Black Holes

if i remember right...black holes form from generally larger mass stars...

stars in there "death" phase go through an expansion phase caused by the running out of nuclear fuel (hydrogen and then helium) which causes its gravitational pull to weaken its hold on the outer layers...thus the star exapands and forms a red supergiant

this pic gives an idea of how big a red supergiant would be in relation to our own solar system

almost at jupiter...completely enveloping all the inner planets

after this comes the supernova...the explosion stage...one was witnessed by astronomers years ago that outshined the entire galaxy it was located in by over a million times

the pic is of a supernova remenant

supernovas occur when all the stars fuel is spent...the star collapses in on itself and in doing so creates a massive explosion

most supernova result in the formation of neutron stars...so called because the gravitational force created actually crushes atoms...the outer shell negatively charged electrons are forced into the atoms nucleus and cancel out the positively charged protons...thus leaving neutrons...and thus the name neutron star

the magentic field of a neutron star is about 100 trillion times that of the earth...they are about the size of a large city but in density and mass...every single person alive today could be squashed into the size of a sugar cube....if you weight 150 lbs on earth...on a neutron star you would weigh 21,000,000,000,000 lbs

a black hole is and even more extreme case borne from the same actions

instead of stopping at a neutron star...the mass continues to collapse in on itself to the point where it is extremely small...but that size is dependant on the mass of the size that created it....

Bah, Superman would take a Black Hole. Black Holes don't have any arms, how could it fight back?

Originally posted by Red Superfly
Bah, Superman would take a Black Hole. Black Holes don't have any arms, how could it fight back?

cause it would have sucked in a entire kryptonite planet....eat that superman you *****

😄

Yeah, but Superman would win.

Beat that logic.

Originally posted by Red Superfly
Yeah, but Superman would win.

Beat that logic.

thats just cause he...always...does....GOD DAMNIT...IT'S JUST NOT FAIR 😠 😠 😠 😆

The theory is that a black hole is not a hole at all but a super super dense mass that resulted form a certain type of star dying. This object is relatively small. If it were possible for you to hold a piece the size of a marble it would way 1000s of tons and pull pull in everting in its surroundings. Theoretically

Originally posted by ToMacco
Yeah, black holes are fat and stupid.

Wait, what?

You don't need a lot of mass!! You need huge energy-density to create black holes.
That is, matter squeezed together to tightly, a mere spoonful would weigh thousands of tons or more.

Galactic center black holes are no mere speculation. Go google it or visit NASA or ESA. They're there all right.

The problems with black holes are not as much that they're "black" since the escape velocity from a black hole exceeds the speed of light. They send out massive amounts of radiation that our telescopes can see.
We don't understand what happens INSIDE a black hole. The center is called a gravitational singularity (just as the moment Big Bang occured), because even EInsteins theory for gravity is not enough to calculate and explain what happens. We still need a socalled quantum-theory for gravity, that is a theory to explain how gravity behaves on VERY small scales.
We have quantum theories for the other three forces of nature (hence teh reason we can use and manipulate these forces), but we need to update gravity.
String-theory, I believe, is NOT the answer. When the LHC opens next year this should be proven, and physicist must go back to the drawing table. About time - I want a floating suitcase 😄

You don't need a lot of mass!! You need huge energy-density to create black holes.

true that you need huge energy density...but given that there isn't a way to produce such density without gravity...and given that the greater the mass of an object the greater its gravitational force...then surely you need mass in order to initiate the sequences that leads to black hole creation

as you state though...once the black hole exists...gravitational physics dont apply as they normally would

You can't have ANY mass without gravity, nor energy-density for that matter, so what's your point? The Milkyway contains a huge amount of MASS! Yes? Is it a black hole? No.
The point that a large amount of mass in ITSELF is not enough to create a black hole is important. It's when you squeeze it into a small space, and the gravitational force becomes so strong you create horizons and the escape velocity exceeds speed-of-light that you get a black hole. Granted, you need to start out with something massive, but the Milkyway itself is rather MASSIVE...

Originally posted by The Omega
You can't have ANY mass without gravity, nor energy-density for that matter, so what's your point? The Milkyway contains a huge amount of MASS! Yes? Is it a black hole? No.
The point that a large amount of mass in ITSELF is not enough to create a black hole is important. It's when you squeeze it into a small space, and the gravitational force becomes so strong you create horizons and the escape velocity exceeds speed-of-light that you get a black hole. Granted, you need to start out with something massive, but the Milkyway itself is rather MASSIVE...

the point is that smaller mass stars dont produce black holes because as they collapse, they gravitional forces generated aren't large enough

hence you do need a large mass...

and while the milky way obviously does have a huge amount of mass and thus gravity...it isn't a single entity who's gravity does't work on itself...all the stars work on each other...

although...given that the milky way is a spiral galaxy...there must obviously be a super massive black hole acting on it

the term "going down the plug hole" would be appropriate...

it would appear we are mere fodder for such a black hole...and that all the mass of the milky way will be enveloped by it...but extremely far off into the future

The Encyclopedia Britannica actually used this as the example question 😄

The presence of the galactic black hole was thought to be indicated by the presence of X-rays presumably from compressed matter... shouldn't the X-rays have been trapped?

Jaden101> You have massive single entities in form of stellar nebulas. It's not enough that something contains a lot of mass, you need it to ALSO be squeezed into a small volume to create a gravitational singularity.

Why do you conclude that because the Milkyway is a spiral galaxy it must contain a supermassive black hole at its center?? The presence of supermassive galaxy-center black holes has nothing to do with the shape of the galaxy. The shape is due to the rotation of the galaxy, and the fact that we can't see all the mass (dark matter) whose gravity act on the galaxy itself.

So there is nothing "going down the plug hole" because of the galactic shape. For all we know everything will be ripped apart in the distance future because of dark energy. To the best of my knowledge we're still to see a "dead" galaxy.

Shaber> When matter falls into a black hole it's accelerated to extremely high velocities and send out radiation. It's not that a black hole can suck up everything that passes it, you need to get "close enough". Check up on event horizons and Schwarschild radius 🙂

Jaden101> You have massive single entities in form of stellar nebulas. It's not enough that something contains a lot of mass, you need it to ALSO be squeezed into a small volume to create a gravitational singularity.

yes but the point is that without the mass it wouldn't collapse in on itself enough to cause the singularity...hence the fact that smaller stars dont form black holes...because their mass and thus their gravitational power isn't strong enough

normally stellar objects work on each other. hence planets going round the sun, moon going around planets...in a nebulla...although it can be considered a single entity...it still contains many seperate sources of gravity which all act on each other thus preventing it collapsing in on itself

when a star dies, its own gravitational force acts on its own mass and pulls it in on itself...thus creating a higher energy density and a higher gravitational force...thus causing it to collapse in on itself

but the extent to which it can do this is dependant on the initial mass

What was the term for the mass of a supernova's lower limit? Something like 1.4 X Sun mass.

Jaden101> Ehrm... Actually, stellar nebulas occasionally Do collapse to form... stars! If the star formed i a stellar giant its gravity may, after going supernova, form a black hole. We do not disagree on that fact. However, it is still important to have high energy-density.

Shaber> Can't remember. I think it's more than 1,4 x Sun. The Sun is nowhere near massive enough to go supernova. It's go... quietly 🙂