Giant Radio Telescope Tackles Black Holes

Cosmiverse ^

[Texaggie79]

ping

[PatrickHenry]

Ping.

[VadeRetro]

Pong.

[RightWhale]

Space exploration requires a great deal of imagination

Even with rudimentary imagination, it is more productive in an atmosphere of deliberate consilience.

[VadeRetro]

I hate "paradigm." I hate "synergy." And now I hate "consilience."

[VadeRetro]

I forgot I hate "meme."

[martin_fierro]

Layman question:

As I understand it, a Black Hole is a "tear" caused in three-dimensional space-time by an infinitely dense object.

All depictions I've ever seen of Black Holes show them to be like infintely deep whirlpools. I assume that these holes "fall off" in all directions, depending on their formation.

So what determines the direction in which a Black Hole forms? Are there variations in the "density" of space-time, such that different Black Holes "fall off" in different directions?

Also, do all known black holes "rotate" in the same direction?

[RightWhale]

Use a word three times in context, and it is yours. :)

[PatrickHenry]

Even with rudimentary imagination, it is more productive in an atmosphere of deliberate consilience.

You know what you can do with your "deliberate consilience." If we were doing space exploration in a small, enclosed ship, I suspect we'd have a knife fight before very long.

[longshadow]

As I understand it, a Black Hole is a "tear" caused in three-dimensional space-time by an infinitely dense object.

First, I'm not sure "tear" is a good term for it. Second, space-time is FOUR dimensional (in Special Relativity, at least), not three. A better way to think of it is that all masses cause a localized curvature of spacetime; the bigger the mass, the greater the curvature. A Black Hole forms when the mass is SO large (and the density so high) that the curvature of Space-time becomes infinite.

All depictions I've ever seen of Black Holes show them to be like infintely deep whirlpools. I assume that these holes "fall off" in all directions, depending on their formation.

So what determines the direction in which a Black Hole forms? Are there variations in the "density" of space-time, such that different Black Holes "fall off" in different directions?

There's no "direction" the Black Hole is falling "into." The Black hole is located exactly where the center of mass of the material that formed the Black Hole was just BEFORE the BH formed. Another way to think of it is that the localized Spacetime curvature caused by a mass has no "direction" either; it causes a uniform curvature in all directions. The space-time curvature of the BH is only moreso.

Also, do all known black holes "rotate" in the same direction?

The short answer is I'm not sure, but I expect the rotational distribution of BH is about the same as the rotational distribution of other celestial matter, such as stars, clusters, galaxies, etc. It is interesting that you ask, in that rotation (actually angular momentum) is one of the few physical characteristics a BH has. The others are mass and (I think) electric charge.

I hereby defer to those more knowledgeable than I am on this subject whom I've pinged to revise and extend my remarks as needed to correct any errors or ommissions.

[RightWhale]

Is this National Hate A Word Day?

If we want to use a defined, autolimited language, why not just speak Arabic or French?

[RightWhale]

the localized Spacetime curvature caused by a mass

What if spacetime curvature and mass are coincidental, circumstantial, and are not cause and effect. Or what if spacetime curvature causes mass? There was a comment quite a while back pertaining to the old vortex theory of gravity, that if a planet were not there, say, Jupiter, its gravitational field would still be present, that the presence of gravity causes the planet to form right there. This is just to point out that these are all hypotheses and that flat statements might close some doors to speculation.

[PatrickHenry]

The others are mass and (I think) electric charge.

I don't think electric charge survives. Just mass and spin. But the mass which was the big bang probably wasn't even spinning, in that there was no reference frame for determining spin.

[<1/1,000,000th%]

Thanks for the ping. Wish he wouldn't have said this,

"It was the United Nations of radio astronomy," said Dr. David Meier, a JPL astrophysicist. "To see different countries working together to build a single, very complex instrument was very impressive."

[VadeRetro]

Is this National Hate A Word Day?

Ugly, trendy neologisms are the noiseless equivalent of fingernails on a blackboard.

[Physicist]

Is this National Hate A Word Day?

I don't know, but as long as we're getting things off our chests, there are some constructions I hate:

• comprised of: The whole comprises the parts; it is never comprised of the parts. The whole is composed of the parts.
• different than: Two things may be different from each other, but not different than each other.
• convince...to: You may convince someone of something, or convince him that something is true or false, but you can't convince him to do something. You persuade him to do something.

Boy, those grate on me.

I also hate the word "twee".

[longshadow]

I don't think electric charge survives. Just mass and spin. But the mass which was the big bang probably wasn't even spinning, in that there was no reference frame for determining spin.

I'm sure there are THREE parameters that describe a BH; if electric charge ISN'T the third one (after mass and angular momentum), then I'm not sure what it would be...

[longshadow]

.... but you can't convince him to do something. You persuade him to do something.

OR, in more technical terms: "persuade" takes the infinitive; "convince" does not.

[RightWhale]

You may have been a pupil in my grandfather's English class. Not your everyday, ordinary English teacher, he knew rules of grammar such as are not often written in textbooks. He corresponded regularly in seven languages, including with a German he met and took prisoner in the trenches in Flanders during WW I.