Brian Cox

Yeah, that's called the – I can never pronounce it. It's the albacore – what's it called? The drive. So you can – Einstein's general theory of relativity, general relativity is his theory of gravity. And it's a theory where space and time are distorted by things, anything in the universe, right? Stars and planets. So that's what gravity is. It's the distortion of space and time by mass and energy.

Yeah, that's called the – I can never pronounce it. It's the albacore – what's it called? The drive. So you can – Einstein's general theory of relativity, general relativity is his theory of gravity. And it's a theory where space and time are distorted by things, anything in the universe, right? Stars and planets. So that's what gravity is. It's the distortion of space and time by mass and energy.

It's Einstein's theory. So you can, and it's been done, you can develop... sort of things where you say, well, if we could make this geometry of space and time, if we could distort it in this way, then indeed you can build a warp drive. Right, right, right. But it always turns out, as far as we can tell, that the other question is, but what kind of stuff would you need?

It's Einstein's theory. So you can, and it's been done, you can develop... sort of things where you say, well, if we could make this geometry of space and time, if we could distort it in this way, then indeed you can build a warp drive. Right, right, right. But it always turns out, as far as we can tell, that the other question is, but what kind of stuff would you need?

It's Einstein's theory. So you can, and it's been done, you can develop... sort of things where you say, well, if we could make this geometry of space and time, if we could distort it in this way, then indeed you can build a warp drive. Right, right, right. But it always turns out, as far as we can tell, that the other question is, but what kind of stuff would you need?

What kind of matter or energy or field, whatever it is, what kind of thing would you need to make that geometry? And it always turns out that those things don't appear to exist. So these particular kinds of matter and energy, that if you had them, you'd be able to do that with space and time. We don't think you can have them. And so it's kind of a bummer, right?

What kind of matter or energy or field, whatever it is, what kind of thing would you need to make that geometry? And it always turns out that those things don't appear to exist. So these particular kinds of matter and energy, that if you had them, you'd be able to do that with space and time. We don't think you can have them. And so it's kind of a bummer, right?

What kind of matter or energy or field, whatever it is, what kind of thing would you need to make that geometry? And it always turns out that those things don't appear to exist. So these particular kinds of matter and energy, that if you had them, you'd be able to do that with space and time. We don't think you can have them. And so it's kind of a bummer, right?

It's not going to be elements. It's going to be kind of some kind of quantum field, some kind of energy or something. And so you can sort of try to speculate. But Stephen Hawking wrote a very famous paper called The Chronology Protection Conjecture. So conjecture is important. It's a guess, not proved.

It's not going to be elements. It's going to be kind of some kind of quantum field, some kind of energy or something. And so you can sort of try to speculate. But Stephen Hawking wrote a very famous paper called The Chronology Protection Conjecture. So conjecture is important. It's a guess, not proved.

It's not going to be elements. It's going to be kind of some kind of quantum field, some kind of energy or something. And so you can sort of try to speculate. But Stephen Hawking wrote a very famous paper called The Chronology Protection Conjecture. So conjecture is important. It's a guess, not proved.

Where he said that whatever the ultimate laws of physics are, we don't have them at the moment, string theory, whatever it is, then they will be such that you can't do this. Because chronology protection means protect the present from the future. So in other words, you can't build a time machine that goes back in time. Right. So that...

Where he said that whatever the ultimate laws of physics are, we don't have them at the moment, string theory, whatever it is, then they will be such that you can't do this. Because chronology protection means protect the present from the future. So in other words, you can't build a time machine that goes back in time. Right. So that...

Where he said that whatever the ultimate laws of physics are, we don't have them at the moment, string theory, whatever it is, then they will be such that you can't do this. Because chronology protection means protect the present from the future. So in other words, you can't build a time machine that goes back in time. Right. So that...

But because Einstein's theory allowed you to imagine such a thing, even though you might not be able to build it, it's not been proven beyond doubt that you can't somehow make these kinds of quantum fields or whatever it is that you need to make wormholes, for example, stable wormholes you can go through. And so it's not been proven. So it's just it's suspected that that's going to be the case.

But because Einstein's theory allowed you to imagine such a thing, even though you might not be able to build it, it's not been proven beyond doubt that you can't somehow make these kinds of quantum fields or whatever it is that you need to make wormholes, for example, stable wormholes you can go through. And so it's not been proven. So it's just it's suspected that that's going to be the case.

But because Einstein's theory allowed you to imagine such a thing, even though you might not be able to build it, it's not been proven beyond doubt that you can't somehow make these kinds of quantum fields or whatever it is that you need to make wormholes, for example, stable wormholes you can go through. And so it's not been proven. So it's just it's suspected that that's going to be the case.

By the way, the final thing, this is very neat because it goes right back to what I said at the start, that one of the pictures of how I said there was this thing, the black hole information paradox. And we thought Stephen's calculation was that no information comes out. We now think it comes out. So we now think that black holes do not destroy information. We're pretty sure.

By the way, the final thing, this is very neat because it goes right back to what I said at the start, that one of the pictures of how I said there was this thing, the black hole information paradox. And we thought Stephen's calculation was that no information comes out. We now think it comes out. So we now think that black holes do not destroy information. We're pretty sure.

By the way, the final thing, this is very neat because it goes right back to what I said at the start, that one of the pictures of how I said there was this thing, the black hole information paradox. And we thought Stephen's calculation was that no information comes out. We now think it comes out. So we now think that black holes do not destroy information. We're pretty sure.