In this engaging episode of Space Nuts, hosts Heidi Campo and Professor Fred Watson embark on a fascinating journey through listener questions that probe the depths of astrophysics and cosmology. From the nature of neutron stars to the mysteries of gravitational waves, this episode is brimming with insights that will expand your understanding of the universe.
Episode Highlights:
- Neutron Stars vs. Pulsars: The episode opens with a thought-provoking question from Dean in Washington, D.C., asking whether all neutron stars are pulsars. Fred clarifies the distinction between these celestial objects, explaining that not all neutron stars emit pulsations, with many having “retired” from their energetic displays.
- Gravitational Waves and Mass Conversion: New listener Ben dives into the complexities of merging neutron stars and the resulting gravitational waves. Fred explores the intricate relationship between mass and energy, shedding light on how these cosmic events contribute to our understanding of the universe's fabric.
- Galactic Mysteries and the Big Bang: Craig from Marimbula raises intriguing questions about the implications of massive galaxies observed by the James Webb Space Telescope. Fred discusses how these findings fit into current cosmological models and the significance of the Big Bang theory in understanding the universe’s age.
- Meteors on Mars: Listener Martin from Bloomington, Indiana, wonders about the appearance of meteors on Mars compared to Earth. Fred explains how the thin Martian atmosphere affects meteor visibility and the likelihood of impacts, offering insights into the unique conditions on the Red Planet.
For more Space Nuts, including our continuously updating newsfeed and to listen to all our episodes, visit our website. Follow us on social media at SpaceNutsPod on Facebook, X, YouTube Music Music, Tumblr, Instagram, and TikTok. We love engaging with our community, so be sure to drop us a message or comment on your favorite platform.
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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.
(00:00) Welcome to Space Nuts with Heidi Campo and Fred Watson
(01:20) Discussion on neutron stars and pulsars
(15:00) Exploring gravitational waves from merging neutron stars
(25:30) Implications of massive galaxies and the Big Bang
(35:00) What meteors would look like on Mars
For commercial-free versions of Space Nuts, join us on Patreon, Supercast, Apple Podcasts, or become a supporter here: https://www.spreaker.com/podcast/space-nuts-astronomy-insights-cosmic-discoveries--2631155/support
00:00:00 --> 00:00:03 Heidi Campo: Welcome back to another fun and exciting
00:00:03 --> 00:00:06 Q and A episode of Space Nuts.
00:00:06 --> 00:00:09 I am your host for this episode, Heidi Campo.
00:00:09 --> 00:00:11 And joining me is Professor Fred
00:00:11 --> 00:00:13 Watson, astronomer at large.
00:00:13 --> 00:00:16 Voice Over Guy: 15 seconds. Guidance is internal.
00:00:16 --> 00:00:19 10, 9. Ignition
00:00:19 --> 00:00:22 sequence star space nuts. 5, 4, 3,
00:00:22 --> 00:00:25 2. 1. 2, 3, 4, 5, 5, 4,
00:00:25 --> 00:00:27 3, 2, 1. Space nuts
00:00:27 --> 00:00:29 Astronauts report. It feels good.
00:00:30 --> 00:00:33 Heidi Campo: Fred, how are you on this fine day?
00:00:33 --> 00:00:35 Professor Fred Watson: I'm very well, thanks, Heidi.
00:00:36 --> 00:00:39 And, um, I'm, um, delighted to see you again
00:00:39 --> 00:00:41 because it is always a pleasure to take our,
00:00:41 --> 00:00:44 uh, listener questions, uh, especially on a
00:00:44 --> 00:00:44 nice fine.
00:00:45 --> 00:00:47 What is here in Australia, Winter's morning?
00:00:48 --> 00:00:51 Uh, uh, it's a sunny day, as we
00:00:51 --> 00:00:54 often get in wintertime in Sydney.
00:00:55 --> 00:00:58 Heidi Campo: Well, you'll be delighted to hear that it has
00:00:58 --> 00:01:00 finally stopped raining here in Houston,
00:01:00 --> 00:01:02 Texas. The sun has come back out,
00:01:02 --> 00:01:05 starting to forget what it looked like. But,
00:01:05 --> 00:01:08 um, we will be going camping this weekend, so
00:01:08 --> 00:01:10 I'm looking forward to that. I will, um,
00:01:10 --> 00:01:12 report back to you guys next week what, uh,
00:01:12 --> 00:01:14 the weather from West Texas looks like.
00:01:16 --> 00:01:19 Professor Fred Watson: If you get any great photos, Heidi, we should
00:01:19 --> 00:01:22 try and post them on the Space Nuts website.
00:01:22 --> 00:01:24 Heidi Campo: Oh, maybe I'll have to bring my telescope,
00:01:24 --> 00:01:27 uh, and do some astrophotography out there.
00:01:27 --> 00:01:29 Actually, that's. I'm gonna, I am gonna do
00:01:29 --> 00:01:29 that.
00:01:30 --> 00:01:33 Um, and speaking of the United States, all of
00:01:33 --> 00:01:35 our questions are from the U.S. this,
00:01:35 --> 00:01:38 uh, this, this go around. And our first
00:01:38 --> 00:01:41 question comes from dean from Washington,
00:01:41 --> 00:01:44 D.C. doesn't get any more United States
00:01:44 --> 00:01:46 than that. Dean asks,
00:01:47 --> 00:01:49 um, are all neutron stars
00:01:49 --> 00:01:52 pulsars in? If so, is it not
00:01:52 --> 00:01:54 theoretically possible that a collapsing star
00:01:54 --> 00:01:57 has so little angular momentum that it
00:01:57 --> 00:02:00 doesn't pulse? If not, what else
00:02:00 --> 00:02:01 can a neutron star be?
