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Cosmic Curiosities: Time Dilation, Supernova Remnants, and Aurora Colors
In this engaging Q&A edition of Space Nuts, hosts Andrew Dunkley and Professor Fred Watson tackle a series of thought-provoking questions from their curious audience. From the enigmatic nature of time in anti-gravity fields to the vibrant colors of auroras, this episode dives deep into the mysteries of the cosmos.
Episode Highlights:
- Time in Anti-Gravity Fields: Andrew and Fred explore the implications of time dilation in gravitational and anti-gravity environments, discussing how time appears to flow differently depending on the observer's frame of reference.
- Supernova Remnants: The hosts address whether we can still see the star remnants that contributed to the formation of heavy elements in our solar system, revealing the complexities of cosmic recycling.
- The Colors of Aurora: Listener Nate's question about the stunning colors of auroras leads to a fascinating discussion on the atmospheric processes that create different hues, from greens to reds and beyond.
- Relativistic Mass and Spacecraft Acceleration: Lee from Sweden poses an intriguing idea about using relativistic mass ejection to enhance spacecraft propulsion, prompting a conversation about the theoretical limits of current technology and the physics involved.
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Stay curious, keep looking up, and join us next time for more stellar insights and cosmic wonders. Until then, clear skies and happy stargazing.
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00:00:00 --> 00:00:02 Andrew Dunkley: Hi there. Thanks for joining us again. This
00:00:02 --> 00:00:04 is Space Nuts, a Q and A edition. My name is
00:00:04 --> 00:00:07 Andrew Dunkley. Hope you're well. Stick
00:00:07 --> 00:00:10 around. We have got questions from, uh,
00:00:10 --> 00:00:13 our audience. One about time in
00:00:13 --> 00:00:16 anti gravity and the speed of time.
00:00:17 --> 00:00:19 Uh, that's always fun to talk about.
00:00:20 --> 00:00:22 Uh, we've got another question about
00:00:22 --> 00:00:25 supernova remnants, uh, the colors
00:00:25 --> 00:00:28 of aurora and uh,
00:00:28 --> 00:00:31 a light speed boost idea. This is a. Could
00:00:31 --> 00:00:34 I. Would I. Should I type of with my
00:00:34 --> 00:00:36 spaceship do something that might give me a
00:00:37 --> 00:00:39 light speed boost? We'll see if it works on
00:00:39 --> 00:00:42 this edition of space nuts. 15
00:00:42 --> 00:00:44 seconds. Guidance is internal.
00:00:44 --> 00:00:47 Professor Fred Watson: 10, 9. Ignition
00:00:47 --> 00:00:49 sequence start. Uh, space nuts.
00:00:49 --> 00:00:50 Andrew Dunkley: 5, 4, 3.
00:00:50 --> 00:00:53 Professor Fred Watson: 2. 1, 2, 3, 4, 5, 5, 4,
00:00:53 --> 00:00:54 3, 2, 1.
00:00:54 --> 00:00:57 Andrew Dunkley: Space nuts. Astronauts report it feels
00:00:57 --> 00:00:59 good. And he's back, uh, once
00:00:59 --> 00:01:02 again to try and solve all your little
00:01:02 --> 00:01:04 riddles. Here's Professor Fred Watson,
00:01:04 --> 00:01:05 astronomer at large. Hello, Fred.
00:01:06 --> 00:01:09 Professor Fred Watson: Hello there, Andrew. It's very good to be
00:01:09 --> 00:01:11 talking with you. It is. I'm sorry I've
00:01:11 --> 00:01:13 turned into an Irishman.
00:01:13 --> 00:01:14 Andrew Dunkley: Because I wonder what was happening there.
00:01:14 --> 00:01:17 Professor Fred Watson: Yeah, I said my trip to Ireland, which is
00:01:17 --> 00:01:17 great.
00:01:18 --> 00:01:19 Andrew Dunkley: There's nothing wrong with the Irish. When we
00:01:19 --> 00:01:22 were there in would have been July.
00:01:23 --> 00:01:23 Professor Fred Watson: Yeah, July.
00:01:24 --> 00:01:27 Andrew Dunkley: Uh, they really bunged it on for us at
00:01:27 --> 00:01:30 um, a place called Cove. It used to be
00:01:30 --> 00:01:32 called, um, I think
00:01:32 --> 00:01:34 Victoria. Was that what it was called?
00:01:35 --> 00:01:38 Um, no, no. Uh, anyway, it's where
00:01:38 --> 00:01:41 the, uh, Titanic, uh, made its last
00:01:41 --> 00:01:44 stop before heading out to the Atlantic and
00:01:44 --> 00:01:46 picked up its last groups of passengers. And
00:01:46 --> 00:01:49 some very sad stories as well. Uh,
00:01:49 --> 00:01:51 yeah, the pier where everybody got on board,
00:01:52 --> 00:01:55 um, the boats to go out to the Titanic
00:01:55 --> 00:01:57 because it couldn't actually anchor it at
00:01:57 --> 00:02:00 port. Have had to anchor outside the harbor
00:02:00 --> 00:02:02 at, um, uh, Cove.
00:02:02 --> 00:02:04 Um, um,
00:02:05 --> 00:02:07 it's still there, parts of it.
00:02:08 --> 00:02:10 So you can still see the remnants of that
00:02:10 --> 00:02:13 old. Um. And the White Star Line
00:02:13 --> 00:02:16 office is still there as well, which is now a
00:02:16 --> 00:02:18 museum where you can learn about the Titanic
00:02:18 --> 00:02:20 through the Titanic experience. I highly
00:02:20 --> 00:02:23 recommend that in the town of COVID which is
00:02:23 --> 00:02:26 nearby. County Cork. County
00:02:26 --> 00:02:29 Cork it is, yeah. Ah, lovely place.
00:02:29 --> 00:02:31 And they had Australian and New Zealand flags
00:02:31 --> 00:02:34 everywhere and music playing and they know
00:02:34 --> 00:02:36 how to party, those people. Yeah, terrific.
00:02:37 --> 00:02:40 Uh, shall we, um, do some questions, Fred?
00:02:40 --> 00:02:43 Professor Fred Watson: No, no, I think we should just have a cup of
00:02:43 --> 00:02:43 tea.
00:02:43 --> 00:02:46 Andrew Dunkley: Yeah, we probably have less trouble.
00:02:47 --> 00:02:49 Uh, let's firstly get a question from
00:02:50 --> 00:02:50 Andy.
00:02:51 --> 00:02:54 Speaker C: Hi guys, it's Andy here from the uk,
00:02:54 --> 00:02:57 first time questioner. Two questions,
00:02:57 --> 00:03:00 both time related. Um,
00:03:00 --> 00:03:02 the first question,
00:03:03 --> 00:03:06 um, as mass and
00:03:06 --> 00:03:08 gravity are so closely related
00:03:09 --> 00:03:12 and the higher a mass is, the
00:03:12 --> 00:03:14 slower time will flow.
00:03:15 --> 00:03:18 What would happen to the flow of time in an
00:03:18 --> 00:03:21 anti gravity field? So that's the
00:03:21 --> 00:03:24 first question. Um, the
00:03:24 --> 00:03:27 second question. If a
00:03:27 --> 00:03:30 planet had life that was
00:03:30 --> 00:03:33 intelligent and um, was evolving
00:03:33 --> 00:03:36 and had the potential to become
00:03:36 --> 00:03:39 space faring, but the planet was
00:03:40 --> 00:03:43 high gravity, is the playoff between
00:03:43 --> 00:03:45 gravity and the speed of time
00:03:46 --> 00:03:48 enough that that will make a significant
00:03:49 --> 00:03:52 difference to the evolution of the planet
00:03:52 --> 00:03:54 on galactic scales? Hope that one makes
00:03:54 --> 00:03:57 sense. Great program, no doubt. I'll be back
00:03:57 --> 00:03:57 again.
