00:00:00 --> 00:00:01 Hello again. Thanks for joining us. This
00:00:01 --> 00:00:04 is Space Nuts Q&A edition. My name is
00:00:04 --> 00:00:05 Andrew Dunley. This will be our last
00:00:06 --> 00:00:09 official show for 2025. We'll go into a
00:00:09 --> 00:00:12 short recess and be back with you early
00:00:12 --> 00:00:15 in the new year. Uh but we've got some
00:00:15 --> 00:00:17 questions to nail down before any of
00:00:17 --> 00:00:20 that happens. And we've got a whole
00:00:20 --> 00:00:22 bunch of topics that seem to have
00:00:22 --> 00:00:25 stirred the imaginations of uh our
00:00:25 --> 00:00:27 audience. Uh Andrew wants to know about
00:00:27 --> 00:00:29 time dilation of stars.
00:00:29 --> 00:00:32 Uh Adriano is talking black holes
00:00:32 --> 00:00:36 becoming stars. Uh Ishtto uh is wanting
00:00:36 --> 00:00:39 to ask about free space.
00:00:40 --> 00:00:41 H
00:00:41 --> 00:00:43 I always thought it was expensive
00:00:43 --> 00:00:45 officially all the space around where we
00:00:45 --> 00:00:49 live. Y and Ggo red shift and graars. We
00:00:49 --> 00:00:51 will tackle all of that in this edition
00:00:51 --> 00:00:53 of Space Nuts.
00:00:53 --> 00:00:58 >> 15 seconds. Guidance is internal. 10 9
00:00:58 --> 00:00:59 ignition sequence start.
00:00:59 --> 00:01:00 >> Space nuts.
00:01:00 --> 00:01:03 >> 5 4 3 2
00:01:03 --> 00:01:05 >> 1 2 3 4 5 5 4 3 2 1
00:01:05 --> 00:01:06 >> Space nuts.
00:01:06 --> 00:01:09 >> Astronauts report. It feels good.
00:01:09 --> 00:01:11 >> And here he is again. It's Professor
00:01:11 --> 00:01:13 Fred Watson, an astronomer at large.
00:01:13 --> 00:01:15 Hello, Fred.
00:01:15 --> 00:01:16 >> Hello, Andrew.
00:01:16 --> 00:01:17 >> Good to see you again.
00:01:18 --> 00:01:19 >> Fancy seeing you.
00:01:19 --> 00:01:21 >> Yeah. How odd. How strange.
00:01:21 --> 00:01:24 >> How strange. Hm. Uh getting ready for
00:01:24 --> 00:01:26 your Christmas break. I mean, you've
00:01:26 --> 00:01:27 just come back from a break, so you'd
00:01:27 --> 00:01:31 be, you know, probably
00:01:31 --> 00:01:34 feeling rather relaxed. Well, no. Uh
00:01:34 --> 00:01:36 because only the last six days weren't
00:01:36 --> 00:01:38 work.
00:01:38 --> 00:01:38 >> Ah.
00:01:38 --> 00:01:40 >> Yeah.
00:01:40 --> 00:01:42 So, um No, that's not quite true because
00:01:42 --> 00:01:44 we did have some time off with my family
00:01:44 --> 00:01:46 in Scotland. Um but we did have a proper
00:01:46 --> 00:01:48 holiday at the end of our trip. But yes,
00:01:48 --> 00:01:50 we did two months of pretty hard work.
00:01:50 --> 00:01:52 Ku had a tour in Japan and then uh the
00:01:52 --> 00:01:54 conference in Ireland and a few other
00:01:54 --> 00:01:57 things like that that um kept us busy.
00:01:57 --> 00:01:57 So uh
00:01:58 --> 00:01:59 >> if you if you want to call international
00:01:59 --> 00:02:02 travel a job that's you know that's
00:02:02 --> 00:02:04 fine.
00:02:04 --> 00:02:05 >> Um
00:02:05 --> 00:02:07 >> want to call it work.
00:02:07 --> 00:02:09 >> Um if you Yeah. But when you've got a
00:02:10 --> 00:02:11 tour group when you got 20 people who
00:02:11 --> 00:02:15 you were entertained for a month or it's
00:02:15 --> 00:02:18 actually three and a half weeks. Um it
00:02:18 --> 00:02:21 is work. Yeah. Yeah. Well, we've got a
00:02:21 --> 00:02:23 similar problem in the coming week or
00:02:23 --> 00:02:25 two with four grandchildren that we're
00:02:25 --> 00:02:26 taking to the co.
00:02:26 --> 00:02:28 >> Yeah. To be honest, I'd rather have 20
00:02:28 --> 00:02:30 tourists than four grandchildren.
00:02:30 --> 00:02:31 Although my grandchildren are now
00:02:32 --> 00:02:33 totally self-propelled, apart from the
00:02:33 --> 00:02:35 youngest one, Agie. She's on it. She's
00:02:36 --> 00:02:37 she's nine months like yesterday
00:02:37 --> 00:02:38 actually.
00:02:38 --> 00:02:38 >> Anyway,
00:02:38 --> 00:02:41 >> anyway, yes,
00:02:41 --> 00:02:44 >> it's a matter of But we Yeah. So, we The
00:02:44 --> 00:02:46 bottom line is we will have a relaxing
00:02:46 --> 00:02:48 end of year break, I hope.
00:02:48 --> 00:02:49 >> Very good.
00:02:49 --> 00:02:51 Um, you mentioned Edinburgh. Well, uh,
00:02:51 --> 00:02:54 our first question comes from Andrew in
00:02:54 --> 00:02:56 Edinburgh. Uh, he says, "I have a
00:02:56 --> 00:02:58 two-part question about, uh, the gravity
00:02:58 --> 00:03:00 and subsequent d time dilation that
00:03:00 --> 00:03:03 occurs in and around super giant stars.
00:03:03 --> 00:03:05 If the super giants can collapse into
00:03:05 --> 00:03:08 black holes, then they must have as much
00:03:08 --> 00:03:10 or even more mass than the resulting
00:03:10 --> 00:03:12 black hole just spread over a much
00:03:12 --> 00:03:15 larger area." Uh, I guess my question
00:03:15 --> 00:03:18 is, is there significant time dilation
00:03:18 --> 00:03:21 near these stars or are they simply not
00:03:21 --> 00:03:23 dense enough to have meaningful amounts
00:03:23 --> 00:03:26 of time dilation? If they do, it's weird
00:03:26 --> 00:03:29 that it never comes up. And a slight
00:03:29 --> 00:03:31 followup would be, what about time
00:03:32 --> 00:03:34 dilation within the star itself?
00:03:34 --> 00:03:37 Presumably near the core of these stars,
00:03:37 --> 00:03:40 the density ramps right up. Does a large
00:03:40 --> 00:03:42 difference in time dilation within a
00:03:42 --> 00:03:45 star have any impact on how it behaves?
00:03:45 --> 00:03:47 Hope that all makes sense. Thanks. Love
00:03:47 --> 00:03:50 the show. That's Andrew in Edinburgh.
00:03:50 --> 00:03:55 >> They're great questions. Um um
00:03:55 --> 00:03:59 I'm just not sure about
00:03:59 --> 00:04:02 the first sentence. If the super giants
00:04:02 --> 00:04:05 can collapse into black holes, then they
00:04:05 --> 00:04:08 must have as much or even more mass than
00:04:08 --> 00:04:09 the resulting black hole. Yeah. Okay.
00:04:09 --> 00:04:11 I've read that properly now. Uh just
00:04:11 --> 00:04:11 spread.
