- The potential for a future black void in our night sky as the universe continues to expand.
- Understanding the graviton: Why do some physicists believe in its existence despite its elusive nature?
- Exploring the properties of photons and their wave-particle duality.
- The impact of long-term weightlessness on astronauts and their return to normal gravity.
- Listener feedback and inspiring stories about engaging younger generations in astronomy.
- 00:00 - Introduction to today's Q&A session and listener engagement
- 02:30 - Clint's question about the future of the night sky and cosmic expansion
- 12:45 - Alan's deep dive into gravitons and their connection to gravity
- 28:00 - Misty's inquiry about the wave function of particles and photons
- 40:15 - Casey's question on the effects of returning to gravity after weightlessness
- 50:30 - Final thoughts and encouragement for listener questions
Join Andrew and Fred Watson for another fascinating exploration of the cosmos, and don't forget to send in your questions for future episodes. Keep your curiosity alive and continue to look up!
00:00:00 --> 00:00:02 Andrew Dunkley: Hello again. Thanks for joining us. This is a
00:00:02 --> 00:00:05 Q and A edition of Space Nuts. We talk
00:00:05 --> 00:00:07 astronomy, space science, and answer
00:00:07 --> 00:00:10 audience questions. Well, maybe we won't do
00:00:10 --> 00:00:12 one of those three things today. I don't
00:00:12 --> 00:00:14 know. We'll see how it goes. Uh, we've got a
00:00:14 --> 00:00:16 lot of questions to get through today. Um,
00:00:16 --> 00:00:17 Fred Watson reckons some of these are very,
00:00:17 --> 00:00:20 very tricky, so we'll see how it all pans
00:00:20 --> 00:00:23 out. Um, a question about the expanding
00:00:23 --> 00:00:25 universe. Never had one of those before. Uh,
00:00:25 --> 00:00:28 a question about gravitons. Never had one of
00:00:28 --> 00:00:31 those before. Yes, we have. Uh, photons
00:00:31 --> 00:00:34 and weight shift. That's all coming up on
00:00:34 --> 00:00:37 this edition of space nuts. 15
00:00:37 --> 00:00:37 seconds.
00:00:37 --> 00:00:40 Professor Fred Watson: Guidance is internal. 10,
00:00:40 --> 00:00:43 9. Ignition sequence start.
00:00:43 --> 00:00:46 Space nuts. 5, 4, 3. 2. 1, 2,
00:00:46 --> 00:00:49 3, 4, 5, 5, 4, 3, 2, 1.
00:00:49 --> 00:00:52 Andrew Dunkley: Space nuts. Astronauts report it feels
00:00:52 --> 00:00:54 good. And joining us once more to
00:00:54 --> 00:00:57 unravel all of that, or maybe ravel it
00:00:57 --> 00:00:59 up even more, is Professor Fred Watson
00:00:59 --> 00:01:00 Watson, astronomer at, uh, large. Hello,
00:01:00 --> 00:01:01 Fred Watson.
00:01:01 --> 00:01:04 Professor Fred Watson: Hello, Andrew. I do feel pretty ravelled at
00:01:04 --> 00:01:05 the moment.
00:01:05 --> 00:01:07 Andrew Dunkley: Yeah, look, we have got some tricky
00:01:07 --> 00:01:10 questions, but before we get to those, uh,
00:01:10 --> 00:01:13 we've received a note from Rennie in
00:01:13 --> 00:01:13 California.
00:01:13 --> 00:01:16 Uh, Rennie quite regularly sends questions
00:01:16 --> 00:01:18 into us, but he sent us a really lovely note
00:01:19 --> 00:01:22 which I want to share. Uh, he says no
00:01:22 --> 00:01:24 questions today, just to thank you. I try to
00:01:24 --> 00:01:26 absorb as much information as I can listening
00:01:26 --> 00:01:28 to your podcast. And when I'm engaged in a
00:01:28 --> 00:01:31 convers conversation with my two grandsons
00:01:31 --> 00:01:33 aged 15 and 12, I try to excite
00:01:33 --> 00:01:36 them and get them to think about our place in
00:01:36 --> 00:01:39 the universe and how it behaves. Now it's
00:01:39 --> 00:01:41 paying off with the announcement that my
00:01:41 --> 00:01:44 older grandson wants to carry on in college
00:01:44 --> 00:01:47 with some form of education in astronomy
00:01:47 --> 00:01:50 or particle physics. Thank you for paying
00:01:50 --> 00:01:52 it forward, Renny. Isn't that lovely?
00:01:52 --> 00:01:54 Professor Fred Watson: Yeah, that's great. Absolutely great.
00:01:54 --> 00:01:56 Andrew Dunkley: Uh, I love it when we get feedback from
00:01:56 --> 00:01:59 people that, that become inspired
00:02:00 --> 00:02:01 despite us.
00:02:04 --> 00:02:05 No, I mean, it's fantastic.
00:02:05 --> 00:02:05 Professor Fred Watson: It is.
00:02:05 --> 00:02:07 Andrew Dunkley: I'm really, really pleased. Really pleased.
00:02:07 --> 00:02:10 So, um, pass on our regards, Rennie, to your
00:02:10 --> 00:02:12 boys or, uh, your grandsons, um, and wish
00:02:12 --> 00:02:14 them well and. Yeah, look, just.
00:02:15 --> 00:02:17 I do the same thing with my grandson and
00:02:17 --> 00:02:20 three granddaughters. Um, I talk to them
00:02:20 --> 00:02:22 whenever there's something interesting to
00:02:22 --> 00:02:24 talk about, and there usually is, uh, in the
00:02:24 --> 00:02:27 astronomical world. And, um, I show
00:02:27 --> 00:02:29 them the images I take with the Telesco, and
00:02:29 --> 00:02:32 I've even had them outside looking up at the
00:02:32 --> 00:02:35 moon. And, um, yeah, it's captivating. Once,
00:02:35 --> 00:02:37 once they, you know, once you can convince
00:02:37 --> 00:02:38 them to actually get outside.
00:02:39 --> 00:02:42 Um, you know, the universe is their
00:02:42 --> 00:02:45 oyster. It's, uh, it's good
00:02:45 --> 00:02:47 stuff. So lovely to hear from you, Rennie.
00:02:47 --> 00:02:49 And that is really fabulous news.
00:02:50 --> 00:02:51 Are you ready for your first question,
00:02:51 --> 00:02:51 Fred Watson?
00:02:53 --> 00:02:55 Professor Fred Watson: Well, after a. Yes. After a build up like
00:02:55 --> 00:02:56 that, I guess we've got to tackle them,
00:02:56 --> 00:02:57 haven't we?
00:02:57 --> 00:02:58 Andrew Dunkley: Uh, we probably should.
00:02:58 --> 00:03:00 Professor Fred Watson: You're right, in a way. You know, the
00:03:00 --> 00:03:02 ultimate notes, I guess,
00:03:03 --> 00:03:06 is to provide that little bit of perhaps
00:03:06 --> 00:03:09 inspiration that might lead people to do
00:03:09 --> 00:03:11 things that might one day change the world.
00:03:11 --> 00:03:12 Who knows?