00:02:03 --> 00:02:06 Professor Fred Watson: So, um, yeah, this, this, this
00:02:06 --> 00:02:09 question has a simple answer. No.
00:02:11 --> 00:02:13 Um, thank you, Dean.
00:02:13 --> 00:02:13 Heidi Campo: Moving on.
00:02:14 --> 00:02:17 Professor Fred Watson: I might elaborate on that a little bit. Um,
00:02:18 --> 00:02:20 not all neutron stars are pulsars. And
00:02:20 --> 00:02:22 actually, look, I'm going to take a direct
00:02:22 --> 00:02:25 quote from a NASA website called Ask an
00:02:25 --> 00:02:28 Astrophysicist. Doesn't come any better than
00:02:28 --> 00:02:30 that. Um, because
00:02:31 --> 00:02:33 I love the opening of this little answer.
00:02:33 --> 00:02:36 Most neutron stars in the universe
00:02:36 --> 00:02:38 are old enough and tired enough that they are
00:02:38 --> 00:02:41 no longer pulsars. Um, and
00:02:41 --> 00:02:44 let me just interrupt that quote
00:02:44 --> 00:02:47 by reminding us what a neutron star
00:02:47 --> 00:02:50 and a pulsar is. A neutron star is this
00:02:50 --> 00:02:52 highly collapsed object. It used to be a
00:02:52 --> 00:02:54 star, but now we're seeing the collapsed core
00:02:54 --> 00:02:57 of the star, only a few kilometers or miles
00:02:57 --> 00:03:00 across. Uh, uh, what makes it a
00:03:00 --> 00:03:02 pulsar is when it's spinning
00:03:02 --> 00:03:05 rapidly, uh, and beaming radiation
00:03:05 --> 00:03:08 from its magnetic Poles. So they behave
00:03:08 --> 00:03:11 just like a lighthouse, flashing, uh, on
00:03:11 --> 00:03:14 and off, pulsing, uh, as the name implies.
00:03:14 --> 00:03:17 So, uh, Dean's question is a good one. Are
00:03:17 --> 00:03:19 all neutron stars pulsars? And they're not.
00:03:20 --> 00:03:23 And as the NASA website says,
00:03:23 --> 00:03:25 most of them are old enough and tired enough
00:03:25 --> 00:03:26 that they're no longer pulsars. They've
00:03:26 --> 00:03:29 stopped spinning. Uh, and just one,
00:03:29 --> 00:03:32 uh, further sentence on that, which I think
00:03:32 --> 00:03:34 is quite illuminating. A recent paper
00:03:34 --> 00:03:37 estimates 1000 million, what we call
00:03:37 --> 00:03:40 a billion, normally 1000 million old
00:03:40 --> 00:03:43 neutron stars in our galaxy in. Even though
00:03:43 --> 00:03:46 the known number of pulsars, uh,
00:03:46 --> 00:03:48 is only about 1000. So
00:03:49 --> 00:03:52 there are many, many more neutron stars
00:03:52 --> 00:03:55 that don't pulsate than there are that do
00:03:55 --> 00:03:57 just because they've lost all their
00:03:57 --> 00:03:59 rotational energy. So, a great question from
00:03:59 --> 00:04:02 Dean, um, sent me to NASA's website,
00:04:02 --> 00:04:04 which is always a good thing.
00:04:05 --> 00:04:07 Heidi Campo: I think they know the right answer.
00:04:08 --> 00:04:09 Professor Fred Watson: One would hope so. Yeah.
00:04:10 --> 00:04:12 Heidi Campo: I saw a T shirt in their gift shop a few
00:04:12 --> 00:04:15 weeks ago when I was there, and it just. The
00:04:15 --> 00:04:17 Earth is round. We checked. Love NASA.
00:04:18 --> 00:04:21 I thought that was kind of cute and cheeky.
00:04:21 --> 00:04:22 Professor Fred Watson: Yeah.
00:04:23 --> 00:04:25 Heidi Campo: Our next question is from Ben,
00:04:26 --> 00:04:29 who is actually a new listener. So thank
00:04:29 --> 00:04:31 you, Ben, for writing in. This is, uh, so
00:04:31 --> 00:04:34 much fun. Ben says, I came across the
00:04:34 --> 00:04:37 podcast last week and I've been zooming
00:04:37 --> 00:04:40 through it. I love the content. Thank you.
00:04:41 --> 00:04:43 And then Ben goes on to say, I've got a
00:04:43 --> 00:04:45 question, and hopefully you haven't already
00:04:45 --> 00:04:46 answered it on the roughly
00:04:46 --> 00:04:49 450 episodes I haven't had
00:04:49 --> 00:04:52 a chance to listen to yet. Um, but he
00:04:52 --> 00:04:55 says one, when neutron stars and
00:04:55 --> 00:04:58 or black holes merged to
00:04:58 --> 00:05:01 produce gravitational waves, they lose mass,
00:05:01 --> 00:05:03 which gets converted to energy, which
00:05:03 --> 00:05:06 comprises. Which comprises of the
00:05:06 --> 00:05:08 gravitational wave. But how does that
00:05:08 --> 00:05:11 conversion work? Specifically? I'm thinking
00:05:11 --> 00:05:14 of a binary neutron star system
00:05:14 --> 00:05:16 merging, since my understanding
00:05:16 --> 00:05:19 is that the mass of the neutron is quite
00:05:19 --> 00:05:22 consistent across the universe. A reduction
00:05:22 --> 00:05:25 in mass would imply that a reduction in the
00:05:25 --> 00:05:27 number of neutrons would imply a
00:05:27 --> 00:05:30 reduction in the number of neutrons. If this
00:05:30 --> 00:05:33 small leap of logic holds, what determines
00:05:33 --> 00:05:36 which neutrons get converted to energy?
