Time Dilation, Black Hole Mysteries & Cosmic Curiosities

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Andrew Dunkley: Hello again. Thanks for joining us. This is

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Space Nuts Q and A edition. My name is Andrew

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Dunkley. This will be our last official show

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for 2025. We'll go into a short

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recess and be back with you early in the

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new year. but we've got some questions

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to nail down before any of that happens.

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And we've got a whole bunch of topics that

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seem to have stirred the imaginations of

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our audience. Andrew wants to know about time

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dilation of stuff. Stars.

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Adriano is talking black holes becoming

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stars. Ishtok is wanting

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to ask about free space.

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I always thought it was expensive, especially

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all the space around where we live. Yo.

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And Gergo, Redshift and Gravastars.

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We will tackle all of that in this edition of

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space nuts. 15 seconds. Guidance is

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internal.

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Professor Fred Watson: 10, 9. Ignition

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sequence. Star space nuts.

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Andrew Dunkley: 5, 4, 3, 2.

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Professor Fred Watson: 1. 2, 3, 4, 5, 5, 4, 3,

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2, 1.

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Andrew Dunkley: Space nuts. Astronauts report it feels good.

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And here he is again. It's professor Fred

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Watson, astronomer at large. Hello Fred.

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Professor Fred Watson: Hello Andrew.

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Andrew Dunkley: Good to see you again.

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Professor Fred Watson: Fancy seeing you here.

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Andrew Dunkley: How odd. How strange.

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Professor Fred Watson: How strange.

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Andrew Dunkley: getting ready for your Christmas break. I

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mean you've just come back from a break so

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you'd be, you know, probably

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feeling rather relaxed.

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Professor Fred Watson: Well, no, because only the last six days

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weren't work.

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Yeah. So, no, it's not quite

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true because we did have some time off with

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my family in Scotland. but we did have a

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proper holiday at the end of our trip. But

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yes, we did two months of pretty hard work

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actually. We had a tour in Japan and then a

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conference in Ireland and a few other things

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like that that kept us busy. So if

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you, if you want.

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Andrew Dunkley: To call international travel a job, that's,

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you know, that's fine.

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Professor Fred Watson: want to call us work. if you. Yeah,

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but when you've got a tour group, when you

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got 20 people who you entertained

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for a month, it's actually three and a half

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weeks. it is work.

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Andrew Dunkley: Yeah. Yeah. Well we've got a similar problem

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in the coming week or two with four

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grandchildren that we're.

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Professor Fred Watson: To the cave.

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Speaker C: Yeah.

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Professor Fred Watson: To be honest, I'd rather have 20 tourists

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than four grandchildren. Although my

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grandchildren are now totally self propelled.

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But for your Yankee swan, Aggie, she's only,

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she's, she's nine months yesterday actually.

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Anyway, anyway, yes, it's

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a matter of. But we. Yeah. So the bottom

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line is we will have a relaxing end of year

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break.

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Andrew Dunkley: I hope very good you mentioned Edinburgh.

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Well, our first question comes from Andrew

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in Edinburgh. he says, I have a two part

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question about the gravity and subsequent

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time dilation that occurs in and around

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supergiant stars. If the supergiants

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can collapse into black holes, then they must

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have as much or even more mass than the

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resulting black hole. Just spread over a much

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large, larger area. I guess my question is,

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is there significant time dilation near these

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stars or are they simply not dense

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enough to have meaningful amounts of time

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dilation? If they do, it's weird that

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comes up and a slight follow up would

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be what about time dilation within

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the star itself? Presumably near the core of

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these stars, the density ramps right up.

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Does a large difference in time dilation

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within a star have any impact on how

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it behaves? Hope that all makes sense.

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Thanks. Love the show. That's Andrew in

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Edinburgh.

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Professor Fred Watson: They're great questions.

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I'm just not sure about

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the first sentence. If the

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supergiants can collapse into black

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holes, then they must have as much or

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even more mass than the resulting black hole.

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Yeah, okay, I've read that properly now. just

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spread it maybe.

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Andrew Dunkley: I didn't read it properly.

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Professor Fred Watson: No, it's all right. No, it's fine.

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so yeah, Andrew's first question. Is there

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significant time dilation near these stars?

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And the answer is yes.

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there would be. it's, I mean the time

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dilation in a black hole is

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so great that to an outside observer,

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time stops on the event horizon.

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for a star because it's spread over

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a larger volume of space, the time dilation

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is nowhere near as great. but time dilation

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will be something that you would have to take

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into account if you had, a

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spacecraft orbiting near a giant star.

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the bottom line is with, and time dilation,

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it's a little bit spooky in the sense that

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to the star itself and to something,

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say you've got something in orbit around this

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star, their time's ticking away at the normal

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rate. The time dilation is only what you see

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from the outside.

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Andrew Dunkley: So this is basically the same as we were

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talking about in the last episode regarding

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Mars. Same problem.

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Professor Fred Watson: Yes, that's right. It is the same thing.

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Yeah. So time ticks away

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normally for the star, but to watch

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it from the outside, you basically see time

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ticking away a little bit more slowly.

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so they would have time dilation. M. Andrew's

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asking whether they're simply not dense

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enough to have a meaningful amount of time

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dilation. And I don't think that's true. I

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think this time dilation is significant,

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especially if you're looking at microseconds,

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as we were in the last episode. yeah,

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so they do. And look,

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you're not talking about time dilation of the

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kind that was depicted in interstellar

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where time kind of grinds to a halt

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almost. it's a more modest amount of

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time dilation, but it would actually happen.

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And Andrew's follow up question. What about

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time dilation within the star itself?

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Presumably near the core of these stars, the

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density ramps right up. There's a large

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difference in.

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Andrew Dunkley: I'm not going in there to find.

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Professor Fred Watson: Out there's a difference

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in time dilation within a star have any

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impact on how it behaves. and

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there's a curious thing there because as you,

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get near the core of an object, with

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spherical symmetry, your gravitational

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field gets less and less. and in fact at the

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center you wouldn't feel any gravity. And

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that's because everything's pulling you in

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the same direction all around. And so

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I believe that time dilation will probably

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stop in the middle of a star. That might be

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something I've never thought about before.

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maybe that's not true because you're still in

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a gravitational field. The fact that it

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cancels out everywhere. I'll check that

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one out actually and try and remember for

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our, first show next year, because that's a

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really interesting question. Time dilation in

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the center of a star, how does it behave?

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Andrew Dunkley: very interesting.

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Professor Fred Watson: But there wouldn't be a. I think the bottom

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line is there wouldn't be a, a big difference

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in time dilation from one part of a star to

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another. That's, that's what I'm trying to

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say.

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Andrew Dunkley: But he brings up another interesting point.

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You've got time dilation around a massive

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star.

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Professor Fred Watson: Yep.

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Andrew Dunkley: Then it goes, you know, whatever black hole,

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the time dilation changes.