00:04:12 --> 00:04:13 >> Maybe I didn't read it properly.
00:04:13 --> 00:04:15 >> No, it's all right. No, it's it's fine.
00:04:15 --> 00:04:17 Um so, so yeah, Andrew's first question
00:04:18 --> 00:04:19 is there significant time dilation near
00:04:20 --> 00:04:23 these stars? And the answer is yes. Uh
00:04:23 --> 00:04:26 the there would be. Um um it's I mean
00:04:26 --> 00:04:30 the time dilation in a black hole is so
00:04:30 --> 00:04:33 great that uh to an outside observer,
00:04:33 --> 00:04:36 time stops on the event horizon. uh for
00:04:36 --> 00:04:39 a star because it's it's spread over a
00:04:40 --> 00:04:41 larger volume of space, the time
00:04:41 --> 00:04:43 dilation is nowhere near as great.
00:04:43 --> 00:04:46 >> Uh but time dilation will be something
00:04:46 --> 00:04:48 that you would have to take into account
00:04:48 --> 00:04:51 if you had um a spacecraft orbiting near
00:04:51 --> 00:04:54 a giant star. Um the bottom line is with
00:04:54 --> 00:04:58 and time dilation is is it's a little
00:04:58 --> 00:05:02 bit spooky in the sense that to to the
00:05:02 --> 00:05:06 star itself and to something uh you know
00:05:06 --> 00:05:07 say you've got something in orbit around
00:05:07 --> 00:05:09 this star their time ticking away at the
00:05:09 --> 00:05:11 normal rate the time dilation is only
00:05:11 --> 00:05:13 what you see from the outside.
00:05:13 --> 00:05:15 >> So this is this is basically the same as
00:05:15 --> 00:05:17 we were talking about in the last
00:05:17 --> 00:05:19 episode regarding Mars. Same problem.
00:05:19 --> 00:05:21 >> Yes that's right it is the same thing.
00:05:21 --> 00:05:25 Yeah. So, so time ticks away normally
00:05:25 --> 00:05:27 for the star, but to to watch it from
00:05:27 --> 00:05:30 the outside, you basically see time
00:05:30 --> 00:05:32 ticking away a little bit more slowly.
00:05:32 --> 00:05:35 Um, so so they they would have time
00:05:35 --> 00:05:37 dilation. Um, and Andrew is asking
00:05:37 --> 00:05:39 whether they're not simply not dense
00:05:39 --> 00:05:41 enough to have a meaningful amount of
00:05:41 --> 00:05:44 time dilation. And um, I don't think
00:05:44 --> 00:05:45 that's true. I think that this time
00:05:45 --> 00:05:47 dilation is significant, especially if
00:05:47 --> 00:05:49 you're looking at microsconds as we were
00:05:49 --> 00:05:53 in the last episode. Um yeah. Uh so they
00:05:53 --> 00:05:56 they do and look you're not talking
00:05:56 --> 00:05:58 about time dilation of the kind that was
00:05:58 --> 00:06:01 depicted in Interstellar where you know
00:06:01 --> 00:06:04 time kind of grinds to a halt almost. Uh
00:06:04 --> 00:06:06 it's a it's a more modest amount of time
00:06:06 --> 00:06:08 dilation but it would would actually
00:06:08 --> 00:06:11 happen. And uh Andrew's follow-up
00:06:11 --> 00:06:13 question. What about time dilation
00:06:13 --> 00:06:14 within the star itself? Presumably near
00:06:14 --> 00:06:17 the core this of these stars the density
00:06:17 --> 00:06:19 ramps right up. Does a large difference
00:06:19 --> 00:06:20 in time?
00:06:20 --> 00:06:23 >> I'm not going in there to find out.
00:06:23 --> 00:06:24 >> Does a large difference in time dilation
00:06:24 --> 00:06:27 within a star have any impact on how it
00:06:27 --> 00:06:30 behaves? Um, and there's a curious thing
00:06:30 --> 00:06:33 there because as you uh get near the the
00:06:33 --> 00:06:35 core of an object uh with spherical
00:06:36 --> 00:06:37 symmetry,
00:06:37 --> 00:06:39 um your gravitational field gets less
00:06:39 --> 00:06:42 and less. Uh and in fact, at the center,
00:06:42 --> 00:06:43 you wouldn't feel any gravity. And
00:06:43 --> 00:06:45 that's because everything's pulling you
00:06:45 --> 00:06:48 in the same direction all around. And I
00:06:48 --> 00:06:49 so I believe that time dilation will
00:06:50 --> 00:06:51 probably stop in the middle of a star.
00:06:51 --> 00:06:53 That might be right. So something I've
00:06:53 --> 00:06:56 never thought about before. Uh maybe
00:06:56 --> 00:06:58 that's not true because you you're still
00:06:58 --> 00:07:00 in a gravitational field. The fact that
00:07:00 --> 00:07:02 it cancels out everywhere. I'll check
00:07:02 --> 00:07:04 that one out actually and try and
00:07:04 --> 00:07:06 remember for our first show next year
00:07:06 --> 00:07:07 because that's a really interesting
00:07:07 --> 00:07:09 question. Time dilation in the center of
00:07:09 --> 00:07:11 a star. How does it behave?
00:07:12 --> 00:07:12 >> Yeah.
00:07:12 --> 00:07:13 >> Very interesting. But there wouldn't be
00:07:14 --> 00:07:15 a I I think the bottom line is there
00:07:15 --> 00:07:17 wouldn't be a a big difference in time
00:07:17 --> 00:07:19 dilation from one part of a star to
00:07:19 --> 00:07:21 another. That's that's what I'm trying
00:07:21 --> 00:07:21 to say.
00:07:21 --> 00:07:23 >> But he brings up another interesting
00:07:23 --> 00:07:25 point. You've got time dilation around a
00:07:25 --> 00:07:28 massive star. Yeah. Then it goes, you
00:07:28 --> 00:07:31 know, whatever black hole. Uh the time
00:07:32 --> 00:07:33 dilation changes.
00:07:33 --> 00:07:35 >> Yes, it does. Because um as it
00:07:35 --> 00:07:38 collapses, the the gravitational field
00:07:38 --> 00:07:43 increases. uh in increases in in um sort
00:07:43 --> 00:07:44 of angle in the sense that you know it's
00:07:44 --> 00:07:47 a steeper gravitational uh field as you
00:07:48 --> 00:07:50 get as the black hole collapses. And by
00:07:50 --> 00:07:51 that I'm thinking of the gravitational
00:07:51 --> 00:07:54 well you know this dip in in the in the
00:07:54 --> 00:07:55 trampoline sheet that's the
00:07:55 --> 00:07:57 gravitational well of an object which
00:07:57 --> 00:08:00 turns into something like a plug hole.
00:08:00 --> 00:08:02 Yeah. With water going around it as a
00:08:02 --> 00:08:05 vortex for a black hole. Uh so that's
00:08:05 --> 00:08:06 what I mean by the steepness of the
00:08:06 --> 00:08:09 gravitational field. Um and yes, it is
00:08:09 --> 00:08:11 so steep that the event horizon
00:08:11 --> 00:08:13 delineates where the time dilation
00:08:13 --> 00:08:16 becomes uh such that time appears to
00:08:16 --> 00:08:17 stop on the surface of the event
00:08:17 --> 00:08:18 horizon.
