A Black Hole's Spinning Heart of Darkness

sciencehabit writes "Like all invisible things that are only partly understood, black holes evoke a sense of mystery. Astronomers know that the tremendous gravitational pull of a black hole sucks matter in, and that the material falling in causes powerful jets of particles to shoot out of the hole at nearly the speed of light. But how exactly this phenomenon occurs remains a matter of conjecture, because astronomers have never quite managed to observe the details – until now. Astrophysicists have taken the closest look to date at the region where matter swirls around a black hole. By measuring the size of the base of a jet shooting out of the supermassive black hole at the center of the M87 galaxy (abstract), the researchers conclude that the black hole must be spinning and that the material orbiting must also be swirling in the same direction. Some of the material from this orbiting 'accretion disk' is also falling into the black hole, like water swirling down a drain."

Comments

Fascinating

[dreamchaser]

I probably won't live to see it but I am looking forward to when we can directly observe in more detail the area surrounding the event horizon of black holes. There is so much we do not understand about the Universe and overall cosmology, but black holes by their very nature will probably be one of the last frontiers as we continue to peel back the layers of knowledge in our understanding of the nature of the Universe as a whole.

There are also potentially practical applications given far greater technology than we have now. Imagine using black holes to generate energy, or as massive particle accelerator laboratories!

Re:Fascinating

[tysonedwards]

Doesn't this point more to a possibility that a black hole is a solid physical body which manifests it's own physical rotation rather than some of the former mysticism explanations that have persisted to date?

Basically a continual increase in material density from neutron star densities to the point where gravitational forces are capable of attracting photons and other larger classifications of matter, either resulting in the fusion of matter to ever increasing densities of conventional matter or recombination of subatomic components in such a fashion of maximum compression density.

Re:Fascinating

[fuzzyfuzzyfungus]

Do you think that black holes receive a notably more 'mystical' treatment than most other scientific phenomena that can only be usefully talked about in terms of fairly high level math? They certainly get their share of time whenever a SyFy special needs some sort of treknobabble to work with; but by the standards of things that eat photons and defy direct observation they seem to be doing reasonably well...

Re:Fascinating

[Anonymous Coward]

To me, I would think it suggests that high-intensity fields, in this case gravitational, can affect matter. Look at it from the opposite end of scale. Lets assume we have a point generating a magnetic field, the space surrounding that point can then be filled with free-floating, very fine iron particles. Ramp up the intensity of the field and set it spinning, it *will* affect the iron particles in the direction of its rotation, which would drag the particles around it.

At least, it sounds plausible. :D

Re:Fascinating

[Cruciform]

The media and a large percentage of the population treat *everything* with a degree of 'mysticism'. Anything that can't be understood in a sentence becomes ghosts, psychic phenomena, "god's hand", etc. etc.
Trained careers like medicine, law, and science become overly dramatic and so highly fictionalized in entertainment that the people who relate to the statement above assume that crimes really are solved in an 8 hour shift, deathly illnesses can always be cured with a single injection in the way we might treat something with epinephrine, and that all physics can be described in a few phrases by Deepak Chopra.
And there's a high level of resistance to combating that 'mysticism'.
Even recently I encountered someone who said that psychics/mediums are frauds... except HER medium...
Sigh.

Re:Fascinating

[Baloroth]

It isn't really physically possible (at least, not so far as we know) for a black hole to be considered as a solid physical body. You see, the event horizon isn't the only place where the gravity prevents matter from escaping. Gravity increases until you hit the "outer" part of any body, which means if we assume for a second the event horizon occurs outside all the matter of the former star (which it does), gravity will be slightly more intense inside the horizon. That means that as you travel into the black hole until you reach the outer limit of the physical object itself, gravity will still increase and retain the property of inescapability. What that means is the outer shell of matter can't interact with everything inside, so the normal pressure from electromagnetic and nuclear forces can't keep the outer shell from collapsing inwards (the force literally can't push outwards, since gravity pulls it back).

That means the outer layer of matter will always collapse inwards, closer to the center, and as that happens, the body becomes more dense and the place where gravity forms a horizon extends ever closer to the center of the black hole. Normally, gravity would decrease after you entered the physical body, so near the center of the black hole there should still be a solid physical body where gravity is less than that required to form a horizon, but as the outer layer of the black hole continually falls downwards (it literally can't do anything else), the space near the center where the black hole retains normal physical properties of a star should diminish to nothing.

Another fascinating thing is that at the very center, there should be no gravity at all, by the simple rule of symmetry. But the black hole is ever shrinking towards that spot, so that the density approaches infinity and the entire matter of the star becomes condensed into a point with infinite gravitational force. So the center should also end up with infinity gravity. Which is impossible, or should be. That's why black holes are and always will remain a huge mystery, barring some incredible new scientific revelation that overturns the entire theory of... well, nearly everything.

In other words, for black holes to be treated as solid physical objects, a new force that defies the theory of general relativity (it would have to travel faster than light to allow the matter towards the center of the hole to interact with the matter towards the outer part of the hole) would need to be discovered. And that seems unlikely, although not impossible by any means.

