APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

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Expand view Topic review: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by neufer » Sun May 05, 2013 2:18 pm

Click to play embedded YouTube video.
http://www.spaceflight101.com/nustar-mi ... dates.html

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Beyond » Thu Mar 28, 2013 3:17 am

OK. Thanks... i think.

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Chris Peterson » Thu Mar 28, 2013 1:02 am

Beyond wrote:I didn't mean to imply that 'scale' had anything to do with the spinning. It's just to show that even if a human was standing still, he would still be spinning, but not in the way that we normally think of spinning. So if what i said doesn't come close, then you will hafta splain what kind of not normal spinning you mean.
What I mean is that electrons and other subatomic particles aren't spinning. They don't physically rotate about some axis. What we call "spin" in this case is a quantized quantum mechanical parameter related to another QM concept only loosely related to the classical concept of the same name, angular momentum.

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by ta152h0 » Thu Mar 28, 2013 12:49 am

this is spinning my head, but my head is not moving !

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Beyond » Thu Mar 28, 2013 12:34 am

Chris Peterson wrote:
Beyond wrote:So what you're saying, Chris, is that if i stand perfectly still on earth, i am spinning. Not only because the earth is spinning on it's axis, but because the earth is also spinning around the sun, and the sun is also spinning around the Milky Way, ECT. But i don't notice all that spinning, because it is tooo Big, and i am tooo small.
No, I'm saying that neither atomic nuclei nor electrons spin in the sense we think of "spinning". Nothing to do with scale.
I didn't mean to imply that 'scale' had anything to do with the spinning. It's just to show that even if a human was standing still, he would still be spinning, but not in the way that we normally think of spinning. So if what i said doesn't come close, then you will hafta splain what kind of not normal spinning you mean.

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Chris Peterson » Wed Mar 27, 2013 11:37 pm

Beyond wrote:So what you're saying, Chris, is that if i stand perfectly still on earth, i am spinning. Not only because the earth is spinning on it's axis, but because the earth is also spinning around the sun, and the sun is also spinning around the Milky Way, ECT. But i don't notice all that spinning, because it is tooo Big, and i am tooo small.
No, I'm saying that neither atomic nuclei nor electrons spin in the sense we think of "spinning". Nothing to do with scale.

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Beyond » Wed Mar 27, 2013 11:32 pm

So what you're saying, Chris, is that if i stand perfectly still on earth, i am spinning. Not only because the earth is spinning on it's axis, but because the earth is also spinning around the sun, and the sun is also spinning around the Milky Way, ECT. But i don't notice all that spinning, because it is tooo Big, and i am tooo small.

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by ta152h0 » Wed Mar 27, 2013 11:24 pm

you are just like my father, who answered with riddles and you had to figure out by yourself. One of them took 30 years. He named his boat 7-11 and for the life of me I could not figure that out until after his passing. It was the solution of a simple equation that described the age difference of his kids. Inside that equation was another equation and bothe of them surfaced at the same time. I myself left a few of these " bombs " to go off sometime in the future for my own kids.

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Chris Peterson » Wed Mar 27, 2013 10:44 pm

ta152h0 wrote:I have no fear revealing my weakness..Does the nucleus of an atom spin as fast as its electrons ?
In addition to Art's response, it is worth keeping in mind that "spin" is a quantum mechanical concept, which through angular momentum is analogous to classical spin of an object. But neither the nucleus nor electrons physically spin in a classically meaningful sense.

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by neufer » Wed Mar 27, 2013 9:12 pm

ta152h0 wrote:
I have no fear revealing my weakness..Does the nucleus of an atom spin as fast as its electrons ?
The proton, neutron & electron all have the same spin angular momentum: ħ/2

They also all have roughly the same sorts of orbital momentum in an atom/nucleus : nħ (for relatively small n).

(But this is probably not what you are asking about.)

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by ta152h0 » Wed Mar 27, 2013 8:39 pm

I have no fear revealing my weakness..Does the nucleus of an atom spin as fast as its electrons ?

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Chris Peterson » Wed Mar 27, 2013 8:19 pm

Psnarf wrote:We still don't know what gravity is, so how can we speculate on the contents of a massive gravity well? How do we know anything gets past the Schwarzschild radius? Can we measure the mass of the accretion disc? What does infinite curvature of space-time mean?
I'd say we understand gravity very well- about as well as we understand anything.

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Psnarf » Wed Mar 27, 2013 7:57 pm

We still don't know what gravity is, so how can we speculate on the contents of a massive gravity well? How do we know anything gets past the Schwarzschild radius? Can we measure the mass of the accretion disc? What does infinite curvature of space-time mean?

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Psnarf » Wed Mar 27, 2013 7:47 pm

Speculation has it that a white hole exists at the other end of a black hole. Instead of drawing everything in, it spews stuff out. Them pesky physicists sure can get wacky sometimes.

