NASA Announces Discovery of 30-Year-Old Black Hole 195
broknstrngz tips news of an announcement today from NASA about the discovery of a black hole in the M100 galaxy, roughly 50 million light-years from Earth. The discovery is notable because, if confirmed, it's now the youngest known black hole, born from the remains of a supernova we observed in 1979. Bad Astronomer Phil Plait explains why scientists think it collapsed to a black hole, rather than a neutron star: "The way a neutron star emits X-rays is different than that of a black hole. As a neutron star cools, the X-ray emission will fade. However, a black hole blasts out X-rays as material falls in; that stuff forms a flat disk, called an accretion disk, around the black hole. As this matter falls onto the newly created black hole, it gets heated to unimaginable temperatures — millions of degrees — and blasts out X-rays. In that case, the X-rays emitted would be steady over time. What astronomers have found is that the X-rays from SN1979c have been steady in brightness over observations from 1995 – 2007. This is very strong evidence that the star’s core did indeed collapse into a black hole." He also warns that we're not certain quite yet, and we'll have to keep our eye on it to make sure it's not a pulsar.
Relativity of Simultaneity (Score:5, Insightful)
To all the inevitable pedantic responses about it not "really" happening 30 years old, I'll be even more pedantic. :) Relativity of Simultaneity, look it up. It's absolutely meaningless to talk of the temporal ordering of space-like separated events. In some suitable reference frame, it "really" did happen 30 years ago.
Re:It was 30 years old, 50 million years ago. (Score:5, Insightful)
Re:Because everyone else will say it too... (Score:5, Insightful)
It's not that hard to figure out. We're looking at what a 30-year old black hole looks like, regardless of how long it took that light to get here.
Re:It was 30 years old, 50 million years ago. (Score:3, Insightful)
Of course. Unless you have some magical way of getting those images to us or us to the black hole faster than the speed of light, for all intents and purposes it is 30 years old, as viewed from our frame of reference.
What a typically anthropocentric way of looking at the universe.
Re:Relativity of Simultaneity (Score:2, Insightful)
Re:Because everyone else will say it too... (Score:3, Insightful)
It all depends on your frame of reference doesn't it, and in the absence of an absolute universal reference I shall accept earths as a reasonable and practical substitute. And seeing as from earth that black hole is 30 years old thats the age I'll accept, anything else is pointless pedantry.
Bad Astronomy? (Score:2, Insightful)
I'm not sure the Bad Astronomer understands this properly... an accretion disk could certainly form around a neutron star as well...
Re:Because everyone else will say it too... (Score:5, Insightful)
"No, it's 50,000,030 years old no matter where you are."
Uhm. I'm moving at 0.8c. It looks very much like 25000015 years old to me.
Are you suggesting that there's a global frame of reference?
Re:Because everyone else will say it too... (Score:3, Insightful)
I thought the whole point of relativity was that it's not just observation that's limited by the finite and constant speed of light in a vacuum, it's that time itself is relative based on relative velocity and acceleration. E.g., we might well be seeing a 50,000,029 year old black hole, based on the way that time passes over there relative to us.
I also was under the impression that time slows down to a crawl within a black hole. (Some sci-fi I read once, aliens cooped themselves up in one to not have to deal with the rest of the universe.) So if you're going by how the black hole feels about time, depending on the coefficient there, we might be looking at a black hole that's only a couple of weeks old.
Re:It was 30 years old, 50 million years ago. (Score:4, Insightful)
Why does *our frame* matter so?
Because it's the one we're observing it from. In a Relativistic universe, everything is relative to a frame of reference and you can't actually say anything about when things happen or their age outside of the context of a specific frame of reference.
Re:It was 30 years old, 50 million years ago. (Score:3, Insightful)
Not at all. It's relativity. No frame of reference is special, but it's easier to talk about things within our own frame of reference for practicality's sake. It's only anthropocentric in the sense that we can't observe things in a reference frame other than our own.
There are astrophysics professors who insist on the idea that if the light cone hasn't hit us yet, then it hasn't happened. No matter if you agree or not, it definitely makes sentence construction easier.
Re:Because everyone else will say it too... (Score:1, Insightful)
Except that the Big Bang happened everywhere simultaneously. There is no "place" where it happened.
Rather weak reporting... (Score:4, Insightful)
As this matter falls onto the newly created black hole, it gets heated to unimaginable temperatures — millions of degrees— and blasts out X-rays
Translation: The temperature is so high, it is somehow unimaginable using numbers. But since you are reading on, let me just pull a totally random number out of my ass and say a million degrees... wait no.. make it a millions, as in more than 1 million, which makes my claim sound sorta vague and not precise but makes it nevertheless appear I know what I'm talking about. That should cover the unimaginable bit of it. Besides, its not like you're going to check anyways so fuck it, lets and some em dashes for extra emphasis for no other reason other than because its really "HOT". I mean wow, can you imagine a place this hot? I'm just siting here in my office, thinking to myself, geeze this black hole stuff is not the usual environment I'm used to, most likely because I would have been obliterated and spit out as really "HOT" x-rays... there, you see where I'm coming from? HOT!
Re:Rather weak reporting... (Score:1, Insightful)
He means "unimaginable" in terms of "you probably have 0 frame of reference for what this temperature is". Stop being a pedantic twat.
Absolute frame of reference (Score:4, Insightful)
Actually, there exists a well defined frame of reference with respect to velocity. In rotation this is pretty obvious, since rotation with respect to the absolute frame causes centrifugal forces to appear.
Constant linear movement is not so easy to measure, but there's the background radiation dipole that can be measured and defines an absolute velocity with respect to the universe.
We cannot define one point as an absolute origin, but we can define one state as being "standing still" with respect to the absolute origin, both in rotation and in translation.