00:03:58 --> 00:04:00 Andrew Dunkley: Wow, Andy, where. Gee whiz, you've been
00:04:00 --> 00:04:02 pondering that for a while. There's some
00:04:02 --> 00:04:04 great questions there. Um, we'll tackle the
00:04:04 --> 00:04:06 first one first. Unless you want to do the
00:04:06 --> 00:04:07 first one second and the second one, I don't
00:04:07 --> 00:04:10 know. Uh, time, the effect of,
00:04:10 --> 00:04:12 um, uh, the effect on time,
00:04:13 --> 00:04:16 um, if it passes through an anti gravity
00:04:16 --> 00:04:19 field or just the effect on time in an anti
00:04:19 --> 00:04:19 gravity field.
00:04:21 --> 00:04:22 Professor Fred Watson: Yes. So, um,
00:04:23 --> 00:04:26 Andy's right actually. Uh, so
00:04:26 --> 00:04:28 what you've got is this phenomenon called
00:04:28 --> 00:04:31 time dilation. Appears that clocks slow
00:04:31 --> 00:04:34 down when you're in a gravitational field.
00:04:35 --> 00:04:37 Um, they only appear to be slowed down
00:04:38 --> 00:04:40 to outside observers. To you as the person
00:04:40 --> 00:04:43 in the gravity field, it makes no difference.
00:04:43 --> 00:04:45 The clock's just ticking at the same speed as
00:04:45 --> 00:04:47 it always did. But to an outside observer,
00:04:47 --> 00:04:50 your clocks are ticking more slowly. Uh, if
00:04:50 --> 00:04:51 there was such a thing as an anti gravity
00:04:51 --> 00:04:54 field, and we have no knowledge of
00:04:54 --> 00:04:56 anything like that at the moment, although
00:04:56 --> 00:04:58 people have worked very hard to try and
00:04:59 --> 00:05:01 demonstrate anti gravity, uh, as you can
00:05:01 --> 00:05:03 imagine, it would be a very useful thing to
00:05:03 --> 00:05:05 be able to harness, um,
00:05:06 --> 00:05:09 um, if you could have anti gravity. In other
00:05:09 --> 00:05:11 words, something that uh,
00:05:12 --> 00:05:14 actually repelled rather than attracted. Yes,
00:05:14 --> 00:05:17 the, the, um, or, or at
00:05:17 --> 00:05:19 least no, Let me put it another way. It's not
00:05:19 --> 00:05:21 repel repulsion, it's reducing the
00:05:21 --> 00:05:24 effect of gravity. I think anti gravity
00:05:24 --> 00:05:27 might, might reduce the effect of gravity.
00:05:27 --> 00:05:29 Uh, and it could, if you reduce it beyond
00:05:29 --> 00:05:32 zero, it could produce a repulsion. But
00:05:32 --> 00:05:35 that is not, that doesn't really matter for
00:05:35 --> 00:05:37 this argument because what happens is,
00:05:37 --> 00:05:40 um. Yes, relativity says that time would
00:05:40 --> 00:05:43 actually speed up. Uh, time, as I
00:05:43 --> 00:05:45 said to the person in the anti gravity field
00:05:45 --> 00:05:48 would keep on ticking away as normal. But to
00:05:48 --> 00:05:50 the outside observer, uh, the time would
00:05:50 --> 00:05:51 appear to be passing more quickly.
00:05:51 --> 00:05:54 Andrew Dunkley: Isn't it the same effect if you are falling
00:05:54 --> 00:05:56 into a black hole, what you're seeing is
00:05:56 --> 00:05:59 happening in real time because you're living
00:05:59 --> 00:06:02 your life like you do anywhere. But to
00:06:02 --> 00:06:04 the observer you would be,
00:06:06 --> 00:06:08 you know, a completely different Bucket of
00:06:08 --> 00:06:09 fish.
00:06:09 --> 00:06:12 Professor Fred Watson: That's right. Time slows down. Uh, everything
00:06:12 --> 00:06:14 appears more slowly. And when you cross the
00:06:14 --> 00:06:16 event horizon, you're sort of frozen on it.
00:06:17 --> 00:06:19 Yeah. Which means that event horizons are
00:06:19 --> 00:06:22 always splattered with things that have
00:06:22 --> 00:06:25 fallen into the. Maybe. Yeah.
00:06:25 --> 00:06:26 Hard to imagine.
00:06:26 --> 00:06:27 Andrew Dunkley: It's like the front of a car.
00:06:29 --> 00:06:29 In summer.
00:06:30 --> 00:06:32 Professor Fred Watson: White hopped. Yes. Um,
00:06:32 --> 00:06:33 yep.
00:06:33 --> 00:06:36 Andrew Dunkley: I think this was portrayed quite well in the
00:06:36 --> 00:06:38 movie Interstellar, where they had to go down
00:06:38 --> 00:06:40 onto a planet that was under the effect of a,
00:06:40 --> 00:06:43 A black hole. And every hour on the planet's
00:06:43 --> 00:06:46 surface equated to seven years back on the
00:06:46 --> 00:06:49 spaceship. Um, they, they did
00:06:49 --> 00:06:50 portray that quite well.
00:06:52 --> 00:06:52 That effect.
00:06:53 --> 00:06:53 Professor Fred Watson: Yeah.
00:06:54 --> 00:06:56 Andrew Dunkley: Okay, so there's no such thing really as an
00:06:56 --> 00:06:58 anti gravity field, but, um,
00:06:59 --> 00:07:01 he'd be right. The effect would be.
00:07:01 --> 00:07:02 Professor Fred Watson: That's right.
00:07:02 --> 00:07:04 But the second part of Andy's question.
00:07:04 --> 00:07:07 Andrew Dunkley: Yes. Um, high levels of gravity and
00:07:07 --> 00:07:09 its effect on the speed of time.
00:07:10 --> 00:07:12 Professor Fred Watson: Well, what he's saying is, if you had a
00:07:13 --> 00:07:15 planet or if you had a
00:07:15 --> 00:07:18 civilization working in a very high
00:07:18 --> 00:07:21 gravitational field, uh, would that mean
00:07:21 --> 00:07:23 that they would evolve more quickly and
00:07:23 --> 00:07:26 things would develop more quickly? Um, and
00:07:26 --> 00:07:27 I suppose the answer is yes, but only to an
00:07:27 --> 00:07:30 outside observer. To the people
00:07:30 --> 00:07:32 doing it, it would be just the same.
00:07:33 --> 00:07:36 Um, so, yes, maybe if our planet had
00:07:36 --> 00:07:39 a hugely different gravitational field
00:07:39 --> 00:07:42 from what it does have. Uh, seen from the
00:07:42 --> 00:07:43 outside, we might look as though we're
00:07:43 --> 00:07:46 evolving more quickly and developing
00:07:46 --> 00:07:49 technology more quickly, but to
00:07:49 --> 00:07:51 us, it would be just the same as if we had,
00:07:51 --> 00:07:53 you know, a lower gravitational field.
00:07:55 --> 00:07:56 Andrew Dunkley: This would complicate the search for
00:07:56 --> 00:07:59 intelligent life, wouldn't it? Uh, I mean,
00:07:59 --> 00:08:02 you might find a planet, um, and go,
00:08:02 --> 00:08:04 hey, something's going on there. Um,
00:08:05 --> 00:08:07 but it's in, it's in a, you know, high
00:08:07 --> 00:08:10 gravity environment. And, um,
00:08:10 --> 00:08:12 maybe it was happening
00:08:13 --> 00:08:15 some time ago, but it's all over. Red Rover.
00:08:15 --> 00:08:18 I mean, I don't know, it's. It's a head
00:08:18 --> 00:08:19 scratcher.
00:08:20 --> 00:08:21 Professor Fred Watson: Or.
00:08:21 --> 00:08:23 Andrew Dunkley: Here's one. If you do find a civilization
00:08:24 --> 00:08:26 living in a, in a, on a planet and, uh, you
00:08:26 --> 00:08:29 land to say hello, and then you take off
00:08:29 --> 00:08:31 again and find out that everyone at home's
00:08:31 --> 00:08:33 dead because you've been gone 500 years, but
00:08:33 --> 00:08:34 you were only gone a week.