00:05:36 --> 00:05:39 Are the faded neutrons extracted evenly
00:05:39 --> 00:05:42 from throughout the merging objects, or
00:05:42 --> 00:05:45 is there a region that seems to be favored?
00:05:45 --> 00:05:48 And what does this process of converting
00:05:48 --> 00:05:50 neutrons to energy look like?
00:05:52 --> 00:05:54 Ben is curious and hungry for answers.
00:05:55 --> 00:05:57 Professor Fred Watson: It's a fabulous question, Ben.
00:05:57 --> 00:05:59 Um, I've got a question for you, Ben, as
00:05:59 --> 00:06:01 well. How did you manage to get through 450
00:06:01 --> 00:06:04 episodes in a week, less
00:06:04 --> 00:06:07 than a week? That defies, um,
00:06:07 --> 00:06:10 probably the laws of physics. I Think, uh,
00:06:10 --> 00:06:12 but that's all right because apparently uh,
00:06:12 --> 00:06:15 merging neutron stars also
00:06:15 --> 00:06:18 apparently derive um,
00:06:18 --> 00:06:21 they, they break the laws of physics.
00:06:22 --> 00:06:24 So um, Ben, your question,
00:06:24 --> 00:06:27 as some of our listener questions often do
00:06:27 --> 00:06:30 because they are so good, sent me to the
00:06:30 --> 00:06:32 World Wide Web. And the
00:06:32 --> 00:06:34 answer to this question is
00:06:36 --> 00:06:38 quite, uh, it's quite subtle and there's
00:06:38 --> 00:06:41 several things going on, partly because
00:06:41 --> 00:06:44 we're dealing with very intense
00:06:44 --> 00:06:47 gravitational fields. Uh, and
00:06:47 --> 00:06:50 um, you know, to answer your question, are
00:06:50 --> 00:06:52 the fated neutrons extracted evenly
00:06:52 --> 00:06:54 throughout the merging objects or
00:06:55 --> 00:06:57 is there a region that seems to be favored,
00:06:58 --> 00:07:01 um, that probably relates to
00:07:01 --> 00:07:03 the event horizon of the neutron
00:07:04 --> 00:07:06 stars because they do have event horizons.
00:07:06 --> 00:07:09 Um, and I don't think
00:07:09 --> 00:07:11 I'm capable of answering that question.
00:07:11 --> 00:07:14 Uh, and in any case
00:07:14 --> 00:07:17 it's more subtle than just um, you
00:07:17 --> 00:07:20 know, neutrons getting thrown away, uh,
00:07:20 --> 00:07:22 than what we were, than what your question
00:07:22 --> 00:07:25 might imply. So I would
00:07:25 --> 00:07:28 actually suggest, uh, Ben, that you have a
00:07:28 --> 00:07:31 look uh, online, uh,
00:07:31 --> 00:07:33 ah, at the uh, physics.stackink
00:07:33 --> 00:07:35 exchange.com website,
00:07:36 --> 00:07:37 uh, because
00:07:37 --> 00:07:39 physics.stackexchange.com
00:07:40 --> 00:07:43 has got a uh, very nice set
00:07:43 --> 00:07:45 of question, question very similar to
00:07:45 --> 00:07:48 yours and some quite lengthy answers
00:07:48 --> 00:07:51 that go into some detail, um, and
00:07:52 --> 00:07:54 look at different aspects of this question.
00:07:55 --> 00:07:58 Um, so if you Google energy conversion from
00:07:58 --> 00:08:00 mass to gravitational wave, the, that will
00:08:00 --> 00:08:03 take you to this website and
00:08:03 --> 00:08:06 maybe I can just um, you know,
00:08:06 --> 00:08:09 talk about uh, one of those
00:08:09 --> 00:08:11 answers. And that is that um,
00:08:12 --> 00:08:14 if you imagine, uh, uh, one of
00:08:14 --> 00:08:17 the sort of subatomic particles and what we
00:08:17 --> 00:08:19 call an alpha particle, which is the nucleus,
00:08:19 --> 00:08:22 a helium 4 nucleus, got two protons,
00:08:22 --> 00:08:25 two neutrons, but its mass
00:08:26 --> 00:08:28 is actually less than the
00:08:28 --> 00:08:31 sum of those protons and neutrons.
00:08:32 --> 00:08:35 And that's because there is something called
00:08:35 --> 00:08:37 binding energy, uh, that's
00:08:37 --> 00:08:40 released when that particle is
00:08:40 --> 00:08:43 formed. And so uh, the
00:08:43 --> 00:08:46 bottom line here is that mass and
00:08:46 --> 00:08:49 energy are uh, highly interchangeable. When
00:08:49 --> 00:08:51 you're talking about the kinds of things, the
00:08:51 --> 00:08:54 sort of extremes that we are looking at in
00:08:54 --> 00:08:57 the case of um, a neutron star, neutron
00:08:57 --> 00:08:59 star collisions. Even in a neutron star doing
00:08:59 --> 00:09:02 its thing, it's still extreme situations.