00:08:18 --> 00:08:20 >> Yeah, I've I've seen that demonstration
00:08:20 --> 00:08:23 done with like a a big rubber sheet and
00:08:23 --> 00:08:25 they say that right that's that's the
00:08:25 --> 00:08:27 time space-time continuum. Then they put
00:08:27 --> 00:08:28 a bowling ball in it and they said
00:08:28 --> 00:08:30 that's gravity.
00:08:30 --> 00:08:34 >> Yeah, that's right. Yep. Um I know.
00:08:34 --> 00:08:36 Yeah,
00:08:36 --> 00:08:38 >> it's a simple way of explaining it, but
00:08:38 --> 00:08:41 that's that's what it is. Um I suppose.
00:08:41 --> 00:08:43 >> Um great questions, Andrew, and I hope
00:08:43 --> 00:08:46 all is well in Edinburgh. Um Fred's uh
00:08:46 --> 00:08:48 Fred's home stomping ground. Um
00:08:48 --> 00:08:49 >> yep.
00:08:49 --> 00:08:50 >> Yeah, I'll give you his address and he
00:08:50 --> 00:08:53 can go and rock his roof. This is Bas
00:08:53 --> 00:08:55 Arts with Andrew Dunley and Professor
00:08:55 --> 00:08:57 Fred Watson. Uh we have got an audio
00:08:57 --> 00:09:01 question, Fred. This is from Adriano.
00:09:01 --> 00:09:03 Hi guys, Adrianiano from Florence in
00:09:03 --> 00:09:05 Italy. I have my first question about
00:09:05 --> 00:09:07 black holes. So if I understood
00:09:07 --> 00:09:09 correctly, a star continue to burn his
00:09:09 --> 00:09:12 fuel like hydrogen and helium and there
00:09:12 --> 00:09:14 are nuclear fusions and there is enough
00:09:14 --> 00:09:17 energy for the star to fight against its
00:09:17 --> 00:09:20 own gravitational pool. But at some
00:09:20 --> 00:09:22 point there is not enough fuel and the
00:09:22 --> 00:09:25 star collapse into a black hole. After
00:09:25 --> 00:09:28 this the black hole will start to absorb
00:09:28 --> 00:09:30 material like hydrogen and then it
00:09:30 --> 00:09:34 should have enough energy enough fuel to
00:09:34 --> 00:09:37 have nuclear fusions and to fight
00:09:37 --> 00:09:40 against the gravitational pool but uh so
00:09:40 --> 00:09:43 why a black hole cannot turn back into a
00:09:43 --> 00:09:45 star? I'm sure this is not possible but
00:09:45 --> 00:09:48 I cannot understand why. And also guys
00:09:48 --> 00:09:50 we had a lot of beautiful updates from
00:09:50 --> 00:09:52 the princess. Can we also have some
00:09:52 --> 00:09:54 updates from Fred? Thank you guys.
00:09:54 --> 00:09:55 Bye-bye,
00:09:55 --> 00:09:57 >> Adrianiano. Thank you very much. Um Fred
00:09:57 --> 00:10:01 gave us his update when he got back.
00:10:01 --> 00:10:04 >> But uh yeah, your point is well made. Um
00:10:04 --> 00:10:06 Florence, what a beautiful beautiful
00:10:06 --> 00:10:06 city.
00:10:06 --> 00:10:08 >> Yeah. Isn't it just
00:10:08 --> 00:10:09 >> uh we we visited Florence a few years
00:10:09 --> 00:10:13 ago and uh it was it was
00:10:13 --> 00:10:15 amazing, but it was also terrible timing
00:10:15 --> 00:10:17 because it was All Saints weekend, which
00:10:17 --> 00:10:19 is a 4-day long weekend, and there were
00:10:19 --> 00:10:22 like tens of thousands of people there.
00:10:22 --> 00:10:24 You couldn't move. You absolutely
00:10:24 --> 00:10:28 couldn't move. So, um uh we went to what
00:10:28 --> 00:10:31 was it called? The Ponttovecia. Um and
00:10:31 --> 00:10:32 we couldn't get near it. You just
00:10:32 --> 00:10:36 couldn't. It was um it was insane. Yeah.
00:10:36 --> 00:10:37 We didn't know until we got there.
00:10:37 --> 00:10:40 That's what was happening. But yeah, we
00:10:40 --> 00:10:41 still got to see it. It was a beautiful
00:10:41 --> 00:10:44 place. And all those amazing statues and
00:10:44 --> 00:10:47 Galileo got got up close with Galileo.
00:10:47 --> 00:10:49 >> Very good. Yeah.
00:10:49 --> 00:10:51 >> Yeah. Yeah. Did you see his um I think
00:10:51 --> 00:10:53 it's his it's one of his fingers or his
00:10:53 --> 00:10:54 thumb. I can't remember which is on
00:10:54 --> 00:10:56 display in the science museum there.
00:10:56 --> 00:10:59 >> Oh, no. No. Couldn't get near that. Um
00:10:59 --> 00:11:01 honestly, it was just mayhem. But um
00:11:01 --> 00:11:04 yeah, understandable though. Um all
00:11:04 --> 00:11:06 right, so the bottom line with Adriano's
00:11:06 --> 00:11:10 question is um why can't a black hole
00:11:10 --> 00:11:13 turned back into a star? Um yeah, I
00:11:13 --> 00:11:14 would I would think there'd be all sorts
00:11:14 --> 00:11:16 of reasons why not.
00:11:16 --> 00:11:18 >> Well, that's right. I think once you've
00:11:18 --> 00:11:22 turned into a singularity uh as the um
00:11:22 --> 00:11:26 >> you can't double down. Boom. Boom.
00:11:26 --> 00:11:27 >> Sorry.
00:11:27 --> 00:11:30 >> That you took the words out of my mouth.
00:11:30 --> 00:11:33 >> No, you didn't. Um I mean all bets are
00:11:33 --> 00:11:35 off basically once you once you've gone
00:11:35 --> 00:11:39 into a singularity. Uh and so um I think
00:11:39 --> 00:11:41 you know it's it's a great thought that
00:11:42 --> 00:11:44 um Adriano's had. I and that it's never
00:11:44 --> 00:11:47 occurred to me before, but but you know,
00:11:47 --> 00:11:49 you're talking about hydrogen uh which
00:11:49 --> 00:11:51 certainly would get sucked into a black
00:11:51 --> 00:11:54 hole because a lot of the gas clouds
00:11:54 --> 00:11:57 that um that a black hole um accretion
00:11:57 --> 00:12:00 disc would would draw in and and suck
00:12:00 --> 00:12:04 into the center. Uh that um uh that
00:12:04 --> 00:12:07 that's that's hydrogen. Uh and hydrogen
00:12:07 --> 00:12:09 is the raw material of stars. Why can't
00:12:09 --> 00:12:12 nuclear fusion kick in again and drive
00:12:12 --> 00:12:14 the star back into being a star rather
00:12:14 --> 00:12:16 than a black hole? And I think the
00:12:16 --> 00:12:19 answer is in structure. Um so stars have
00:12:20 --> 00:12:23 quite a complex structure uh to make
00:12:23 --> 00:12:26 them work uh with the the core with all
00:12:26 --> 00:12:28 the nuclear burning taking place. Then
00:12:28 --> 00:12:30 there's a convection zone and then
00:12:30 --> 00:12:32 there's an sort of outer layer before
00:12:32 --> 00:12:33 you get to the photosphere. the layer
00:12:33 --> 00:12:36 that you can see um when you've put
00:12:36 --> 00:12:39 something into a singularity all
00:12:39 --> 00:12:44 structure disappears and um it almost
00:12:44 --> 00:12:48 relates to um an issue that occupied the
00:12:48 --> 00:12:50 mind of Steven Hawking for a while which
00:12:50 --> 00:12:53 is that does information get lost when
00:12:53 --> 00:12:55 when it goes into a black hole
00:12:55 --> 00:12:58 >> and I think there was some argument with
00:12:58 --> 00:12:59 another well-known physicist in fact I
00:13:00 --> 00:13:03 think they had a bet uh which Hawin lost
00:13:03 --> 00:13:06 Um because the um the the b the I think
00:13:06 --> 00:13:08 the bottom line was hawking bet that
00:13:08 --> 00:13:10 information couldn't come out of a black
00:13:10 --> 00:13:12 hole but somebody proved a theory that
00:13:12 --> 00:13:14 information could come out of a black
00:13:14 --> 00:13:15 hole. I think I've got the the right way
00:13:15 --> 00:13:16 round.