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Professor Fred Watson: Yes, it does because, as it collapses, the

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gravitational field increases.

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it increases in sort of

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angle in the sense that, you know, it's a

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steeper gravitational field as you

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get as the black hole collapses. And by that

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I'm thinking of the gravitational well, you

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know, this dip in the trampoline sheet.

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That's the gravitational well of an object

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which turns into something like a plug hole

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with water going around it as a vortex for

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a black hole. so that's what I mean by the

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steepness of the gravitational field. and

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yes, it is so steep that the Event horizon

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delineates where the time dilation becomes,

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such that time appears to stop on the surface

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of the event horizon.

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Andrew Dunkley: Yeah, I've seen that demonstration done with

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like a big rubber sheet and they say

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that that's the time, space time

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continuum and they put a bowling ball in it

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and they say. And that's gravity.

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Professor Fred Watson: That's right, yep. I know,

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yeah.

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Andrew Dunkley: It'S a simple way of explaining it, but

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that's what it is. I suppose. Great.

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questions, Andrew. I hope all is well in

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Edinburgh. Fred's home

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stomping ground. yep, yep. I'll give you his

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address and you can go and rock his roof.

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This is Space Nuts with Andrew Dunkley and

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Professor Fred Watson.

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Ah, we have got an audio question. Fred,

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this is from Adriano.

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Speaker C: Hi guys. Adriano from Florence in Italy. I

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have my first question about black holes. So

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if I understood correctly, a star continued

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to burn his fuel like hydrogen and helium.

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And there are nuclear fusions and there is

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enough energy for the star to fight against

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its own gravitational pull. But, at some

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point there is not enough, fuel and the star

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collapses into a black hole. After this, the

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black hole will start to absorb material like

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hydrogen and then it should have enough

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energy, enough fuel to have, nuclear

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fusions and to fight against the

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gravitational pull. But, so why a

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black hole cannot, turn back into a star?

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I'm sure this is not possible, but I cannot

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understand why. And also guys, we had a lot

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of beautiful updates from the princess. Can

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we also have some updates from Fred? Thank

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you guys.

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Andrew Dunkley: Bye bye, Adriano, thank you very much. Fred

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gave us his update when he got back,

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but. Yeah, your point is well made. Florence,

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what a beautiful, beautiful city.

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Speaker C: Yeah.

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Professor Fred Watson: isn't it just?

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Andrew Dunkley: we, we visited Florence a few years ago and

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it was, it was amazing.

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But it was also terrible timing because it

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was All Saints weekend, which is a four day

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long weekend and there were like tens of

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thousands of people there. You couldn't move.

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You absolutely couldn't move. So,

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we went to, what was it called, the Ponte

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Vecchia, and we couldn't get near it.

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You just couldn't. It was it was insane.

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Yeah, we didn't know until we got there

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that's what was happening. But yeah, we still

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got to see it. It was a beautiful place and

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all those amazing statues and Galileo got,

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got, got up close with Galileo.

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Professor Fred Watson: Very good.

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Andrew Dunkley: Yeah, yeah.

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Professor Fred Watson: Did you see his? I think it's his. It's one

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of his fingers or his thumb, I can't remember

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which is on display in the science museum

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there.

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Andrew Dunkley: Oh, no, no, couldn't get near that. yeah,

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honestly, it was just mayhem. But, yeah,

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understandable though.

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all right, so the bottom line with Adriano's

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question is, why can't a black hole

267
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turn back into a star? yeah, I

268
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would think there'd be all sorts of reasons

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why not.

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Professor Fred Watson: Well, that's right. I think once you've

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turned into a singularity, as the, you can't

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double down.

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Andrew Dunkley: Sorry that,

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Professor Fred Watson: You took the words out of my mouth. No, you

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didn't. I mean, all bets are off basically

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once you, Once you've gone into a

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singularity. and so I,

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think, you know, it's a great thought that,

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Adriano's had. I. And it's never occurred

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to me before, but, but you know, you're

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talking about hydrogen, which certainly would

282
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get sucked into a black hole because a lot of

283
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the gas clouds that, the black

284
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hole, accretion disk would draw

285
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in and suck into the center,

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that's hydrogen. and hydrogen is the raw

287
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material of stars. Why can't nuclear fusion

288
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kick in again and drive the star back into

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being a star rather than a black hole? And I

290
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think the answer is in structure. so

291
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stars have quite a complex

292
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structure, to make them work. with the,

293
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core, with all the nuclear burning taking

294
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place, then there's a convection zone and

295
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then there's a sort of outer layer before you

296
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get to the photosphere, the layer that you

297
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can see. when you've put something into a

298
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singularity, all structure disappears.

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And it

300
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almost relates to, an issue

301
00:12:08.860 --> 00:12:11.340
that occupied the m. Mind of Stephen Hawking

302
00:12:11.340 --> 00:12:13.860
for a while, which is that does information

303
00:12:14.180 --> 00:12:16.940
get lost when it goes into a black

304
00:12:16.940 --> 00:12:19.620
hole? And I think there was some

305
00:12:19.620 --> 00:12:21.620
argument with another well known physicist.

306
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In fact, I think they had a bet, which

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Hawking lost. because,

308
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I think the bottom line was Hawking back that

309
00:12:30.250 --> 00:12:31.930
information couldn't come out of a black

310
00:12:31.930 --> 00:12:34.170
hole. But somebody proved a theory that

311
00:12:34.170 --> 00:12:35.890
information could come out of a black hole. I

312
00:12:35.890 --> 00:12:37.170
think I've got the right way.

313
00:12:38.830 --> 00:12:41.190
Basically, it's all completely mangled in

314
00:12:41.190 --> 00:12:43.930
terms of, we don't understand the

315
00:12:43.930 --> 00:12:45.770
physics of what would happen inside a

316
00:12:45.770 --> 00:12:48.170
singularity. We just have no idea what the

317
00:12:48.170 --> 00:12:50.690
physical processes would be. And they almost

318
00:12:50.690 --> 00:12:53.090
certainly would rule out hydrogen

319
00:12:53.090 --> 00:12:56.090
atoms getting together, and with

320
00:12:56.090 --> 00:12:59.010
enough temperature to produce the nuclear

321
00:12:59.010 --> 00:13:01.790
fusion that we see in a normal star. a

322
00:13:02.110 --> 00:13:04.350
black hole is a very abnormal object.

323
00:13:04.750 --> 00:13:07.540
Nothing relates to normal in a black

324
00:13:07.540 --> 00:13:10.020
hole. And so I think that is the answer to

325
00:13:10.020 --> 00:13:12.770
Adriana's question. physics

326
00:13:12.770 --> 00:13:14.690
doesn't work the way it works on the outside

327
00:13:14.690 --> 00:13:16.850
of a black hole, and I think that's why we

328
00:13:16.850 --> 00:13:18.810
don't see black holes turning into stars.