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Luis » Mon Mar 18, 2013 5:32 pm

The illustration does not look the way a back hole is descrobed. If the matter is being sucked up at the speed of light, the image looks like a peaceful lake, the matter needs to be shown thinned down as it approaches the black hole in a spiral motion. The image looks too nice to describe such a chaotic and tremendous activity

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Chris Peterson » Wed Mar 13, 2013 4:35 am

ta152h0 wrote:is there such a thing as a white hole yet ?
Only in abstract mathematics.

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by ta152h0 » Wed Mar 13, 2013 3:01 am

is there such a thing as a white hole yet ?

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Boomer12k » Wed Mar 13, 2013 2:41 am

Well, at any rate it is like a Vinyl Record...The needle starts at the beginning of the song and when it reaches the end of the GROOVE....GAME OVER MAN!!!! Buh-Bye particle. Hello, Energy...

:---[===] *

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by deathfleer » Tue Mar 12, 2013 11:55 pm

It is hard to believe.
The hole must be matterless, otherwise the contents of the would have been spewed outwards by the great centrifugal force

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Chris Peterson » Tue Mar 12, 2013 11:16 pm

Psnarf wrote:We can never know what's the deal in there, no information has ever escaped.
I disagree, except in the sense that we can never know anything with 100% certainty. That doesn't mean we can't come to understand the interior of black holes (assuming they have interiors) with a high degree of confidence. It isn't a requirement that we ever be able to observe inside one, only that we have testable theories that provide solid implications regarding the matter. Much of what we "know" we know because of indirect observations, after all (indeed, we could argue that all observations are indirect).

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by MargaritaMc » Tue Mar 12, 2013 8:40 pm

Gosh, Psnarf - I had to look up "virgule" in the dictionary... I wonder if 'backslash' has a Sunday Best name as well?
Margarita

PS. We can't be sure about the back of our own necks - and we can't be sure that there are any other people actually on the Starship Asterisk, can we? This might be the perfect Turing test...

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Psnarf » Tue Mar 12, 2013 8:24 pm

The more massive the black hole spinning near light speed drags space-time around it in such a way than you can get closer to the event horizon without crossing it.
We can never know what's the deal in there, no information has ever escaped. Argument seems similar to what's beyond the farthest photon source, with no verifiable information, we can never know. Same with consciousness, since consciousness cannot observe itself. I've never seen the back of my neck directly, just illusions in a mirror. I have a sneaking suspicion it's there based upon mosquito bites.

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by Psnarf » Tue Mar 12, 2013 8:13 pm

At least I found the answer to my question about the accretion disk.
Spin results from a transfer of angular momentum, like playing on a children’s swing. If you kick at random times while you swing, you’ll never get very high. But if you kick at the beginning of each downswing, you go higher and higher as you add angular momentum.

Similarly, if the black hole grew randomly by pulling in matter from all directions, its spin would be low. Since its spin is so close to the maximum possible, the black hole in NGC 1365 must have grown through “ordered accretion” rather than multiple random events.
http://smithsonianscience.org/2013/02/s ... uper-fast/

(Edit: I forgot the closing tag includes a virgule, not a backslash.)

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by neufer » Tue Mar 12, 2013 6:52 pm

Chris Peterson wrote:
It's really not worth speculating about the inside of a black hole, unless you're a theoretical physicist exploring HIGHLY speculative ideas, most of which barely rise to scientific standards of testability.
http://blogs.scientificamerican.com/critical-opalescence/2012/12/14/when-you-fall-into-a-black-hole-how-long-have-you-got/ wrote:
When You Fall into a Black Hole, How Long Have You Got?
By George Musser | Scientific American, December 14, 2012 |

<<In chatting with colleagues after a talk this week, Joe Polchinski said he’d love to fall into a black hole. Most theoretical physicists would. They are just insanely curious about what would happen. Black holes are where the known laws of physics come into their most direct conflict. The worst trouble is the black hole information paradox that Stephen Hawking loosed upon the world in 1976. Polchinski and his colleagues have shown that the predicament is even worse than physicists used to think.
........
The least radical conclusion is that the no-drama principle is false. Someone falling into a black hole doesn’t pass uneventfully through the horizon, but hits a wall of fire and is instantly incinerated. “I think it’s crazy,” Polchinski admitted. But in order for a black hole to decay and its contents to spill out, as quantum mechanics demands, the infalling observer can’t see just a vacuum. The firewall idea strikes me as similar to past speculation that black holes are somehow material objects—so-called black stars or dark matter stars—rather than merely blank space.

“I spent 20 years confused by this,” Polchinski said, “and now I’m as confused as ever.” It would be nice to answer the question, if only so that no one ever has to undertake the journey to answer the question.>>

Re: APOD: Spin up of a Supermassive Black Hole (2013 Mar 12)

by ta152h0 » Tue Mar 12, 2013 5:54 pm

soooo... we don't have that little pesky problem of a singularity having a unit of measure called " spin rate " ?

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