00:08:34 --> 00:08:37 Professor Fred Watson: Yeah. Well, there's that, too. That's right.
00:08:38 --> 00:08:41 Yeah. That's, um, special relativity. That's,
00:08:41 --> 00:08:41 uh, the.
00:08:41 --> 00:08:42 Andrew Dunkley: That's the one.
00:08:42 --> 00:08:44 Professor Fred Watson: The relativistic difference in time. Well,
00:08:44 --> 00:08:46 because you're traveling at speeds near the
00:08:46 --> 00:08:47 speed of light. Yeah.
00:08:47 --> 00:08:50 Andrew Dunkley: I mean, it happens. Happens. On Earth,
00:08:50 --> 00:08:52 they've done those tests with, um, highly
00:08:52 --> 00:08:55 sensitive clocks and tested them at
00:08:55 --> 00:08:58 different altitudes and they've come back
00:08:58 --> 00:09:00 and went, well, look, there's a thousandth of
00:09:00 --> 00:09:03 a second difference in their performance. So
00:09:03 --> 00:09:06 we've moved through time. I read a story the
00:09:06 --> 00:09:08 other day, Fred, which I wish I'd kept it,
00:09:09 --> 00:09:12 um, about a cosmonaut, I think it was, who'd
00:09:12 --> 00:09:15 spent so much time in space that they
00:09:15 --> 00:09:17 estimated that, um,
00:09:18 --> 00:09:21 he was actually slightly ahead of time
00:09:21 --> 00:09:23 than everybody else. And I can't
00:09:23 --> 00:09:26 remember the details, but, uh, it was really
00:09:26 --> 00:09:27 fascinating.
00:09:27 --> 00:09:28 Professor Fred Watson: Um.
00:09:29 --> 00:09:31 Andrew Dunkley: They'Ve released a paper about it. I'll see
00:09:31 --> 00:09:34 if I can find it interesting. I might do
00:09:34 --> 00:09:36 that while you answer this next question.
00:09:36 --> 00:09:39 Thank you, Andy. I love that idea though. Um,
00:09:39 --> 00:09:40 keep them coming.
00:09:43 --> 00:09:45 Three, two, one.
00:09:45 --> 00:09:47 Speaker C: Space nuts.
00:09:48 --> 00:09:50 Andrew Dunkley: Uh, this question comes from Mark. Hi, Andrew
00:09:50 --> 00:09:53 and Fred and team. My name is Mark Turner
00:09:53 --> 00:09:55 and I live in the south of England. I'm sorry
00:09:55 --> 00:09:58 about that. About five, about five minutes
00:09:58 --> 00:10:01 from Patrick Moore's house as a point of
00:10:01 --> 00:10:04 interest. Wow. Um, I've been
00:10:04 --> 00:10:06 listening now for just over three years and
00:10:06 --> 00:10:08 always look forward to Thursday lunchtime
00:10:08 --> 00:10:09 when I sit down and listen to you guys.
00:10:10 --> 00:10:12 Sorry, we were talking about toilet stuff
00:10:12 --> 00:10:14 earlier. I hope that didn't mess you up. Uh,
00:10:14 --> 00:10:17 my question is, it's generally accepted
00:10:17 --> 00:10:19 that all of the heavy elements were produced
00:10:19 --> 00:10:22 in an even larger star than ours that
00:10:22 --> 00:10:25 went supernova. Which leads me, uh, to this.
00:10:26 --> 00:10:29 Can we still see the remains of the star
00:10:29 --> 00:10:31 that made us in the night sky,
00:10:31 --> 00:10:34 or do we know, uh, at what point in the
00:10:34 --> 00:10:37 night sky the star would have been by turning
00:10:37 --> 00:10:40 back the cosmic time clock? Keep up the great
00:10:40 --> 00:10:41 work, Mark.
00:10:43 --> 00:10:44 What do you reckon about that one?
00:10:44 --> 00:10:47 Professor Fred Watson: Um, so the answer is no.
00:10:47 --> 00:10:48 Um, because.
00:10:50 --> 00:10:52 So, yes, um, uh,
00:10:54 --> 00:10:56 what we call the interstellar medium, the gas
00:10:56 --> 00:10:58 between the stars, is enriched
00:10:58 --> 00:11:01 in its chemical, um,
00:11:01 --> 00:11:03 abundance. The amount of heavier elements
00:11:03 --> 00:11:06 that are in it enriched over time because
00:11:06 --> 00:11:08 of supernova explosions.
00:11:09 --> 00:11:12 Stars that have detonated and
00:11:12 --> 00:11:14 gone through this high temperature process
00:11:14 --> 00:11:16 where you get heavier elements created. And
00:11:17 --> 00:11:20 some of the heavy elements we now know are
00:11:20 --> 00:11:22 created in neutron star collisions,
00:11:22 --> 00:11:25 um, but that doesn't matter which
00:11:25 --> 00:11:28 it is. Um, the bottom line is that
00:11:28 --> 00:11:31 it's the general interstellar
00:11:31 --> 00:11:33 medium that is enriched. So you've got an
00:11:33 --> 00:11:36 explosion that takes place and over
00:11:36 --> 00:11:39 millions of years, the debris from
00:11:39 --> 00:11:42 that explosion just gets absorbed into
00:11:42 --> 00:11:44 the clouds of gas and dust that are then
00:11:44 --> 00:11:47 going to form, uh, later generations of
00:11:47 --> 00:11:50 stars. So there's really no way
00:11:50 --> 00:11:53 that the remnants of the star that gave
00:11:53 --> 00:11:55 us. Uh,
00:11:56 --> 00:11:59 the heavier elements, um, there's
00:11:59 --> 00:12:01 no way that we can pinpoint
00:12:01 --> 00:12:04 that it may be that some of the
00:12:04 --> 00:12:07 supernova remnants that we see, and we see
00:12:07 --> 00:12:10 many around the sky, that some of those
00:12:10 --> 00:12:13 were responsible for some of the
00:12:13 --> 00:12:14 stuff.
00:12:17 --> 00:12:19 They were probably responsible for enriching
00:12:19 --> 00:12:22 the interstellar medium closer to them than
00:12:22 --> 00:12:25 we are. That's kind of the point, I guess, I
00:12:25 --> 00:12:28 want to make. The debris that gave us
00:12:28 --> 00:12:30 our enriched interstellar medium
00:12:30 --> 00:12:33 is probably long dissipated. And we could
00:12:33 --> 00:12:36 not identify, uh, it with any of
00:12:36 --> 00:12:38 the known supernova remnants because
00:12:39 --> 00:12:41 they're still enriching their local
00:12:41 --> 00:12:43 environment, if I can put it that way,
00:12:43 --> 00:12:45 because they're still intact structures.
00:12:45 --> 00:12:48 They're expanding and dissipating, but we see
00:12:48 --> 00:12:51 them as intact structures. And so the
00:12:51 --> 00:12:53 debris that made us 4.6
00:12:53 --> 00:12:56 billion years ago is, uh,
00:12:56 --> 00:12:59 basically is nowhere near. You know,
00:12:59 --> 00:13:01 it's nothing to do with them.
00:13:02 --> 00:13:04 Um, and partly because those explosions took
00:13:04 --> 00:13:06 place more recently than the 4.6 billion
00:13:06 --> 00:13:09 years ago origin of our own solar system.
00:13:10 --> 00:13:12 So, uh, the.