00:13:16 --> 00:13:16 >> Okay.
00:13:16 --> 00:13:18 >> But basically it's all completely
00:13:18 --> 00:13:21 mangled in in terms of you know we don't
00:13:21 --> 00:13:23 understand the physics of what would
00:13:23 --> 00:13:25 happen inside a singularity. We just
00:13:25 --> 00:13:27 have no idea what the physical processes
00:13:27 --> 00:13:29 would be and they almost certainly would
00:13:29 --> 00:13:34 rule out hydrogen atoms getting together
00:13:34 --> 00:13:36 uh and with enough temperature to to to
00:13:36 --> 00:13:38 produce the nuclear fusion that we see
00:13:38 --> 00:13:41 in a normal star.
00:13:41 --> 00:13:43 A a black hole is a very abnormal
00:13:43 --> 00:13:46 object. Nothing relates to normal in a
00:13:46 --> 00:13:49 black hole. And so I think that is the
00:13:49 --> 00:13:51 answer to Adriana's question. uh physics
00:13:52 --> 00:13:53 physics doesn't work the way it works on
00:13:54 --> 00:13:55 the outside of a black hole and I think
00:13:55 --> 00:13:57 that's why we don't see black holes
00:13:57 --> 00:13:58 turning into stars.
00:13:58 --> 00:14:01 >> Yeah. Well, there's also the fuel issue
00:14:01 --> 00:14:03 like um you know the the star has
00:14:03 --> 00:14:06 collapsed because of fuel depletion has
00:14:06 --> 00:14:07 it not?
00:14:07 --> 00:14:08 >> Yes, that's right. But what we're saying
00:14:08 --> 00:14:10 and what Adriano is saying is that um
00:14:10 --> 00:14:13 among the stuff that is accreted by the
00:14:13 --> 00:14:15 black hole when it's sitting there
00:14:15 --> 00:14:17 gobbling stuff up, a lot of that is
00:14:17 --> 00:14:20 hydrogen which is the fuel. So, they're
00:14:20 --> 00:14:22 getting more fuel, but they don't any
00:14:22 --> 00:14:24 longer have the process to make it turn
00:14:24 --> 00:14:27 into something that will deliver energy.
00:14:27 --> 00:14:28 >> I think that's the bottom line.
00:14:28 --> 00:14:31 >> I get it. I get it. Okay. Um, great
00:14:32 --> 00:14:35 question though because uh
00:14:35 --> 00:14:37 we we've
00:14:37 --> 00:14:39 been talking black holes for I don't
00:14:39 --> 00:14:41 know how long. Probably since the very
00:14:41 --> 00:14:44 beginning of the time that this podcast
00:14:44 --> 00:14:46 began. And I don't think we've ever been
00:14:46 --> 00:14:47 asked that question before.
00:14:47 --> 00:14:50 >> No, I think that's right. Yeah.
00:14:50 --> 00:14:53 >> Says a lot for our for our listeners,
00:14:53 --> 00:14:55 doesn't it? That they can produce
00:14:55 --> 00:14:57 questions that we've never had before
00:14:57 --> 00:14:59 after however many episodes. Is it? It's
00:14:59 --> 00:15:01 getting on for 500 now.
00:15:01 --> 00:15:02 >> This is 582.
00:15:02 --> 00:15:04 >> Oh, 582. Okay.
00:15:04 --> 00:15:05 >> 582. Yeah.
00:15:05 --> 00:15:07 >> Right. There you go. Getting on for 600.
00:15:07 --> 00:15:10 >> I know. It's nuts. I mean, it's
00:15:10 --> 00:15:11 happening faster because of time
00:15:11 --> 00:15:14 dilation and the fact that we
00:15:14 --> 00:15:15 decided to do two episodes a week
00:15:16 --> 00:15:19 instead of one, but
00:15:19 --> 00:15:20 I think it's nuts by definition, isn't
00:15:20 --> 00:15:23 it? Um, I've got a feeling
00:15:23 --> 00:15:24 >> probably.
00:15:24 --> 00:15:25 >> Yeah.
00:15:25 --> 00:15:27 >> Uh, anyway, thank you, Adriano, and hope
00:15:27 --> 00:15:30 all is well in the beautiful Florence.
00:15:30 --> 00:15:32 This is Space Nuts with Andrew Dunley
00:15:32 --> 00:15:36 and Professor Fred Watson.
00:15:36 --> 00:15:37 Let's take a break from the show to tell
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00:17:08 --> 00:17:10 or you can tap on the link in the show
00:17:10 --> 00:17:12 notes.
00:17:12 --> 00:17:15 >> 3 2 1
00:17:15 --> 00:17:17 >> Space nuts.
00:17:17 --> 00:17:18 >> Our next question doesn't come from
00:17:18 --> 00:17:21 Italy. It comes from Slovenia. Um Russia
00:17:21 --> 00:17:22 next door.
00:17:22 --> 00:17:24 >> Yeah. Uh I am listening to your podcast
00:17:24 --> 00:17:27 while driving to and from work. Great
00:17:27 --> 00:17:29 show. I hope you managed to keep control
00:17:29 --> 00:17:31 because you know this gets a bit crazy
00:17:31 --> 00:17:33 sometimes. Uh I'm curious about wait for
00:17:33 --> 00:17:36 it Fred black holes. Uh we know that an
00:17:36 --> 00:17:38 atom is actually a lot of free space
00:17:38 --> 00:17:41 where electrons fly around. Uh
00:17:41 --> 00:17:44 eliminating that we probably probably
00:17:44 --> 00:17:47 get a neutron star uh with high density.
00:17:47 --> 00:17:49 But what about a black hole? How does
00:17:49 --> 00:17:52 this work? Where is the free space uh
00:17:52 --> 00:17:53 that can be squeezed even further to get
00:17:54 --> 00:17:56 a black hole uh get black hole material
00:17:56 --> 00:17:58 and density and to calculate the density
00:17:58 --> 00:18:00 of the black hole? Would it be a correct
00:18:00 --> 00:18:03 assumption to take the event horizon as
00:18:03 --> 00:18:07 the boundary and um based on that
00:18:07 --> 00:18:09 calculate the volume or is it something
00:18:09 --> 00:18:12 else? Um thank you. Best regards Isht.
00:18:12 --> 00:18:14 Um another black hole question. Not
00:18:14 --> 00:18:17 surprising we get a lot of them.