00:03:12 --> 00:03:14 Andrew Dunkley: Yep, you just don't know. You just don't
00:03:14 --> 00:03:17 know. Maybe that's our lot in life is to just
00:03:18 --> 00:03:20 try to inspire, uh, just a handful of people
00:03:20 --> 00:03:23 to pick up the baton, Fred Watson. Who knows?
00:03:24 --> 00:03:27 All right, question one. It's like a test,
00:03:27 --> 00:03:27 isn't it?
00:03:27 --> 00:03:30 Question one. Uh, if space is
00:03:30 --> 00:03:32 expanding faster than the speed of light,
00:03:32 --> 00:03:35 then in millions or billions of years from
00:03:35 --> 00:03:38 now, will our night sky be completely black
00:03:38 --> 00:03:41 or a completely black void? Um,
00:03:41 --> 00:03:44 uh, or completely black, devoid of
00:03:44 --> 00:03:47 all light except our local solar system. That
00:03:47 --> 00:03:50 comes from Clint. Uh, this is
00:03:50 --> 00:03:53 something that has come up occasionally and I
00:03:53 --> 00:03:55 think even in one of our most recent
00:03:55 --> 00:03:58 episodes, we were talking about the expansion
00:03:58 --> 00:04:00 of the universe and its significance. And,
00:04:00 --> 00:04:02 and I think in our Q and A episode, someone
00:04:02 --> 00:04:04 asked about the expansion of the universe.
00:04:05 --> 00:04:07 Um, so here it is again.
00:04:08 --> 00:04:11 Um, we are, ah,
00:04:11 --> 00:04:13 expanding, and it's
00:04:13 --> 00:04:16 expanding at an accelerating rate. Although
00:04:16 --> 00:04:17 it's debatable whether or not that
00:04:17 --> 00:04:20 acceleration is actually as m. Significant
00:04:20 --> 00:04:23 as it was. That is a
00:04:23 --> 00:04:26 separate debate. Um, but I think it's pretty
00:04:26 --> 00:04:29 clear that in the long distant future
00:04:29 --> 00:04:32 of this universe, it will become a black
00:04:32 --> 00:04:33 void, won't it?
00:04:34 --> 00:04:37 Professor Fred Watson: Uh, yes. So the answer to Clint's question
00:04:37 --> 00:04:37 is yes.
00:04:38 --> 00:04:39 Andrew Dunkley: Okay, question
00:04:41 --> 00:04:43 Professor Fred Watson: no. Exactly. As you said, um,
00:04:43 --> 00:04:46 if you've got, um. So
00:04:47 --> 00:04:50 when you say the universe is expanding more
00:04:50 --> 00:04:52 than the speed of light, you've got to be a
00:04:52 --> 00:04:54 bit specific because really what you're
00:04:54 --> 00:04:57 talking about is objects within
00:04:57 --> 00:04:59 the universe which are being carried along by
00:04:59 --> 00:05:02 the expansion of the universe. And so,
00:05:03 --> 00:05:05 uh, there will be, at a certain
00:05:05 --> 00:05:07 distance from us now,
00:05:08 --> 00:05:10 objects whose, what we call the recession
00:05:10 --> 00:05:13 velocity is faster than the speed of light,
00:05:13 --> 00:05:16 but they're actually, they're beyond
00:05:16 --> 00:05:18 the wall that we can't see beyond anyway,
00:05:18 --> 00:05:20 which is the cosmic microwave background
00:05:20 --> 00:05:22 radiation. But you can imagine as the
00:05:22 --> 00:05:25 expansion continues to accelerate, and you're
00:05:25 --> 00:05:27 right, it is still thought to be
00:05:27 --> 00:05:29 accelerating. We just don't quite know
00:05:29 --> 00:05:31 whether that acceleration is a constant.
00:05:31 --> 00:05:34 That's the thing you were alluding
00:05:34 --> 00:05:37 to because there's some evidence that
00:05:37 --> 00:05:39 maybe the acceleration is reducing,
00:05:40 --> 00:05:42 but nevertheless it's still accelerating. So
00:05:42 --> 00:05:45 it's still getting bigger, faster, uh, all
00:05:45 --> 00:05:47 the time. And so what that would do,
00:05:48 --> 00:05:51 um, you can, you can sort of
00:05:51 --> 00:05:53 imagine in your head what this situation
00:05:53 --> 00:05:55 would lead to. It means that the,
00:05:56 --> 00:05:59 the, the sort of black horizon, the horizon
00:05:59 --> 00:06:02 which is where light can never get to you
00:06:02 --> 00:06:04 because it's being carried away. The objects
00:06:04 --> 00:06:05 are being carried away faster than the speed
00:06:05 --> 00:06:08 of light. That black horizon will, will
00:06:08 --> 00:06:11 approach, um, it'll get nearer
00:06:11 --> 00:06:14 as the universe's expansion continues to
00:06:14 --> 00:06:16 accelerate. So eventually you can imagine
00:06:16 --> 00:06:19 that maybe you would see just
00:06:19 --> 00:06:22 the other galaxies in the Local Group, uh,
00:06:22 --> 00:06:24 which is Andromeda and the, uh, triangular
00:06:24 --> 00:06:27 whirlpool galaxy and things like that. But
00:06:27 --> 00:06:29 eventually, yeah, it might just be
00:06:30 --> 00:06:33 objects in our own solar system, uh,
00:06:33 --> 00:06:36 which makes astronomy a little bit of a.
00:06:36 --> 00:06:38 Boring. Yeah.
00:06:38 --> 00:06:39 Yeah.
00:06:39 --> 00:06:41 Andrew Dunkley: Well, let's go see what we can find. Oh,
00:06:41 --> 00:06:41 there's the moon.
00:06:41 --> 00:06:43 Professor Fred Watson: Yeah. Yeah. Oh, wait, it's gone.
00:06:46 --> 00:06:48 Andrew Dunkley: Well, it's moving away from us too.
00:06:48 --> 00:06:50 Professor Fred Watson: So it is rather slower than the speed of
00:06:50 --> 00:06:52 light. Yeah. Six centimetres a year.
00:06:52 --> 00:06:54 Andrew Dunkley: I can't imagine this is going to happen in an
00:06:54 --> 00:06:55 awful hurry, Fred Watson.
00:06:55 --> 00:06:58 Professor Fred Watson: No, it's not. It's very, very long way down
00:06:58 --> 00:06:59 the track. And of course, from our
00:06:59 --> 00:07:01 perspective here on, ah, Earth, long, uh,
00:07:01 --> 00:07:04 before anything like that takes place,
00:07:04 --> 00:07:07 um, we'll have been
00:07:07 --> 00:07:09 confronted by the expansion of the sun
00:07:09 --> 00:07:12 itself, um, as it turns into
00:07:12 --> 00:07:13 a red giant star.
00:07:14 --> 00:07:16 Andrew Dunkley: Yeah. Who knows where we'll be in the
00:07:16 --> 00:07:19 universe by then. We might have moved out
00:07:19 --> 00:07:21 into other parts of the galaxy by then if
00:07:21 --> 00:07:24 we've managed, um, to find some kind of
00:07:24 --> 00:07:27 propulsion system or learn how to fold
00:07:27 --> 00:07:29 space or whatever it is you need to do. Uh,
00:07:29 --> 00:07:32 maybe develop wormholes and be able
00:07:32 --> 00:07:34 to travel mega distances.
