Neutron Stars are semi-collapsed stars, in a sense. What happens when you run out of protons (Helium) fuel? All you have are neutrons. The pressure in a neutron star is so great that it squashes protons and electrons into more neutrons, and thus they DO have a very intense gravitational pull, enough to warp light. Don't believe me? Here's a computer simulation using software provided by Nasa. This is the earth as a neutron star. NOTE: MPEG MOVIE. APPROX: 147k Click here

I never said planets could be black holes, I said 'if', so I'm making a point you can understand easier. And the gravitational law of attraction STILL EXISTS, but since you haven't ADDED anything to the black hole, it's still going to have EXACTLY the same mass as it did as a star. And like I said, if you fall into the regular-star gravity-well, where there used to be a star, but there is now nothing, then you'll be pulled in with a much greater force. This is where your Gravitational Law comes in.

And please type a little clearer, it's hard to take you seriously when you say 'omgz0r teh accreation disc pwnz0r u'. You may be right, but seriously...

And only one thing can truely escape from a black hole: It's radioactive decay, known as Hawking Radiation. Black Holes will eventually decay away.



Edited by - uranium - 235 on 09-03-2003 04:34:07

quote(Uranium - 235): thus they DO have a very intense gravitational pull, enough to warp light
when did i say it doesn't have intense gravitational pull?

quote(Uranium - 235): If the earth turned into a black hole (Became ultra-dense) then you'll be pulled in with a much greater force.
the law of the gravational force of attraction directly states that the force of attraction, thus the gravitational pull, increases with a decreases in radius.

quote(Uranium - 235):then you'll be pulled in with a much greater force.
quote(Uranium - 235):If the earth turned into a black hole (Became ultra-dense) we'd still experience regular earth gravity

you didn't make it clear, thats why i bothered to mention it

To clarify: Newton's law of gravitation states that the force of the gravitational pull increases proportionally to the square of the distance between the two objects. This distance is the distance between the center-of-masses of the objects and not the distance between the surfaces. For a sphere (and most astronomical bodies can be approximated as spheres) the centre-of-mass is in the center of the sphere. The only other variable affecting the gravitational pull is the masses of the objects involved. When a star collapses to a black hole, it's mass remains unchanged (or is, if something, lessened). Therefore, if you were to remain at the same place in space and watch a star collapse into a black hole, you would experience no change in gravitational pull. The thing that makes the black hole's gravity so strong is that it is now possible to get much closer to it's centre-of-mass. If the earth's radius was to decrease from 6000 km to 6 km the gravitational pull at it's surface would increase 1 000 000 times but the gravitational pull at 6000 km would remain unchanged.

... and hence a discussion on Freelancer is turned into a scientific debate...

Black holes don't really have "surfaces". Also if they do Newton's laws would not apply, you need to look to good old Einie for answers... too bad he's dead...

Don't forget the key pressure keeping a neutron star 'up'. It's the degenerency. Same thing that keeps White Dwarfs 'up'. Only in a White Dwarf, they're entirely made up of electrons. Black holes don't really have a radioactive decay. It's the vacuum fluctuations that occur near the horizon that cause the decay. The radiation is not of the radio variety.... Uranium has the right idea. Planets -can- become black holes. It's just highly unlikely. There is no law of physics that says a black hole must be of a certain mass, it only has to have a certain circumference. This is known as the critical circumference. Several physicists have theorized of microscopic black holes having been created in the big bang. Gravity is a good way to press something below the critical circumference, and this is why we see stars turning into black holes naturally. Of course, a star won't turn into a black hole unless it has around two solar masses after it runs out of fuel. Otherwise it'll just go neutron, or white dwarf. It's also interesting to note that a star must have around 20 solar masses at death to collapse into a black hole. The other 18 solar masses are expelled in the nova!

