Huh, BLACK Holes aren't "Entirely" Black?

chandra.harvard.edu...

reminds me of Obama

anyways, considering the growing possibility of a black hole closer to our own (binary?) solar system than previously though, it's alittle comforting to learn that even if our Sun turned into a black hole overnight, it doesn't necessarily mean Earth would be guaranteed to be swallowed up even over much time. a possibility yes but apparently certain bodies would stay in orbit/moment/acretion?

or something like that..

I would have never thought it could blow something out! And the fact/theory that it could be the size of the sun and not draw in the other planets is odd. I think we might move at least a few inches if it were the size of the sun. After all it would take about 1.3 million Earths to fill up a sun.

Seeing as the sun is essential for all life on Earth, we seemed to be doomed either way, that is of course if our sun ever turned into a black hole overnight.

reply to post by CommandoRenegade


If the Sun became a black hole, the resultant black hole would have the same mass as the Sun (things don't gain mass just by becoming a black hole, they just get crammed into a smaller volume), so it would have the exact same gravitational pull. All of the planets, asteroids, comets, and other assorted orbiting objects would stay exactly where they are.

Theres not enough mass in our sun for it to become a blackhole. Our sun will end its life with it getting larger (red giant) and then it will collapse into a white dwarf.

reply to post by CLPrime


Even if the black hole is the same mass as the sun they are suppose to have such heavy gravitational pull that not even light can escape from its clutches. Actually there is a thing called the event horizon where if your in it the gravitational pull is so strong that you are pulled in at the speed of light! But hey you might be right. Maybe its gravitational pull is only so strong at a short distance.

reply to post by CommandoRenegade


The gravitational force at the black hole's "surface" (it's event horizon) is only so strong because it's so compact, making it much closer to the center of gravity. At the event horizon, the gravitational pull is ridiculously strong, but at the distance of the Earth, for example, it's just as strong as that of the Sun. Also, at a distance equal to the radius of the Sun, the gravitational pull of the solar-mass black hole would be just as strong as that at the surface of the Sun now.

reply to post by CLPrime

Not quite the same. The gravity gradient would be altered a bit, there would be tidal effects.

reply to post by Phage


Yes...for the detail oriented, they wouldn't be exactly the same, but the mass itself stays the same (the common misconception being that the mass of the star magically increases when it becomes a black hole). Given the rotation rate of the Sun, we could calculate the tidal effects if we wanted to. I'll leave that to you