00:09:03 --> 00:09:05 And because of the relationship that we're
00:09:05 --> 00:09:07 all aware of between mass and energy, E
00:09:07 --> 00:09:10 equals MC squared. That is,
00:09:10 --> 00:09:12 uh, why you know,
00:09:13 --> 00:09:15 you've got this potential to
00:09:16 --> 00:09:19 transform what looks like a mass of a
00:09:19 --> 00:09:21 single particle, uh, into energy,
00:09:22 --> 00:09:25 uh, to result in a lower
00:09:25 --> 00:09:27 gravitational mass for the pair of
00:09:27 --> 00:09:29 neutron stars. Sorry, the bottom line here,
00:09:29 --> 00:09:31 which I should have said at the beginning, is
00:09:31 --> 00:09:34 that often when you've got this neutron star,
00:09:34 --> 00:09:37 neutron star collision, uh, you Get
00:09:37 --> 00:09:40 a gravitational wave which
00:09:40 --> 00:09:43 essentially, uh, has enough energy
00:09:43 --> 00:09:46 to account for a difference in mass. It's not
00:09:46 --> 00:09:48 just the sum of the two neutron stars that
00:09:48 --> 00:09:50 come together. There is a mass loss as well,
00:09:50 --> 00:09:53 which we see as the gravitational wave. And
00:09:53 --> 00:09:55 this is one of the mechanisms that causes
00:09:55 --> 00:09:57 that. So have a look Ben, at that
00:09:57 --> 00:10:00 webpage. Uh, and if you still
00:10:00 --> 00:10:03 don't get it, ask us again, uh, and
00:10:03 --> 00:10:06 I'll have another shot at it. But it is a
00:10:06 --> 00:10:08 really interesting question and a good one
00:10:08 --> 00:10:10 too. Um, um, got me
00:10:10 --> 00:10:13 thinking yesterday. I was worrying all day
00:10:13 --> 00:10:16 about this question, uh, trying to
00:10:16 --> 00:10:18 take my mind off the root canal treatment
00:10:18 --> 00:10:20 that I was having at the dentist. At the same
00:10:20 --> 00:10:21 time.
00:10:24 --> 00:10:26 Heidi Campo: I also think of particle, uh, physics while
00:10:26 --> 00:10:26 I'm at the dentist.
00:10:27 --> 00:10:30 Professor Fred Watson: It's the only thing to do really, isn't it?
00:10:30 --> 00:10:33 Heidi Campo: So I actually, I will give my dentist a shout
00:10:33 --> 00:10:35 out. My dentist, um, was one of my good
00:10:35 --> 00:10:38 friends in, uh, doing my undergrad. And it
00:10:38 --> 00:10:40 was kind of cute because the whole little
00:10:40 --> 00:10:43 cohort of us, we um, started, we were in
00:10:43 --> 00:10:45 a powerlifting club in my undergrad
00:10:46 --> 00:10:48 and uh, we were just,
00:10:49 --> 00:10:51 you know, just a bunch of kids. And now he's
00:10:51 --> 00:10:53 a grown up who's a dentist and we're all
00:10:53 --> 00:10:55 doing our things. One of the other ones went
00:10:55 --> 00:10:57 on to be um, a
00:10:57 --> 00:11:00 neurosurgeon. And so I'm like, it's quite a
00:11:00 --> 00:11:03 little brainiac group of strength athletes.
00:11:04 --> 00:11:07 So shout out to, uh, Dr. Gatlin
00:11:07 --> 00:11:10 Marks, dentist at Platinum Dentistry
00:11:10 --> 00:11:13 in Utah. On that's, you know, unprompted.
00:11:14 --> 00:11:15 Not paid for free advertising, but he's
00:11:15 --> 00:11:16 great.
00:11:18 --> 00:11:20 Professor Fred Watson: Well, I should advertise mine, shouldn't I?
00:11:22 --> 00:11:23 Nothing like as nice a story, but I won't
00:11:23 --> 00:11:24 bother.
00:11:30 --> 00:11:31 Heidi Campo: Space nuts.
00:11:31 --> 00:11:34 Um, well, our next question is an audio
00:11:34 --> 00:11:37 question from Craig and
00:11:37 --> 00:11:39 we are going to play that question for you
00:11:40 --> 00:11:40 right now.
00:11:41 --> 00:11:44 Professor Fred Watson: Hi professors, it's Craig down in
00:11:44 --> 00:11:47 sunny Marimbula. Um, I've been
00:11:47 --> 00:11:50 seeing items about James Webb, uh,
00:11:50 --> 00:11:52 seeing really massive galaxies
00:11:53 --> 00:11:56 much bigger than they, than current
00:11:56 --> 00:11:59 cosmology expects. Are we
00:11:59 --> 00:12:01 in an older universe? Could we
00:12:01 --> 00:12:04 tell the difference between a big bang and a
00:12:04 --> 00:12:06 supermassive white hole that's erupted into
00:12:06 --> 00:12:08 an existing space time?
00:12:09 --> 00:12:12 They're just an uh, overactive imagination. I
00:12:12 --> 00:12:14 hope you're enjoying your week. Ciao.
00:12:14 --> 00:12:17 Heidi Campo: All right, that was Craig's, uh, question.
00:12:18 --> 00:12:21 Professor Fred Watson: Craig, the only person asking uh, a
00:12:21 --> 00:12:23 question this week from.
