Black hole at center of Milky Way

[Bill Morris]

Here's a link about confirmation of a massive black hole at the center of our galaxy, about 27,000 light-years from Earth, based on observing the movements of 28 stars around it:

http://news.bbc.co.uk/1/hi/sci/tech/7774287.stm

 

[All Seeing Eye]

I was always under the impression that we already knew there was a SMBH in the centre of the Milky Way. To me this isn't news *shrug*

 

[David Payne]

Me too, I'm not sure what's been proven here.

 

[Meredith]

one it will pay us a visit and swallow up the entire earth in one fell shwooop

 

[Jadzia]

I was always under the impression that we already knew there was a SMBH in the centre of the Milky Way. To me this isn't news *shrug*

Black holes have never been clearly "seen", and they are still theoretical objects. Although they are common place in scientific discussion nowadays, it isn't fact until it is observed.

Just like Newton's simple inverse square law doesn't model mass-gravitation perfectly. Yet for 300 years, everybody believed it was a perfect description of reality. Einstein modified our "beliefs".

So where event horizons are purportedly created, space-time may not actually behave like that. We've never seen it. Although the Einstein equations say it does, it is yet to be proven.

Remember that the equations don't define reality; they model it. And if that model is incomplete, then it doesn't describe reality in some circumstances, like 'event horizons' might not happen... so no black holes.

This report above with the stars is creating a mass estimate, and assuming this means black hole, based on Einstein's laws.

I discourage anyone from making the same mistakes that pre-Einstein people did. Understand the limitations of the theory, and don't make premature assumptions just because you want the theory to be true.

 

[John Picard]

*Note to self: avoid travel near the center of the Milky Way*

Thanks for the info.

 

[Arrqh]

Ars has a more comprehensive story, and the actual paper can be found here.

 

[David Payne]

Thanks for those links. I've only had a chance to have a quick look at the first one, but the story is that they estimated its mass? Still a good find, but not the "Scientists have discovered a black hole" story that I'm still seeing reported. Reporters are so stupid when it comes to science.

 

[Shaw]

I discourage anyone from making the same mistakes that pre-Einstein people did. Understand the limitations of the theory, and don't make premature assumptions just because you want the theory to be true.

And this coming from someone whose long time bias against General Relativity kept her from understanding it to begin with? Just because General Relativity doesn't fit into your infinite flat universe with it's universal time doesn't mean that the rest of us should view the universe in such limited ways. So please don't discourage others from attempting to understand what you refuse to.

Besides, the shortcomings of what Newton put forward (the fact his equations described the general effect but not the cause of gravity) were known by Newton himself.



I encourage everyone to attempt to understand this stuff, specially because it so utterly different from how we experience the world around us in our daily lives. Don't let anyone project their own (self-imposed) limitations on you.

 

[Brent]

So no alien who is in need of a starship lives there afterall?

 

[IJD GAF]

So no alien who is in need of a starship lives there afterall?

I'll take it if he doesn't want it.

 

[Jadzia]

And this coming from someone whose long time bias against General Relativity kept her from understanding it to begin with?

I don't have any bias against it. I just wanted to approach it differently that the traditional way, and if that didn't work then it would have become apparent in the equations.

But that isn't even relevant Shaw. Whatever approach is taken it is just mathematics, which doesn't define reality, it only models it. If readers are so certain that these mathematical models are perfect, then make your presumptions... Believe in your event horizons and black holes and other theoretical objects... go right ahead.

 

[Shaw]

I don't have any bias against it. I just wanted to approach it differently that the traditional way, and if that didn't work then it would have become apparent in the equations.

But that isn't even relevant Shaw. Whatever approach is taken it is just mathematics, which doesn't define reality, it only models it. If readers are so certain that these mathematical models are perfect, then make your presumptions... Believe in your event horizons and black holes and other theoretical objects... go right ahead.

Your bias predates your efforts to understand Relativity, and your efforts to understand Relativity turned out to actually be efforts to find fault in the theory rather than learn it. And because of this you have become my primary example (IRL) of how someone's preconceptions can stop their progress in learning.

I know quite a few people on both sides of the Relativity/Quantum Gravity divide, but none have limited themselves the way you have.

And yeah, I'm embarrassed that I ever thought you had any honest interest in learning this when in fact your motivations were to attack the theory from the out set.

Of the two of us, you are the only one who has made presumptions and then taken great pains to support them (even to the point of doing the math badly).