00:18:17 --> 00:18:21 >> We do. Yeah. So um the it's a it's a
00:18:21 --> 00:18:23 great question and I you that's
00:18:23 --> 00:18:25 absolutely right. An atom is a lot of
00:18:25 --> 00:18:27 free space empty space
00:18:27 --> 00:18:29 >> uh with cloud of electrons doing their
00:18:29 --> 00:18:33 quantum thing. Um if you collapse the
00:18:33 --> 00:18:35 space down so that only the electrons
00:18:35 --> 00:18:37 are pushing uh the atoms apart, you've
00:18:37 --> 00:18:39 got a white dwarf star uh which is
00:18:39 --> 00:18:42 called electron degenerate. Uh and if
00:18:42 --> 00:18:43 you get rid of the electrons, then you
00:18:43 --> 00:18:45 get a neutron star. Exactly as Ishtuk
00:18:45 --> 00:18:49 says uh with um very high density uh
00:18:49 --> 00:18:52 where only the neutrons keep the thing
00:18:52 --> 00:18:54 from collapsing into a black hole. But
00:18:54 --> 00:18:58 with a black hole um well the free space
00:18:58 --> 00:19:00 is is is basically disappeared down the
00:19:00 --> 00:19:05 black hole. Um it's uh it's and in terms
00:19:05 --> 00:19:09 of its density, you have a definition of
00:19:09 --> 00:19:12 a black hole. Uh, one of the definitions
00:19:12 --> 00:19:13 is a point in space with infinite
00:19:14 --> 00:19:16 density. So, the volume the volume is
00:19:16 --> 00:19:18 zero. See, Jordi Jordi thinks that as
00:19:18 --> 00:19:21 well. He does. Gosh, I don't know what's
00:19:21 --> 00:19:22 happening out there, but
00:19:22 --> 00:19:23 >> yeah,
00:19:23 --> 00:19:25 >> I love it.
00:19:25 --> 00:19:27 >> Oh, we had to hear we had to hear him
00:19:27 --> 00:19:29 from the last show of the year, didn't
00:19:29 --> 00:19:29 he?
00:19:29 --> 00:19:32 >> Last show of the year. That's right.
00:19:32 --> 00:19:34 >> In full flight.
00:19:34 --> 00:19:36 >> Um, so yes, so it's a point of infinite
00:19:36 --> 00:19:39 density. So um it's a comment about
00:19:39 --> 00:19:41 calculating the density of the black
00:19:41 --> 00:19:42 hole. Would it be a correct assumption
00:19:42 --> 00:19:44 to take the event horizon as the
00:19:44 --> 00:19:47 boundary? Uh no it wouldn't. The event
00:19:47 --> 00:19:49 horizon is just that imaginary point
00:19:49 --> 00:19:52 where of no return. Uh and the volume is
00:19:52 --> 00:19:54 zero. Uh the volume of the black hole is
00:19:54 --> 00:19:57 zero which is how the the density gets
00:19:57 --> 00:20:01 infinite because um mass over density
00:20:01 --> 00:20:03 sorry mass over volume is density. The
00:20:03 --> 00:20:06 mass is a is a parameter. Um, but the
00:20:06 --> 00:20:08 volume is zero. I have no idea what's
00:20:08 --> 00:20:09 happening out there. I drew it with
00:20:10 --> 00:20:11 Jordy, but he obviously likes this
00:20:11 --> 00:20:12 conversation.
00:20:12 --> 00:20:16 >> Yes. Yes, he does. He wants in.
00:20:16 --> 00:20:17 >> Yeah.
00:20:17 --> 00:20:21 >> Oh dear. Um, yeah. Look, I still don't
00:20:21 --> 00:20:23 get
00:20:23 --> 00:20:26 >> receding into the distance.
00:20:26 --> 00:20:29 >> Yeah. Probably chasing a snake. Um,
00:20:29 --> 00:20:30 yeah. Uh,
00:20:30 --> 00:20:34 >> go ahead, Andrew. No, it's it's hard to
00:20:34 --> 00:20:36 get your head around something like a
00:20:36 --> 00:20:38 black hole
00:20:38 --> 00:20:41 having
00:20:41 --> 00:20:45 no density.
00:20:45 --> 00:20:46 >> No volume.
00:20:47 --> 00:20:49 >> It's got no size. It's got zero
00:20:49 --> 00:20:50 dimensions.
00:20:50 --> 00:20:53 >> I mean, we we we give them names based
00:20:53 --> 00:20:56 on size and yet it has no size. Has no
00:20:56 --> 00:20:56 volume.
00:20:56 --> 00:20:58 >> Super massive. Yeah. Well, but it's the
00:20:58 --> 00:21:00 mass. That's the thing. So the mass is
00:21:00 --> 00:21:02 defined for a black hole. It's one of
00:21:02 --> 00:21:03 the properties that they have. The
00:21:03 --> 00:21:06 there's this thing called the the no
00:21:06 --> 00:21:09 hair theorem uh which I like very much.
00:21:09 --> 00:21:10 >> Yeah.
00:21:10 --> 00:21:11 >> And it's about you know
00:21:11 --> 00:21:12 >> would that wouldn't
00:21:12 --> 00:21:15 >> Yeah, that's right. Which there's it's
00:21:15 --> 00:21:18 about the very few parameters that you
00:21:18 --> 00:21:20 can get from a black hole. I think it's
00:21:20 --> 00:21:22 mass, charge and spin. I think that's
00:21:22 --> 00:21:25 all you know about a black hole. Um
00:21:25 --> 00:21:27 because the volume's zero and that's why
00:21:27 --> 00:21:29 the density is zero. Density is mass
00:21:29 --> 00:21:31 over volume. Volume zero. So the density
00:21:31 --> 00:21:33 goes to infinite infinity but you can
00:21:34 --> 00:21:36 vary the mass and that's why we talk
00:21:36 --> 00:21:37 about super massive black holes and
00:21:37 --> 00:21:39 intermediate mass black holes and things
00:21:39 --> 00:21:40 of that sort.
00:21:40 --> 00:21:43 >> Okay. So what was the answer to the
00:21:43 --> 00:21:44 question?
00:21:44 --> 00:21:48 >> Uh no. Right. Right. What was the
00:21:48 --> 00:21:51 question again? Hang on. Uh yeah. Would
00:21:51 --> 00:21:53 it be yes would it be correct assumption
00:21:53 --> 00:21:55 to take the event horizon as a boundary
00:21:55 --> 00:21:56 and and use that to calculate the
00:21:56 --> 00:21:58 volume? No. The event horizon is an
00:21:58 --> 00:22:02 imaginary sphere that um is where the
00:22:02 --> 00:22:03 thing turns black basically because no
00:22:04 --> 00:22:05 light can escape
00:22:05 --> 00:22:07 >> precisely.
00:22:07 --> 00:22:10 Um hope that helped is uh it's a great
00:22:10 --> 00:22:11 question.
00:22:11 --> 00:22:13 >> It is terrific question. Uh just a very
00:22:13 --> 00:22:16 difficult subject cuz we we just don't
00:22:16 --> 00:22:19 know a hell of a lot about black holes.
00:22:19 --> 00:22:23 They're just such a mysterious and
00:22:23 --> 00:22:26 weird object. And um we we're we're
00:22:26 --> 00:22:28 still trying to gather information about
00:22:28 --> 00:22:30 them and they just keep throwing up
00:22:30 --> 00:22:32 these curve balls at us and not letting
00:22:32 --> 00:22:34 us in. Not that you want to go in, but
00:22:34 --> 00:22:36 you know what I mean.
00:22:36 --> 00:22:37 >> Yes, that's right.
00:22:38 --> 00:22:39 >> Yeah, quite s.
00:22:39 --> 00:22:42 >> All right, thanks.
