Kip Thorne - Why Black Holes Are Astonishing

Kip described the structure of black hole so a black hole has a horizon which is the surface of the black hole except it's not a hard surface like a surface or a billiard ball and it has a singularity of the center and it is made in the vicinity of the horizon and down to the singularity by warped space and time the horizon is a very special place it's the place that the that has the property that if you fall into a black hole you pass through the horizon you don't notice anything special until you try to get back out and you can't get back out you're pulled inexorably toward the center and we know they are there with 99.9% confidence from observations mixed with a little bit of theory we know that in our own galaxy there are roughly a hundred million of these objects that have sizes of about say ten miles or so across things sizes like that we know that the center of our galaxy and all almost all other large galaxies there's a huge black hole that has a size more like the distance between the Earth and the moon and the equivalent of mass of how many Suns and yes and in the center of the galaxies masses of a million to a billion to ten billion times the mass of the Sun all contained in this size that is more like a small piece of our solar system the smaller black holes the ones that maybe 10 miles across weighing the same as maybe ten Suns so they're remarkable objects from that point of view but the thing that has gripped me about black holes is in the same way as black holes gripped by their gravity anything that falls in their vicinity is the fact that a black hole is an object that is made not for matter but from warped space and warp time what does that mean well so suppose that you were to measure the circumference around a black hole so you go marching around and around and you see that the circumference is 30 miles and then suppose that you measure the diameter you would think that diameter ought to be 30 divided by pi or 10 miles roughly 10 then oh you measure that diameter and it is enormous ly larger than 10 miles and maybe a thousand miles it may be a million miles it's unbelievably large so the space is warped and you might ask me well how is it possible that that you can have a huge diameter in a small circumference don't the laws of Euclidean geometry forbid it the answer yes they do so Euclidean geometry doesn't apply it's like you take a child's trampoline a large rubber sheet and you put a heavy rock heavy very dense rock in the center and it sinks way down and then you're a bland ant but you're a blind at so you can't see what's going on and you march around and measure the circumference around the trampoline and then you go in and you measure the diameter by marching down and back up around the rock and the diameters huge compared to the circumference Wow it's the same thing and that is what the black hole's made of there is no matter in that black hole it's not a dense object made of very dense matter there's no matter at all there was matter in the star that gave birth to the black hole long ago a star like our Sun but somewhat heavier will have burned its nuclear fuel can no longer keep itself puffed out by its internal heat it starts to cool off and it then implodes and all of the matter in that star much more matter than we have in our Sun goes crashing into the center and is destroyed at what we call a singularity of the center where that rock was on the child's trampoline all the matters destroyed there's nothing left to accept this warped space and warp time now most people would think that if we have this 10 mile object like a big bowling ball if it was possible not to be destroyed and I got there I could knock on it would be solid but if I pass through that boundary I wouldn't know the difference that's right you wouldn't know the difference however you would know the difference if you try to come back out but there's nothing special the boundary that you can see locally in your vicinity there's no hard surface and if you look above yourself you can still see the universe above your head they just can't see you so one way membrane light can come in from the universe into the interior bringing you an image of what's going on in the universe but you can't send any light back out to your friends outside to tell you what's going on you paid the ultimate price when you go in that you can never publish the results of your operations of course and by the way you also die Einstein taught us that mass and energy are the same thing you can convert them back and forth ok equals MC squared C squared and so the mass or energy in this black hole is actually not concentrated in the singularity it's concentrated in the warping of space and time in the same way is if you take the child's trampoline and you put the rock on it and the rock deforms it it takes energy to deform it you have to really push on it to deform and you've got to put energy in to stretch the rubber in the same way as the star gives birth to the black hole the star does a lot of work it's increased the black hole as it implodes and all of them and mass and energy of the star in the end goes into the warping of space and the walking of time

Channel: Closer To Truth

Views: 127,897

Rating: 4.9296522 out of 5

Keywords: Kip Thorne, Physics (Field Of Study), Black Hole (Celestial Object Category), Closer To Truth (TV Program), Universe (Quotation Subject)

Id: oj1AfkPQa6M

Length: 5min 49sec (349 seconds)

Published: Mon Nov 17 2014

Reddit Comments

[u/quantizedself]

A couple years ago as an undergrad I was at a national physics conference getting on the elevator with some other undergrads to some event. This old guy comes up and we let the doors close on him, mostly because we were oblivious undergrads. Turns out it was Kip Thorne. We felt terrible.

[u/_herefortheshow_]

I went down a great rabbit hole there. Thanks!