00:12:24 --> 00:12:25 Not from the usa.
00:12:27 --> 00:12:30 Okay, his question about big galaxies,
00:12:30 --> 00:12:32 is it telling us that the universe is older
00:12:32 --> 00:12:35 than we think? Maybe, uh, that's a, it's
00:12:35 --> 00:12:38 a nice way of Thinking about it, um, except
00:12:39 --> 00:12:42 that we, we still,
00:12:43 --> 00:12:45 you know, all the evidence points
00:12:46 --> 00:12:48 to the
00:12:49 --> 00:12:51 universe having a beginning which
00:12:52 --> 00:12:54 was 13.8 billion years ago,
00:12:54 --> 00:12:57 um, which, um, we think was,
00:12:57 --> 00:13:00 um, the result of a, an event called the Big
00:13:00 --> 00:13:02 Bang, an explosive event.
00:13:03 --> 00:13:06 Uh, we believe that's the case partly
00:13:06 --> 00:13:08 because of what we observe today. But we can
00:13:08 --> 00:13:10 also still see the flash of that Big Bang by
00:13:10 --> 00:13:13 the fact that the light has taken 13.8
00:13:13 --> 00:13:16 billion years to get to us. So, um,
00:13:16 --> 00:13:18 it's very hard to see how,
00:13:19 --> 00:13:21 uh, if the universe was older than that Big
00:13:21 --> 00:13:21 Bang,
00:13:24 --> 00:13:26 how galaxies would survive that
00:13:27 --> 00:13:29 explosive event. Um,
00:13:29 --> 00:13:32 so you know what, um,
00:13:33 --> 00:13:35 Craig's question is about is,
00:13:35 --> 00:13:37 uh, are, uh, there galaxies that are older
00:13:37 --> 00:13:40 than we think the universe is? And
00:13:41 --> 00:13:44 it defies logic. It's like saying,
00:13:44 --> 00:13:47 um. And in fact, for a while, this was one of
00:13:47 --> 00:13:49 the problems with the Big Bang theory. People
00:13:49 --> 00:13:51 thought, uh, the um,
00:13:52 --> 00:13:55 planets, uh, stars and
00:13:55 --> 00:13:58 atoms were actually older than the
00:13:58 --> 00:13:59 measurement of the age of the universe that
00:13:59 --> 00:14:01 we got. And that was one of the problems for
00:14:01 --> 00:14:04 the Big Bang theory, uh, which was, uh,
00:14:04 --> 00:14:06 only really resolved in the 60s,
00:14:07 --> 00:14:09 1950s and 60s. Um,
00:14:10 --> 00:14:13 so I think that's still a
00:14:13 --> 00:14:16 step of logic that we're not prepared to
00:14:16 --> 00:14:19 dismiss, uh, that yes, there is that,
00:14:19 --> 00:14:22 um, the Big Bang does mark the
00:14:22 --> 00:14:25 start of, uh, the formation of galaxies
00:14:25 --> 00:14:27 and the galaxies in the universe. Um, I have
00:14:27 --> 00:14:30 a colleague and uh, friend, uh,
00:14:30 --> 00:14:33 who's a, uh, very distinguished astronomer in
00:14:33 --> 00:14:36 the uk, Richard Ellis. And he is
00:14:36 --> 00:14:39 absolutely. He's a cosmologist. He's somebody
00:14:39 --> 00:14:40 who looks at the history of the universe,
00:14:40 --> 00:14:42 very interested in the history of the early
00:14:42 --> 00:14:45 universe. He is absolutely certain,
00:14:46 --> 00:14:49 uh, that those galaxies that we can see
00:14:49 --> 00:14:51 that do look bigger and older than what we
00:14:51 --> 00:14:54 expected them to be, uh, that they do not
00:14:54 --> 00:14:57 defy, uh, conventional cosmology,
00:14:57 --> 00:15:00 that we can still, um,
00:15:00 --> 00:15:02 you know, work out theoretical models that
00:15:02 --> 00:15:04 would allow those galaxies still to be young,
00:15:05 --> 00:15:08 even though they look more advanced in years
00:15:08 --> 00:15:10 than we thought they would be.
00:15:11 --> 00:15:14 So, uh, it's all about our understanding of
00:15:14 --> 00:15:16 galaxy formation rather than having the
00:15:16 --> 00:15:19 cosmology wrong, rather than having, uh,
00:15:19 --> 00:15:22 the age of the universe wrong. So, a good
00:15:22 --> 00:15:25 suggestion, uh, uh, but I think we are
00:15:25 --> 00:15:27 still stuck with trying to understand how
00:15:27 --> 00:15:30 these galaxies got so big so quickly.
00:15:31 --> 00:15:33 Heidi Campo: And stuck is what it is. Sometimes
00:15:35 --> 00:15:37 that's what I get excited about with space.
00:15:37 --> 00:15:40 There's so many questions that have to be
00:15:40 --> 00:15:43 answered. Other sciences are so defined,
00:15:43 --> 00:15:46 but space is infinite for us to figure out.
00:15:48 --> 00:15:50 Professor Fred Watson: Okay, we checked all four systems and.
00:15:50 --> 00:15:53 Heidi Campo: Dealing with the space nets, our, um,
00:15:53 --> 00:15:55 our last Question is from another curious
00:15:55 --> 00:15:58 listener. Mark from Bloomington,
00:15:58 --> 00:16:01 Indiana says hello there.
