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."

Comments

wheee

[smaughster]

>>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. :)

Re:Not necessarily

[mmontour]

A black hole without the "doughnut" of hot matter is not in conflict with current theory, if it is massive enough.

But according to the article, this black hole *does* have the hot accretion disk (as well as a huge jet blasting out of it). The missing "doughnut" is cooler matter (emitting in infrared, not X-rays) that they expected to find around the disk.

I think (but I'm too lazy to check) that there's a picture in the Kip Thorne book you mentioned showing a few possible theories for what the gas around a black hole could look like, with a variety of electric and magnetic field patterns. So this "no doughnut" observation will probably help to refine those calculations, but I don't see it overturning any fundamental black-hole concepts.

This is about torus, not the disk

[Caid Raspa]

\begin{rant}
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.

Re:Is inference an art?

[IngramJames]

Oh, boy, will you get flamed!

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? :) 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.

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.

Re:Is it my imagination...

[Lowther]

It isn't your imagination. Astrophysicists don't know - they are making a best guess on the limited information they have available. Just a matter of a few hundred years ago, we were prepared to throw a man in jail because he declared his belief that the Earth circled the Sun, and not vice versa. At that time it was also a matter of debate as to whether the planet was a sphere (or oblate spheroid even), or whether it was flat. And we were living on it at the time !

Given the fact that our technology will only allow us to venture a miniscule distance from our planet in universe terms, and achieving more will take centuries (if we survive that long), and at best we can observe but a miniscule fraction of it from our planet, and it is supposed to be growing, it follows that we know nothing of the universe, and this will not change in our lifetimes or our children's.

And yes, massive amounts of funding are tied up in this exploration. We need to explore the universe. But if the astrophysicists said "Well chaps, we have looked into the skies for centuries, spent trillions on manned and unmanned missions, and, to tell the truth, we still know jack s**t", I suspect the funding would dry up. It is better for them to present each new discovery as something which enhances and expands our comprehension, and challenges our hypotheses, rather than admitting that in real terms, we still know nothing about the Universe and how it works.

Gump said it best, "stupid is as stupid was"

[f00zbll]

We humans have a tendency to think we are smart and know how the physical world works. That is until some scientists come across a phenomenon that counters current theories. The last time I checked, science defines/accepts theories as laws after a sufficiently long test period. Once the theory is put to test and proves to be better than other theories, it is accepted as a physical law. One important fact people tend to forget is everything we based on observable information. There are numerous phenomena we can't observe or are beyond our abilities, therefore all theories are subject to a large margin of error.

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.

Re:Is inference an art?

[Jerf]

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.