00:22:42 --> 00:22:44 >> Time to take a break from the show to
00:22:44 --> 00:22:46 tell you about our sponsor, NordVPN. If
00:22:46 --> 00:22:49 you're online, your data is always at
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00:22:56 --> 00:22:58 private network is the way to go. Uh
00:22:58 --> 00:23:00 there are lots of hackers and trackers
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00:24:08 --> 00:24:09 And don't forget the code word Space
00:24:09 --> 00:24:11 Nuts at the checkout.
00:24:11 --> 00:24:12 >> Space Nuts.
00:24:12 --> 00:24:15 >> We have one more question to finish
00:24:15 --> 00:24:19 things off for 2025 and it it's a real
00:24:19 --> 00:24:21 European flavor for this episode. This
00:24:21 --> 00:24:22 is Ggo.
00:24:22 --> 00:24:25 >> Greetings gentlemen. GGO from Slovakia
00:24:25 --> 00:24:27 here. I have a question about red
00:24:27 --> 00:24:30 shifting. Does it have a limit? Is there
00:24:30 --> 00:24:32 a point beyond which light cannot be
00:24:32 --> 00:24:34 stretched any further? If so, what
00:24:34 --> 00:24:36 happens if the light continues to travel
00:24:36 --> 00:24:39 through expanding space? And the second
00:24:39 --> 00:24:41 question, could you talk a bit about
00:24:41 --> 00:24:44 gra? Do you think they might be real?
00:24:44 --> 00:24:46 Uh, thank you for your time and for the
00:24:46 --> 00:24:48 great show. Bye.
00:24:48 --> 00:24:52 >> Thanks, Ggo. Uh, yeah, it's we an
00:24:52 --> 00:24:55 eclectic mix of nationalities this week.
00:24:55 --> 00:24:56 Yeah, it's terrific.
00:24:56 --> 00:24:57 >> Yeah, it's great.
00:24:57 --> 00:25:00 >> Uh, so two questions he's um he's thrown
00:25:00 --> 00:25:03 into the mix. Um, yeah. Is there a limit
00:25:03 --> 00:25:06 on red shift? Um,
00:25:06 --> 00:25:09 yeah, good one. So,
00:25:09 --> 00:25:12 uh, yeah, it is a good question. I mean,
00:25:12 --> 00:25:19 so, so red shift as a term we define as
00:25:19 --> 00:25:20 being due to the expansion of the
00:25:20 --> 00:25:23 universe. Um, and it's slightly
00:25:23 --> 00:25:26 different from the Doppler shift. Uh,
00:25:26 --> 00:25:28 Doppler shift is something we understand
00:25:28 --> 00:25:30 well. It's the way the light changes
00:25:30 --> 00:25:32 wavelength from a moving object. But
00:25:32 --> 00:25:34 with red shift, we're talking about
00:25:34 --> 00:25:36 space itself rather than rather than
00:25:36 --> 00:25:38 objects moving through space. We're
00:25:38 --> 00:25:40 talking about the way space behaves. Uh
00:25:40 --> 00:25:43 and so it's a a much more fundamental
00:25:43 --> 00:25:46 thing than the Doppler shift. So in a
00:25:46 --> 00:25:49 sense, um there's already a limit to red
00:25:49 --> 00:25:55 shift. Uh but it's one that is exactly
00:25:55 --> 00:25:58 related to the age of the universe. Um,
00:25:58 --> 00:26:02 so and for so what I'm thinking of here
00:26:02 --> 00:26:05 is the the uh cosmic microwave
00:26:06 --> 00:26:08 background radiation. That's the wall of
00:26:08 --> 00:26:11 radiation which corresponds to the
00:26:11 --> 00:26:15 brightness of the big bang fireball
00:26:15 --> 00:26:17 which we're still seeing because as we
00:26:17 --> 00:26:19 look further into space, we look back in
00:26:19 --> 00:26:22 time. So everywhere in space we see this
00:26:22 --> 00:26:24 wall of radiation which is now in the
00:26:24 --> 00:26:26 microwave region of the spectrum which
00:26:26 --> 00:26:28 is why we call it the cosmic microwave
00:26:28 --> 00:26:29 background radiation.
00:26:29 --> 00:26:29 >> Yeah.
00:26:29 --> 00:26:34 >> And so um it's if I remember rightly
00:26:34 --> 00:26:38 that is basically the visible flash of
00:26:38 --> 00:26:42 the big bang because it was it was
00:26:42 --> 00:26:46 basically a a visible light flash. It's
00:26:46 --> 00:26:50 the visible flash redshifted by I think
00:26:50 --> 00:26:54 about 1300 times. So everything in the
00:26:54 --> 00:26:57 universe must have a that we can observe
00:26:57 --> 00:27:00 must have a red shift less than that. Uh
00:27:00 --> 00:27:03 I think 1300 is the the number that
00:27:03 --> 00:27:05 comes into my mind. I've looked at this
00:27:05 --> 00:27:07 for a long time. Um but it's visible
00:27:07 --> 00:27:11 light um whose uh which whose waves have
00:27:11 --> 00:27:14 been stretched by that amount to give us
00:27:14 --> 00:27:17 microwaves. So stretched about 1300
00:27:17 --> 00:27:19 times thereabouts.
00:27:19 --> 00:27:21 Now um
00:27:21 --> 00:27:24 as the universe expands and time goes on
00:27:24 --> 00:27:27 that number will increase not by much
00:27:27 --> 00:27:31 might become 131 or 135 but as time goes
00:27:31 --> 00:27:34 on that number is increasing. So
00:27:34 --> 00:27:37 >> in a sense that's a limit to red shift.
00:27:37 --> 00:27:39 Uh physically though I don't think there
00:27:39 --> 00:27:41 is a limit. You could, you know, if if
00:27:41 --> 00:27:43 you expand the universe, if you're
00:27:43 --> 00:27:44 talking about 40 billion years into the
00:27:44 --> 00:27:46 future and the universe is expanding
00:27:46 --> 00:27:48 more, yes, the cosmic microwave
00:27:48 --> 00:27:50 background is going to be the cosmic
00:27:50 --> 00:27:53 long wavelength radio background. Uh,
00:27:53 --> 00:27:57 and so it's uh it's the the wavelength
00:27:57 --> 00:27:59 will have stretched more. Uh, so there
00:27:59 --> 00:28:03 isn't a physical limit, but there is a a
00:28:03 --> 00:28:06 limit in the real universe. uh simply
00:28:06 --> 00:28:07 because of the age of the universe. The
00:28:07 --> 00:28:10 universe hasn't hasn't expanded for long
00:28:10 --> 00:28:12 enough for the red shift to be more than
00:28:12 --> 00:28:14 about 1300.
00:28:14 --> 00:28:17 >> Right. Okay. Yeah. Got it.
00:28:17 --> 00:28:19 >> Good. What was the other thing? Oh,
00:28:19 --> 00:28:19 gravity stars.
00:28:20 --> 00:28:21 >> Oh, grav stars. Yeah, we've had we've
00:28:21 --> 00:28:24 had questions about gravis stars before
00:28:24 --> 00:28:26 more than once. Um it it seems to be
00:28:26 --> 00:28:28 something that sort of captured the
00:28:28 --> 00:28:31 imagination of uh of people that are so
00:28:31 --> 00:28:33 interested in astronomy and space
00:28:33 --> 00:28:36 science. So, I suppose we should start
00:28:36 --> 00:28:39 by reminding people what a graar is
00:28:39 --> 00:28:40 supposed to be because I don't think
00:28:40 --> 00:28:42 we've ever found one.