Re:Fascinating

[Anonymous Coward]

Today's black holes allow for âoeevaporationâ and the making of âoejetsâ.

Jets aren't really escaping the black hole, that matter never actually fell in. And if by evaporation you mean Hawking radiation, those particles were never inside the black hole either, but they do steal energy, but not information.

Re:Fascinating

[Baloroth]

The jets don't come from inside the black hole at all, they are a result of the interaction of the black hole and the disk of matter falling into it. The exact mechanism for their production isn't certain yet, but the simple explanation is that as the matter gets close to the disk, it spins faster and faster while losing energy (since it is falling into a negative gravity well) which can be focused into some few particles (through magnetic effects or possible relativistic "frame dragging") that are then propelled outwards well before they reach the event horizon. The evaporation is more complex and I don't understand it so I won't try to explain it.

Attempting to explain the universe through electro-magnetism alone is... a useful exercise, but also really not true, and demonstrably so. Gravitation effects are radically different from electrical ones. You can alter electrical theory to fit the observations, but only if you introduce arbitrary new rules and exceptions, which is, if not exactly forbidden in science, at the least extremely questionable (and the more complexities you have to introduce the less likely your theory is to be accurate). Gravitational theory, on the other hand, proceeds from and naturally fits with the observations. Now, it is well known in physics that our understanding of gravity is incomplete (classical and quantum theories do not agree, for one thing, despite both seeming to be true on their respective scales), but to argue that because gravity is "weak" it cannot also be the strongest force en masse (so to speak) is, well, faulty logic. There are numerous examples of weak things aggregating to provide effects well outside their individual strength. When we say electrical forces are "stronger" than gravity, we mean only on a certain scale (atomic, to be specific). Over they scale of a few feet, the nuclear force is nonexistent, despite the fact it is even stronger than the electrical force on small scales.

Re:Fascinating

[tragedy]

Warning! The above post is an electric universe/plasma cosmology theorist spouting off. They believe that the sun is a giant ball of iron powered by electric currents flowing through space. The whole thing is pretty wacky and is basically a conspiracy theory/collective schizophrenic delusion. You've heard it all before. They think all the so-called "scientists" are either part of a big coverup or are just complete and total fools who don't understand anything whereas they, the electric universe theorists, are the truly intelligent and enlightened.

Re:Fascinating

[brisk0]

[...] the electrical force, which is 39 orders of magnitude greater than gravity.

Where are you getting this from? Assuming metric units (I hope you're not doing physics with imperial) neither the difference between coulombic and gravitational constants nor the difference between charge and mass of a proton (the next -place I'd expect one to get that difference from). Regardless, claiming such a difference is a pointless endeavour, given that it's entirely a product of the unit system. In the system of Planck units gravity and coulombic force are identical!
Point is, gravity isn't weak, nucleons are just kind of light.

Re:Fascinating

[Rich0]

The one thing I don't really see reflected in your treatment of the physics is time.

If I fell into a black hole, I'd accelerate towards the center. By the time that I got there, would anything still be left there? I'd never encounter matter before the center, since it would be falling in ahead of me and so would any force carriers it emits in my direction. From my own frame of reference little time would have passed by the time I reached the center. However, from the external universe's perspective quite a bit of time would pass. So, could the entire black hole dissipate via Hawking radiation before I get there?

Of course, who knows how physics works inside a black hole in the first place. I just think that when you factor in time the picture of the inside of a black hole likely gets quite a bit more complicated.

Re:Fascinating

[Anonymous Coward]

The beliefs of “gravity only” cosmology are founded almost exclusively on computer modeling. Some parts of the electric universe theory can be verified experimentally right here on earth in the laboratory. In the electric universe model, electricity and gravity work together to explain observations without resorting to computerized fiction.

And out comes the part about astrophysicist ignoring electromagnetism. This is the part of electric universe fans that really grinds my gears and clearly suggests they have never actually looked into any astrophysics research. It is as naive as trying to claim astronomers have never looked at or thought about stars.

And I don't think you know what a computer model actually does, especially in the fields of astronomy or physics. Those computer models are just solving equations that cannot be solved analytically... just like computer models used to solve Maxwell's equations when you are not dealing with a perfect box/sphere/cylinder. Since the universe is not filled with stuff in the shape of one of the simple cases allowing analytic solutions to Maxwell's equations, MHD, etc., the electric universe theories would have to resort to computer models to check the equations produce the same results on scales larger than Earth (or a laboratory that is the same size or larger than the universe...).

In the electric universe model, electricity and gravity work together to explain observations

And welcome to astrophysics, which uses electromagnetism and gravity (along with plasma and particle physics) to explain observation... to explain a metric fuck ton of observation. To imply what you describe as different from mainstream astrophysics is either disingenuous, or completely ignorant of what astrophysics does.

Re:Fascinating

[redlemming]

I believe the idea of black holes largely developed as a result of Einstein's General Theory of Relativity. In particular, the Schwarzschild solution to the equations Einstein proposed described a stationary black hole, and the Kerr solution described a rotating black hole. Several others contributed. The math associated with the General Theory of Relativity is fairly dense IMHO, with things like tensor calculus that are rarely addressed until graduate level classes.