329
00:13:18.970 --> 00:13:21.130
Andrew Dunkley: Yeah, well, there's also the fuel issue,

330
00:13:21.369 --> 00:13:24.230
like, you know, the star has collapsed

331
00:13:24.230 --> 00:13:27.110
because of fuel depletion, has it

332
00:13:27.110 --> 00:13:27.390
not?

333
00:13:27.550 --> 00:13:29.230
Professor Fred Watson: Yes, that's right. But what we're saying and

334
00:13:29.230 --> 00:13:31.180
what Adriano is saying is that, among the

335
00:13:31.180 --> 00:13:34.020
stuff that is accreted by the black hole,

336
00:13:34.190 --> 00:13:36.830
when it's sitting there gobbling stuff up, a

337
00:13:36.830 --> 00:13:39.390
lot of that is hydrogen, which is the fuel.

338
00:13:39.790 --> 00:13:42.150
So they're getting more fuel, but they don't

339
00:13:42.150 --> 00:13:44.470
any longer have the process to make it turn

340
00:13:44.470 --> 00:13:47.070
into something that will deliver energy. I

341
00:13:47.070 --> 00:13:48.110
think that's the bottom line.

342
00:13:48.110 --> 00:13:50.110
Andrew Dunkley: I get it, I get it. Okay.

343
00:13:51.380 --> 00:13:52.660
great question, though, because,

344
00:13:55.420 --> 00:13:58.180
we've been talking black holes

345
00:13:58.180 --> 00:14:01.060
for I don't know how long, probably since the

346
00:14:01.060 --> 00:14:02.940
very beginning of the time that this

347
00:14:03.670 --> 00:14:06.230
podcast began, and I don't think we've ever

348
00:14:06.230 --> 00:14:07.350
been asked that question before.

349
00:14:07.350 --> 00:14:08.630
Professor Fred Watson: No, I think that's right.

350
00:14:08.630 --> 00:14:09.110
Andrew Dunkley: Yeah.

351
00:14:10.150 --> 00:14:12.750
Professor Fred Watson: So it's a lot for our. For our, listeners,

352
00:14:12.750 --> 00:14:15.110
doesn't it, that they can produce questions

353
00:14:15.110 --> 00:14:17.510
that we've never had before after however

354
00:14:17.510 --> 00:14:20.030
many episodes. It's getting on for 500 now.

355
00:14:20.350 --> 00:14:21.870
Andrew Dunkley: This is 582.

356
00:14:22.110 --> 00:14:23.670
Professor Fred Watson: Oh, 582. Okay.

357
00:14:23.670 --> 00:14:24.510
Andrew Dunkley: 582.

358
00:14:24.670 --> 00:14:25.110
Speaker C: Yeah.

359
00:14:25.110 --> 00:14:26.990
Professor Fred Watson: Right. There you go. Getting on for 600.

360
00:14:27.150 --> 00:14:29.980
Andrew Dunkley: Oh, no, it's not. I mean, it's happening

361
00:14:29.980 --> 00:14:32.180
faster because of time dilation and the fact

362
00:14:32.180 --> 00:14:35.100
that we decided to do two episodes

363
00:14:35.100 --> 00:14:36.300
a week instead of one. But.

364
00:14:37.980 --> 00:14:40.300
Professor Fred Watson: But I think it's nuts by definition, isn't

365
00:14:40.300 --> 00:14:41.520
it? I've got a feeling.

366
00:14:43.040 --> 00:14:43.520
Yeah.

367
00:14:44.020 --> 00:14:46.710
Andrew Dunkley: anyway, thank you, Adriano, and hope all is

368
00:14:46.710 --> 00:14:49.590
well in the beautiful Florence. This is Space

369
00:14:49.590 --> 00:14:52.150
Nuts with Andrew Dunkley and Professor Fred

370
00:14:52.150 --> 00:14:52.750
Watson.

371
00:14:54.820 --> 00:14:56.420
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Three, two, one.

407
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Space nuts.

408
00:16:34.620 --> 00:16:36.640
Our, next question doesn't come from Italy,

409
00:16:36.640 --> 00:16:39.550
it comes from Slovenia. Russian store.

410
00:16:39.550 --> 00:16:42.060
Yeah. I am listening to your podcast while

411
00:16:42.060 --> 00:16:44.850
driving to and from work. Great show. I hope

412
00:16:44.850 --> 00:16:46.610
you managed to keep control because, you

413
00:16:46.610 --> 00:16:49.120
know, this gets a bit crazy sometimes. I'm

414
00:16:49.120 --> 00:16:51.080
curious about. Wait for it, Fred. Black

415
00:16:51.080 --> 00:16:53.930
holes. we know that an atom is actually a

416
00:16:53.930 --> 00:16:56.770
lot of free space where electrons fly around.

417
00:16:57.260 --> 00:17:00.020
eliminating that, we probably, probably

418
00:17:00.020 --> 00:17:02.710
get a neutron star. Ah, with high density.

419
00:17:02.710 --> 00:17:04.990
But what about a black hole? How does this

420
00:17:04.990 --> 00:17:07.920
work? Where is the free space, that can

421
00:17:07.920 --> 00:17:10.150
be squeezed even further to get a black hole?

422
00:17:10.100 --> 00:17:12.950
get black hole material and density and to

423
00:17:12.950 --> 00:17:14.810
calculate the density of the black hole.

424
00:17:14.810 --> 00:17:17.410
Would it be a correct assumption to take the

425
00:17:17.410 --> 00:17:20.170
event horizon as the boundary and,

426
00:17:20.890 --> 00:17:23.850
based on that, calculate the volume? Or is

427
00:17:23.850 --> 00:17:26.580
it something else? Thank you. Best regards.

428
00:17:26.580 --> 00:17:29.039
Ishtok. another black hole question. Not

429
00:17:29.039 --> 00:17:30.440
surprising. We get a lot of them.

430
00:17:31.560 --> 00:17:32.920
Professor Fred Watson: We do, yeah. So,

431
00:17:34.480 --> 00:17:37.170
it's a great question and, that's absolutely

432
00:17:37.170 --> 00:17:39.330
right. An atom is a lot of free space, empty

433
00:17:39.330 --> 00:17:42.240
space, with a, cloud of electrons doing their

434
00:17:42.240 --> 00:17:44.980
quantum thing. if, you collapse the

435
00:17:44.980 --> 00:17:47.140
space down so that only the electrons are

436
00:17:47.140 --> 00:17:49.350
pushing the, atoms apart, you've got a white

437
00:17:49.350 --> 00:17:51.690
dwarf star, which is called electron

438
00:17:51.690 --> 00:17:53.680
degenerate. and if you get rid of the

439
00:17:53.680 --> 00:17:55.360
electrons, then you get a neutron star

440
00:17:55.360 --> 00:17:57.800
exactly as Ishtok, says, with

441
00:17:58.440 --> 00:18:01.210
very, high density, where only the neutrons

442
00:18:01.210 --> 00:18:03.890
keep the thing from collapsing into a black

443
00:18:03.890 --> 00:18:05.850
hole. But with a black hole,

444
00:18:07.010 --> 00:18:09.410
well, the free space is basically

445
00:18:09.410 --> 00:18:11.090
disappeared down the black hole.

