Black holes of same mass of the mother star?

[shreeraj]

HOW CAN A BLACK HOLE HAVE A GREATER GRAVITATIONAL FORCE WHEN IT IS MADE UP OF THE SAME MASS OF ITS MOTHER STAR!

[rikbe]

What theory are you refering to?

[Gregz]

The smaller the volume of a given objects mass becomes the greater the gravitational attraction to it.

Any amount of mass at all can in principle be made to form a black hole if you compress it to a high enough density. If a neutron star is too large, the gravitational forces overwhelm the pressure gradients and collapse cannot be halted. The neutron star continues to shrink until it finally becomes a black hole.

As a body is crushed into a smaller and smaller volume, the gravitational attraction increases, and hence the escape velocity gets bigger. Things have to be thrown harder and harder to escape. Eventually a point is reached when even light, which travels at thousand miles a second, is not travelling fast enough to escape. At this point, nothing can get out as nothing can travel faster than light. This is a black hole.


"Make everything as simple as possible, but not simpler. "
- Albert Einstein

Gregz



[Edited by Gregz on 9th October 2001 at 15:13]

[mastodon]

"black holes are where god divided by zero."

[Marinus]

The idea of "mass" is usually related to our material world in 3 dimensions. It is difficult to imagine "mass" as a non-material entity (e.g. in a black hole). But it is possible to describe "mass" in a non-material way, by using non-euclidian geometry in 4 dimensions. Unfortunately the mathematical formulation is very difficult. (You have to know what "tensor calculus" is.)

I'll try to describe this 4-dimensional cosmos by reducing it to 2 dimensions: a plane. So all the stars and galaxies are present in this "plane". When this plane is non-euclidic, deformations of the plane are allowed and possible. E.g. "mountains" or "valleys". A certain amount of mass can be represented by a "pit" in this plane. Now you may consider "mass" in a non-material way: the deeper the "pit", the heavier the mass. Big stars are deep pits. And a planet approaching such a pit, NECESSARILY is going to move in a circle-like way: the planetary orbit.

In this mathematical model a black hole simply is a BOTTOMLESS PIT. A nearby object wil fall... and fall... and fall. The CURVATURE of the plane around the black hole is related to our concept of "mass".

[butterfly_27684]

The idea of a black being like a bottomless pit is interesting but unfounded in some ways. Since we have been unable (and will most likely continue to be) to explore black holes, all scientists are able to do is hypothesise about what laws black holes to abide by. Certainly I agree that matter and energy 'fall' into black holes but once inside, will they continue to fall? My brother suggested that the Big Bang began as a black hole and our universe exists inside it, abiding by our own laws. The energy and matter being drawn in could account for our ever expanding universe. In this case there would be the black holes in our universe existing inside a universal sized black hole. So it would be impossible for us to explore outside of our black holes as saying there are two universal states of existence those which are found upon entrance to known black holes and those found within our 'stable' universe. Therefore at the entrance to our universal blackhole there again would be inverse conditions to what we are accustomed to - or what is found at the entrance of normal black holes. This of course is all pure conjecture and I have no evidence to support it,but idealogical cosmology has always been a human indulgence. IF this was so we could assume that inside our black holes more infinite universes existed and so on. Mind boggling isn't it? Well that's my first post, but I'll be back. High Thoughts Kym.

[Petri]

Perhaps we should learn to understand Gravity before thinking too much about black holes.

Can anyone explain why gravity can change the path of light? Light has no mass!!

Anything new on the "gravitons"?

-THX