Scratch

Sunrise-Moon · 2011-01-14 21:37:35

Taken from the Wikipedia article "List of common misconceptions":
"Black holes, unlike their common image, do not act as "cosmic vacuum cleaners" any more than other stars. The collapse of a star into a black hole is an explosive process, which means, according to Mass–energy equivalence, that the resulting black hole would be of lower mass than its parent object, and actually have a weaker gravitational pull. The source of the confusion comes from the fact that a black hole is much smaller and orders of magnitude more dense than a star, causing its gravitational pull to be much stronger closer to its surface. But, as an example, were the Sun to be replaced by a black hole of the same mass, the orbits of all the planets surrounding it would be unaffected."

Does this mean everything we've been taught is wrong? Can light really escape from a black hole? Will Dorothy make it back to Kansas?

Discuss.

Kileymeister · 2011-01-14 21:42:56

Well, the stars that become black holes are really dense to start with, so I'm not sure.

Plus those implode, which doesn't lose mass...

Last edited by Kileymeister (2011-01-15 08:50:32)

agscratcher · 2011-01-14 21:50:42

Sunrise-Moon wrote:
Will Dorothy make it back to Kansas?

She already has, Toto.

SpaceManMike · 2011-01-15 08:38:52

Wikipedia isn't the most reliable source...

werdna123 · 2011-01-15 08:45:16

SpaceManMike wrote:
Wikipedia isn't the most reliable source...

Get. Out. Of. Here. tongue

agscratcher · 2011-01-15 09:55:16

werdna123 wrote:
SpaceManMike wrote:
Wikipedia isn't the most reliable source...
Get. Out. Of. Here.

Sunrise-Moon · 2011-01-15 11:12:36

agscratcher wrote:
werdna123 wrote:
SpaceManMike wrote:
Wikipedia isn't the most reliable source...
Get. Out. Of. Here.

throughthefire · 2011-01-15 11:37:07

Black holes are a large star mass, compressed into the size of an atom, so it's immensely dense, and also has a large gravitational pull due to the large mass. With each thing it "sucks up", it adds to the mass of the black hole, making it larger, so if a black hole exists for a long time (which most have), the mass will add up, increasing it's mass to eventually a point where light cannot escape. Of course, it is predicted that a black hole can eventually get too large and become unstable, resulting in a "Meganova" where all that mass is expelled from a black hole. They aren't "cosmic vacuum cleaners", but they can BECOME Cosmic Vacuum cleaners.

There. Happy? tongue

Sunrise-Moon · 2011-01-15 11:49:20

throughthefire wrote:
Black holes are a large star mass, compressed into the size of an atom, so it's immensely dense, and also has a large gravitational pull due to the large mass. With each thing it "sucks up", it adds to the mass of the black hole, making it larger, so if a black hole exists for a long time (which most have), the mass will add up, increasing it's mass to eventually a point where light cannot escape. Of course, it is predicted that a black hole can eventually get too large and become unstable, resulting in a "Meganova" where all that mass is expelled from a black hole. They aren't "cosmic vacuum cleaners", but they can BECOME Cosmic Vacuum cleaners.

There. Happy?

Yep yikes .

Kileymeister · 2011-01-15 12:44:58

throughthefire wrote:
Black holes are a large star mass, compressed into the size of an atom,

There are none that we know of that are atom sized though. I heard a small dense one can be about three miles in diameter (on a cosmic scale, that's still tiny).

Last edited by Kileymeister (2011-01-15 12:45:38)

SpaceManMike · 2011-01-15 13:18:50

Sunrise-Moon wrote:
agscratcher wrote:
werdna123 wrote:

Get. Out. Of. Here.

*boots self out*

Scratch

archived forums

#1 2011-01-14 21:37:35

Black holes aren't "cosmic vacuum cleaners"

#2 2011-01-14 21:42:56

Re: Black holes aren't "cosmic vacuum cleaners"

#3 2011-01-14 21:50:42

Re: Black holes aren't "cosmic vacuum cleaners"

Sunrise-Moon wrote:

#4 2011-01-15 08:38:52

Re: Black holes aren't "cosmic vacuum cleaners"

#5 2011-01-15 08:45:16

Re: Black holes aren't "cosmic vacuum cleaners"

SpaceManMike wrote:

#6 2011-01-15 09:55:16

Re: Black holes aren't "cosmic vacuum cleaners"

werdna123 wrote:

SpaceManMike wrote:

#7 2011-01-15 11:12:36

Re: Black holes aren't "cosmic vacuum cleaners"

agscratcher wrote:

werdna123 wrote:

SpaceManMike wrote:

#8 2011-01-15 11:37:07

Re: Black holes aren't "cosmic vacuum cleaners"

#9 2011-01-15 11:49:20

Re: Black holes aren't "cosmic vacuum cleaners"

throughthefire wrote:

#10 2011-01-15 12:44:58

Re: Black holes aren't "cosmic vacuum cleaners"

throughthefire wrote:

#11 2011-01-15 13:18:50

Re: Black holes aren't "cosmic vacuum cleaners"

Sunrise-Moon wrote:

agscratcher wrote:

werdna123 wrote:

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