00:07:34 --> 00:07:37 Professor Fred Watson: Yeah. Fast. You're the person, you're the
00:07:37 --> 00:07:39 science fiction writer. You've got to tell us
00:07:39 --> 00:07:40 what it is we're going to do.
00:07:40 --> 00:07:43 Andrew Dunkley: Uh, I'm working, um, uh, on
00:07:44 --> 00:07:46 warp, uh, warp travel at the moment.
00:07:46 --> 00:07:46 Professor Fred Watson: Oh, good.
00:07:47 --> 00:07:49 Andrew Dunkley: In m. My. In my novels. So,
00:07:49 --> 00:07:52 yeah, I'm doing the final editing at this
00:07:52 --> 00:07:55 stage and it's, uh, it's the most horrible
00:07:55 --> 00:07:55 job.
00:07:56 --> 00:07:57 Professor Fred Watson: It is, isn't it? Yeah.
00:07:57 --> 00:07:59 Andrew Dunkley: Especially writing's fun.
00:07:59 --> 00:07:59 Professor Fred Watson: Yeah.
00:07:59 --> 00:08:01 Andrew Dunkley: But then you've got to fix all your blunders
00:08:01 --> 00:08:04 and you don't realise how really hopeless you
00:08:04 --> 00:08:05 are until you have
00:08:05 --> 00:08:07 Professor Fred Watson: to edit your own stuff.
00:08:07 --> 00:08:10 Andrew Dunkley: Yeah, yeah. I'd pay someone, but I can't
00:08:10 --> 00:08:13 afford it. It's not a, it's not a cheap
00:08:13 --> 00:08:15 thing to get Done book editing. Um,
00:08:16 --> 00:08:18 but anyway, uh, so the basic
00:08:18 --> 00:08:21 answer to Clint's question is yes, it's going
00:08:21 --> 00:08:24 to happen. Uh, there will be complete black
00:08:24 --> 00:08:26 nothingness, um,
00:08:27 --> 00:08:29 in a matter of about three weeks time, or
00:08:29 --> 00:08:31 could be three gazillion years time.
00:08:31 --> 00:08:32 Professor Fred Watson: I think the latter's more likely.
00:08:32 --> 00:08:35 Andrew Dunkley: More likely the latter. Thank you, Clint.
00:08:35 --> 00:08:36 Great to hear from you.
00:08:37 --> 00:08:39 Our next question comes from
00:08:40 --> 00:08:42 somebody whose name I forgot to write down.
00:08:42 --> 00:08:44 Uh, no, it didn't. It comes from, uh, Alan.
00:08:44 --> 00:08:47 Now, this is a pretty big question, so I'll
00:08:47 --> 00:08:48 just go straight through it and we can figure
00:08:48 --> 00:08:51 all out the rest out later. Uh, I know you
00:08:51 --> 00:08:54 want audio questions, but you know how they
00:08:54 --> 00:08:57 say you have a face made for radio? I've got
00:08:57 --> 00:09:00 one of those. Well, uh, I have a voice made
00:09:00 --> 00:09:03 for text. That's very
00:09:03 --> 00:09:05 good. I, um, hope it's not true. Uh, I
00:09:05 --> 00:09:08 discovered space nuts more than a year ago
00:09:08 --> 00:09:10 and have listened to your entire back
00:09:10 --> 00:09:11 catalogue.
00:09:11 --> 00:09:11 Professor Fred Watson: Wow.
00:09:12 --> 00:09:15 Andrew Dunkley: Wow. Get a job. No. Fantastic. Thank
00:09:15 --> 00:09:18 you. Uh, still listening and have not lost my
00:09:18 --> 00:09:19 mind yet.
00:09:19 --> 00:09:19 Professor Fred Watson: Wow.
00:09:20 --> 00:09:20 Andrew Dunkley: That's a record.
00:09:21 --> 00:09:22 Uh, here's something that's been bothering me
00:09:22 --> 00:09:25 for, uh, some months. Some physicists
00:09:25 --> 00:09:28 don't believe relativity, uh, when it says
00:09:28 --> 00:09:30 that gravity is not a force. Also, they
00:09:30 --> 00:09:32 believe that all forces are conveyed by
00:09:32 --> 00:09:35 particles. To unify gravity with other
00:09:35 --> 00:09:38 forces, they postulate the graviton to be
00:09:38 --> 00:09:41 that particle for gravity. It's said that
00:09:41 --> 00:09:42 nothing escapes a black hole, but actually
00:09:42 --> 00:09:45 gravity does. If gravitons exist
00:09:46 --> 00:09:49 and convey the force of gravity, then they
00:09:49 --> 00:09:51 escape black holes. So they are not affected
00:09:51 --> 00:09:54 by gravity. That means they do not affect
00:09:54 --> 00:09:57 each other. We know gravity does affect all
00:09:57 --> 00:09:59 massive particles and photons, massless
00:09:59 --> 00:10:01 particles that convey the electromagnetic
00:10:01 --> 00:10:04 force. I don't know if gravitons affect other
00:10:04 --> 00:10:06 massless particles. This is the interesting
00:10:06 --> 00:10:09 part. If f equals gm 1 m
00:10:09 --> 00:10:12 2 divided by d squared is
00:10:12 --> 00:10:15 the complete calculation for the force
00:10:15 --> 00:10:17 of gravity, no modifications introduced by
00:10:17 --> 00:10:20 relativity or quantum physics, then gravitons
00:10:20 --> 00:10:23 are not affected by anything. So gravitons
00:10:23 --> 00:10:25 affect every particle except gravitons and
00:10:25 --> 00:10:28 are not affected by anything. So is
00:10:28 --> 00:10:30 an asymmetry that breaks
00:10:32 --> 00:10:34 conservation, uh, of energy and momentum. My
00:10:34 --> 00:10:37 question is. Here it is. Why do some
00:10:37 --> 00:10:39 physicists still believe in
00:10:40 --> 00:10:42 gravitons? That comes from Alan in San
00:10:42 --> 00:10:45 Antonio, Texas. Boy, Alan, you've put a lot
00:10:45 --> 00:10:46 of thought into that. You really have.
00:10:47 --> 00:10:49 Professor Fred Watson: Yeah. And these are questions that are right
00:10:49 --> 00:10:51 on money as well. Yeah. Uh, especially the
00:10:51 --> 00:10:54 last one. Why do physicists believe in
00:10:54 --> 00:10:56 gravitons? I think most physicists probably
00:10:56 --> 00:10:58 do. Uh, Alan, because
00:10:58 --> 00:11:01 um, we know that gravity is a fundamental
00:11:01 --> 00:11:03 force and all the other fundamental forces
00:11:03 --> 00:11:05 have their subatomic particles,
00:11:06 --> 00:11:09 uh, which are basically
00:11:09 --> 00:11:12 um, um,
00:11:13 --> 00:11:16 particles that can. That sort of what we
00:11:16 --> 00:11:18 call, we call them bosons. They're what, they
00:11:18 --> 00:11:21 carry a field in a way. And the field is
00:11:21 --> 00:11:24 another way of looking at how a uh,
00:11:24 --> 00:11:27 force works. I didn't
00:11:27 --> 00:11:30 phrase that very well, but uh, that's why
00:11:30 --> 00:11:33 some physicists believe in gravitons. We've
00:11:33 --> 00:11:35 never found them. We don't have a particle
00:11:35 --> 00:11:38 physics theory of gravity. Uh, so we don't
00:11:38 --> 00:11:40 know that they exist. But I think most
00:11:40 --> 00:11:43 physicists would assume that they exist.