446
00:18:13.320 --> 00:18:15.800
and in terms of its density,

447
00:18:16.520 --> 00:18:19.040
you have a definition of a black

448
00:18:19.040 --> 00:18:21.550
hole. one of the definitions is A point in

449
00:18:21.550 --> 00:18:24.390
space with infinite density. So the

450
00:18:24.390 --> 00:18:27.390
volume is zero. See, Jordy thinks that ah, as

451
00:18:27.390 --> 00:18:29.910
well. He does. Gosh, I don't know what's

452
00:18:29.910 --> 00:18:32.880
happening out there, but yeah, I love it.

453
00:18:34.640 --> 00:18:35.840
Andrew Dunkley: We had to hear him from.

454
00:18:35.920 --> 00:18:36.440
Professor Fred Watson: Yeah.

455
00:18:36.440 --> 00:18:37.920
Andrew Dunkley: For the last show of the year.

456
00:18:38.880 --> 00:18:41.840
Professor Fred Watson: That's right. In full

457
00:18:41.840 --> 00:18:44.510
flight. so. Yes, so it's a point of

458
00:18:44.510 --> 00:18:47.010
infinite density. So it talks a comment about

459
00:18:47.010 --> 00:18:48.810
calculating the density of the black hole.

460
00:18:48.810 --> 00:18:50.450
Would it be a correct assumption to take the

461
00:18:50.450 --> 00:18:52.940
event horizon as the boundary? no, it

462
00:18:52.940 --> 00:18:54.980
wouldn't. The event horizon's just that

463
00:18:54.980 --> 00:18:57.140
imaginary point where of no return.

464
00:18:57.780 --> 00:19:00.440
and the volume is zero. the volume of the

465
00:19:00.440 --> 00:19:02.480
black hole is zero, which is how the, the

466
00:19:02.800 --> 00:19:04.960
density gets infinite because,

467
00:19:06.000 --> 00:19:08.560
mass over density. Sorry, Mass over volume is

468
00:19:08.560 --> 00:19:11.200
density. The mass is a, ah, is a parameter,

469
00:19:12.080 --> 00:19:14.520
but the volume is zero. I've no idea what's

470
00:19:14.520 --> 00:19:16.680
happening out there, Andrew, with Jordy, but

471
00:19:16.680 --> 00:19:18.320
he obviously likes this conversation.

472
00:19:18.320 --> 00:19:20.240
Andrew Dunkley: Yes, yes, he does. He wants in.

473
00:19:23.520 --> 00:19:25.960
dear. yeah, look, I still

474
00:19:26.280 --> 00:19:28.440
don't get black holes

475
00:19:29.160 --> 00:19:32.120
receding into the distance. Yeah,

476
00:19:32.120 --> 00:19:35.040
probably chasing a snake. yeah,

477
00:19:35.870 --> 00:19:36.830
go ahead, Andrew.

478
00:19:36.830 --> 00:19:37.630
Professor Fred Watson: No, it's.

479
00:19:37.870 --> 00:19:40.270
Andrew Dunkley: It's hard to get your head around

480
00:19:40.509 --> 00:19:42.670
something like a black hole

481
00:19:43.870 --> 00:19:44.270
having.

482
00:19:46.750 --> 00:19:48.270
No, no density.

483
00:19:48.320 --> 00:19:49.710
Professor Fred Watson: M. No.

484
00:19:49.710 --> 00:19:50.360
Andrew Dunkley: In my brain.

485
00:19:50.830 --> 00:19:51.430
Professor Fred Watson: No volume.

486
00:19:51.430 --> 00:19:52.030
Andrew Dunkley: No volume.

487
00:19:52.030 --> 00:19:54.470
Professor Fred Watson: It's got no size. It's got zero

488
00:19:54.470 --> 00:19:55.230
dimensions.

489
00:19:55.630 --> 00:19:58.390
Andrew Dunkley: I mean, we, we give them names

490
00:19:58.390 --> 00:20:00.750
based on size and yet it has no size.

491
00:20:01.230 --> 00:20:03.470
Professor Fred Watson: Superlastic. Yeah, well, but it's the mass

492
00:20:03.470 --> 00:20:06.070
that's the thing. So the mass is defined for

493
00:20:06.070 --> 00:20:08.110
a black hole. It's one of the properties that

494
00:20:08.110 --> 00:20:11.070
they have. There's this thing called the no

495
00:20:11.070 --> 00:20:13.920
hair theorem, which I like very much.

496
00:20:14.080 --> 00:20:16.560
Yeah. And it's about, you know, wouldn't.

497
00:20:16.560 --> 00:20:16.940
Andrew Dunkley: They wouldn't.

498
00:20:17.490 --> 00:20:19.170
Professor Fred Watson: Yeah, that's right. Which is.

499
00:20:20.130 --> 00:20:23.050
It's about the very few parameters that you

500
00:20:23.050 --> 00:20:25.410
can get from a black hole. I think it's mass,

501
00:20:25.810 --> 00:20:27.850
charge and spin. I think that's all you know

502
00:20:27.850 --> 00:20:30.800
about a black hole. because the volume zero.

503
00:20:30.880 --> 00:20:33.480
And that's why the density zero. Density is

504
00:20:33.480 --> 00:20:36.000
mass over volume, volume zero. So the density

505
00:20:36.000 --> 00:20:38.760
goes to infinite infinity, but you can vary

506
00:20:38.760 --> 00:20:39.200
the mass.

507
00:20:39.440 --> 00:20:41.440
And that's why we talk about supermassive

508
00:20:41.440 --> 00:20:43.470
black holes and intermediate mass black holes

509
00:20:43.470 --> 00:20:44.550
and things of that sort.

510
00:20:44.550 --> 00:20:47.550
Andrew Dunkley: Okay, so what was the answer to the

511
00:20:47.550 --> 00:20:47.830
question?

512
00:20:49.190 --> 00:20:49.590
Professor Fred Watson: no.

513
00:20:51.110 --> 00:20:51.750
Andrew Dunkley: Righto.

514
00:20:52.550 --> 00:20:54.150
Professor Fred Watson: What was the question again? Hang on.

515
00:20:55.240 --> 00:20:57.120
yeah. Would it be. Yes. Would it be correct

516
00:20:57.120 --> 00:20:58.840
assumption to take the event horizon as a

517
00:20:58.840 --> 00:21:00.720
boundary and use that to calculate the

518
00:21:00.720 --> 00:21:03.080
volume? No. The event horizon is an imaginary

519
00:21:03.480 --> 00:21:06.200
sphere that is where the thing

520
00:21:06.200 --> 00:21:08.280
turns black Basically because no light can

521
00:21:08.280 --> 00:21:08.720
escape.

