Info 'bout black holes, and is there one in the center of the galaxy?

AI Thread Summary
Black holes are regions in space where gravity is so strong that nothing can escape, and the discussion confirms the existence of a supermassive black hole at the center of our galaxy, estimated to have a mass of approximately 3.7 million solar masses. Time-lapse images show stars orbiting this black hole, providing visual evidence of its gravitational influence. Recommended resources for further reading include articles from Scientific American and Wikipedia, which offer detailed information on black holes and their properties. Einstein-online is also suggested as a valuable source for understanding black holes. The consensus is clear: the supermassive black hole at the Milky Way's center is a well-supported scientific fact.
The-BRA!N
Messages
7
Reaction score
0
1. What are some specifics about black holes?

2. I've heard there's a supermassive one at the center of our galaxy--FACT or FICTION?

Relevant websites, articles, etc. highly welcome! (I'm really interested in cosmology, obviously.)
 
Space news on Phys.org
The-BRA!N said:
2. I've heard there's a supermassive one at the center of our galaxy--FACT or FICTION?
...

Fact. Time-lapse pictures have been taken of stars orbiting it over an interval of 10-15 years, maybe more.
Its available online as a movie. You see the stars come in close and whip around and sail out----some of them have elliptial orbits.
If I remember right the estimated mass of our galaxy's central black hole is around 2.5 million or 3 million solar masses.
So the mass of a couple of million stars.

You said you would like some facts about BHs. What have you been able to find out from Wikipedia?

Is there anything about BHs at the Einstein-online website? It's a good source. A public outreach website maintained by one of the world's top research institutes.

Give us some links to what you have been reading already, if you like, so we know where you are coming from and have stuff to comment on.

I have a link to Einstein-online in my sig.
 
Last edited:
The-BRA!N said:
2. I've heard there's a supermassive one at the center of our galaxy--FACT or FICTION?

According to this sci-am article, astronomers put the size of source of gravity, equivelent to ~3.7 million sol mass at the centre of our galaxy, within a diameter of 30 million km. If you work out what the Schwarzschild radius is of 3.7e6 sol mass then this puts it in the right ball park to be a black hole-

http://www.sciam.com/article.cfm?id=virtual-telescope-galactic-black-hole

another sci-am article-

http://www.sciam.com/article.cfm?id=milky-way-black-hole
 
I highly recommend you high-tail it over to Wikipedia and read up. It has some interesting things, if you don't know much about BHs, and it's always a good read. 95% of stuff is cited, so it's completely true. While I haven't been there, Einstein Online sounds like a great website, too. Just need to time to dig in deep. :)
 
https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
The formal paper is here. The Rutgers University news has published a story about an image being closely examined at their New Brunswick campus. Here is an excerpt: Computer modeling of the gravitational lens by Keeton and Eid showed that the four visible foreground galaxies causing the gravitational bending couldn’t explain the details of the five-image pattern. Only with the addition of a large, invisible mass, in this case, a dark matter halo, could the model match the observations...
Hi, I’m pretty new to cosmology and I’m trying to get my head around the Big Bang and the potential infinite extent of the universe as a whole. There’s lots of misleading info out there but this forum and a few others have helped me and I just wanted to check I have the right idea. The Big Bang was the creation of space and time. At this instant t=0 space was infinite in size but the scale factor was zero. I’m picturing it (hopefully correctly) like an excel spreadsheet with infinite...
Back
Top