Starship Asterisk*

I am not a scientist but but I do love astronomy . I understood ( correct me if I am wrong ) that most if not all galaxies
have a black in their very center. Therefore my question is: Will we ever find where is the black hole that hold our
universe together ? that suggest that there are many universes otherwise we would be already suck in . no ?

I just wonder !

Yvon

Yvon.B wrote:I am not a scientist but but I do love astronomy . I understood ( correct me if I am wrong ) that most if not all galaxies
have a black in their very center. Therefore my question is: Will we ever find where is the black hole that hold our
universe together ? that suggest that there are many universes otherwise we would be already suck in . no ?

I just wonder !

Hi Yvon,

You seem to imply that galaxies
like the Milky Way [of mass ~600,000 million solar masses]
are somehow "held together" by their
central black holes [of mass ~4 million solar masses].
Nothing could be further from the truth.

You also imply that the universe, itself, is somehow "held together"
when in fact the universe is flying apart.

Any lurking super cluster size black holes out there
[of mass ~1,000,000,000 million solar masses]
should be detectable
with current infrared & x-ray space telescopes.

I was also under the false impression that black holes somehow held galaxies together. What holds the stars together? Their mutual gravitational attraction? Dark matter?

50bmg wrote:I was also under the false impression that black holes somehow held galaxies together. What holds the stars together? Their mutual gravitational attraction? Dark matter?

In my limited understanding, the answers to your questions are yes and yes. That is, dark matter and baryonic ("normal") matter are both part of the system we see as a galaxy, and their mutual gravitational attraction and interaction are what has formed and shaped the galaxy.

Rob

neufer wrote:You seem to imply that galaxies
like the Milky Way [of mass ~600,000 million solar masses]
are somehow "held together" by their
central black holes [of mass ~4 million solar masses].
Nothing could be further from the truth.

Next you'll be saying, The Earth is orbiting the Sun for no reason at all. Bit Of A coincidence Huh? Billions of galaxies, Trillions Of stars all going round and round for no reason. Tut Tut.

tc

swainy (tc) wrote:

neufer wrote:
You seem to imply that galaxies
like the Milky Way [of mass ~600,000 million solar masses]
are somehow "held together" by their
central black holes [of mass ~4 million solar masses].
Nothing could be further from the truth.

Next you'll be saying, The Earth is orbiting the Sun for no reason at all.

Bit Of A coincidence Huh?

Billions of galaxies, Trillions Of stars all going round and round for no reason.

Next you'll be saying, (with no black hole at its center)
the Sun is held together for no reason at all.

Bit Of A coincidence Huh?

2×10³⁰ kg of hot gas all going round and round for no reason
(i.e., with nothing at its center to attract it and keep it all from flying out into space).

But with the sun or any gravitationally bound object (planetary body), the object's external portions are held by the gravity of the internal portions, while the internal portions are compressed and heated by the pressure exerted by the external portions.
In the case of a Galaxy, It would seem to stand to reason that the mass/gravity of the Central Black Hole holds the Core Stars in orbit around it while their combined mass/gravity holds the next successive group in orbit.
Our star is orbiting the Central Black hole as well as the combined mass/gravity of ALL the stars between us and the center
It is rather the combined mass/gravity of the internal portions that holds the external portions in orbit.

BMAONE23 wrote:But with the sun or any gravitationally bound object (planetary body), the object's external portions are held by the gravity of the internal portions, while the internal portions are compressed and heated by the pressure exerted by the external portions.
In the case of a Galaxy, It would seem to stand to reason that the mass/gravity of the Central Black Hole holds the Core Stars in orbit around it while their combined mass/gravity holds the next successive group in orbit.
Our star is orbiting the Central Black hole as well as the combined mass/gravity of ALL the stars between us and the center
It is rather the combined mass/gravity of the internal portions that holds the external portions in orbit.

The mass of the central black hole is negligible compared with the mass of the entire galaxy. We don't observe any structural difference in galaxies with large, small, or absent central black holes. If you could simply remove the central black hole, there would be almost no difference in the orbits of any of the stars, except possibly the handful in close orbit around it.

The mass distribution in a galaxy is very different from that of the Solar System.

Chris Peterson wrote:The mass of the central black hole is negligible compared with the mass of the entire galaxy. We don't observe any structural difference in galaxies with large, small, or absent central black holes. If you could simply remove the central black hole, there would be almost no difference in the orbits of any of the stars, except possibly the handful in close orbit around it.

The mass distribution in a galaxy is very different from that of the Solar System.

Two Words. Collective Mass. What did Saturn And Jupiter do together That they could not have done alone? Is not all that Dark Matter that completely encircles our galaxy, there for a reason?

I cant see us, orbiting a 100 thousand (Light Year) central point, just out of coincidence. And the Andromeda galaxy, seems to want to get to know us very well. Not out of choice me thinks. Who made that decision? Was it the three Billion Stars, Or Its Black Hole's

Interesting stuff.

tc