00:13:13 --> 00:13:16 Basically, uh, yes, the answer is,
00:13:16 --> 00:13:19 well, no, we can't identify those
00:13:19 --> 00:13:22 remains. Uh, and turning back the cosmic time
00:13:22 --> 00:13:25 clock, we can do that, but we can't do it in
00:13:25 --> 00:13:27 the sort of detail. I mean, we can do it in a
00:13:28 --> 00:13:30 physical modeling sense. We're not looking at
00:13:30 --> 00:13:32 anything unless we're looking at things at
00:13:32 --> 00:13:34 great distances where we are looking back in
00:13:34 --> 00:13:37 time. Uh, but for the
00:13:37 --> 00:13:39 physics that we use to model the universe,
00:13:40 --> 00:13:43 um, we can't, um, wind back the clock
00:13:43 --> 00:13:45 in enough detail to see where
00:13:45 --> 00:13:48 these objects exploded. Uh, they may be,
00:13:48 --> 00:13:51 you know, many, many thousands, tens of
00:13:51 --> 00:13:53 thousands of light years away, uh, from where
00:13:53 --> 00:13:56 we are now. Uh, all they did was enrich the
00:13:56 --> 00:13:58 medium around them. And that's where we found
00:13:58 --> 00:14:01 our own, uh, solar system being formed.
00:14:01 --> 00:14:03 So we can't. We can't look back in time in
00:14:03 --> 00:14:06 that regard. Okay, thank you,
00:14:06 --> 00:14:08 Mark. Uh, by the way, I, uh, was a pretty
00:14:08 --> 00:14:10 regular visitor to Patrick Moore while, uh,
00:14:11 --> 00:14:13 he was still alive. So I know that house.
00:14:13 --> 00:14:15 Well, at Selsey, it was called Farthings, uh,
00:14:15 --> 00:14:18 is a lovely house, actually. Uh, and, um,
00:14:18 --> 00:14:21 when I used to visit him, he was always very
00:14:21 --> 00:14:23 welcoming, uh, and, um, always glad to show
00:14:23 --> 00:14:24 me around.
00:14:25 --> 00:14:27 Andrew Dunkley: Wonderful. Wow. Lucky you. Yeah.
00:14:27 --> 00:14:28 Professor Fred Watson: Yeah.
00:14:28 --> 00:14:31 Andrew Dunkley: Now, um, just to sort of draw on
00:14:31 --> 00:14:33 Mark's question, um, so he's
00:14:33 --> 00:14:36 right about a supernova creating the heavy
00:14:36 --> 00:14:36 elements.
00:14:37 --> 00:14:37 Professor Fred Watson: Yes.
00:14:37 --> 00:14:40 Andrew Dunkley: So how do they end up being a
00:14:40 --> 00:14:42 part of our planet? Is that because the
00:14:42 --> 00:14:44 supernovas created the.
00:14:45 --> 00:14:48 The spawning ground or being, you know,
00:14:48 --> 00:14:50 run through it? What. How does that work?
00:14:51 --> 00:14:53 Professor Fred Watson: Yeah, I mean, it's what I was saying.
00:14:53 --> 00:14:55 Basically, the, the. You Know, you get a
00:14:55 --> 00:14:57 supernova explosion which um,
00:14:57 --> 00:15:00 sends shockwaves out, uh, it sends
00:15:00 --> 00:15:03 enriched gas out and that gas
00:15:03 --> 00:15:06 gradually diffuses into the
00:15:06 --> 00:15:09 background, uh, what we call the
00:15:09 --> 00:15:11 interstellar medium. This, the, the gas
00:15:11 --> 00:15:14 between the stars. It's very, very rarefied,
00:15:14 --> 00:15:17 but that's where that stuff. And as
00:15:17 --> 00:15:20 you then get concentrations of that gas
00:15:20 --> 00:15:23 into clouds of hydrogen, mostly hydrogen, but
00:15:23 --> 00:15:25 other M elements as well, because it's been
00:15:25 --> 00:15:28 enriched, then that is what would form the
00:15:28 --> 00:15:31 next solar system. Uh, and so that, you
00:15:31 --> 00:15:33 know, that gradual process of
00:15:34 --> 00:15:36 uh, stars forming, exploding,
00:15:36 --> 00:15:39 enriching the uh, interstellar medium,
00:15:39 --> 00:15:42 then interstellar medium creates other star
00:15:42 --> 00:15:45 systems which do the same thing. It's why
00:15:45 --> 00:15:48 as the universe ages, you're going to get an
00:15:48 --> 00:15:50 enrichment of the number of heavy,
00:15:50 --> 00:15:53 of, you know, quantities of heavier elements
00:15:53 --> 00:15:54 that there are within the universe. And
00:15:54 --> 00:15:57 that's actually one way that we can measure
00:15:57 --> 00:16:00 the ages of stars, by how much of this stuff
00:16:00 --> 00:16:02 they've got in them. Because when they were
00:16:02 --> 00:16:03 formed, the universe would have been at a
00:16:03 --> 00:16:06 certain point of enrichment. Uh, and you
00:16:06 --> 00:16:09 know, that point is fossilized,
00:16:09 --> 00:16:12 if I can put it that way, in the star itself
00:16:12 --> 00:16:14 by the chemical composition that it
00:16:14 --> 00:16:15 demonstrates.
00:16:16 --> 00:16:18 Andrew Dunkley: Okay, very good. Um, it's a law
00:16:18 --> 00:16:20 of diminishing returns though, isn't it?
00:16:20 --> 00:16:22 Eventually all of this is going to stop
00:16:22 --> 00:16:23 happening.
00:16:23 --> 00:16:25 Professor Fred Watson: Yes, that's right. Eventually the universe
00:16:25 --> 00:16:27 will die because of that. Because there won't
00:16:27 --> 00:16:29 be any more. There won't be any gas
00:16:29 --> 00:16:32 in which to create supernova explosions,
00:16:32 --> 00:16:34 which is the raw material of stars, hydrogen
00:16:34 --> 00:16:37 gas that will all be used up eventually and
00:16:37 --> 00:16:39 we'll have what used to be called the heat
00:16:39 --> 00:16:41 death of the universe. Unless it starts
00:16:41 --> 00:16:43 collapsing on itself again.
00:16:43 --> 00:16:45 Andrew Dunkley: Well, yeah, I mean there's all these
00:16:46 --> 00:16:48 terrible perilous things that are going to
00:16:48 --> 00:16:51 happen, but um. It'S
00:16:51 --> 00:16:52 not going to happen next week, the week after
00:16:52 --> 00:16:55 maybe, because we're on holidays, if we're
00:16:55 --> 00:16:55 lucky.
00:16:55 --> 00:16:57 Professor Fred Watson: The week after. Yeah, that's right.
00:16:58 --> 00:16:59 Andrew Dunkley: Yeah. Thank, uh, you Mark. Great question.
00:17:00 --> 00:17:02 Uh, now that thing I was trying to look up, I
00:17:02 --> 00:17:04 can't find the exact story, but um,
00:17:05 --> 00:17:08 I found something that kind of explains the
00:17:08 --> 00:17:10 concept. Apparently, um, for a six month
00:17:10 --> 00:17:12 mission on the International Space Station.
00:17:12 --> 00:17:14 And as astronaut ages,
00:17:14 --> 00:17:17 0 seconds less than they
00:17:17 --> 00:17:20 would on Earth. So this, this particular
00:17:21 --> 00:17:23 um, ah, cosmonaut that I'm talking about
00:17:23 --> 00:17:25 apparently has spent so much time in space
00:17:26 --> 00:17:29 that he's actually, I think it's
00:17:29 --> 00:17:31 0.22, um,
00:17:32 --> 00:17:34 minutes younger than he.
00:17:35 --> 00:17:37 Had he drawn into space.
00:17:38 --> 00:17:40 Professor Fred Watson: It's only seconds rather than minutes. Yeah.
00:17:40 --> 00:17:42 Andrew Dunkley: Oh, 0.22 seconds. Yes, exactly.
00:17:43 --> 00:17:46 Yeah. Um, so I, I, yeah, I read
00:17:46 --> 00:17:48 it last week. I meant to send it to you and I
00:17:48 --> 00:17:50 completely forgot. So, uh, but that's the,
00:17:50 --> 00:17:52 that's the, the, the guts of the story.