522
00:21:09.640 --> 00:21:12.480
Andrew Dunkley: Precisely. hope that helped Ishok.

523
00:21:12.660 --> 00:21:13.620
Professor Fred Watson: it's a great question.

524
00:21:13.620 --> 00:21:16.370
Andrew Dunkley: It is terrific question. just a very

525
00:21:16.370 --> 00:21:18.730
difficult subject because we just don't

526
00:21:19.050 --> 00:21:21.850
know a hell of a lot about black

527
00:21:21.850 --> 00:21:24.250
holes. They're just such a mysterious and

528
00:21:25.610 --> 00:21:26.970
weird object. And,

529
00:21:28.410 --> 00:21:30.250
we're still trying to gather information

530
00:21:30.330 --> 00:21:32.450
about them and they just keep throwing up

531
00:21:32.450 --> 00:21:35.180
these curveballs at us and not letting us in.

532
00:21:35.580 --> 00:21:37.420
Not that you want to go in, but you know what

533
00:21:37.420 --> 00:21:37.820
I mean.

534
00:21:38.940 --> 00:21:40.060
Professor Fred Watson: Yes, that's right.

535
00:21:40.220 --> 00:21:40.780
Andrew Dunkley: Yeah.

536
00:21:40.940 --> 00:21:41.660
Professor Fred Watson: Quite soon.

537
00:21:41.820 --> 00:21:43.020
Andrew Dunkley: All right, thanks Ishtok.

538
00:21:44.700 --> 00:21:46.700
Time to take a break from the show to tell

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complaints. So go to

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569
00:23:03.536 --> 00:23:05.104
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573
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Professor Fred Watson: Space Nuts.

574
00:23:14.020 --> 00:23:16.579
Andrew Dunkley: We have one more question to finish things

575
00:23:16.579 --> 00:23:19.300
off for 2025. And

576
00:23:19.620 --> 00:23:22.380
it's a real European flavor for this episode.

577
00:23:22.380 --> 00:23:25.220
This is Gergo. Greetings gentlemen.

578
00:23:25.380 --> 00:23:28.300
Gergo from Slovakia here. I have a question

579
00:23:28.380 --> 00:23:31.140
about redshifting. Does it have a limit?

580
00:23:31.140 --> 00:23:33.700
Is there a point beyond which light cannot be

581
00:23:33.700 --> 00:23:36.620
stretched any further? If so, what happens if

582
00:23:36.620 --> 00:23:38.380
the light continues to travel through

583
00:23:38.380 --> 00:23:40.860
expanding space? And the second question.

584
00:23:41.180 --> 00:23:43.860
Could you talk a bit about Gravastars? Do you

585
00:23:43.860 --> 00:23:46.510
think they might be real? thank you for your

586
00:23:46.510 --> 00:23:47.950
time and for The Great show.

587
00:23:48.350 --> 00:23:48.830
Speaker C: Bye.

588
00:23:49.470 --> 00:23:51.140
Andrew Dunkley: Thanks, Georgia. yeah, it's

589
00:23:52.340 --> 00:23:55.060
an eclectic mix of nationalities. This

590
00:23:55.220 --> 00:23:56.900
Fabius was. Yeah, it's terrific.

591
00:23:57.200 --> 00:23:57.840
Professor Fred Watson: Yeah, it's great.

592
00:23:58.050 --> 00:24:00.820
Andrew Dunkley: so two questions he's, thrown into the mix.

593
00:24:00.850 --> 00:24:03.140
yeah. Is there a limit on redshift?

594
00:24:05.100 --> 00:24:05.980
yeah. Good one.

595
00:24:07.020 --> 00:24:10.020
Professor Fred Watson: So, yeah,

596
00:24:10.100 --> 00:24:13.060
it is a good question. I mean, so redshift,

597
00:24:13.490 --> 00:24:15.650
as a term we

598
00:24:16.290 --> 00:24:19.130
define as being due to the expansion of the

599
00:24:19.130 --> 00:24:22.010
universe. and it's slightly

600
00:24:22.010 --> 00:24:24.960
different from the Doppler shift. Doppler,

601
00:24:25.320 --> 00:24:27.520
shift is something we understand. Well, it's

602
00:24:27.520 --> 00:24:29.480
the way the light changes wavelength from a

603
00:24:29.480 --> 00:24:31.880
moving object. But with redshift, we're

604
00:24:31.880 --> 00:24:34.800
talking about space itself. Rather

605
00:24:34.800 --> 00:24:36.719
than objects moving through space. We're

606
00:24:36.719 --> 00:24:39.340
talking about the way space behaves. and so

607
00:24:39.340 --> 00:24:41.900
it's a much more fundamental thing than the

608
00:24:41.900 --> 00:24:44.660
Doppler shift. So in a sense,

609
00:24:45.180 --> 00:24:47.740
there's already a limit to redshift.

610
00:24:48.380 --> 00:24:51.260
but it's one that is

611
00:24:52.140 --> 00:24:54.700
exactly related to the age of the universe.

612
00:24:57.240 --> 00:24:59.240
so what I'm thinking of here is

613
00:25:00.280 --> 00:25:02.830
the, cosmic microwave background

614
00:25:02.830 --> 00:25:05.630
radiation. That's the wall of radiation

615
00:25:05.950 --> 00:25:08.630
which corresponds to the brightness of

616
00:25:08.630 --> 00:25:11.550
the Big Bang fireball. Which

617
00:25:11.550 --> 00:25:14.080
we're still seeing. Because as we look

618
00:25:14.080 --> 00:25:17.000
further into space, we look back in time. So

619
00:25:17.000 --> 00:25:19.000
everywhere in space we see this wall of

620
00:25:19.000 --> 00:25:21.480
radiation. Which is now in the microwave

621
00:25:21.480 --> 00:25:23.320
region of the spectrum. Which is why we call

622
00:25:23.320 --> 00:25:24.840
it the cosmic m. Microwave background

623
00:25:24.840 --> 00:25:27.550
radiation. Yeah. And so, if I

624
00:25:27.550 --> 00:25:30.110
remember rightly, that

625
00:25:30.350 --> 00:25:33.310
is basically the visible flash

626
00:25:33.870 --> 00:25:36.110
of the Big Bang. Because

627
00:25:36.830 --> 00:25:38.550
it was, basically

628
00:25:39.590 --> 00:25:42.590
a visible light flash. It's the visible

629
00:25:42.590 --> 00:25:45.510
flash redshifted by, I think,

630
00:25:45.910 --> 00:25:47.990
about 1300 times.

631
00:25:48.870 --> 00:25:51.390
So everything in the universe must have a.

