Gravity Demo Part 4 Black Holes

you know another thing that Einstein's theory of relativity predicted was black holes and let me show you how you can explain what black holes are all about using this equipment over here this is a four pound ball which I will put in my fabric of space-time and you can see that it curves it a certain amount over there a heavier ball would curve it more a bowl that's not so much would curve it less but the point is is that four pounds of ball curves the space like that it doesn't matter how I get four pounds over there out here it will still curve it the same amount so if I were to take a different ball and crush it down let's say I'd make it out of lead it still was four pounds it would be a lot smaller over here but out here it would be exactly the same or if I took that other but you know ball like really squeezed it down so it was really dense like plutonium or something like that it might only be this big and four pounds it would pull down that cloth differently down over there but out here four pounds of pull is four pounds of pull well supposing that I were to keep on compressing that four pounds smaller and smaller and smaller it's like a BB now it's like a pinpoint eventually I would get a situation where you still have that curvature but the ball is so small that you can't even see it anymore and that's really what the idea of a black hole is is that the space-time is curved but the mass that's curving it is so small that you can't even see it another way to think about it is this watch if the planet rolls around up here it goes a certain speed if the planet rolls around down there it's going faster as a matter of fact it goes faster and faster and faster and faster as you get closer and closer and closer to it if you were to have a star you know you can only get so close to the four pounds because the the star is in the way and so it'll only go so fast but if you don't have that star there it'll go faster and faster and if it goes faster than the speed of light that's when it drops through that hole that's when you can never get it out and that's really what a black hole is so the way that Einstein's theory of relativity predicted black holes is because of this curved space-time where the mass doing the curve is so small and so tiny that things move faster than the speed of light as they get closer to it it's another thing you can show with this piece of equipment

Channel: SpaceSciNewsroom

Views: 2,602,716

Rating: 4.8633237 out of 5

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Id: uBRBSJzFmEs

Length: 2min 54sec (174 seconds)

Published: Fri Jun 14 2013

Reddit Comments

[u/leperOutcastUnclean]

He says "things move faster than the speed of light as they get closer to it".

I didn't think it was possible to accelerate something to faster than the speed of light... What am I missing?

[u/Tyro231]

Holy shit, this is where I work, at the Denver Museum of Nature and Science, in Space Odyssey...that guy is my co-worker, and he’s awesome!!

[u/MeddYatek]

But the mass is demonstrated as a 3D object while the black hole is represented in 2D. This confuses me a bit.

[u/space_mog]

We had the same demonstration at the University of Birmingham. The cool thing is that you can also use it to demonstrate gravitational lensing which is what I worked on

[u/CumfartablyNumb]

Here's an ELI5 for you.

What is space time? How can it curve? That's the thing that my mind just can't wrap itself around. When I think of space, I think of a void. How can a void have curvature? How can time be bent?

Is there a book or anything short of a physics degree that could explain this concept to me?

[u/PigSkinPoppa]

I really don’t have any better understanding of a black hole after watching this. Someone help me understand...What would happen if you went into a “black hole”? Would you come out on the other side? Is there another side? So many questions.....

[u/Djeiwisbs28336]

This is an awful explanation that doesn't really describe general relativity. All of these explanations, rely on gravity to explain gravity, which makes it a bad explanation.

They should talk about geodesics on spacetime. Once people understand that on a 2d level, general relativity (and black holes) make more sense.

[u/the6thReplicant]

The real way to see this is directly from above. The you don’t actually see the curvature but see these objects curve when they should go in a straight line.

[u/Nintura]

So you have to go faster than the speed of light to fall into the surface of the object causing the black hole? So what happens if you fly right down into it, ignoring the curvature near the outside?