00:17:53 --> 00:17:55 This uh, is Space Nuts. Andrew Dunkley with
00:17:56 --> 00:17:57 Professor Fred Watson.
00:17:58 --> 00:17:59 Professor Fred Watson: Space Nets.
00:18:00 --> 00:18:03 Andrew Dunkley: Uh, we have a, uh, question from one of
00:18:03 --> 00:18:05 our regular contributors. This is Casey.
00:18:05 --> 00:18:08 Speaker C: Hi guys. This is Casey from Colorado. Um,
00:18:08 --> 00:18:11 I just saw red northern lights and it
00:18:11 --> 00:18:13 was, it was really incredible.
00:18:13 --> 00:18:15 Professor Fred Watson: I, um, was hoping that you could.
00:18:15 --> 00:18:17 Speaker C: Please explain why auroras come in different
00:18:17 --> 00:18:20 colors. I hope you're both well and thanks
00:18:20 --> 00:18:20 for the podcast.
00:18:21 --> 00:18:23 Andrew Dunkley: Uh, thank you, Casey. Casey sent in a few,
00:18:24 --> 00:18:26 um, questions in recent times and we're more
00:18:26 --> 00:18:28 than happy to answer. She comes up with some
00:18:28 --> 00:18:30 interesting ideas. Uh, I just thought this
00:18:30 --> 00:18:32 was a good question to answer. Uh, I know
00:18:32 --> 00:18:35 we've talked about it before, but there's
00:18:35 --> 00:18:37 been some great auroral activity of late.
00:18:38 --> 00:18:41 And even in parts of
00:18:41 --> 00:18:42 Australia where you just don't see them, they
00:18:42 --> 00:18:45 have been absolutely stunning. Even as
00:18:45 --> 00:18:47 recently as a week or two ago, we had some
00:18:47 --> 00:18:50 fabulous photographs coming out of, um,
00:18:50 --> 00:18:52 many, many parts of southeastern Australia
00:18:53 --> 00:18:56 and. Prompted a
00:18:56 --> 00:18:59 thought in my mind that the one, the aurora
00:18:59 --> 00:19:02 we see here generally are pink.
00:19:02 --> 00:19:05 But when you see photos up in the northern
00:19:05 --> 00:19:07 hemisphere, when you're practically
00:19:07 --> 00:19:10 underneath them, they're green. Uh, and
00:19:10 --> 00:19:12 I'm sure the colors can vary
00:19:13 --> 00:19:16 into many areas. Fred,
00:19:16 --> 00:19:18 uh, I mean you've taken tours on these, um,
00:19:18 --> 00:19:21 to see these things you've seen that like
00:19:21 --> 00:19:22 this is boring for you.
00:19:22 --> 00:19:25 Professor Fred Watson: But, uh, it's never boring.
00:19:25 --> 00:19:27 Actually. I didn't imagine it wouldn't be
00:19:27 --> 00:19:29 just always spectacular. But you're
00:19:29 --> 00:19:31 absolutely right. So when we're up in uh,
00:19:32 --> 00:19:34 uh, Alta, which is far northern
00:19:34 --> 00:19:37 Norway, or um, Kirino, which is
00:19:37 --> 00:19:39 far northern Sweden, or Abisko, which is also
00:19:39 --> 00:19:41 far northern Sweden. And looking at the
00:19:41 --> 00:19:44 aurora, you're basically standing
00:19:44 --> 00:19:47 underneath it. And so you see the aurora
00:19:47 --> 00:19:50 as it really is. Uh, and
00:19:50 --> 00:19:53 you've got lots of colors in it. Um,
00:19:53 --> 00:19:56 but the pink and red
00:19:56 --> 00:19:58 aurorae are typically, uh, seen
00:19:59 --> 00:20:01 when you're a long way from the action.
00:20:02 --> 00:20:05 Uh, and the green, the bottom line is the
00:20:05 --> 00:20:05 green.
00:20:05 --> 00:20:08 Andrew Dunkley: Is we talking rate shift? No,
00:20:08 --> 00:20:10 no, but we're talking atmospheric.
00:20:12 --> 00:20:12 Uh.
00:20:12 --> 00:20:15 Professor Fred Watson: We'Re talking emission line spectroscopy.
00:20:16 --> 00:20:17 Andrew Dunkley: I never would have thought about.
00:20:18 --> 00:20:20 Professor Fred Watson: Yeah, so, um, the pink
00:20:20 --> 00:20:23 and red aurorae, uh, you'd see them
00:20:23 --> 00:20:25 if you're in the northern hemisphere. You'd
00:20:25 --> 00:20:27 see them on the northern horizon in the
00:20:27 --> 00:20:29 southern hemisphere here in Tasmania, you see
00:20:29 --> 00:20:32 them very often down in the south Usually the
00:20:32 --> 00:20:34 green part is below the horizon.
00:20:35 --> 00:20:37 It's too far over the Earth's curvature to
00:20:37 --> 00:20:40 see. And that's why you only see the red. And
00:20:40 --> 00:20:43 that's a clue to what's happening here. So,
00:20:43 --> 00:20:45 um, what you've got is the
00:20:45 --> 00:20:47 atmosphere, uh, being excited
00:20:48 --> 00:20:50 by radiation from the sun.
00:20:51 --> 00:20:54 Um, these subatomic particles charge
00:20:55 --> 00:20:57 out from the sun. If you've got a solar flare
00:20:57 --> 00:20:59 or something like that. They going at
00:20:59 --> 00:21:01 typically a million kilometers an hour. Uh,
00:21:01 --> 00:21:04 so they take a couple of days to get here.
00:21:04 --> 00:21:06 And then they're sort of funneled down the
00:21:06 --> 00:21:09 Earth's, uh, magnetic field lines. Um, and
00:21:09 --> 00:21:11 they're most concentrated near the magnetic
00:21:11 --> 00:21:13 poles. Which is why it's around the magnetic
00:21:13 --> 00:21:16 poles that you see most aurora. This is a
00:21:16 --> 00:21:18 sort of simplified version of the story. But,
00:21:18 --> 00:21:21 um, what happens is these electrons,
00:21:21 --> 00:21:23 they're accelerated. They're quite high
00:21:23 --> 00:21:25 energy. They hit atoms
00:21:26 --> 00:21:28 of oxygen and nitrogen in
00:21:28 --> 00:21:30 the Earth's atmosphere and they make them
00:21:30 --> 00:21:33 glow. And the important
00:21:33 --> 00:21:35 thing here is that those
00:21:36 --> 00:21:38 atoms of oxygen and nitrogen, actually
00:21:38 --> 00:21:41 they're molecules as well. Uh, O2,
00:21:41 --> 00:21:44 which is a pair of oxygen atoms, or N2, which
00:21:44 --> 00:21:47 is a pair of nitrogen atoms. Um, they behave
00:21:47 --> 00:21:49 differently at different pressures. And of
00:21:49 --> 00:21:51 course, as you go up through the atmosphere,
00:21:51 --> 00:21:54 the pressure gets steadily lower. So the most
00:21:54 --> 00:21:57 common one is the green light. And
00:21:57 --> 00:21:59 that's, uh, when you've got
00:21:59 --> 00:22:02 oxygen burn. Being excited to emit
00:22:02 --> 00:22:04 this green color. It's what we call a
00:22:04 --> 00:22:06 spectrum line. It's a particular wavelength,
00:22:06 --> 00:22:09 which means it's a particular color. Uh, but
00:22:09 --> 00:22:11 it's green. Uh, and that, uh,
00:22:11 --> 00:22:14 works for pressures that you see
00:22:14 --> 00:22:16 between about 100 and 200
00:22:16 --> 00:22:19 kilometers above the Earth's atmosphere.
00:22:20 --> 00:22:22 Above 200 kilometers, the
00:22:22 --> 00:22:25 pressure is lower, uh, and
00:22:25 --> 00:22:27 the green line doesn't form, or the green
00:22:27 --> 00:22:30 light is not formed. Uh, it's actually
00:22:30 --> 00:22:33 quenched. And there is a different atomic
00:22:33 --> 00:22:35 process that gives rise to red light.
