplate at the moment. In my opinion it will turn out that we are only just scratching the surface of what the universe is actually all about. Its a great time to be a human and witness the stunning discoveries that are happening at a seemingly accelerated pace.
edd raises an interesting point on rotation. Agree that with what we know at the moment the actual galactic rotation in unlikely to be driven by Sgt A*, local stars to the singularity though are indeed heavily influenced by its presence and display this with highly eccentric orbits. I do wonder if the actual galactic rotation is driven by dark matter and that the universe is a far stranger place than we can even contemplate at the moment. In my opinion it will turn out that we are only just scratching the surface of what the universe is actually all about. Its a great time to be a human and witness the stunning discoveries that are happening at a seemingly accelerated pace.
The nature of all matter is the attraction it has to other matter. Gravity.
Just as stars form by matter, repeatedly attracting more and more matter, eventually the mutual gravitational of that matter causes the star to emit various forms of radiation. Not least, (for our purposes) light.
A black hole is essentially the same, except it is a much denser point and therefore has a much greater gravity, both mutual and to other matter near by. The greater density results in a greater gravitational attraction such that even light which is emitted past the event horizon, cannot escape
Galaxies must have formed around something, which has enough gravity to attract the matter toward it in sufficient amounts to create stars. This is why it is supposed that all galaxies will have a black home at their centre. That is the nature of the universe.
A simplistic comparison might be to imagine the entire immensity of the universe is emptied of all matter except two particles of equal mass, positioned at opposite end of the universe. It doesn't seem to matter how far apart they are, they will attract each other and continue to do so.
Include other matter and each will create their own gravitational attraction, proportional to their mass.
I can sit at my desk for example and there is a gravitational attraction between me, the desk and everything around me. But that attraction is dwarfed by the gravitational attraction of the Earth.
#Surfinjo
Not sure if you picked up the correct part of what I had written as I don't think your post addresses the quote. But I will answer your post thus.
I see your point although I am not sure it holds up with Dark Matter and Dark Energy. For instance where you state that "Galaxies must have formed around something", maybe they formed within something i.e. some sort of Dark Matter soup. Galactic rotation is not explained by the presence of a central black hole which I guess is what you allude to. Of course I agree that gravity has a major role to play in the universe but it is almost certainly not the prime architect of what we observe.
I appreciate the discussion, All the best
Pete
Not sure if you picked up the correct part of what I had written as I don't think your post addresses the quote. But I will answer your post thus.
I see your point although I am not sure it holds up with Dark Matter and Dark Energy. For instance where you state that "Galaxies must have formed around something", maybe they formed within something i.e. some sort of Dark Matter soup. Galactic rotation is not explained by the presence of a central black hole which I guess is what you allude to. Of course I agree that gravity has a major role to play in the universe but it is almost certainly not the prime architect of what we observe.
I appreciate the discussion, All the best
Pete
Respectfully, guesswork.
Too little is known, at this time about dark matter and dark energy.
We can and must only work on what we can know. That is what I have tried to do.
As for spin I suggest you read Hawking's musings on quarks.
Guesswork on what might be is about as relevant as saying, somewhere out in the universe, there is another civilisation that speaks English!. Or the rather more important question, do those people, somewhere out in the universe who speak English, drive of the British (and therefore correct) side of the road.
All jolly good stuff and super for possible inclusion in future updates of Elite or perhaps a SiFi film series, but the opening question would seem to have been intended as a serious discussion on what is known.