00:28:42 --> 00:28:45 >> No, that's correct. Um, I'm I'm going to
00:28:45 --> 00:28:47 read from uh that font of all knowledge,
00:28:47 --> 00:28:51 Wikipedia, who I do subscribe to uh
00:28:51 --> 00:28:52 despite the fact that they keep asking
00:28:52 --> 00:28:54 me for another subscription. Anyway,
00:28:54 --> 00:28:55 that's probably because I've got more
00:28:55 --> 00:28:58 than one username. Never mind. Let me
00:28:58 --> 00:29:01 read from Wikipedia. In astrophysics,
00:29:01 --> 00:29:04 the graar which is a blend word of
00:29:04 --> 00:29:07 gravitational vacuum star is an object
00:29:07 --> 00:29:11 hypothesized in a 2001 paper by Pavl O
00:29:11 --> 00:29:16 Mazour and Emil Moah as an alternative
00:29:16 --> 00:29:19 to the black hole theory. It has the
00:29:19 --> 00:29:21 usual black hole metric outside of the
00:29:21 --> 00:29:23 horizon and a metric is just a way of
00:29:23 --> 00:29:27 describing space but ditter metric
00:29:27 --> 00:29:30 inside and that's a different one. Don't
00:29:30 --> 00:29:32 worry about that. A typical grav star is
00:29:32 --> 00:29:36 as big as London but weighs 10 solar
00:29:36 --> 00:29:37 masses.
00:29:37 --> 00:29:38 >> Why?
00:29:38 --> 00:29:40 >> Yeah. So a neutron star would be about
00:29:40 --> 00:29:42 the size of London but weigh one solar
00:29:42 --> 00:29:44 mass basically.
00:29:44 --> 00:29:46 >> Didn't they find one in a sewer? Um,
00:29:46 --> 00:29:47 they called it a fatburgg or something.
00:29:48 --> 00:29:50 >> Fatburgg. That's right. Yeah. Which was
00:29:50 --> 00:29:52 just about to turn into a graver star.
00:29:52 --> 00:29:56 Yes. Um, on the horizon there is an
00:29:56 --> 00:29:59 ultra thin, incredibly tight shell of
00:29:59 --> 00:30:03 entirely new unique exotic matter named
00:30:03 --> 00:30:05 Galactic Flubber.
00:30:05 --> 00:30:07 >> I was close.
00:30:07 --> 00:30:09 >> You weren't far off. That's right. Which
00:30:09 --> 00:30:11 is the next thing to a fatburg. Yeah.
00:30:11 --> 00:30:13 Anyway, continuing to read. This
00:30:13 --> 00:30:15 solution to the Einstein equations is
00:30:15 --> 00:30:18 stable and there's no singularities
00:30:18 --> 00:30:20 which we've just been talking about
00:30:20 --> 00:30:23 singularities points of zero volume.
00:30:23 --> 00:30:25 Instead, a grav star is filled with
00:30:25 --> 00:30:28 either dark energy or with vacuum energy
00:30:28 --> 00:30:30 but also vacuum
00:30:30 --> 00:30:33 only the inside one 10 to the 44 times
00:30:33 --> 00:30:36 denser than the outside. I'm not sure
00:30:36 --> 00:30:37 how you can have a vacuum that's 10 to
00:30:38 --> 00:30:40 the 44 times denser than another one,
00:30:40 --> 00:30:43 but I'll just let that pass. Yes.
00:30:43 --> 00:30:46 >> Uh, as a bonus, further theoretical
00:30:46 --> 00:30:48 considerations of grav stars include the
00:30:48 --> 00:30:51 notion of a nest star, a second graar
00:30:51 --> 00:30:54 nested within the first one. So, that's
00:30:54 --> 00:30:56 the technical definition. I bet you're
00:30:56 --> 00:30:59 no wiser than I am. Um, but the bottom
00:30:59 --> 00:31:03 line is that um um and I'll read again.
00:31:03 --> 00:31:06 Mazour and Matahus suggest that the
00:31:06 --> 00:31:09 violent creation of a grab star might be
00:31:09 --> 00:31:11 an explanation for the origin of our
00:31:11 --> 00:31:14 universe and many other universes
00:31:14 --> 00:31:15 because all the matter from a collapsing
00:31:16 --> 00:31:18 star would implode through the central
00:31:18 --> 00:31:20 hole and explode into a new dimension
00:31:20 --> 00:31:22 and expand forever which would be
00:31:22 --> 00:31:25 consistent with the con current theories
00:31:25 --> 00:31:27 regarding the big bang.
00:31:27 --> 00:31:31 >> Okay. So now that we know what it is.
00:31:31 --> 00:31:33 >> Yeah. Do you think they exist? And will
00:31:34 --> 00:31:35 we ever find one?
00:31:35 --> 00:31:39 >> Uh, no and no, basically. Uh, it's um
00:31:39 --> 00:31:42 it's a it's a an alternative theory for
00:31:42 --> 00:31:43 the Big Bang.
00:31:43 --> 00:31:46 >> Uh, and it's certainly interesting and
00:31:46 --> 00:31:50 uh I you know I I think um uh GGO's
00:31:50 --> 00:31:52 asked us to talk about it and now we
00:31:52 --> 00:31:56 have so so um that's perhaps doing the
00:31:56 --> 00:31:59 best we can. Um interesting. There's
00:31:59 --> 00:32:01 there's just one other sentence I might
00:32:01 --> 00:32:04 like to read. Uh
00:32:04 --> 00:32:09 uh if I can find it. I've lost it now.
00:32:09 --> 00:32:12 Oh yeah. The the new dimension that will
00:32:12 --> 00:32:15 be created in this implosion. The new
00:32:15 --> 00:32:18 dimension exerts an outward pressure on
00:32:18 --> 00:32:21 the Bose Einstein condensate layer and
00:32:21 --> 00:32:23 present prevents it from collapsing
00:32:23 --> 00:32:26 further. So the Bose Einstein
00:32:26 --> 00:32:28 condensate, it sounds as though that's
00:32:28 --> 00:32:30 this thinned crust that it's got rather
00:32:30 --> 00:32:33 than an event horizon. And a Bose
00:32:33 --> 00:32:35 Einstein condensate is really
00:32:35 --> 00:32:37 interesting. I think we've just
00:32:37 --> 00:32:39 celebrated,
00:32:39 --> 00:32:43 is it the 30th anniversary of the first
00:32:43 --> 00:32:46 example of a Bose Einstein condenser
00:32:46 --> 00:32:48 being produced? I think that's right. I
00:32:48 --> 00:32:51 think it's 30 years. I think it's 1995.
00:32:51 --> 00:32:54 Uh what is it? It's a a it's a
00:32:54 --> 00:32:56 condensation of atoms at very low
00:32:56 --> 00:32:59 temperature that behave like one quantum
00:32:59 --> 00:33:02 object. Uh that's the crucial thing. So
00:33:02 --> 00:33:04 they it's almost like entanglement,
00:33:04 --> 00:33:05 Andrew, where you've got quantum
00:33:05 --> 00:33:07 particles being entangled. This is a
00:33:07 --> 00:33:09 whole bunch of stuff that is so
00:33:09 --> 00:33:11 entangled it just looks like one quantum
00:33:11 --> 00:33:14 object and we've we can now create them.