00:22:37 --> 00:22:39 Uh, 630 nanometers, if I remember rightly,
00:22:40 --> 00:22:42 is the wavelength. So you get this red light,
00:22:42 --> 00:22:45 which is still oxygen, but it's oxygen at
00:22:45 --> 00:22:48 a lower pressure than what comes out
00:22:48 --> 00:22:50 from the green. So between 1 and 200
00:22:50 --> 00:22:52 kilometers, you're going to see green aurora.
00:22:52 --> 00:22:54 Above that, you're going to see red aurorae.
00:22:54 --> 00:22:57 And that's why we only see the red ones. If
00:22:57 --> 00:22:58 you're looking from Australia, because the
00:22:58 --> 00:23:01 green is way below the horizon. Um,
00:23:01 --> 00:23:04 if you've got a really, um, powerful
00:23:05 --> 00:23:08 stream of subatomic particles, then
00:23:08 --> 00:23:10 they will penetrate below 100km.
00:23:11 --> 00:23:14 And that then excites not
00:23:14 --> 00:23:16 the oxygen, but the Nitrogen. You get um,
00:23:16 --> 00:23:19 what's called molecular excitation. Nitrogen
00:23:19 --> 00:23:21 molecules start emitting light and they
00:23:21 --> 00:23:24 emit in several different colors. Light,
00:23:24 --> 00:23:27 um, deep blue, um, there is
00:23:28 --> 00:23:30 different red, there's sort of greens, uh,
00:23:30 --> 00:23:32 and all those mixed together to give you
00:23:32 --> 00:23:35 something like a purple. Often in a bright
00:23:35 --> 00:23:37 aurora you've got the green auroral curtains
00:23:38 --> 00:23:40 and below that there might be a purple layer
00:23:40 --> 00:23:42 as well. And sometimes the colors are so
00:23:42 --> 00:23:45 mixed that it turns white that you actually
00:23:45 --> 00:23:47 get a white bottom edge to an aurora. Then
00:23:47 --> 00:23:50 you know, you've got really high energy
00:23:50 --> 00:23:52 electrons and then you saw all.
00:23:52 --> 00:23:53 Andrew Dunkley: You see in one of those.
00:23:53 --> 00:23:56 Professor Fred Watson: Yes, I have. Uh, yeah, actually the very
00:23:56 --> 00:23:57 first time we went up there, I've got
00:23:57 --> 00:23:59 photographs taken from a place called
00:23:59 --> 00:24:02 Lingenfjord in northern Norway. A very dark
00:24:02 --> 00:24:04 site. It was a wonderful place to see the
00:24:04 --> 00:24:06 aurora from. And yeah, there were definitely
00:24:06 --> 00:24:09 white, white, white bottoms on my auroral
00:24:09 --> 00:24:11 curve. Um, so
00:24:12 --> 00:24:14 uh, but what I was going to say
00:24:14 --> 00:24:17 was that's the basic story. But in
00:24:17 --> 00:24:20 reality you get these things all mixing and
00:24:20 --> 00:24:21 so sometimes you do get pinks and you get,
00:24:21 --> 00:24:23 you can actually get some quite odd colors.
00:24:25 --> 00:24:27 Actually I took some photographs at the
00:24:27 --> 00:24:30 beginning of this year in uh, far, again far
00:24:30 --> 00:24:32 northern Norway, uh, and later in Greenland
00:24:32 --> 00:24:35 where the coloring was almost like a brown
00:24:35 --> 00:24:37 color rather than the reddish that you expect
00:24:38 --> 00:24:41 uh, from high altitude aurora. So it's the
00:24:41 --> 00:24:42 way the colors mix that give you the
00:24:43 --> 00:24:45 different effects. Plus you've got to add to
00:24:45 --> 00:24:47 that the color response of your camera as
00:24:47 --> 00:24:50 well, which can sometimes tell you
00:24:50 --> 00:24:53 um, you know, give you falsehoods. Because
00:24:53 --> 00:24:56 the, the camera itself is, is basically
00:24:56 --> 00:24:58 tuned to take photographs of everyday
00:24:58 --> 00:25:00 objects. It's not really tuned to take
00:25:00 --> 00:25:02 photographs of things that are emitting only
00:25:02 --> 00:25:05 on one wavelength, uh, which the aurora does.
00:25:05 --> 00:25:08 Andrew Dunkley: Yes, yes, I know. Um, although while we were
00:25:08 --> 00:25:10 uh, up there, um, northern,
00:25:11 --> 00:25:13 northern parts of Europe, Norway, um,
00:25:13 --> 00:25:16 Greenland, Iceland, people, um,
00:25:16 --> 00:25:18 did try to um, take photos of
00:25:18 --> 00:25:20 aurora and a couple of them were successful.
00:25:21 --> 00:25:23 I was not. Yeah, I'll say
00:25:23 --> 00:25:24 one.
00:25:24 --> 00:25:27 Professor Fred Watson: But it was summer. Yes, summer's the, that's
00:25:27 --> 00:25:28 the problem because there's still so much
00:25:28 --> 00:25:31 twilight there. Um, I used to
00:25:31 --> 00:25:34 cut around a digital, proper digital
00:25:34 --> 00:25:36 camera with me and a tripod to do all these
00:25:36 --> 00:25:38 long exposure photographs. But to be honest,
00:25:38 --> 00:25:41 now with a smartphone they are so sensitive
00:25:41 --> 00:25:44 you can hand hold them and get really
00:25:44 --> 00:25:46 fantastic auroral photographs.
00:25:47 --> 00:25:49 Um, which blew me away the first time I did
00:25:49 --> 00:25:52 it, which was the beginning of this year.
00:25:52 --> 00:25:55 Uh, I tried it a little bit on the previous
00:25:55 --> 00:25:57 trip that we had up to northern parts which
00:25:57 --> 00:26:00 was in Canada, actually. Uh, but this time at
00:26:00 --> 00:26:01 the beginning of this year, in Norway,
00:26:01 --> 00:26:04 Sweden, Iceland, uh, and Greenland. I just
00:26:04 --> 00:26:06 held the smartphone up and, well, I've
00:26:06 --> 00:26:08 got more photographs than I know what to do
00:26:08 --> 00:26:11 with, and they're all dramatically good. Uh,
00:26:11 --> 00:26:13 the smartphone is such amazing technology.
00:26:14 --> 00:26:17 Andrew Dunkley: It's changed the world. Has in many ways, uh,
00:26:17 --> 00:26:18 particularly when it comes to photography.
00:26:18 --> 00:26:21 Um, it was the old, um, the old
00:26:21 --> 00:26:23 Canon Snappies and all those that we used to
00:26:23 --> 00:26:26 have with film in them. You got one shot at
00:26:26 --> 00:26:27 it and you didn't find out if it was any good
00:26:27 --> 00:26:28 for a couple of weeks.
00:26:28 --> 00:26:31 Professor Fred Watson: Yeah, the odds are that it, it wouldn't be
00:26:31 --> 00:26:33 because this sensitivity of film is so much
00:26:33 --> 00:26:35 lower than the, you know, than the sensors
00:26:35 --> 00:26:38 that we now use for images. That's the bottom
00:26:38 --> 00:26:38 line. Yep. Yeah.
00:26:38 --> 00:26:40 Andrew Dunkley: The gears are good now. Makes. Makes
00:26:40 --> 00:26:43 everybody a professional. Well, not quite,
00:26:43 --> 00:26:43 but you know what I'm saying.
00:26:43 --> 00:26:45 Professor Fred Watson: Talk to a professional photographer. And they
00:26:45 --> 00:26:46 won't actually agree with that?
00:26:46 --> 00:26:48 Andrew Dunkley: No, they would. They work out.