00:11:44 --> 00:11:46 And so uh, that
00:11:46 --> 00:11:49 first um, conundrum
00:11:51 --> 00:11:52 that you mentioned,
00:11:53 --> 00:11:56 if nothing escapes a black hole, well,
00:11:56 --> 00:11:58 gravity does. And so if
00:11:58 --> 00:12:00 gravitons exist and convey the force of
00:12:00 --> 00:12:03 gravity, then they escape black holes. So
00:12:03 --> 00:12:05 they're not affected by gravity. That means
00:12:05 --> 00:12:08 they do not affect each other. But in
00:12:08 --> 00:12:10 fact, um, uh,
00:12:11 --> 00:12:14 the bottom line with black holes it's
00:12:14 --> 00:12:16 quite complicated. Uh, but you
00:12:17 --> 00:12:19 don't have gravitons escaping
00:12:20 --> 00:12:22 from the black hole. Uh,
00:12:23 --> 00:12:26 the way people who know a lot more about
00:12:26 --> 00:12:28 these things than me, uh, the way they
00:12:28 --> 00:12:31 envisage this is that the gravitational
00:12:31 --> 00:12:34 field of the black hole is a kind
00:12:34 --> 00:12:37 of fossilised one that was
00:12:37 --> 00:12:39 established before the collapse
00:12:40 --> 00:12:43 into uh, a black hole.
00:12:44 --> 00:12:46 Or, and here's another way of looking at it.
00:12:49 --> 00:12:51 This really, you're gonna think, um, Alan,
00:12:51 --> 00:12:54 this is a cop out, but this is the way the
00:12:54 --> 00:12:57 physicists see it. Uh, the,
00:12:57 --> 00:12:59 the gravitational field of black hole
00:12:59 --> 00:13:02 basically uh, includes
00:13:02 --> 00:13:04 something called virtual gravitons.
00:13:05 --> 00:13:08 Uh, and so that sort of ties in with the fact
00:13:08 --> 00:13:10 that the, the gravitational field is a
00:13:10 --> 00:13:13 fossilised footprint, if I can put it that
00:13:13 --> 00:13:15 way. Um, the
00:13:16 --> 00:13:18 virtual gravitons, uh, are an
00:13:18 --> 00:13:21 embodiment of that, but they don't
00:13:21 --> 00:13:23 necessarily obey the
00:13:23 --> 00:13:25 normal laws of physics.
00:13:28 --> 00:13:28 So
00:13:30 --> 00:13:31 uh,
00:13:34 --> 00:13:36 basically what you've got here, and
00:13:37 --> 00:13:40 I think, um, the
00:13:40 --> 00:13:42 physicists who look at this problem probably
00:13:42 --> 00:13:45 just automatically drop into the two
00:13:45 --> 00:13:48 camps of relativist people who
00:13:48 --> 00:13:51 are ah, experts in general relativity. That's
00:13:51 --> 00:13:53 Einstein's theory of gravity that says, yes,
00:13:53 --> 00:13:56 um, gravity is not a force, it's just a
00:13:56 --> 00:13:58 distortion of space. Uh, and the quantum
00:13:58 --> 00:14:01 mechanics people who look at it from the
00:14:01 --> 00:14:04 perspective of gravitons.
00:14:05 --> 00:14:08 Um, and so yeah, the virtual particles,
00:14:08 --> 00:14:11 uh, the quantum mechanics
00:14:11 --> 00:14:13 person's answer to this,
00:14:15 --> 00:14:17 uh, they're basically
00:14:17 --> 00:14:20 just mathematical constructs, uh, in a
00:14:20 --> 00:14:23 quantum field. And so they don't have to
00:14:23 --> 00:14:26 obey speed limits or anything like that, or
00:14:26 --> 00:14:28 even don't have to worry about the event
00:14:28 --> 00:14:31 horizon so they can continually
00:14:32 --> 00:14:34 basically, uh, keep the gravitational force
00:14:34 --> 00:14:37 there without actually being
00:14:37 --> 00:14:40 trapped by it. I think that's the way
00:14:40 --> 00:14:42 physicists look at it.
00:14:43 --> 00:14:46 Andrew Dunkley: Uh, all that says to me is
00:14:48 --> 00:14:50 something. It's still a big mystery. There
00:14:50 --> 00:14:52 are so many different theories behind
00:14:52 --> 00:14:55 gravity, and we really don't know what it is.
00:14:56 --> 00:14:58 We know what it is, but we don't know why it
00:14:58 --> 00:14:58 is.
00:14:58 --> 00:15:01 Professor Fred Watson: Well, no. So all we know about
00:15:01 --> 00:15:04 gravity is the way it behaves. Um,
00:15:04 --> 00:15:07 we really don't know what it is. And in a
00:15:07 --> 00:15:10 way, Alan's question is well posed
00:15:10 --> 00:15:13 because it could end up that it's something
00:15:13 --> 00:15:14 different and there aren't gravitons.
00:15:15 --> 00:15:18 Um, and, uh, that's why we haven't found
00:15:18 --> 00:15:21 them, because they're not there. Um,
00:15:22 --> 00:15:24 it's fascinating. I mean, in a sense,
00:15:25 --> 00:15:28 uh, gravitons are along the same line as the
00:15:28 --> 00:15:31 hypothetical dark matter particles. We know,
00:15:31 --> 00:15:34 um, dark matter is real. We know it's
00:15:34 --> 00:15:37 there. Uh, we assume it's subatomic
00:15:37 --> 00:15:40 particles. We've seen some recent works. Uh,
00:15:40 --> 00:15:42 work. Sorry. We've seen some recent work that
00:15:42 --> 00:15:45 suggests perhaps they're not, um,
00:15:45 --> 00:15:47 perhaps it's not subatomic particles, but
00:15:47 --> 00:15:49 primordial black holes, which can be very
00:15:49 --> 00:15:52 small and very difficult to detect. Uh, which
00:15:52 --> 00:15:55 takes us back to the, um, macho
00:15:55 --> 00:15:57 theory. Massive compact halo objects, the
00:15:57 --> 00:16:00 macho theory of dark matter, as distinct from
00:16:00 --> 00:16:01 the WIMP theory, the weakly interacting
00:16:01 --> 00:16:04 massive particles. I
00:16:04 --> 00:16:07 think gravitons almost fall into the same
00:16:07 --> 00:16:10 boat as dark matter particles in the sense
00:16:10 --> 00:16:12 that we haven't detected them. We hypothesise
00:16:12 --> 00:16:14 that they're there. We've built constructs
00:16:14 --> 00:16:17 like virtual gravitons that allow us to do
00:16:17 --> 00:16:19 that without going completely mad. Um,
00:16:19 --> 00:16:22 but, uh, at the moment, still, I think,
00:16:23 --> 00:16:25 uh, the door is wide open for all kinds of
00:16:25 --> 00:16:27 new ideas that might change our view
00:16:27 --> 00:16:27 completely.