632
00:25:51.390 --> 00:25:54.310
That we can observe. Must have a redshift

633
00:25:54.310 --> 00:25:57.100
less than that. I think 1300

634
00:25:57.100 --> 00:25:59.580
is the number that comes into my mind. I've

635
00:25:59.580 --> 00:26:02.300
looked at this for a long time, but it's

636
00:26:02.300 --> 00:26:05.140
visible light, Whose

637
00:26:05.140 --> 00:26:07.940
waves have been stretched by that amount to

638
00:26:07.940 --> 00:26:10.940
give us microwaves. So stretched about

639
00:26:10.940 --> 00:26:13.820
1300 times thereabouts. Now,

640
00:26:15.540 --> 00:26:18.299
as the universe expands and time goes

641
00:26:18.299 --> 00:26:21.020
on, that number will increase not

642
00:26:21.020 --> 00:26:24.020
by much. Might become 1301 or

643
00:26:24.020 --> 00:26:26.860
1305. But as time goes on, that number's

644
00:26:26.860 --> 00:26:29.660
increasing. So in a sense, that's a limit

645
00:26:29.660 --> 00:26:32.490
to redshift. physically though,

646
00:26:32.490 --> 00:26:34.170
I don't think there is a limit. You could,

647
00:26:34.410 --> 00:26:36.690
you know, if you expand the universe. If

648
00:26:36.690 --> 00:26:38.410
you're talking about 40 billion years into

649
00:26:38.410 --> 00:26:40.730
the future. And the universe is expanding

650
00:26:40.730 --> 00:26:42.970
more. Yes. The cosmic microwave background.

651
00:26:42.970 --> 00:26:45.130
Is going to be the cosmic long wavelength

652
00:26:45.130 --> 00:26:48.120
radio background. and so,

653
00:26:49.030 --> 00:26:51.350
the wavelength Will have stretched more.

654
00:26:51.910 --> 00:26:54.710
So there isn't a physical limit, but

655
00:26:54.710 --> 00:26:57.350
there is a, ah, a limit in the real

656
00:26:57.350 --> 00:27:00.070
universe, simply because of the age of the

657
00:27:00.070 --> 00:27:02.950
universe. The universe hasn't expanded

658
00:27:02.950 --> 00:27:05.110
for long enough for the redshift to be more

659
00:27:05.110 --> 00:27:07.710
than about 1300. Right,

660
00:27:08.110 --> 00:27:08.710
okay.

661
00:27:08.710 --> 00:27:09.550
Andrew Dunkley: Yeah, got it.

662
00:27:10.030 --> 00:27:10.430
Professor Fred Watson: Good.

663
00:27:11.390 --> 00:27:12.870
What was the other thing? Oh, Gravisars.

664
00:27:12.870 --> 00:27:14.670
Andrew Dunkley: Oh, Gravastars. Yeah, we've had, we've had

665
00:27:14.670 --> 00:27:17.390
questions about Gravastars before, more than

666
00:27:17.390 --> 00:27:20.020
once. it seems to be something that sort of

667
00:27:20.020 --> 00:27:23.000
captured the imagination of people that

668
00:27:23.000 --> 00:27:25.120
are so interested in astronomy and space

669
00:27:25.120 --> 00:27:28.000
science. So I suppose we should

670
00:27:28.000 --> 00:27:30.920
start by reminding people what a gravastar

671
00:27:30.920 --> 00:27:32.400
is supposed to be, because I don't think

672
00:27:32.400 --> 00:27:33.280
we've ever found one.

673
00:27:34.160 --> 00:27:37.090
Professor Fred Watson: No, that's correct. I'm going to read

674
00:27:37.090 --> 00:27:39.340
from that font of all knowledge,

675
00:27:39.340 --> 00:27:42.330
Wikipedia, who I do subscribe to, despite

676
00:27:42.330 --> 00:27:44.330
the fact that they keep asking me for another

677
00:27:44.330 --> 00:27:46.170
subscription. Anyway, that's probably because

678
00:27:46.170 --> 00:27:48.250
I've got more than one username. Never mind,

679
00:27:48.810 --> 00:27:51.770
let me read from Wikipedia. In astrophysics,

680
00:27:52.170 --> 00:27:54.910
a Gravis star, which is a blend word

681
00:27:54.910 --> 00:27:57.270
of gravitational vacuum star,

682
00:27:57.830 --> 00:28:00.070
is an object Hypothesized in a

683
00:28:00.070 --> 00:28:02.710
2001 paper by Pavel O.

684
00:28:02.710 --> 00:28:05.430
Mazur and Emil Motola

685
00:28:05.750 --> 00:28:08.470
as an alternative to the black hole theory.

686
00:28:09.110 --> 00:28:11.750
It has the usual black hole metric

687
00:28:11.830 --> 00:28:14.030
outside of the horizon. And the metric is

688
00:28:14.030 --> 00:28:17.030
just a way of describing space, but de

689
00:28:17.030 --> 00:28:19.500
sittomatric inside. And that's a different

690
00:28:19.500 --> 00:28:22.460
one, don't worry about that. A typical

691
00:28:22.460 --> 00:28:24.740
gravastar is as big as London,

692
00:28:25.460 --> 00:28:27.700
but weighs 10 solar masses.

693
00:28:28.900 --> 00:28:31.420
Yeah. So a neutron star would be about the

694
00:28:31.420 --> 00:28:34.140
size of London, but weigh one solar mass,

695
00:28:34.140 --> 00:28:34.660
basically.

696
00:28:35.140 --> 00:28:37.210
Andrew Dunkley: Didn't they find one in a sewer? they called

697
00:28:37.210 --> 00:28:38.370
it a fratberg or something.

698
00:28:38.370 --> 00:28:41.170
Professor Fred Watson: Fatberg. That's right, yeah. Which was

699
00:28:41.170 --> 00:28:43.090
just about to turn into a gravastar.

700
00:28:43.090 --> 00:28:43.490
Andrew Dunkley: Yes.

701
00:28:44.190 --> 00:28:46.830
Professor Fred Watson: on the horizon there is an ultra thin,

702
00:28:46.990 --> 00:28:49.670
incredibly tight shell of entirely

703
00:28:49.670 --> 00:28:52.270
new unique exotic matter

704
00:28:52.990 --> 00:28:54.830
named galactic Flubber.

705
00:28:55.550 --> 00:28:56.430
Andrew Dunkley: That was close.

706
00:28:57.390 --> 00:28:59.750
Professor Fred Watson: You weren't far off. That's right. Which is

707
00:28:59.750 --> 00:29:02.230
the next thing to a fatberg. Yeah. Anyway,

708
00:29:02.230 --> 00:29:04.070
continuing to read this solution to the

709
00:29:04.070 --> 00:29:06.870
Einstein equations is stable and has

710
00:29:06.870 --> 00:29:09.760
no singularities, which we've just been

711
00:29:09.760 --> 00:29:12.440
talking about singularities, points of zero

712
00:29:12.520 --> 00:29:15.200
volume. Instead, Gravastar is filled with

713
00:29:15.200 --> 00:29:17.800
either dark energy or with vacuum energy,

714
00:29:17.880 --> 00:29:20.880
but also vacuum. only

715
00:29:20.880 --> 00:29:23.800
the inside one, 10 to the 44 times denser

716
00:29:23.800 --> 00:29:26.560
than the outside. I'm not sure how you can

717
00:29:26.560 --> 00:29:28.920
have a vacuum that's 10 to the 44 times

718
00:29:28.920 --> 00:29:31.480
denser than another one, but I'll just let

719
00:29:31.480 --> 00:29:32.600
that pass. Yes.