00:26:49 --> 00:26:51 Uh, thank you, Casey. Great question and
00:26:51 --> 00:26:54 good, uh, to hear from you again. Okay, we
00:26:54 --> 00:26:56 checked all four systems, and being with a
00:26:56 --> 00:26:58 girl, space nuts, our final question today.
00:26:59 --> 00:27:02 Uh, hi, guys, love the show,
00:27:02 --> 00:27:04 etc. Etc. He doesn't bandy around
00:27:04 --> 00:27:07 much. He's straight to the point. Uh, an idea
00:27:07 --> 00:27:09 just occurred to me. Uh, mass increases
00:27:10 --> 00:27:13 the faster you go, becoming infinite
00:27:13 --> 00:27:16 at the speed of light. So if it were possible
00:27:16 --> 00:27:18 to accelerate particles up to a
00:27:18 --> 00:27:20 relativistic. I hate that word.
00:27:20 --> 00:27:23 Relativistic speeds in some compact
00:27:23 --> 00:27:26 device and then throw them out of the back of
00:27:26 --> 00:27:29 a spacecraft, would the acceleration increase
00:27:29 --> 00:27:32 because you're throwing more mass out
00:27:32 --> 00:27:35 the back? Yeah, I did that the other day.
00:27:35 --> 00:27:38 It's not pleasant. Uh, kind of
00:27:38 --> 00:27:40 an ion engine on. On
00:27:40 --> 00:27:43 steroids. Uh, I'm envisioning some kind
00:27:43 --> 00:27:46 of small particle accelerator powered by a
00:27:46 --> 00:27:48 nuclear power source, preferably fission.
00:27:49 --> 00:27:51 Any thoughts? Absolutely. Welcome.
00:27:51 --> 00:27:51 Speaker C: Many.
00:27:51 --> 00:27:53 Andrew Dunkley: Uh, thanks, and keep up the great work. Lee
00:27:53 --> 00:27:56 in Sweden, not to be confused with Swede in
00:27:56 --> 00:27:57 Leighton.
00:27:59 --> 00:28:00 Professor Fred Watson: Oh, okay.
00:28:00 --> 00:28:01 Speaker C: Really? Yeah.
00:28:01 --> 00:28:04 Andrew Dunkley: That's somebody else. Um,
00:28:05 --> 00:28:07 no, Lee in Sweden. So, um,
00:28:08 --> 00:28:10 okay, so he's got a particle accelerator on
00:28:10 --> 00:28:13 his spaceship, and he's accelerating
00:28:13 --> 00:28:16 the particles up to relativistic
00:28:16 --> 00:28:19 speeds and then he's shooting them
00:28:19 --> 00:28:21 out the back of the spacecraft. Bigger mass,
00:28:22 --> 00:28:24 whatever. Can it accelerate the spacecraft?
00:28:26 --> 00:28:27 Professor Fred Watson: Um, yeah.
00:28:27 --> 00:28:29 All right, I'm going to read, uh, what I've
00:28:29 --> 00:28:32 just brought up on the screen in front of me.
00:28:33 --> 00:28:36 Um, relativistic mass ejection in
00:28:36 --> 00:28:38 ion motors is not a current technology, but a
00:28:38 --> 00:28:40 theoretical concept. For future propulsion,
00:28:40 --> 00:28:43 where ions would be accelerated to speeds
00:28:43 --> 00:28:45 approaching the speed of light. The
00:28:45 --> 00:28:47 relativistic aspect refers to the effect of
00:28:47 --> 00:28:50 special relativity, where an object's mass
00:28:50 --> 00:28:52 appears to increase as it approaches the
00:28:52 --> 00:28:54 speed of light, making it harder to
00:28:54 --> 00:28:56 accelerate it further. This would require
00:28:56 --> 00:28:59 extremely high energy inputs and would
00:28:59 --> 00:29:02 involve complex physics. Unlike current ion
00:29:02 --> 00:29:04 thrusters that use less energetic but still
00:29:04 --> 00:29:07 very high ion, uh, ejection velocities
00:29:08 --> 00:29:10 that came from A.I. so how's that?
00:29:10 --> 00:29:12 Andrew Dunkley: Yeah, well, I mean,
00:29:13 --> 00:29:14 A.I. can be very useful.
00:29:15 --> 00:29:17 Professor Fred Watson: Yeah, that's kind of what I steer.
00:29:17 --> 00:29:19 Andrew Dunkley: You up the wrong path. It kept getting done.
00:29:19 --> 00:29:20 Professor Fred Watson: Yeah.
00:29:20 --> 00:29:22 Andrew Dunkley: Like, I had to make some pretty significant
00:29:22 --> 00:29:25 inquiries last, uh, last
00:29:25 --> 00:29:27 year, early this year, whatever, uh, about a
00:29:27 --> 00:29:30 housing situation, and it just got it
00:29:30 --> 00:29:33 so wrong constantly. Yeah,
00:29:33 --> 00:29:36 um. But. Yeah, um.
00:29:37 --> 00:29:39 Professor Fred Watson: So what I've just read out is putting nicely
00:29:39 --> 00:29:42 into words what I was going to say, but
00:29:43 --> 00:29:45 it's putting it rather more nicely than I
00:29:45 --> 00:29:47 would have put it. So there you go. Yeah.
00:29:47 --> 00:29:49 Andrew Dunkley: All right. So the. The
00:29:50 --> 00:29:53 concept of, um, creating
00:29:53 --> 00:29:56 engines that can do these
00:29:56 --> 00:29:58 kinds of things is real in science,
00:29:58 --> 00:30:00 but only to a certain degree.
00:30:00 --> 00:30:03 Professor Fred Watson: Yeah, My only worry about it would be, um,
00:30:03 --> 00:30:06 and I guess this is what, you know, the
00:30:06 --> 00:30:07 complex physics bit was.
00:30:08 --> 00:30:11 Um, you've got different reference frames.
00:30:11 --> 00:30:13 You've got the reference frame of the. Of the
00:30:13 --> 00:30:16 spacecraft, You've got the reference frame of
00:30:16 --> 00:30:18 the flow of, uh, charged
00:30:18 --> 00:30:20 particles coming out the back of it, and
00:30:20 --> 00:30:23 you've got a stationary reference frame, and
00:30:23 --> 00:30:26 the mass looks different to all of those. Uh,
00:30:26 --> 00:30:29 so, uh, that will be my only
00:30:29 --> 00:30:31 worry about that. And it's the thing that I
00:30:31 --> 00:30:32 would like to go a bit further into it rather
00:30:32 --> 00:30:35 than rely on A.I. uh, but
00:30:36 --> 00:30:38 the basic principle, I think, is quite right.
00:30:39 --> 00:30:42 Uh, but I have a
00:30:42 --> 00:30:44 caveat about just watch out for your
00:30:44 --> 00:30:46 reference frame, if I can put it that way.
00:30:46 --> 00:30:49 Andrew Dunkley: Yeah. Um, I've been toying
00:30:49 --> 00:30:51 with AI just to, uh, sort of get some
00:30:51 --> 00:30:54 concepts in my head about. You know, I
00:30:54 --> 00:30:56 mentioned. I don't know if it was this
00:30:56 --> 00:30:58 podcast or the previous one where we, uh,
00:30:58 --> 00:31:00 where I'm writing a new book, but, um.
00:31:02 --> 00:31:04 I. There's some concepts I wanted to
00:31:04 --> 00:31:07 include, but my brain wouldn't go there.
00:31:07 --> 00:31:10 So, um, I did use AI to try and
00:31:10 --> 00:31:13 learn what I needed to learn to make
00:31:13 --> 00:31:16 the. The thing work the way I wanted to in
00:31:16 --> 00:31:18 the story. Uh, it's very clever when you want
00:31:18 --> 00:31:19 to do things like that.
00:31:20 --> 00:31:20 Professor Fred Watson: Did it help?
00:31:21 --> 00:31:22 Andrew Dunkley: Yeah, very much.
00:31:22 --> 00:31:22 Professor Fred Watson: That's interesting.