00:16:28 --> 00:16:31 Andrew Dunkley: Yeah, I guess the day we crack it will
00:16:31 --> 00:16:33 go, uh. Yeah, I should have thought of that.
00:16:35 --> 00:16:37 Professor Fred Watson: Exactly. Well, Alan's already thought of it.
00:16:37 --> 00:16:37 Andrew Dunkley: Yeah.
00:16:38 --> 00:16:40 Professor Fred Watson: Yeah. In terms of, you know, what, what the
00:16:40 --> 00:16:43 conundrums are and why it is. Why it's so
00:16:43 --> 00:16:44 difficult. Yeah, it's a great question.
00:16:45 --> 00:16:47 Andrew Dunkley: I guess the question that comes from that is,
00:16:47 --> 00:16:49 does it have to be a particle? And the answer
00:16:49 --> 00:16:52 is no. Um, it doesn't, uh, have to be
00:16:52 --> 00:16:54 just because everything else is made of
00:16:54 --> 00:16:55 particles. So.
00:16:56 --> 00:16:58 Professor Fred Watson: Yes, that's right. I mean, it's.
00:16:59 --> 00:17:01 So what's called the standard model of
00:17:01 --> 00:17:04 subatomic particles is this
00:17:04 --> 00:17:07 group of 17 particles which we don't
00:17:07 --> 00:17:09 think can be broken down into Anything
00:17:09 --> 00:17:10 smaller. That's why they're called
00:17:10 --> 00:17:13 fundamental, um, and
00:17:13 --> 00:17:15 they account. Among them are, uh,
00:17:16 --> 00:17:19 the force, um, particles,
00:17:19 --> 00:17:22 um, electromagnetic, strong
00:17:22 --> 00:17:24 and weak nuclear forces, um,
00:17:26 --> 00:17:29 uh, which we know about. Gravity is just
00:17:29 --> 00:17:32 assumed to be, uh, a fundamental force
00:17:32 --> 00:17:34 with its fundamental particle because it
00:17:34 --> 00:17:37 behaves in every other way. It behaves like
00:17:37 --> 00:17:39 the other ones do. Uh, but we just haven't
00:17:39 --> 00:17:41 managed to pinpoint the particle itself.
00:17:43 --> 00:17:43 There you go.
00:17:43 --> 00:17:46 Andrew Dunkley: Ah, Alan, you've kind of, um, put
00:17:46 --> 00:17:49 your thumb on one of the big mysteries of the
00:17:49 --> 00:17:52 universe and expected us to have an answer.
00:17:53 --> 00:17:56 Uh, no, it's just
00:17:56 --> 00:17:59 one of those great big, um, question marks in
00:17:59 --> 00:18:00 space. If you look up, you can see a giant
00:18:00 --> 00:18:03 question mark in space. That's gravity.
00:18:04 --> 00:18:06 Professor Fred Watson: That's right, yeah.
00:18:06 --> 00:18:08 Andrew Dunkley: Uh, whether or not there are gravitons, the
00:18:08 --> 00:18:11 debate remains. Thank, uh, you, Alan, for the
00:18:11 --> 00:18:14 question. This is Space Nuts Andrew Dunkley
00:18:14 --> 00:18:16 here with Professor Fred Watson Watson.
00:18:18 --> 00:18:20 Professor Fred Watson: I believe that this nation should commit
00:18:20 --> 00:18:22 Andrew Dunkley: itself to achieving the goal
00:18:23 --> 00:18:26 before this decade is out, of landing a
00:18:26 --> 00:18:26 man
00:18:26 --> 00:18:28 Professor Fred Watson: on the moon and returning him safely to the
00:18:28 --> 00:18:28 Earth.
00:18:28 --> 00:18:30 Andrew Dunkley: Beast nuts, Fred Watson.
00:18:30 --> 00:18:33 Our next question comes from, uh,
00:18:33 --> 00:18:35 somebody else who's thinking particles. I
00:18:35 --> 00:18:38 spend a lot of time thinking about
00:18:38 --> 00:18:41 photons and have, uh, so many questions about
00:18:41 --> 00:18:44 them. Uh, you know, I know
00:18:44 --> 00:18:46 this about Misty because, um, she's always
00:18:46 --> 00:18:48 walking around with a light bulb above her
00:18:48 --> 00:18:50 head. So that explains that,
00:18:51 --> 00:18:53 um, photons are really weird to understand.
00:18:54 --> 00:18:56 I'm curious to know if there are any
00:18:56 --> 00:18:59 fundamental particles that do not have a
00:18:59 --> 00:19:02 wave function. And then is it possible
00:19:02 --> 00:19:05 to detect a particle or photon that does not
00:19:05 --> 00:19:08 have any properties of a wave?
00:19:08 --> 00:19:10 And the last part of the question. Is it
00:19:10 --> 00:19:13 possible for a photon or particle to have
00:19:13 --> 00:19:15 such a long wavelength that we don't have a
00:19:15 --> 00:19:17 detector big enough to pick it up? That's,
00:19:17 --> 00:19:19 uh, from Misty in Pennsylvania, one of our
00:19:19 --> 00:19:21 administrators on the Facebook PODC Ask
00:19:21 --> 00:19:24 Group. So, um, uh, thank you, Misty,
00:19:24 --> 00:19:26 for sending in a question. Nice to hear from
00:19:26 --> 00:19:28 you and beautiful part of the world,
00:19:28 --> 00:19:30 Pennsylvania. Got to drive through that last
00:19:30 --> 00:19:33 year. And, uh, yeah, it is
00:19:33 --> 00:19:36 absolutely lovely in summer. Don't
00:19:36 --> 00:19:38 think I want to be there in winter.
00:19:41 --> 00:19:44 Nevertheless. Okay, so, um,
00:19:44 --> 00:19:47 photons. Yeah. What can we talk? What
00:19:47 --> 00:19:50 can you tell us about? Are there any
00:19:50 --> 00:19:52 particles that don't have wavelengths? That's
00:19:52 --> 00:19:53 an interest question.
00:19:53 --> 00:19:56 Professor Fred Watson: Yes. So that's M, more or less what
00:19:56 --> 00:19:59 it amounts to. So we see
00:19:59 --> 00:20:01 in quantum mechanics, uh,
00:20:02 --> 00:20:04 we see this fundamental thing that particles,
00:20:05 --> 00:20:08 m, uh, display the properties
00:20:08 --> 00:20:11 both of a particle and a wave. And so we
00:20:11 --> 00:20:14 call it a wave function. And as
00:20:14 --> 00:20:16 I understand it, and I Think, uh, quantum
00:20:16 --> 00:20:19 mechanics backs, uh, this up.
