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Black Hole Sans Donut Puzzles Astronomers
Anonymous Squonk writes: "This time, a telescope made news by not finding something. According to this Honolulu Star-Bulletin article, a black hole was found that did not contain the expected 'donut' of warm matter swirling around it. This discovery (or lack of discovery) may lead scientists to rethink what they know about the core of active galaxies."
(as homer is sucked into said blackhole)
mmmm.... intergalactic donut...
d'oooooooohhhhhhh!!
The article doesn't say, but perhaps the reason they are puzzled is because this black hole is thought to be far less massive than Thorne's hypothetical "Gargantua". Nonetheless, the lack of a so-called "doughnut" is not necessarily in conflict with current theory.
Free Hans!
Is actually here: http://astra.hi.gemini.edu/gallery/science/m87/
>>This discovery (or lack of discovery) may lead scientists to rethink what they know about the core of active galaxies."
:)
ermz, isn't this the essential part of science? Every astrophysic I know is among the first to admit that the current theories are still based on several large assumptions, and can are turned over every once in a while. This makes it one of the most exciting parts of science since there still is lots of new things to find out and do. So next time, replace the word may with should or will.
I intend to live forever, so far so good.
Or has almost every astrophysics-related story I've seen lately included something like "this discovery will force scientists to rethink everything they know about [insert specialty here]?"
Is this a requirement for continued research funding? Or is our understanding of astrophysics in general so incomplete that none of our theories form a coherent system that can stand the addition of even one more observation?
If you see 'theory + astronomy + black hole' this does not automatically mean theory==relativity.
RTFA
\end{rant}
It is so massive that its event horizon is far enough away from the center so that the tidal forces are not enough to produce the large, flattened disk of hot spiraling matter
The 'flattened disk' you refer to is the accretion disk that is easily seen in M87. For example, the X-ray spectrum would be completely different if there was no disk.
The 'doughnut' or torus is a cloud of cool matter, that is feeding the disk. It is about just as 'flat' as a real doughnut. Generally the torus of an average active galaxy is far enough from the black hole to make all relativistic effects insignificant. Relativity is very important at the inner edge of the accretion disk, where the disk meets the event horizon. However, this is literally light-years from the torus.
Now, the astronomers can not see the torus. This means that the matter fed to the black hole is almost finished, and should not be able to power such a bright accretion disk. I believe this is the 'problem'.
Either the accreted matter comes from some unknown source, and/or some mechanism makes the accretion disk brighter than expected. Thus theoretical problems are more probably related to galaxy evolution and/or accretion disks. These are both rather ill-understood issues when compared to general relativity.
What has a black hole got to do with System Administration and Network Security?
Am I missing something here?
And, surely, it's "doughnut"?
Backward%20compatibility%20is%20over-rated
Oh, boy, will you get flamed!
;)
:) Better telescopes will only reveal older galaxies, further away up to the point where galaxies were first created. Once you get to that point, you can't see new galaxies, onlythe material from which they were formed.. which probably will be undetectable. And this assumes, of course, that the earliest galaxies gave off light and radiation which has not been blocked by an object between them and the Earth (say a younger galaxy in our own cluster). It also assumes that the radiation is strong enough to be picked up.. it's travelled an awful long way and it may be impossible to detect no matter how sensitive the device.
But not by me. I'm nowhere near a pro, but even I recognise the huge faws in your arguments.
Wobbly suns mean planets are orbiting around them, even though they cant be seen. Maybe they just wobble once in awhile. I know I do.
Nothing moves without a force being applied to it. If there is no force, there is no motion. In your case, the force is alchol and gravity. In the case of a star it must be gravity, unless there's some really bizarre other force as yet undiscovered. However, since our own sun wobbles in accordance with the laws of gravity, as do the planets with moons, it's pretty safe to assume other stars are acting under the same forces.
There are also other methods of detecting extra-solar planets.
The universe keeps getting older, because we know exactly how light behaves over time and space. What happens when we invent yet larger and/or more powerful telescopes? Will galaxies continue to be found which are further and further away?
Up to a point. You never read "A Brief History of Time", did you?
The moon must only be about 5-10 thousand years old, since it only had a half-inch or so of dust on it, uniformly and consistently.
This article should cover pretty much everything there. Here's a brief quote:
Even though the creationists themselves have refuted this argument, (and refutations from the mainstream community have been around for at least a decade longer than that), the "moon dust" argument continues to be propagated in their "popular" literature, and continues to appear in talk.origins on a regular basis
So you've fallen foul of a popular myth propogated by some Creationists. Took me 2 minutes to find that article using Google and a search for "age of the moon".. please do some basic checking of this kind of thing.. propogation of ignorance is not a good thing.
'No rational religion claims "supernatural" exists, that's an atheist slander.' - seen on slashdot.
Well, of course astronomers are always being surprised. This field, which essentially relates to observational cosmology, is incredibly young. Observational cosmology only really started with Hubble (the man, not the machine...). When you think of how long other sections of physics have been going, this is a minute amount of time.
Astronomy itself is ancient, but this has essentially been only data-collection, rather than trying to understand the processes. It has been more like botany than biology - a taxonomic exercise rather than a science. Now we have the instruments so that theories we formulate can be tested observationally, so we are bound to have a lot of theories lost along the way.
Remember, only a hundred or so years ago, we thought the sun was acually combusting - burning some fuel in a chemical reaction with oxygen! Don't be surprised if theories change - perhaps we are missing some fundamental information. In fact, most cosmologists would say we definitely are - they know that the present system of physics we have breaks down in 'extreme' situations. And a black hole most definitely counts as extreme.
Trev - used to be interesting. Honest.
Statements like "this will change how scientists think about x" really shows how self centered our species are. I find the scientists' reaction far more interesting than the fact there is no donut around the blackhole.
Maybe it's shy :p or it let his neighbor borrow his donut.
Let's just shortcut the whole debate, OK? In the final analysis, all things are taken on faith, because none of us can be sure that our senses are telling the truth. Period.
Once you accept the reality of the outside world, if indeed you do (and if you don't, you might as well 'stop reading' now, inasmuch as that has meaning), you can reason about it.
While we can never make statements with 100% confidence, I'm certainly vastly more confident about "A large mass, which can only be a planet (basically, the definition of a planet is "a large mass in orbit around a star" (though there's more of course), is causing the star to wobble", then whatever other explanation you can come up with.
"The star wobbles for no reason, in flat contradiction to every other observed behavior of physical objects"? Sorry, that doesn't rate highly with me.
You make the classic mistake... that because nothing is 100% certain, all things are 0% certain. The logic doesn't hold; there are middle grounds, certainties between 0% and 100%, and as soon as that is true, the "either-or" breaks down. And you are thrust, kicking and screaming, back into the world the rest of us inhabit, where you actually have to decide, and act upon, what you believe to be true.
Personally, I recommend continuing to act as if gravity and intertia are true. It gets messy when you try to deny those things. I'd link the rotton.com pictures but that's probably just mean... besides, I don't particularly like looking at them.
When will they stop fooling around with this kind of lame stuff, and give me hyperspace or warpdrives. I'm getting restless!
And in my experience...
Please don't give me bad karma just because I prefer quality.
Or is it just me who read that Black Hole Sun .
In my eyes, indisposed, in disguises no one knows...
The biggest clue they had was not only the lack of the donut, but the lack of police cars in the vicinity.