720
00:29:34.340 --> 00:29:36.140
as a bonus, further theoretical

721
00:29:36.140 --> 00:29:38.140
considerations of gravastars include the

722
00:29:38.140 --> 00:29:40.900
notion of a nestar. A second gravastar

723
00:29:40.900 --> 00:29:43.860
nested within the first one. So that's

724
00:29:43.860 --> 00:29:46.020
the technical definition. I bet you're no

725
00:29:46.020 --> 00:29:48.560
wiser than I am. but the bottom

726
00:29:48.640 --> 00:29:50.320
line is that,

727
00:29:51.800 --> 00:29:54.310
And I'll read again. Mazur and Mottola

728
00:29:54.310 --> 00:29:56.790
suggest that the violent creation of a

729
00:29:56.790 --> 00:29:59.590
gravastar might be an explanation for the

730
00:29:59.590 --> 00:30:02.430
origin of our universe and, many other

731
00:30:02.430 --> 00:30:04.430
universes, because all the matter from a

732
00:30:04.430 --> 00:30:06.870
collapsing star would implode through the

733
00:30:06.870 --> 00:30:09.750
central hole and explode into a new dimension

734
00:30:09.750 --> 00:30:12.310
and expand forever, which would be consistent

735
00:30:12.310 --> 00:30:14.910
with the current theories regarding the Big

736
00:30:14.910 --> 00:30:15.350
Bang.

737
00:30:16.790 --> 00:30:19.790
Andrew Dunkley: Okay, so now that we know what

738
00:30:19.790 --> 00:30:22.750
it is, do you think they exist and

739
00:30:22.750 --> 00:30:23.830
will we ever find one?

740
00:30:24.280 --> 00:30:26.530
Professor Fred Watson: no and no. Basically, it's,

741
00:30:28.840 --> 00:30:31.400
an alternative theory for the Big Bang,

742
00:30:31.960 --> 00:30:34.360
and it's certainly interesting. And,

743
00:30:34.860 --> 00:30:37.180
I, you know, I, I think m.

744
00:30:37.470 --> 00:30:39.660
Gago's asked us to talk about it, and now we

745
00:30:39.660 --> 00:30:42.299
have. So, so,

746
00:30:42.270 --> 00:30:44.590
that's perhaps doing the best we can.

747
00:30:45.390 --> 00:30:47.470
Interesting. There's. There's just one other

748
00:30:47.710 --> 00:30:49.310
sentence I might like to read.

749
00:30:51.500 --> 00:30:54.340
if I can find

750
00:30:54.340 --> 00:30:57.300
it, I've lost it now. Oh, yeah. The

751
00:30:57.300 --> 00:31:00.060
new dimension that will be created in this

752
00:31:00.060 --> 00:31:02.540
implosion. The new dimension

753
00:31:02.620 --> 00:31:05.580
exerts an outward pressure on the Bose

754
00:31:05.580 --> 00:31:08.220
Einstein condensate layer and

755
00:31:08.620 --> 00:31:11.500
prevents it from collapsing further. So

756
00:31:11.500 --> 00:31:14.260
the Bose Einstein condensate. It sounds as

757
00:31:14.260 --> 00:31:16.740
though that's this thinned crust that it's

758
00:31:16.740 --> 00:31:19.440
got rather than an event horizon. And the

759
00:31:19.440 --> 00:31:22.160
Bose Einstein condensate is really

760
00:31:22.160 --> 00:31:24.440
interesting. I think we've just celebrated.

761
00:31:25.560 --> 00:31:28.520
Is it the 30th anniversary

762
00:31:28.680 --> 00:31:31.440
of the first example of a Bose

763
00:31:31.440 --> 00:31:34.440
Einstein condenser being produced? I

764
00:31:34.440 --> 00:31:36.360
think that's right. I think it's 30 years. I

765
00:31:36.360 --> 00:31:38.900
think it's 1995. what is it?

766
00:31:39.710 --> 00:31:42.590
it's a condensation of atoms at very low

767
00:31:42.590 --> 00:31:45.270
temperature that behave like one quantum

768
00:31:45.270 --> 00:31:47.990
object. that's the crucial things. So

769
00:31:48.150 --> 00:31:50.870
it's almost like entanglement, Andrew, where

770
00:31:50.870 --> 00:31:52.950
you've got quantum particles being entangled.

771
00:31:52.950 --> 00:31:55.350
This is a whole bunch of stuff that is so

772
00:31:55.350 --> 00:31:57.310
entangled it just looks like one quantum

773
00:31:57.310 --> 00:32:00.210
object and we can now create them. so

774
00:32:00.210 --> 00:32:01.770
that's what they're saying, that maybe this

775
00:32:01.770 --> 00:32:04.650
thing is made of a Bose Einstein condenser. I

776
00:32:04.650 --> 00:32:07.200
think this is a really good way to end, the

777
00:32:07.200 --> 00:32:09.890
year's, Space Nuts episode because it is

778
00:32:09.890 --> 00:32:12.650
completely off the wall and talking about

779
00:32:12.810 --> 00:32:15.460
stuff that is right at the cutting edge of

780
00:32:15.460 --> 00:32:16.460
physics, which I love.

781
00:32:16.620 --> 00:32:19.070
Andrew Dunkley: Indeed. Thank you for your questions. Gergo

782
00:32:19.070 --> 00:32:21.250
and Hope, you're well. Good, to hear from

783
00:32:21.250 --> 00:32:23.530
you. He's sending questions before so it's

784
00:32:23.530 --> 00:32:25.380
nice to catch up. in fact, I think, I think

785
00:32:25.620 --> 00:32:28.580
Ishtok, has sent questions in before as

786
00:32:28.580 --> 00:32:30.550
well. But, yeah, thank you for your questions

787
00:32:30.550 --> 00:32:32.460
everybody, for contributing to this, the

788
00:32:32.460 --> 00:32:34.980
final episode of 2025. Keep the questions

789
00:32:34.980 --> 00:32:37.940
coming in because we're coming back next

790
00:32:37.940 --> 00:32:40.100
year and we'll need some fresh stuff because

791
00:32:40.100 --> 00:32:42.470
we're down to the last one or two,

792
00:32:43.000 --> 00:32:44.960
which I didn't use because they all came from

793
00:32:44.960 --> 00:32:46.960
the same source and I like to spread the love

794
00:32:46.960 --> 00:32:48.770
a bit. So, we'll get into those next year.