00:31:22 --> 00:31:25 Andrew Dunkley: Yeah. Um, in fact, it
00:31:26 --> 00:31:28 sometimes gave me way too many concepts. I
00:31:28 --> 00:31:31 only wanted one, but it gave me 10. And I'm
00:31:31 --> 00:31:34 thinking, oh, hang on, that's all good
00:31:34 --> 00:31:36 stuff. I can't use it all, so I had to pick.
00:31:37 --> 00:31:38 But um.
00:31:40 --> 00:31:43 I found it very useful. But um, if you use
00:31:43 --> 00:31:45 it the right way, it's a great tool. Uh,
00:31:45 --> 00:31:48 but if, um, for general
00:31:48 --> 00:31:51 information, sometimes it can just hit the.
00:31:52 --> 00:31:55 You're throwing a dart and hitting that metal
00:31:55 --> 00:31:55 thing around the edge.
00:31:56 --> 00:31:57 Professor Fred Watson: All right, okay.
00:31:57 --> 00:31:59 Andrew Dunkley: Because it's throwing information back at you
00:31:59 --> 00:32:02 that's too generic, I suppose.
00:32:02 --> 00:32:03 Professor Fred Watson: Yeah.
00:32:03 --> 00:32:06 Andrew Dunkley: Sometimes I uh, think when it comes to AI,
00:32:07 --> 00:32:09 you've got to know how to use it to get the
00:32:09 --> 00:32:10 best out of it.
00:32:11 --> 00:32:12 Professor Fred Watson: Otherwise maybe that's right. Yes. Mhm.
00:32:13 --> 00:32:14 Otherwise it's dangerous.
00:32:14 --> 00:32:17 Andrew Dunkley: Yeah. Absolutely
00:32:17 --> 00:32:20 true. Yeah. I have found it very handy
00:32:20 --> 00:32:23 for like I, I've had a few photos over
00:32:23 --> 00:32:24 the years that I've wanted to keep, but
00:32:24 --> 00:32:27 they've, they've not been really good photos
00:32:27 --> 00:32:29 and it's been really good at cleaning them
00:32:29 --> 00:32:32 up. Taking, taking out some of the um,
00:32:32 --> 00:32:34 this one particular photo that I really love.
00:32:35 --> 00:32:36 But it's, it's grainy.
00:32:37 --> 00:32:37 Professor Fred Watson: Yeah.
00:32:37 --> 00:32:40 Andrew Dunkley: So you just upload the photo and say, can
00:32:40 --> 00:32:43 you um. I can't remember the terminology I
00:32:43 --> 00:32:46 used, but can um, you do this? And it
00:32:46 --> 00:32:48 takes like a minute or two to
00:32:49 --> 00:32:52 re. Calibrate the photo and then it gives
00:32:52 --> 00:32:55 you its result. And uh, I
00:32:55 --> 00:32:57 had a couple of big hits with that. That uh.
00:32:58 --> 00:32:58 Professor Fred Watson: Well.
00:32:58 --> 00:33:00 Andrew Dunkley: But I've had a couple that didn't.
00:33:00 --> 00:33:01 Professor Fred Watson: Yeah.
00:33:01 --> 00:33:03 Andrew Dunkley: Um, because the um, it had to
00:33:03 --> 00:33:06 try and fill in spaces because of
00:33:06 --> 00:33:09 the graininess of the photo and what it
00:33:09 --> 00:33:11 filled them in with actually changed the
00:33:11 --> 00:33:13 subject too much and I didn't like it, if
00:33:13 --> 00:33:16 that makes any sense at all. But
00:33:16 --> 00:33:19 um, yeah, I do find it useful. But m.
00:33:20 --> 00:33:22 It's not a perfect science and you've got to
00:33:22 --> 00:33:23 keep that in mind.
00:33:24 --> 00:33:25 Lee, thanks for your question. Uh, did we
00:33:25 --> 00:33:26 finish with Lee?
00:33:26 --> 00:33:27 Professor Fred Watson: I'm pretty sure we did.
00:33:27 --> 00:33:29 Andrew Dunkley: Yeah. Yeah. Good on you, Lee. Hope all is
00:33:29 --> 00:33:31 well in Sweden and I'm sure you get to see
00:33:32 --> 00:33:34 lots of aurorae. To you, lucky duck.
00:33:34 --> 00:33:37 Um, that's it, Fred. We are
00:33:37 --> 00:33:38 finished. Thank you.
00:33:40 --> 00:33:41 Professor Fred Watson: Uh, you're welcome.
00:33:43 --> 00:33:46 Yeah, uh, I, um, I've enjoyed um,
00:33:46 --> 00:33:48 going, getting my mind bent around some of
00:33:48 --> 00:33:51 those issues myself. So thank you Space
00:33:51 --> 00:33:53 Nuts listeners. You keep me on my toes.
00:33:54 --> 00:33:56 Andrew Dunkley: Yes, they do, don't they? If you would like
00:33:56 --> 00:33:59 to send us a question, you uh, can do that
00:33:59 --> 00:34:02 through our website, spacenutspodcast.com
00:34:02 --> 00:34:04 or spacenuts IO
00:34:05 --> 00:34:08 and you click on the AMA link at the top
00:34:08 --> 00:34:11 of the home page. And, uh, just fill in
00:34:11 --> 00:34:12 the blanks. Uh, you can send us your text
00:34:12 --> 00:34:15 questions that way. Or you can send us an
00:34:15 --> 00:34:18 audio question if you've got a device with a
00:34:18 --> 00:34:20 microphone. And just remember, uh, to tell us
00:34:20 --> 00:34:21 who you are and where you're from. Most
00:34:21 --> 00:34:24 people do these days. Or you can send us
00:34:24 --> 00:34:25 questions via YouTube Music. We've been
00:34:25 --> 00:34:27 getting a few of those and sometimes they
00:34:27 --> 00:34:30 just turn up on social media. Uh, it doesn't
00:34:30 --> 00:34:31 matter. We'll, um, we'll get to them.
00:34:31 --> 00:34:34 Although on social media, the audience
00:34:34 --> 00:34:37 tends to deal with them for us. Um,
00:34:37 --> 00:34:39 not many of them filter through, but, uh,
00:34:39 --> 00:34:42 yeah, keep, uh, those questions coming. Um,
00:34:42 --> 00:34:45 and, uh, yeah, that'll all be good, Fred.
00:34:45 --> 00:34:47 We'll see you next week. I think it'll be our
00:34:47 --> 00:34:49 last couple of programs before the Christmas
00:34:49 --> 00:34:49 break.
00:34:49 --> 00:34:51 Professor Fred Watson: May well be. That's right.
00:34:51 --> 00:34:53 Andrew Dunkley: All right, we'll catch you then. Thanks,
00:34:53 --> 00:34:53 Fred.
00:34:53 --> 00:34:54 Professor Fred Watson: Sounds great.
00:34:54 --> 00:34:56 Andrew Dunkley: And thanks to Huw in the studio, who went
00:34:56 --> 00:34:58 supernova on us because he's got a lot of
00:34:58 --> 00:35:00 heavy elements and he's gone to see a
00:35:00 --> 00:35:02 dietitian. And from me, Andrew Dunkley,
00:35:02 --> 00:35:04 thanks for your company. We'll see you on the
00:35:04 --> 00:35:05 next episode of Space Nuts.
00:35:05 --> 00:35:06 Speaker C: Bye. Bye.
00:35:07 --> 00:35:09 Andrew Dunkley: Uh, you'll be listening to the Space Nuts
00:35:09 --> 00:35:12 podcast. Available at
00:35:12 --> 00:35:14 Apple Podcasts, Spotify,
00:35:15 --> 00:35:17 iHeartRadio or your favorite podcast
00:35:17 --> 00:35:19 player. You can also stream on
00:35:19 --> 00:35:22 demand@bytes.com. this has been another
00:35:22 --> 00:35:24 quality podcast production from
00:35:24 --> 00:35:25 bytes.com.