I am in no way a professional physicist, but it is a hobby of mine. I'm down to shoot theory with anyone if it's an interest of their's as well. My AIM name is trieste5.

i dont understand the whole time taking longer or what not, time is a mesurement not really an object that can be warped

Actually...... time can be warped. Relativity is a strange thing. The effects on time around the horizon of a black hole, or any gravity well, is called gravitational time dilation. There is a lot to it, but suffice it to say 'it happens'. Time is just as relative as length. It moves at different rates depending on who's observing what, and what reference frame they're in. The only time two clocks agree on time is when they're stationary in relation to eachother. Einie's big thing was Spacetime.... a combination of space and time that can be warped. Hasn't been proven wrong yet

....oh....time to get out my trusty science book and verify all your fake attempts at intelligence equal to mine HAHAHA im jk...although i will get out my science book...*thumbs through pages*

*If you have a cat and a dog in the same house, will that be a problem? Of course not, you might just have solved world hunger*

I can't explain gravitational time dilation.... I'd love to see a good explanation. I only have a fuzzy idea. You shouldn't have any trouble verifying that time is relative however

so what's all this about black hoes?

I think the whole thread started about the unrealistic characteristics of black holes / neutron stars protrayed in the game that is known as "Freelancer".

A discussion then ensued to enclose scientific theories and facts; perhaps to boast various posters' knowledge on such subjects or to induce an interest in astronomical anomilies or could simply just to speculate on current Newtonian and Einsteinian formulations.

The most current topic of interest is on the idea of time dilation near extreme gravatational distorted space and the idea of time warp relative to such distortions.

*bump*
No more physics stuff? LOL

GOOD LORD - lets make Physics hash now shall we?
#1 - the picture is not accurate - duh! all we have on black holes is radio telescope images - we do not have visual images of one.
#2 - the picture is VERY similar to on in the britannica science encyclopaedia volume 1, old edition.
#3 - visual distortion results as a bending of light - please don't mock true science by mentioning the "fabric of space and time" <- save that for star trek.
#4 - "the smaller the black hole, the more intense... ...once you're inside..." - inside what? the black hole?? look up roche limitm and the definition of THEORY.
no you wont go "inside" the hole - you'll just become a smear of neutrons, the energy let loose, streams off in pulses as it spins (pulsar)
#5 - time distortion - yes it DOES do with relativity, but it does with an object being accelerated close to the speed of light Tsub = Trel/(1-(v^2/c^2)^(1/2))
where Trel is relative time, Tsub is the person moving. - as velocity approaches the speed of light, mass increases, length decreases, and time relative to that of a stationary object decreases.
#6 - "This is because light from behind it gets bent around and hides the black hole" we have no visual pictures, even hubble wont see it optically, only radio telescopes have seen these, and interpreted pictures.
#7 - look up a GOOD physics book - like a university text, or old english text - wanna know what happens to form a neutron star? add the relative atomic masses of an electron and a proton (hydrogen - most common isotope) and compare it to a neutron, its not exact, there is mass loss = energy (mc^2).
#8 - ordinary planets warp light - in fact, there were two recorded galaxies that were astonishingly similar and close - then it was realized that another galaxy between ours and the other 2 warped light such that by looking on either side, the galaxy behind was seen (britannica science encyclopaedia vol1).
#9 - thank god physics is just a hobby for you - the white dwarf - a celestial luminiscent body made of nothing but electrons? i'm hoping i misinterpreted what you were saying!

No, it's not made entirely of electrons, but it's no longer fusion keeping the pressure. It's the electrons.... I know what I'm talking about. Feel free to post the equations for the lay person and further illustrate my original attempt to spread the love.

If a person chooses to use the terms fabric of space and time. I can deduce what they mean. They're using terms easier for them. So what if they're using the same term as the rest of the physics community.

All he was trying to say is that we can see the effects of a black hole on the space around it. Of course we cannot see a black hole in the visual spectrum. No need to belittle his point. Hubble has several pictures of gravitational lensing coming from supermassive black holes and clusters of stars.

The smaller the black hole, the more intense the tital gravity is near the horizon. When we say 'in' a black hole, we're talking about the horizon. Not the singularity. I thought I should clarify, since we're just lay-people talking about something we find interesting. Anyway, there are differences in the gravitational 'turbulence' beyond the horizon based on size and age of the hole. It is theorized you could keep a molecule intact beyond the horizon of a supermassive black hole where the tidal gravitational forces aren't as crazy.

I'll make sure and pick up an old English physics text. Then I'm sure to learn more than something written in German, or Italian. Thanks for the pointer.

I'm not trying to prove my knowledge. As I said, it's a hobby of mine. A hobby among building race cars, playing video games, dating women, and drinking at clubs. I appreciate you further clarifying everything for the forum. You have a gift for speech.

You got some good stuff in that head. Just try not to be such an asshole.

-- T