00:16:01 --> 00:16:04 What might meteors look like to a person on
00:16:04 --> 00:16:07 the surface of Mars or Venus, if that were
00:16:07 --> 00:16:09 possible. The planets are at uh,
00:16:09 --> 00:16:12 extremes of atmospheric density. But carbon
00:16:12 --> 00:16:14 dioxide is the primary aspheric gas
00:16:15 --> 00:16:18 for each. The primary aspheric gas
00:16:18 --> 00:16:20 for each. And there is very little oxygen
00:16:20 --> 00:16:23 present compared to Earth and to each other.
00:16:23 --> 00:16:25 Would meteors appear brighter or dimmer,
00:16:26 --> 00:16:28 different colors travel faster or slower,
00:16:28 --> 00:16:31 more or less likely to be seen given the
00:16:31 --> 00:16:33 thick or thin clouds and the uh, clouds
00:16:33 --> 00:16:36 altitudes more or less likely to strike the
00:16:36 --> 00:16:39 surface. Thanks for any insights or even
00:16:39 --> 00:16:40 guesses.
00:16:42 --> 00:16:44 Professor Fred Watson: I think we've been sprung here, Heidi. People
00:16:44 --> 00:16:47 have realized that we just take guesses at
00:16:47 --> 00:16:47 these things.
00:16:50 --> 00:16:51 Um, so it's uh,
00:16:52 --> 00:16:54 it's another great question. You know, we uh,
00:16:54 --> 00:16:57 this is, I think none of the questions that
00:16:57 --> 00:16:59 we've had today have ever come in before.
00:17:00 --> 00:17:02 Uh, maybe, maybe people have been speculating
00:17:02 --> 00:17:05 about the um, the mystery of these early
00:17:05 --> 00:17:08 galaxies. But this is a great question. What
00:17:08 --> 00:17:10 would meteorites, sorry, what would meteors
00:17:10 --> 00:17:13 look like, uh, to somebody. Let's
00:17:13 --> 00:17:15 just stick with Mars for now because that's
00:17:15 --> 00:17:18 the easier one to deal with. I um,
00:17:18 --> 00:17:20 think Venus will be a problem because the
00:17:20 --> 00:17:22 atmosphere is so thick, uh, so
00:17:22 --> 00:17:25 opaque that uh, you probably wouldn't see any
00:17:25 --> 00:17:26 meteors at all just because,
00:17:28 --> 00:17:30 you know, there's very little transparency in
00:17:30 --> 00:17:32 the atmosphere. Mars however, is different.
00:17:33 --> 00:17:35 Uh, it does have clouds, but not as many as
00:17:35 --> 00:17:38 we have here on Earth. Uh, let's get
00:17:38 --> 00:17:40 to the easy question, the easy part of this
00:17:40 --> 00:17:42 question, uh, which is, um,
00:17:44 --> 00:17:47 Query. Are they more or less likely to
00:17:47 --> 00:17:49 strike the surface? And the answer is they're
00:17:49 --> 00:17:52 more likely because Mars's atmosphere is much
00:17:52 --> 00:17:55 thinner. It's less than 1% of the pressure of
00:17:55 --> 00:17:57 the Earth's atmosphere. That means that um,
00:17:57 --> 00:18:00 it's uh, more likely that a meteoritic
00:18:00 --> 00:18:03 object would survive its passage
00:18:03 --> 00:18:05 through the atmosphere to reach the ground.
00:18:06 --> 00:18:08 Um, and we do find meteorites on Mars. There
00:18:08 --> 00:18:11 are many examples that the uh, various Mars
00:18:11 --> 00:18:14 rovers have found meteorites on the planet
00:18:14 --> 00:18:17 Mars. A uh, meteorite is a meteor
00:18:17 --> 00:18:19 that's got as far as landing on the, on the
00:18:19 --> 00:18:22 ground, but what they would look like in
00:18:22 --> 00:18:25 the uh, in the sky, uh,
00:18:26 --> 00:18:28 uh, doesn't really have that much to do with
00:18:28 --> 00:18:30 what the constituents of the atmosphere are.
00:18:30 --> 00:18:33 Uh, uh, because what you
00:18:33 --> 00:18:35 see when you see a meteor, a shooting star
00:18:36 --> 00:18:38 is the fact that it is simply
00:18:39 --> 00:18:41 um, it's being um, heated
00:18:41 --> 00:18:44 up to incandescence. It's not
00:18:44 --> 00:18:45 burning in the sense that
00:18:47 --> 00:18:50 things burn in the presence of oxygen. Uh,
00:18:50 --> 00:18:52 and that I think is the thrust of, uh, Mark's
00:18:52 --> 00:18:55 question. But what you're seeing is this
00:18:55 --> 00:18:57 thing shooting through the atmosphere. It is
00:18:57 --> 00:19:00 meeting a gas. Uh, the gas is
00:19:00 --> 00:19:03 providing some resistance, but also a lot of
00:19:03 --> 00:19:05 friction on the outside of this particle or
00:19:05 --> 00:19:08 stone or rock or baseball, whatever it is
00:19:08 --> 00:19:10 that's coming in, uh, whatever size it is
00:19:10 --> 00:19:12 that's coming, coming in. And that's what
00:19:12 --> 00:19:15 causes the brightness of the meteorites being
00:19:15 --> 00:19:18 flashed into incandescence by its speed
00:19:18 --> 00:19:20 rather than a chemical reaction taking place.