00:20:19 --> 00:20:22 Uh, there are no fundamental particles
00:20:23 --> 00:20:26 that don't have a wave function, so they
00:20:26 --> 00:20:28 all exhibit this wave particle
00:20:28 --> 00:20:29 duality.
00:20:30 --> 00:20:30 Andrew Dunkley: Um,
00:20:35 --> 00:20:36 Professor Fred Watson: It is, uh,
00:20:38 --> 00:20:41 I guess, you know, the way that,
00:20:41 --> 00:20:43 um, particle physicists think about
00:20:43 --> 00:20:46 these things are uh, a little bit different
00:20:47 --> 00:20:50 from the way we might interpret it. So when I
00:20:50 --> 00:20:52 think of the wave particle duality,
00:20:53 --> 00:20:55 my mind immediately goes to the photon,
00:20:56 --> 00:20:59 um, which, um, Misty's already mentioned.
00:21:00 --> 00:21:02 Uh, yes, we understand
00:21:03 --> 00:21:05 photons as particles because we see the
00:21:05 --> 00:21:08 photoelectric effect, which insists that
00:21:08 --> 00:21:10 they've got to be particles because you get
00:21:10 --> 00:21:13 basically quantized amounts of energy out of
00:21:13 --> 00:21:15 them. But then when I think about the waves,
00:21:15 --> 00:21:18 I think about things like polarisation,
00:21:19 --> 00:21:21 uh, where you've got waves that are
00:21:21 --> 00:21:23 oscillating in different directions. I think
00:21:23 --> 00:21:24 we talked about that a couple of episodes
00:21:24 --> 00:21:27 ago, we did, in the mapping of the magnetic
00:21:27 --> 00:21:30 fields of the galaxy of the universe. Um, and
00:21:30 --> 00:21:32 so I always think about waves vibrating
00:21:32 --> 00:21:34 through a median. But,
00:21:35 --> 00:21:37 um, the physicists
00:21:38 --> 00:21:41 kind of combine those two ideas
00:21:42 --> 00:21:45 and, uh, think in terms of, uh, something
00:21:45 --> 00:21:48 it's usually called quantized
00:21:48 --> 00:21:50 excitations of underlying
00:21:51 --> 00:21:53 fields. So
00:21:53 --> 00:21:56 that's to say that, um,
00:21:56 --> 00:21:59 it kind of mixes both relativity and
00:21:59 --> 00:22:02 quantum physics here because the
00:22:02 --> 00:22:04 underlying field is what?
00:22:05 --> 00:22:08 Um, it's the sort of,
00:22:08 --> 00:22:10 if I can put it that way, the background
00:22:10 --> 00:22:13 canvas on which the information
00:22:13 --> 00:22:16 is superimposed and the particle
00:22:16 --> 00:22:19 is a bit of that background canvas that is
00:22:19 --> 00:22:22 excited to vibrate and
00:22:22 --> 00:22:24 give you a wave, but it's
00:22:24 --> 00:22:27 excited in a way that is quantized. That
00:22:27 --> 00:22:30 means there isn't an
00:22:30 --> 00:22:33 infinite number of different excitations
00:22:33 --> 00:22:34 that can be set up.
00:22:36 --> 00:22:39 They're specific numbers,
00:22:39 --> 00:22:41 which means you get specific wavelengths
00:22:42 --> 00:22:44 from the excitation. So it is all a
00:22:44 --> 00:22:46 mix of, of
00:22:47 --> 00:22:50 particles and waves, but it kind of brings
00:22:50 --> 00:22:52 it together and once you think of it in those
00:22:52 --> 00:22:54 terms, uh, then
00:22:56 --> 00:22:58 it becomes clear that you can't have a
00:22:58 --> 00:23:00 particle without its wave function.
00:23:00 --> 00:23:03 Andrew Dunkley: Which kind of writes off her second question.
00:23:03 --> 00:23:06 If there's, um, a long enough wavelength that
00:23:06 --> 00:23:07 we haven't got the equipment to detect it.
00:23:08 --> 00:23:10 Professor Fred Watson: Um, no, I don't think it does
00:23:11 --> 00:23:13 because I think, um,
00:23:14 --> 00:23:17 I mean we, you know, we. In, in
00:23:17 --> 00:23:20 a way the ultra low
00:23:20 --> 00:23:23 frequency radio waves are a bit like that,
00:23:23 --> 00:23:26 uh, because they are,
00:23:27 --> 00:23:29 uh. Some of them have got a wavelength bigger
00:23:29 --> 00:23:31 than the Earth. And
00:23:31 --> 00:23:34 so how do you detect that? Well, you've got
00:23:34 --> 00:23:36 to have a spacecraft that's got the other end
00:23:36 --> 00:23:38 of the aerial on it, you know, that sort of
00:23:38 --> 00:23:41 thing. Um, there's also,
00:23:42 --> 00:23:45 uh. What was I going to say,
00:23:45 --> 00:23:48 um, yeah, we know that there are
00:23:48 --> 00:23:50 gravitational waves that have got
00:23:51 --> 00:23:54 wavelengths measured in light years. Uh,
00:23:54 --> 00:23:56 I think the gravitational
00:23:57 --> 00:24:00 properties of the Big Bang. So the
00:24:00 --> 00:24:02 gravitational waves that were set up by the
00:24:02 --> 00:24:05 Big Bang are extremely long
00:24:05 --> 00:24:07 wavelength. I think I've got that the right
00:24:07 --> 00:24:10 way around. Um,
00:24:10 --> 00:24:12 it's so, uh. And we, you know, there are
00:24:12 --> 00:24:15 ones that we don't have normal,
00:24:16 --> 00:24:18 everyday ways of detecting them. There are
00:24:18 --> 00:24:20 subtleties because you expect some of these
00:24:20 --> 00:24:22 waves to be polarised. And that, I think,
00:24:22 --> 00:24:24 gives you an insight into it. But, yeah,
00:24:24 --> 00:24:27 it's, uh. Look, it is a good question.
00:24:28 --> 00:24:31 Uh, and I, uh, think, um, once again,
00:24:31 --> 00:24:34 mist is thinking outside the box. Uh,
00:24:34 --> 00:24:36 no particles without their wave
00:24:36 --> 00:24:39 function, because a particle is an
00:24:39 --> 00:24:42 excitation of the underlying field, a
00:24:42 --> 00:24:44 quantized excitation of the underlying field.
00:24:45 --> 00:24:47 Andrew Dunkley: So it is possible we cannot detect certain
00:24:47 --> 00:24:49 wavelengths because they're too big, but they
00:24:49 --> 00:24:50 still exist.
00:24:50 --> 00:24:51 Professor Fred Watson: I think that's right, yes.
00:24:51 --> 00:24:54 Andrew Dunkley: Yeah. All right. What about gravitons? Do you
00:24:54 --> 00:24:55 reckon they have a wavelength?
00:24:55 --> 00:24:57 Professor Fred Watson: Well, yes, they do. That's the thing. Um, if
00:24:57 --> 00:24:59 they exist, yes. Uh, because, um,
00:25:01 --> 00:25:03 uh, we've got gravitational waves. So the
00:25:03 --> 00:25:06 wave particle duality works both ways. If
00:25:06 --> 00:25:07 you've got a wave, you've got a particle.