795
00:32:48.770 --> 00:32:50.940
But, go to our website if you'd like to send

796
00:32:50.940 --> 00:32:53.740
a question in. Click on the AMA link at the

797
00:32:53.740 --> 00:32:56.500
top and you can send text and audio questions

798
00:32:56.500 --> 00:32:59.100
there. As always, please remember to tell us

799
00:32:59.100 --> 00:33:01.100
who you are and where you're from while

800
00:33:01.100 --> 00:33:03.190
you're at, on the website. check out how you

801
00:33:03.190 --> 00:33:05.740
might be able to support us, through various

802
00:33:05.740 --> 00:33:08.210
channels. whatever you choose or don't choose

803
00:33:08.210 --> 00:33:10.410
to, we're not going to make you do it. you

804
00:33:10.410 --> 00:33:11.890
can check out the shop as well. That's

805
00:33:11.890 --> 00:33:14.800
another way of supporting us and so on and

806
00:33:14.800 --> 00:33:16.820
so forth. while I think.

807
00:33:16.820 --> 00:33:18.380
Professor Fred Watson: Andrew, while you're talking about the

808
00:33:18.380 --> 00:33:20.020
questions, I think we've got a pending one

809
00:33:20.020 --> 00:33:22.900
still from Rusty, which we just wish to.

810
00:33:23.540 --> 00:33:25.260
We'll take it next year.

811
00:33:25.260 --> 00:33:28.121
Andrew Dunkley: Yes, yes, I recall that. But, we.

812
00:33:28.201 --> 00:33:29.961
I thought we'd sit on it till the new year

813
00:33:29.961 --> 00:33:31.721
because reading the question will actually

814
00:33:31.721 --> 00:33:33.801
take the pulp of the episode.

815
00:33:37.542 --> 00:33:39.062
Professor Fred Watson: Thank you, Andrew. Sorry to interrupt you.

816
00:33:39.062 --> 00:33:41.662
Andrew Dunkley: That's okay. No, that's okay. I just want to

817
00:33:41.662 --> 00:33:43.142
say thank you to you, Fred.

818
00:33:44.572 --> 00:33:47.072
and, and I should also, thank

819
00:33:47.072 --> 00:33:49.602
Jonti because he, he did a, fair chunk of the

820
00:33:49.602 --> 00:33:52.442
show and we also

821
00:33:52.442 --> 00:33:54.802
had our guest presenter, Heidi while I was

822
00:33:54.802 --> 00:33:57.212
away. So thank you to Heidi for her amazing,

823
00:33:57.692 --> 00:33:59.962
contribution because, it really saved my,

824
00:34:00.762 --> 00:34:03.512
my back because, there's probably no way in

825
00:34:03.512 --> 00:34:05.232
the world I could have recorded from a cruise

826
00:34:05.232 --> 00:34:07.122
ship and got away with it. But, yeah,

827
00:34:07.122 --> 00:34:08.892
fantastic. we've got a great team.

828
00:34:10.262 --> 00:34:13.072
and, and you know, bring on the next, the

829
00:34:13.072 --> 00:34:14.552
next year of Space Nuts.

830
00:34:14.552 --> 00:34:14.872
Speaker C: And I.

831
00:34:14.872 --> 00:34:16.752
Andrew Dunkley: Look, I give him a hard time every week, I

832
00:34:16.752 --> 00:34:18.872
do. But I've got to say thanks to Huw in the

833
00:34:18.872 --> 00:34:21.722
studio for his, amazing work.

834
00:34:22.042 --> 00:34:24.322
It's not just our podcast that he looks

835
00:34:24.322 --> 00:34:26.262
after. He's got a whole stable of them and

836
00:34:26.212 --> 00:34:29.092
it's it's basically a full time job trying to

837
00:34:29.092 --> 00:34:32.002
run all and you know there's not much money

838
00:34:32.002 --> 00:34:34.492
in it but there's certainly joy in putting

839
00:34:34.492 --> 00:34:37.302
our skills into something in our

840
00:34:37.302 --> 00:34:39.932
semi retirement from, from radio. So.

841
00:34:40.092 --> 00:34:43.002
Yeah. But also without the audience we would

842
00:34:43.002 --> 00:34:45.922
be nothing. So we send out our

843
00:34:47.362 --> 00:34:49.522
our thanks. We are so grateful to have you

844
00:34:49.522 --> 00:34:52.452
behind us and I do keep an eye on the

845
00:34:52.452 --> 00:34:55.422
audience through the Space Nuts podcast group

846
00:34:55.422 --> 00:34:57.792
on Facebook because they they spend a lot of

847
00:34:57.792 --> 00:34:59.512
time there talking to each other, sharing

848
00:34:59.512 --> 00:35:02.382
pictures, and posing unusual

849
00:35:02.382 --> 00:35:04.262
questions which occasionally we will bring up

850
00:35:04.262 --> 00:35:06.902
on the show. And special thanks to our

851
00:35:06.902 --> 00:35:08.902
sponsors. We've had a few sponsors who've

852
00:35:08.902 --> 00:35:11.422
been with us for quite some time now and, and

853
00:35:11.662 --> 00:35:13.222
you know, obviously we're doing something

854
00:35:13.222 --> 00:35:15.662
right if they're willing to stick with us. So

855
00:35:16.062 --> 00:35:18.482
very much appreciated. thank you

856
00:35:18.722 --> 00:35:21.552
Fred. thank you Jordi and,

857
00:35:21.702 --> 00:35:24.312
and we'll talk to you in the new year.

858
00:35:25.432 --> 00:35:27.312
Professor Fred Watson: Sounds great. Look forward to it Andrew. And

859
00:35:27.312 --> 00:35:29.072
all the very best for the festive season to

860
00:35:29.072 --> 00:35:29.232
you.

861
00:35:29.232 --> 00:35:31.582
Andrew Dunkley: And to you Imani. thank you very much,

862
00:35:31.742 --> 00:35:33.782
Professor Fred Watson, Astronomer at large,

863
00:35:33.782 --> 00:35:35.742
and from me, Andrew Dunkley. Have a great

864
00:35:35.742 --> 00:35:37.902
Christmas. A happy new year. We'll see you in

865
00:35:37.902 --> 00:35:40.582
2026. Until then, bye

866
00:35:40.582 --> 00:35:43.542
bye. You'll be listening to the

867
00:35:43.542 --> 00:35:44.862
Space Nuts podcast

868
00:35:46.712 --> 00:35:49.272
available at Apple Podcasts, Spotify,

869
00:35:49.432 --> 00:35:52.192
iHeartRadio or your favorite podcast

870
00:35:52.192 --> 00:35:53.912
player. You can also stream on

871
00:35:53.912 --> 00:35:56.232
demand@bytes.comm this.

872
00:35:56.232 --> 00:35:58.592
Professor Fred Watson: Has been another quality podcast production

873
00:35:58.592 --> 00:35:59.822
from bytes.com