00:19:21 --> 00:19:23 Um, that would, um, make uh, that much
00:19:23 --> 00:19:26 difference. Although certainly we do see
00:19:26 --> 00:19:28 evidence of the oxygen in the light of some
00:19:28 --> 00:19:31 of these. So meteors on Mars would look
00:19:31 --> 00:19:34 similar to what they do on Earth. There's
00:19:34 --> 00:19:36 some dispute because the
00:19:37 --> 00:19:39 atmosphere of Mars, whilst it's also much
00:19:39 --> 00:19:41 thinner than Earth's atmosphere, is
00:19:41 --> 00:19:44 distributed differently. You know, uh,
00:19:45 --> 00:19:47 the way in which it falls off in pressure as
00:19:47 --> 00:19:50 you go up in height, uh, is different
00:19:50 --> 00:19:53 from what it is on Earth. So that might mean
00:19:53 --> 00:19:56 that the height at which meteors start to
00:19:56 --> 00:19:59 glow as they come through the surface, sorry,
00:19:59 --> 00:20:02 come through the atmosphere of Mars might be
00:20:02 --> 00:20:04 different. And if they were lower, if they
00:20:04 --> 00:20:06 were burning up lower down in the atmosphere,
00:20:06 --> 00:20:08 then they would look a bit brighter than they
00:20:08 --> 00:20:10 do here on Earth. If they were burning up
00:20:10 --> 00:20:12 higher in the atmosphere, they would, uh,
00:20:12 --> 00:20:15 look a bit fainter. And it's not quite
00:20:15 --> 00:20:18 clear which of those is the case. Uh, there's
00:20:18 --> 00:20:21 some dispute among the. Certainly the things
00:20:21 --> 00:20:23 I've read about whether they will be brighter
00:20:23 --> 00:20:25 or fainter, but they will be much the same.
00:20:26 --> 00:20:29 So, uh, we hope that maybe one
00:20:29 --> 00:20:32 day when, uh, astronauts are
00:20:32 --> 00:20:35 exploring, uh, but not colonizing
00:20:35 --> 00:20:38 Mars, uh, that they might send us
00:20:38 --> 00:20:40 back reports of meteors that they've seen in
00:20:40 --> 00:20:42 the night skies of Mars. And maybe you'll
00:20:42 --> 00:20:44 hear about it on Space notes.
00:20:45 --> 00:20:48 Heidi Campo: Maybe so. And it is my understanding that
00:20:48 --> 00:20:50 that is one. I mean, there's so many concerns
00:20:50 --> 00:20:52 with Moon to Mars missions. And a potential
00:20:52 --> 00:20:55 Mars colony is it's not as safe.
00:20:55 --> 00:20:58 Our atmosphere does surprisingly a lot to
00:20:58 --> 00:21:01 protect us. And that is, um, in a
00:21:01 --> 00:21:04 lot of student design competitions that
00:21:04 --> 00:21:06 is something they're really asking for
00:21:06 --> 00:21:08 students to look at is, hey, how can we
00:21:08 --> 00:21:11 protect potential analogs
00:21:11 --> 00:21:14 or colonies or any other assets we put
00:21:14 --> 00:21:16 on Mars? How do we protect those from these
00:21:16 --> 00:21:19 constant, um, impacts? And
00:21:19 --> 00:21:21 ah, that is really kind of an interesting
00:21:21 --> 00:21:24 question right now. And that's not really my
00:21:24 --> 00:21:26 wheelhouse. But, um, people in the
00:21:26 --> 00:21:29 engineering world are, um. There's a lot
00:21:29 --> 00:21:30 of fun things for them. To do with those
00:21:30 --> 00:21:31 projects.
00:21:32 --> 00:21:35 Professor Fred Watson: Indeed. That's right. Look, it's a different
00:21:35 --> 00:21:36 world from ours.
00:21:38 --> 00:21:40 Everything's different. Uh, radiation,
00:21:40 --> 00:21:42 meteoritic bombardment, all of those things.
00:21:42 --> 00:21:45 Low pressure, low gravity, different
00:21:45 --> 00:21:48 world and a lot to think about if we are
00:21:48 --> 00:21:51 ever going to have humans walking on Mars.
00:21:52 --> 00:21:55 Heidi Campo: All right, Fred. Well, ah, this has been
00:21:55 --> 00:21:58 another fantastic Q and A episode. I
00:21:58 --> 00:22:00 always, I love the way you answer these
00:22:00 --> 00:22:03 questions. I feel like, uh, every time we
00:22:03 --> 00:22:06 write in, I feel like each one of us
00:22:06 --> 00:22:08 has an opportunity to be a, uh, collaborator
00:22:08 --> 00:22:11 with you and gets to experience what it's
00:22:11 --> 00:22:14 like to be on this intellectual journey
00:22:14 --> 00:22:17 together. So keep sending in your amazing
00:22:17 --> 00:22:19 questions. You guys are, you guys are half
00:22:19 --> 00:22:21 of the brilliance of this show. So thank you
00:22:21 --> 00:22:22 so much.
00:22:22 --> 00:22:24 Professor Fred Watson: That's right. I agree there
00:22:24 --> 00:22:26 wholeheartedly, Heidi. At least half. In
00:22:26 --> 00:22:28 fact, maybe more than that.
00:22:30 --> 00:22:32 Heidi Campo: Excellent. Well, thank you everybody to
00:22:32 --> 00:22:34 listening to another episode of Space Nuts.
00:22:34 --> 00:22:37 We will catch you next time.
00:22:37 --> 00:22:39 Professor Fred Watson: Sounds great. Thanks again, Heidi.
