et al

[Guest Unregistered]

I was trying to relate black holes and pi and circles-I tried asking dr Karl...

I was thinking that the one side of the line measures the other side of the line...whereas with a circle this is not true.

...this might reperesent the communication breakdown that is always the same..{haHa}

The number pi goes on forever, and given the chance it would..

{..I wanted to ask dr Karl about what would happen if you looked at a black hole...but that was not my first question and so i never got to it...}

So a black hole,,something something-i can't explain it twice...jeez.Have a look at dr karl!!

 

Shanks Jon

Q1

[blike]

I wanted to ask dr Karl about what would happen if you looked at a black hole

 

Since light on the visible spectrum cannot escape a black hole, we wouldn't see much. We could see everything up to the event horizon, and then nothingness.

 

As for watching someone fall into a black hole, we might see some interesting things. Say the person is blinking their flashlight at us everyone second as they approach the black hole. We would see their flashlight blinking slower and slower as their time slows relative to ours. The flashlight would also be getting redder and redder, as the light changes wavelengths(redshift). Eventually we would no longer be able to see the flashlight beause the wavelength would be too long for our eye to pick up. The time dialation would be so extreme as they approached the event horizon, that they would appear to be stopped at the edge. For us watching, we would live our whole lives and die and they would still be at the edge of the horizon. In fact, stars would live and die before the person crossed the event horizon. But for the observer looking out, he sees the universe accelerated. He watches us grow and die in an instant. He watches stars birth and then supernova before he finally crosses the line and is crunched into a singularity.

[blike]

As for the geometry of a black hole I don't know much. I believe I have a book somewhere that goes into some detail, but I've never read it.

[fafalone]

It is hard to talk about the geometry of a black hole because you essentially cannot rely on Euclidean geometry to explain the relationship of space and time. Mass warps space time, and a black hole has an extremely large mass. Only very strange particles are believed to escape black holes.

[aman]

It would be true that everything at a certain radius to a black hole would fall at a constant rate but some things falling into the black hole would also have near tangent velocities besides. Some matter would have a large velocity a little tangent but mostly straight into the black hole.

I feel you might be ripped to shreds by passing matter before you ever reached the event horizon. A constant abrasive cloud continualy collapsing. Maybe I'm wrong. Just for thought.

Just aman

[Radical Edward]

Originally posted by aman

I feel you might be ripped to shreds by passing matter before you ever reached the event horizon.

 

the ripped to shreds thing is usually regarded as the result of tidal forces, in that the force of gravity at your feet is hundreds of times the force of gravity at your head. hence you get somewhat spaghettified. however this is only the result of small black holes that are a few solar masses.

 

if you grind your way though the general relativistic equations however, you find that the density required to overcome the electromagnetic, and stron force actually degreases as the total mass increases. hence, and this is one of the reasons why a super-massive black hole is postulated as being at the centre of the galaxy, you can actually have a very disperse medium becoming a black hole. In short, if you fall into a big enough black hole, you can actually fall over the event horizon and not suffer all that much. Of course you look 'down' and see black, as no light can ever reach you