We only get simple math if we apply Newton's Gravity to the concepts predicted by Einstein's Gravity.

That's not a bad approximation for many circumstances, of course.

There's a further complication in that quantum mechanics and theories of gravity are not well integrated. If the black hole really could be a point or anything really small, then it would seem that quantum mechanics would be applicable, but nobody knows exactly how that would work.

Attempts to integrate these two theories are incomplete at best, and tend to involve high level math.

Nothing in physics (or any science) depends upon mysticism.

Re:Fascinating

[tragedy]

Gravitational lensing has been observed. That should be all it takes for you to realize how massively wrong your statements are.

Re:Fascinating

[grantspassalan]

Because gravity is so weak, it is very hard to learn much about it. Gravitational waves have been postulated for a long time, but have never been found despite massive expenditures to do so. Electromagnetic waves on the other hand are ubiquitous right here at home. We make use of them every day. Electrical phenomena, such as the electromagnetic radiation we receive from the depths of space, obey the laws of electricity, not gravity. All of the energetic radiation we receive is ELECTROMAGNETIC. Gravity, even the most extreme gravity imaginable, does not and cannot produce electromagnetic effects. Gravity only works in places that are almost perfectly electrically neutral, such as where we live here on earth. Life as we know it cannot exist in environments of extreme energies. Gravity can only attract, whereas electrical charges can attract and repel. That fact alone opens up many more possible interactions and makes plasma physics very complicated but also very interesting.

looked yesterday

[WGFCrafty]

I read an article about this same black hole yesterday. It talked about measuring the diameter of the black hole, yet even when I tracked down the press release I couldn't find a measurement

Any one see that figure?


I tried to use my laser rangefinder to measure it but it kept coming back infinity.

approximately 3 billion solar masses

[MRe_nl]

concentrated in a region at the galactic core that is only about the size of the Solar System.

http://csep10.phys.utk.edu/astr162/lect/active/smblack.html

Re:Niche Market

[wonkey_monkey]

What about "the popularity of Justin Bieber"?

Re:I've never understood this contradiction

[MRe_nl]

Vacuum fluctuations cause a particle-antiparticle pair to appear close to the event horizon of a black hole. One of the pair falls into the black hole whilst the other escapes. In order to preserve total energy, the particle that fell into the black hole must have had a negative energy (with respect to an observer far away from the black hole). By this process, the black hole loses mass, and, to an outside observer, it would appear that the black hole has just emitted a particle.

http://en.wikipedia.org/wiki/Hawking_radiation

Re:I've never understood this contradiction

[fa2k]

Both the replies are correct, but the AC is more relevant. We can't measure the Hawking radiation from particle-antiparticle production and it most certainly doesn't come out in a jet. The article is behind a paywall, but I think they concluded that the black hole itself was spinning based on the gravitational effect on the jet. The distortion of spacetime is different for a spinning black hole and a stationary one.

Re:I've never understood this contradiction

[amRadioHed]

In order to preserve total energy, the particle that fell into the black hole must have had a negative energy

That's the thing I never understood about Hawking radiation. Why must it always be the negative particle that falls into the black hole? I don't see how that preserves any energy, or why it even matters that it does. It would make more sense and would seem to preserve total energy better if the particle that enters is random.

Re:I have never really understood..

[RedDeadThumb]

There is no mystery of what happens if you get close to one. The mystery comes from not knowing what goes on inside of one. You know that a neutron star is just a bunch of neutrons clumped together. But a black hole is a barrier where stuff can go in, but nothing can come out. We don't know what happens to gravity or space or matter that is inside of one. So we really have no clue what is going on in there, it is all just guesses. My own theory is that inside each one is another universe. The UNIVERSE is an infinite tree of holes with holes inside them. Our universe is 13.5 billion years old because 13.5 billion years ago a black hole formed inside of the parent universe that contains it. Crap could still be falling into it from the parent and that may be what causes the readings we attribute to such things as dark matter and expansion. For example if it could be shown that the expansion rate varies that could be explained by the availability of matter in the parent universe to be sucked into this one.

It's so dense that most of your comment

[kumanopuusan]

was compressed into the subject

Re:I've never understood this contradiction

[Anonymous Coward]

Actually yes, all the time. In many cases, the relevant quantity is change in energy and not absolute value of energy. Hence, where you set the zero point is arbitrary and usually chosen some place to just simplify the math (instead of carrying some junk around that you can demonstrate will disappear when you calculate a measurable value). For example, it is pretty common to treat the zero point at infinity, and so any bound system will be consider negative energy. For an example, an electron being captured by an ion goes from zero energy far away from the ion to releasing energy when captured, hence the electron is at negative energy. It is a matter of bookkeeping, not some deep statement of how the world works in the end.

Additionally, another example that is also relevant is how some solutions to an equation that gave negative energy ultimately lead to the prediction of antimatter. In the end that negative sign didn't mean much, as they still act just like regular matter, and it only was relevant in interactions between the two.

Both of those cases are relevant to Hawking radiation, and both of those have observational backing.