00:22:40 --> 00:22:42 Andrew Dunkley: Hi, Fred. Hi, Huw. Hi,
00:22:42 --> 00:22:43 Heidi.
00:22:43 --> 00:22:46 It's Andrew from the southwestern
00:22:46 --> 00:22:48 Indian Ocean. We've just finished a seven day
00:22:48 --> 00:22:50 crossing of the Indian Ocean and stopped
00:22:50 --> 00:22:53 yesterday at the beautiful island
00:22:53 --> 00:22:56 country of Mauritius. And it's
00:22:56 --> 00:22:59 winter there, but the temperature was in the
00:22:59 --> 00:23:02 uh, mid to high 20s. So,
00:23:02 --> 00:23:04 um, yeah, if that's winter, I'll take it.
00:23:04 --> 00:23:06 It's been beautiful. The seas were quite
00:23:06 --> 00:23:09 smooth after our, uh, treacherous rounding
00:23:09 --> 00:23:12 of south, uh, southern Australia. Uh, but
00:23:12 --> 00:23:14 now that we've left Mauritius, we're heading
00:23:14 --> 00:23:17 into, into some heavy seas as we move
00:23:17 --> 00:23:20 towards the Cape of Good Hope and then
00:23:20 --> 00:23:22 come up the other side of Africa. But
00:23:22 --> 00:23:25 Mauritius was absolutely beautiful, lovely,
00:23:25 --> 00:23:26 uh, people, interesting story behind
00:23:26 --> 00:23:29 Mauritius. It's a, an island that
00:23:29 --> 00:23:32 was discovered by Arabian, uh, sailors.
00:23:32 --> 00:23:35 Uh, it was unoccupied, so they moved in and
00:23:36 --> 00:23:37 uh, of course they brought their slaves with
00:23:37 --> 00:23:40 them. Um, somewhere along the line they
00:23:40 --> 00:23:43 handed us over to, um, the Dutch
00:23:43 --> 00:23:46 and the Portuguese. Uh, the Dutch
00:23:46 --> 00:23:48 kind of decimated everything they possibly
00:23:48 --> 00:23:51 could. My wife's half Dutch, so I've got
00:23:51 --> 00:23:53 to be careful what I say. But, uh, they
00:23:53 --> 00:23:56 killed off the dodo bird, they destroyed most
00:23:56 --> 00:23:59 of the forests. Uh, they killed off the
00:23:59 --> 00:24:02 native giant turtles. Uh,
00:24:02 --> 00:24:05 so, um, yeah, nothing like that is there
00:24:05 --> 00:24:08 today. But then, uh, the French moved in and
00:24:08 --> 00:24:10 they stayed there for a very long time until
00:24:10 --> 00:24:11 they were tipped out by the British. And the
00:24:11 --> 00:24:14 British held sovereignty over Mauritius until
00:24:14 --> 00:24:17 independence late last century. Beautiful
00:24:17 --> 00:24:20 country, very rugged volcanic
00:24:20 --> 00:24:23 landscape. Uh, saw, uh,
00:24:23 --> 00:24:24 the volcano at the top that still, uh,
00:24:25 --> 00:24:27 exists. It's dormant. It hasn't erupted for a
00:24:27 --> 00:24:28 long, long time. And I hope it doesn't
00:24:28 --> 00:24:31 because it's got houses all over it. Uh, but,
00:24:31 --> 00:24:33 um, just a, just a beautiful landscape. They
00:24:33 --> 00:24:36 speak French and English as their
00:24:36 --> 00:24:39 predominant, uh, languages. But the, but the,
00:24:39 --> 00:24:42 the native people who are originally, uh, you
00:24:42 --> 00:24:44 know, from the slaves of South Africa speak
00:24:44 --> 00:24:47 French Creole. So it's really, really
00:24:47 --> 00:24:50 interesting mix of people. But, uh, a lovely
00:24:50 --> 00:24:52 country and, and very, very much
00:24:52 --> 00:24:55 worth visiting. Uh, and a very big
00:24:55 --> 00:24:57 Hindu population as well.
00:24:57 --> 00:25:00 And so we visited, visited a Hindu temple and
00:25:00 --> 00:25:03 the sacred waters that were discovered by a
00:25:03 --> 00:25:06 Hindu many, many years ago, uh, where
00:25:06 --> 00:25:08 people were blessing children and uh,
00:25:09 --> 00:25:11 walking through the waters, which are just as
00:25:11 --> 00:25:13 sacred as the Ganges, apparently. Uh,
00:25:14 --> 00:25:16 and um, there was a little monument there to
00:25:16 --> 00:25:19 the sun and the planets. So, uh, there
00:25:19 --> 00:25:22 was a little astronomical connection,
00:25:23 --> 00:25:24 uh, while I was there.
00:25:24 --> 00:25:27 Anyway, that's where we're up to. Next stop
00:25:27 --> 00:25:29 will be Cape Town. It's going to take us five
00:25:29 --> 00:25:31 days of sailing to get there, so I'll report
00:25:31 --> 00:25:34 on that next time. So hope all is
00:25:34 --> 00:25:36 going well with Space Nuts. See you soon.
00:25:37 --> 00:25:39 Professor Fred Watson: You've been listening to the Space Nuts.
00:25:39 --> 00:25:42 Podcast, available at
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00:25:44 --> 00:25:47 iHeartRadio or your favorite podcast
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00:25:50 --> 00:25:52 bitesz.com This has been another quality
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