00:25:07 --> 00:25:10 Andrew Dunkley: There you go. Uh, good one. Thanks,
00:25:10 --> 00:25:13 Misty. Hope all is well in Pennsylvania.
00:25:16 --> 00:25:18 Three, two, one.
00:25:18 --> 00:25:20 Professor Fred Watson: Space nuts.
00:25:20 --> 00:25:23 Andrew Dunkley: And our final question, uh, comes from
00:25:23 --> 00:25:25 another one of our regular contributors,
00:25:25 --> 00:25:28 Casey in Colorado. What does it feel
00:25:28 --> 00:25:30 like to go from weightlessness to normal
00:25:30 --> 00:25:33 gravity for astronauts when returning to
00:25:33 --> 00:25:36 Earth? I think it would depend
00:25:36 --> 00:25:38 on how long you've been up there and, uh,
00:25:38 --> 00:25:40 whether or not you've actually bothered to
00:25:40 --> 00:25:41 use the treadmill.
00:25:43 --> 00:25:45 Professor Fred Watson: Well, that's right. The treadmill is all
00:25:45 --> 00:25:46 about keeping up your muscle strength.
00:25:46 --> 00:25:49 Andrew Dunkley: Exactly. Um, because once you're out there,
00:25:49 --> 00:25:51 your muscles immediately start to wither. Uh,
00:25:52 --> 00:25:52 they do.
00:25:52 --> 00:25:55 Professor Fred Watson: And you don't really have anything against
00:25:55 --> 00:25:58 which to push to keep them,
00:25:58 --> 00:26:00 you know, keep them going, other than the.
00:26:00 --> 00:26:02 The, um, torture equipment that
00:26:03 --> 00:26:06 NASA and Roscosmos provide on their space
00:26:06 --> 00:26:06 station.
00:26:06 --> 00:26:08 Andrew Dunkley: I think on Space Lab, they didn't have a
00:26:08 --> 00:26:10 treadmill. They had a running track that ran
00:26:10 --> 00:26:13 around the inside of
00:26:14 --> 00:26:17 wall of, uh, Skylab, I think. And
00:26:17 --> 00:26:20 so I've seen footage of astronauts actually
00:26:20 --> 00:26:23 running in a circle around the
00:26:23 --> 00:26:25 interior of Skylab.
00:26:25 --> 00:26:28 Professor Fred Watson: So they're keeping themselves, um, running
00:26:28 --> 00:26:30 just by the centrifugal force that they're
00:26:30 --> 00:26:32 setting up. Yeah, yeah, yeah. That's
00:26:32 --> 00:26:34 interesting. I didn't know that. That's, uh.
00:26:34 --> 00:26:37 Andrew Dunkley: Yeah, I'm sure that if you had online, you'd
00:26:37 --> 00:26:40 find Footage of it. I. I strongly remember
00:26:40 --> 00:26:42 that M. I saw it on the news one day and
00:26:42 --> 00:26:44 thought, wow, how did they do that? Well,
00:26:44 --> 00:26:45 there's no gravity, duh. Uh,
00:26:47 --> 00:26:49 Professor Fred Watson: yeah. Um,
00:26:50 --> 00:26:53 wasn't there something like that in 2001 A
00:26:53 --> 00:26:55 Space Odyssey? I think there was. Could have
00:26:55 --> 00:26:55 been.
00:26:55 --> 00:26:58 Andrew Dunkley: I think I watched that very recently.
00:26:58 --> 00:27:00 I just thought I really wanted to watch it
00:27:00 --> 00:27:02 again. But, um, I fell asleep. But
00:27:02 --> 00:27:04 it's very late. Judy had gone to bed, and I
00:27:04 --> 00:27:07 thought, oh, I might just start this. Uh,
00:27:07 --> 00:27:08 yeah, I was gone.
00:27:11 --> 00:27:13 Um, what was the question? Oh, uh, what's the
00:27:13 --> 00:27:16 feel like? I also remember seeing
00:27:16 --> 00:27:19 footage of cosmonauts, uh, coming back
00:27:19 --> 00:27:22 from very long haul time in space.
00:27:23 --> 00:27:25 And they'd get them out of the capsule once
00:27:25 --> 00:27:27 they came back to Earth and they couldn't
00:27:27 --> 00:27:27 stand up.
00:27:27 --> 00:27:29 Professor Fred Watson: Couldn't stand up. Yeah. I've seen similar
00:27:29 --> 00:27:32 things and. Well, you know, even with the
00:27:32 --> 00:27:34 exercise that the Artemis II crew
00:27:35 --> 00:27:38 were doing, they were a little bit wobbly
00:27:38 --> 00:27:40 when they got out of the spacecraft. And we
00:27:40 --> 00:27:43 all saw them going across the deck of the,
00:27:44 --> 00:27:46 uh, recovery ship. Uh,
00:27:47 --> 00:27:49 so I think how wobbly you are probably
00:27:49 --> 00:27:51 depends on just how much effort you've put
00:27:51 --> 00:27:53 into keeping up your muscle strength. So I
00:27:53 --> 00:27:56 think that's the key thing that Casey
00:27:57 --> 00:28:00 might be thinking of. Um, exactly. As
00:28:00 --> 00:28:02 you've said, your muscles go to waste very
00:28:02 --> 00:28:05 quickly. Uh, and if you. You don't
00:28:05 --> 00:28:06 exercise, then you're going to be in big
00:28:06 --> 00:28:08 trouble. You simply would not be able to
00:28:08 --> 00:28:11 walk. Um, so quite a
00:28:11 --> 00:28:14 significant, uh, thing. Ah. Which would also,
00:28:14 --> 00:28:16 of course, depend on how long you've been in
00:28:16 --> 00:28:17 space, how long you've been weightless.
00:28:17 --> 00:28:20 Andrew Dunkley: And the other thing they might suffer from is
00:28:20 --> 00:28:23 fatigue because they have
00:28:23 --> 00:28:26 to work so much harder to achieve the same
00:28:26 --> 00:28:29 mobility as they were used to. When they had
00:28:29 --> 00:28:32 full muscle strength, they'd get
00:28:32 --> 00:28:34 very tired very fast. I think,
00:28:35 --> 00:28:37 all jokes aside, I think the,
00:28:38 --> 00:28:39 um, everyday person,
00:28:41 --> 00:28:43 uh, who's been through, um,
00:28:43 --> 00:28:46 immunotherapy or some
00:28:46 --> 00:28:49 form of, um, um, um,
00:28:49 --> 00:28:51 inhibitor for, um,
00:28:53 --> 00:28:56 testosterone, for example, for cancer
00:28:56 --> 00:28:58 treatment or something like that, that
00:28:58 --> 00:29:01 has the same effect on your muscles. Muscle
00:29:01 --> 00:29:03 wastage. When you stop producing testosterone
00:29:04 --> 00:29:06 as a male, your muscles
00:29:07 --> 00:29:09 actually do fade away. And you've got to do
00:29:09 --> 00:29:12 exercise to keep. Like astronauts, you've got
00:29:12 --> 00:29:14 to keep your exercise up to keep your muscles
00:29:14 --> 00:29:17 in trim, but it
00:29:17 --> 00:29:20 does slow you down. Um, and case in
00:29:20 --> 00:29:22 point, I did have that sort of treatment for
00:29:22 --> 00:29:24 my prostate cancer. And for six months
00:29:25 --> 00:29:28 I went into basically the
00:29:28 --> 00:29:30 equivalent to menopause. I had muscle
00:29:30 --> 00:29:32 wastage. Um, I kept up my
00:29:32 --> 00:29:35 exercise, but it wasn't enough. And I
00:29:35 --> 00:29:38 had a situation where I'd go out and play
00:29:38 --> 00:29:40 golf. I lost 40 yards on
00:29:40 --> 00:29:43 shots simply because my muscles had wasted
00:29:43 --> 00:29:46 away. And it's probably taken a year to get
00:29:46 --> 00:29:46 it all back.
