cicerone imposter wrote:What happens to light relative to the black hole?
Time and Space are distorted by a black hole such that the flow of time and the curvature of space are changed relative to external reference points (as E_Brown has pointed out, relativity demands that everything appear normal from each particular vantage point).
At first blush, relativity would seem to say that you wouldn't be able to tell if you were near a black hole or not, because things in free fall are indistinguishable from stationary objects from within their own reference frame. [In point of fact, the whole idea of non-accelerated motion has no meaning without reference to something external. The same thing applies with freefall in a gravitational field (general relativity, rather than special relativiity) because the free fall is a result of spacial curvature.]
However, the reason Black holes can be destructive to matter even when that matter is in free fall is because of strong gravitational gradients which cause differing forces at different places (matter tends to get "stretched" by the gradient). Having strong differential forces pulling on solid objects can damage them.
Wow, once again thanks for all the posts.
I think I finally get it now, but I'll definitely look into Special Relativity more. Relative motion certainly makes sense, I realized I am in constant movement even sitting at my desk right now (ie. by the earth's rotation, revolution, this whole solar system's revolution), but of course I feel stationary. I think my problem was failing to know that light is not affected by inertia, since it is weightless (right?). Or does this even matter? Is everything relative to everything else in a certain view point? Say I shot a bullet from a gun and it's speed was 750 mph. Then I drive a rocket car the same exact speed, and shoot the gun, will the bullet pass me at 750 mph? Or does it have to be traveling in the rocket car to pass me at 750 mph? Light is the same relativeness in all views points because it is not affected by the laws of physics.
Another example to help explain what I'm saying...imagine I'm in a car, and I bounce a red ball. My friend, AJ, is on the sidewalk, and watches me pass by. He sees the ball go down in a arc and come up with an arc. To me the ball just bounces normally. Now if this ball were replaced with a photon, it would go down without an arc to AJ and me (and anyone, anywhere else watching).
I just read what I wrote, and well sorry for this ramble. I think I'm just digging myself a hole...ah well...
That's why your name is "BlueAbyss." LOL
rosborne, Thank you. In other words, it doesn't affect light in Black holes because it's not matter.
cicerone imposter wrote:rosborne, Thank you. In other words, it doesn't affect light in Black holes because it's not matter.
Well, light can't be "damaged" in the same way matter can be "damaged", but light does follow the curvature of space, and near black holes, space is greatly curved.
I'm still not sure I understand what you are asking about light in relation to black holes.
Somehow we got from velocity and relative motion to gravity. Special relativity deals with the former, and general relativity with the latter.
Since black holes are 'gravitational' and light is non-matter, it has no effect on light. That's the conclusion I drew from your earlier post. So light in relation to black holes has no effect.
CI-
Gravity doesn't directly affect light, but it does affect the spacetime that the light is travelling through. Large gravity wells cause spacetime to curve. Light follows those curves. So light is "bent" as it passes near a star for instance. When dealing with a black hole the curvature is so great that the light "falls in" and can't escape.
I'm crap at explaining things but I hope that makes some sense.
Correct me if I am wrong... but as I remember it....
E=MC^2
or
M = E/C^2 which means as we approach the speed of light, mass approaches infinity.
So:
The spaceship would have infinate mass if it traveled at the speed of light.
That means it would need an infinate amount of fuel to get it to that speed.
So: if the spaceship has infinite mass... that means it occupies the entire universe and more... and had to gobble up the universe and more for fuel.
But, we now have ion drive... which is used at the moment on one of the deep space voyagers. I think this machine approaches 10% the speed of light -80,000 m/s. but it uses hardly any fuel!!! now go figure. This would seem to indicate traveling at the speed of light is possible someday... and the infinate mass problem is just something that is relative to perspective.
With this in mind... since light is a constant 800,000 m/s. it cant increase or decrease in velocity. That means, as you approached the speed of light and you turned on a light, you would see the begining of the light beam slowly moving away from the source... any source. If you were traveling the speed of light, you would not see anything. There would be no reflections, no color, no light. Remeber though... all Einsteins stuff is just theory, most if it has been proven... but not everything.
Adrian, Thank you. Yes, it makes sense - somewhat. It's a hard concept to grasp.