00:33:14 --> 00:33:16 >> Um so that's what they're saying that
00:33:16 --> 00:33:18 maybe this thing is made of a Bose
00:33:18 --> 00:33:20 Einstein condenser. I think this is a
00:33:20 --> 00:33:23 really good way to end uh the year's uh
00:33:23 --> 00:33:25 space nuts episode because it is
00:33:25 --> 00:33:28 completely off the wall and talking
00:33:28 --> 00:33:30 about stuff that is right at the cutting
00:33:30 --> 00:33:32 edge of physics which I love
00:33:32 --> 00:33:34 >> indeed. Uh thank you for your questions
00:33:34 --> 00:33:37 Ggo and uh hope you're well. Uh good to
00:33:37 --> 00:33:39 hear from you. You sent in questions
00:33:39 --> 00:33:41 before so it's nice to catch up. Uh in
00:33:41 --> 00:33:45 fact I think um I think Isht uh has sent
00:33:45 --> 00:33:47 questions in before as well. But uh
00:33:47 --> 00:33:48 yeah, thank you for your questions
00:33:48 --> 00:33:50 everybody for uh contributing to this
00:33:50 --> 00:33:52 the final episode of 2025. Keep the
00:33:52 --> 00:33:54 questions coming in because we're coming
00:33:54 --> 00:33:55 back
00:33:55 --> 00:33:57 >> next year and we'll we'll need some
00:33:57 --> 00:33:59 fresh stuff cuz we're we're down to the
00:33:59 --> 00:34:02 last one or two um which I didn't use
00:34:02 --> 00:34:03 because they all came from the same
00:34:03 --> 00:34:05 source and I like to spread the love a
00:34:05 --> 00:34:07 bit. So um we'll get into those next
00:34:07 --> 00:34:09 year. Uh if you go to our website if
00:34:09 --> 00:34:11 you'd like to send a question in, click
00:34:11 --> 00:34:14 on the AMA link at the top and you can
00:34:14 --> 00:34:16 send text and audio questions there. As
00:34:16 --> 00:34:18 always, please remember to tell us who
00:34:18 --> 00:34:20 you are and where you're from. While
00:34:20 --> 00:34:22 you're at on the website, um check out
00:34:22 --> 00:34:24 how you might be able to support us uh
00:34:24 --> 00:34:27 through various channels. Um whatever
00:34:27 --> 00:34:29 you choose or don't choose to, we're not
00:34:29 --> 00:34:31 going to make you do it. Uh you can
00:34:31 --> 00:34:32 check out the shop as well. That's
00:34:32 --> 00:34:35 another way of supporting us. And so on
00:34:35 --> 00:34:37 and so forth. Um, while I
00:34:37 --> 00:34:39 >> I think Andrew, while you were talking
00:34:39 --> 00:34:40 about the questions, I think we've got a
00:34:40 --> 00:34:43 pending one still from Rusty, which we
00:34:43 --> 00:34:44 should
00:34:44 --> 00:34:46 >> I'm sure we'll take it next year.
00:34:46 --> 00:34:50 >> Yes. Yes, I I recall that. But, um, we I
00:34:50 --> 00:34:51 thought we'd sit on it till the new year
00:34:51 --> 00:34:53 because reading the question will
00:34:53 --> 00:34:59 actually take the pulp of the episode.
00:34:59 --> 00:35:00 >> Thank you, Andrew. Sorry to interrupt
00:35:00 --> 00:35:02 you there. That's okay. No, it's okay.
00:35:02 --> 00:35:04 Um, I just want to say thank you to you,
00:35:04 --> 00:35:06 Fred. Um,
00:35:06 --> 00:35:09 And and I should also um thank Jonty
00:35:10 --> 00:35:12 because he he did a fair chunk of the
00:35:12 --> 00:35:16 show and we also had our guest presenter
00:35:16 --> 00:35:18 Heidi while I was away. So thank you to
00:35:18 --> 00:35:21 Heidi for uh her amazing contribution
00:35:21 --> 00:35:24 because uh it really saved my uh my back
00:35:24 --> 00:35:27 because um there was probably no way in
00:35:27 --> 00:35:28 the world I could have recorded from a
00:35:28 --> 00:35:30 cruise ship and got away with it. But um
00:35:30 --> 00:35:32 yeah, fantastic. Uh we've got a great
00:35:32 --> 00:35:37 team. Um and and you know bring on the
00:35:37 --> 00:35:39 next uh the next year of Space Nuts. And
00:35:39 --> 00:35:41 I look I give him a hard time every
00:35:41 --> 00:35:42 week. I do. But I've got to say thanks
00:35:42 --> 00:35:46 to Hugh in the studio for his um amazing
00:35:46 --> 00:35:48 work. It's not just our podcast that he
00:35:48 --> 00:35:50 looks after. He's got a whole stable of
00:35:50 --> 00:35:53 them. And uh it's it's basically a
00:35:53 --> 00:35:55 full-time job trying to run all this. uh
00:35:55 --> 00:35:57 and you know there's not much money in
00:35:57 --> 00:36:00 it but uh uh there's certainly joy in
00:36:00 --> 00:36:03 putting our skills into something uh in
00:36:03 --> 00:36:06 our semi-retirement um from from radio.
00:36:06 --> 00:36:09 So um yeah but uh also without the
00:36:09 --> 00:36:12 audience we would be nothing. So we send
00:36:12 --> 00:36:16 out our um uh our thanks. We are so
00:36:16 --> 00:36:19 grateful to have you behind us. And I do
00:36:19 --> 00:36:21 keep an eye on the audience through the
00:36:21 --> 00:36:24 Space Nuts podcast group on Facebook
00:36:24 --> 00:36:26 because they uh they spend a lot of time
00:36:26 --> 00:36:27 there talking to each other, sharing
00:36:27 --> 00:36:31 pictures uh and uh posing unusual
00:36:31 --> 00:36:32 questions which occasionally we will
00:36:32 --> 00:36:35 bring up on the show. And special thanks
00:36:35 --> 00:36:37 to our sponsors. We've had a few
00:36:37 --> 00:36:38 sponsors who've been with us for quite
00:36:38 --> 00:36:41 some time now and and you know obviously
00:36:41 --> 00:36:42 we're doing something right if they're
00:36:42 --> 00:36:45 willing to stick with us. So very much
00:36:45 --> 00:36:49 appreciated. Uh thank you Fred. Um thank
00:36:49 --> 00:36:53 you uh Jordy and um we'll talk to you in
00:36:53 --> 00:36:55 the new year.
00:36:55 --> 00:36:56 >> Sounds great. Look forward to it Andrew
00:36:56 --> 00:36:58 and all the very best for the festive
00:36:58 --> 00:36:58 season to you
00:36:58 --> 00:37:01 >> and to you and um thank you very much.
00:37:02 --> 00:37:03 Professor Fred Watson, astronomer at
00:37:03 --> 00:37:05 large. And from me, Andrew Dunley, have
00:37:05 --> 00:37:07 a great Christmas, a happy new year.
00:37:07 --> 00:37:10 We'll see you in 2026. Until then,
00:37:10 --> 00:37:11 bye-bye.
00:37:11 --> 00:37:14 >> Space. your Venus to the Space Nuts
00:37:14 --> 00:37:16 podcast
00:37:16 --> 00:37:19 >> available at Apple Podcasts, Spotify,
00:37:19 --> 00:37:22 iHeart Radio, or your favorite podcast
00:37:22 --> 00:37:24 player. You can also stream on demand at
00:37:24 --> 00:37:26 byes.com.
00:37:26 --> 00:37:28 This has been another quality podcast
00:37:28 --> 00:37:32 production from byes.com.