So please, by all means, discourage yourself all you want (I'm not stopping you)... but please let others reach their own conclusions.

 

[Jadzia]

Your bias predates your efforts to understand Relativity

That was an exploration of something I had pondered over. Are you suggesting it is wrong for me to make an inquiry into something? How is that a bias? Learning isn't about taking sides. Inquiry into one things doesn't mean I'm against another.

..and your efforts to understand Relativity turned out to actually be efforts to find fault in the theory rather than learn it.

You are incorrect. Observing possibilities for failure is a reasonable way of testing validity. It is perfectly reasonable to ask "Why can't it be like this?", and have an answer. Else we're blindly led on some nebulous adventure, and unable to justify why alternatives are invalid.

And yeah, I'm embarrassed that I ever thought you had any honest interest in learning this

No, you're upset because I didn't want to learn in the way you wanted to teach me. And so you turned that upset into an attack on my motives.

 

[Deckerd]

I was always under the impression that we already knew there was a SMBH in the centre of the Milky Way. To me this isn't news *shrug*

No you weren't, since it was only mooted in the 1990s and you're older than that.

 

[Shaw]

How is that a bias? Learning isn't about taking sides. Inquiry into one things doesn't mean I'm against another.

That was the earliest example I could recall... and at the time I (wrongly) assumed your position was based on not knowing General Relativity. But if you would like more examples of what you've said, PM me and I'll be happy to supply you with quotes and links (though you really should already know what you've said in the past).

You are incorrect. Observing possibilities for failure is a reasonable way of testing validity. It is perfectly reasonable to ask "Why can't it be like this?", and have an answer. Else we're blindly led on some nebulous adventure, and unable to justify why alternatives are invalid.

Well, as I pointed out on our last exchange on this subject, if you are unwilling to give the theory a fair chance then you aren't going to know one way or the other.

No, you're upset because I didn't want to learn in the way you wanted to teach me. And so you turned that upset into an attack on my motives.

I wasn't upset... I just learned that you weren't worth wasting any more time on. But I know that my way of learning anything isn't to look at it incompletely and make presumptions on that basis.

But if you are feeling attacked, then maybe you were the one who was upset rather than I. I was (again) just stating that we shouldn't be discouraging anyone here. And I would encourage everyone (especially you) to learn as much about this subject as possible to help reach your own conclusions.

I, personally, don't really care what you want to believe... but when you discourage others from learning (so they can reach their own conclusions), I'm going to speak up. And I would point to the fact that you've stated many times your beliefs without me posting a word against you... because I just don't care about them.

Maybe you should follow your own advice though... you said "don't make premature assumptions just because you want the theory to be true." Maybe you shouldn't make premature assumptions just because you want the theory to be false.

 

[Jadzia]

This is all just hot air Shaw.

I don't make premature assumptions about things. It's wrongful for you to say that.

Black holes remain the hypothetical prediction of an equation; they're not an observed phenomenon. Why is it so terrible for me to raise this point?

 

[Tobin_Dax]

Black holes remain the hypothetical prediction of an equation; they're not an observed phenomenon. Why is it so terrible for me to raise this point?

Black holes have never been clearly "seen", and they are still theoretical objects. Although they are common place in scientific discussion nowadays, it isn't fact until it is observed.

In this case, they are an observed phenomenon. There is an object at the center of the galaxy that is very massive and very small (for that mass). This isn't hypothetical, this is from observations. Do you deny that this small, dense object exists?

 

[All Seeing Eye]

I thought there were some Galaxies where they 'saw' matter/particles being spewed out of SMBH's?

 

[Jadzia]

In this case, they are an observed phenomenon. There is an object at the center of the galaxy that is very massive and very small (for that mass). This isn't hypothetical, this is from observations. Do you deny that this small, dense object exists?

Well these observations are principally of orbital periods and heights, which when interpreted through gravitational theory, does indeed suggest a small massive object. I would be surprised if a small dense mass didn't exist there.

But what I am saying here is, that we should not go around stating "there goes a black hole", because at present it is only a theoretical footnote to Einstein's equations, that space and time will bend to such an extreme by small dense masses.

I'm cautious to jump to conclusions, because I don't like being wrong, and this is what I'm trying to promote.

All of our verifications of einstein are in relatively tame space -- we've never had a small massive objects to experiment with, so we do not know whether or not it defines a black hole. We do not know whether einstein's model of our universe remains accurate in that setup, if the actual behaviour begins to diverge from einstein's model.