00:29:47 --> 00:29:47 Professor Fred Watson: Yeah, interesting.
00:29:48 --> 00:29:51 Andrew Dunkley: Yeah. Um, it would be the same effect for an
00:29:51 --> 00:29:53 astronaut on it. Exactly the same. Different,
00:29:53 --> 00:29:56 different, you know, different mechanism.
00:29:56 --> 00:29:58 Mechanism, but same effect.
00:29:59 --> 00:30:01 Um, and. And yet the
00:30:01 --> 00:30:03 other thing that they'd probably have to deal
00:30:03 --> 00:30:05 with is some, some of them have very
00:30:05 --> 00:30:08 significant health effects from, from
00:30:08 --> 00:30:10 being in zero G and you come back to Earth.
00:30:10 --> 00:30:13 Like we had a, um, didn't. Wasn't there an
00:30:13 --> 00:30:15 astronaut recently who was temporarily
00:30:15 --> 00:30:18 blinded from,
00:30:18 --> 00:30:21 from zero G? And there's all sorts of
00:30:21 --> 00:30:24 things that um, they can suffer from. And
00:30:24 --> 00:30:26 a lot of the time when they come back to
00:30:26 --> 00:30:28 Earth, it does fix itself because you're back
00:30:28 --> 00:30:31 in your normal environment. But when you're
00:30:31 --> 00:30:33 out there orbiting or going to the moon and
00:30:33 --> 00:30:36 back, it is not a human environment.
00:30:36 --> 00:30:39 Professor Fred Watson: That's not normal. Yeah, so it was an
00:30:39 --> 00:30:42 evacuation the uh, beginning of the year, I
00:30:42 --> 00:30:44 think it was, that we only really found out a
00:30:44 --> 00:30:46 few snippets about not very long ago.
00:30:47 --> 00:30:49 And I can't remember what the details were
00:30:50 --> 00:30:52 because my brain's atrophy because of
00:30:54 --> 00:30:55 old age.
00:30:56 --> 00:30:59 Andrew Dunkley: Yes, indeed. But, uh, there
00:30:59 --> 00:31:02 would be various levels of, um,
00:31:02 --> 00:31:04 dysfunction as a consequence of spending time
00:31:04 --> 00:31:07 in space. It would be a
00:31:07 --> 00:31:10 person to person variable.
00:31:10 --> 00:31:13 Um, it's not a one size
00:31:13 --> 00:31:15 fits all situation. Some people who'd come
00:31:15 --> 00:31:18 back probably not feel anything. But if, um,
00:31:18 --> 00:31:20 if you're up there long enough. Yeah, it's
00:31:20 --> 00:31:22 going to have a big impact on you.
00:31:22 --> 00:31:23 Professor Fred Watson: Yes, indeed.
00:31:24 --> 00:31:26 Andrew Dunkley: Thank you so much for the question, Kasey. I
00:31:26 --> 00:31:29 hope we covered it
00:31:29 --> 00:31:32 reasonably well. Um, anyway,
00:31:32 --> 00:31:34 uh, in the not too distant future, I'm pretty
00:31:34 --> 00:31:36 sure there'll be so many people going in and
00:31:36 --> 00:31:38 out of space, they'll come up with ways of
00:31:38 --> 00:31:41 dealing with it. Who knows? And
00:31:41 --> 00:31:42 I think that brings us to the end.
00:31:42 --> 00:31:44 Don't forget, if you've got, uh, questions
00:31:44 --> 00:31:47 for us or observations or comments or
00:31:47 --> 00:31:49 whatever you like, you can go to our website,
00:31:49 --> 00:31:51 send it to us in a text or audio
00:31:51 --> 00:31:53 format@spacenuts
00:31:53 --> 00:31:55 IO or
00:31:55 --> 00:31:58 spacenutspodcast.com
00:31:58 --> 00:32:01 and just click on the little ama button at
00:32:01 --> 00:32:04 the top that stands for Ask me Anything. And
00:32:04 --> 00:32:07 um, you can send it through. Don't forget to
00:32:07 --> 00:32:09 tell us who you are or where you're from.
00:32:11 --> 00:32:13 And Fred Watson, that's it. Thanks so much
00:32:13 --> 00:32:15 for answering those. That was a tough batch
00:32:15 --> 00:32:15 today.
00:32:17 --> 00:32:19 Professor Fred Watson: Great questions though. Well done. To all our
00:32:19 --> 00:32:22 listeners for what they do in terms
00:32:22 --> 00:32:24 of, uh, thinking through a lot of these
00:32:24 --> 00:32:25 issues. It's great.
00:32:25 --> 00:32:27 Andrew Dunkley: Very good. All right, we'll catch you real
00:32:27 --> 00:32:28 soon. Fred Watson, thanks so much.
00:32:28 --> 00:32:30 Professor Fred Watson: Looking forward to it. Thanks, Andrew.
00:32:30 --> 00:32:32 Andrew Dunkley: Professor Fred Watson Watson, astronomer at
00:32:32 --> 00:32:34 large. And thanks to Huw in the studio, who
00:32:34 --> 00:32:35 couldn't be with us today because, um,
00:32:36 --> 00:32:39 there was, um, so much going on with
00:32:39 --> 00:32:41 gravitons and weightlessness, he just
00:32:42 --> 00:32:45 decided to float away. And from me,
00:32:45 --> 00:32:46 Andrew Dunkley. Thanks for your company.
00:32:46 --> 00:32:47 We'll catch you on the next episode of
00:32:47 --> 00:32:48 SpaceNuts real soon.
00:32:48 --> 00:32:49 Professor Fred Watson: Soon.
00:32:49 --> 00:32:51 Andrew Dunkley: Bye. Bye. You've been listening
00:32:51 --> 00:32:53 to the Space Nuts podcast,
00:32:55 --> 00:32:58 available at Apple Podcasts, Spotify,
00:32:58 --> 00:33:00 iHeartRadio or your favourite podcast
00:33:00 --> 00:33:02 player. You can also stream on
00:33:02 --> 00:33:04 demand@bytes.com.
00:33:04 --> 00:33:06 Professor Fred Watson: this has been another quality podcast
00:33:06 --> 00:33:08 production from bytes.com.