Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / Dark Matter Mysteries, Telescope Innovations & the Quest for Gravitons | SN602 Q&A

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Dark Matter Mysteries, Telescope Innovations & the Quest for Gravitons | SN602 Q&A · Space Nuts: Astronomy Insights & Cosmic Discoveries

• 0:00
  Speaker 1: Hi there, thanks again for joining us. This is Space Nuts,
• 0:02
  Speaker 1: a Q and A edition. This is where we answer
• 0:06
  Speaker 1: audience questions. Well, we read them out and then we
• 0:09
  Speaker 1: pretend we know what we're talking about, and most people
• 0:12
  Speaker 1: fall for it. They might not fall for it today though,
• 0:15
  Speaker 1: because we've got some really interesting questions about a matter
• 0:20
  Speaker 1: of matter that we cannot see. Does it matter? We
• 0:23
  Speaker 1: will find out questions come up about gravitons. We're also
• 0:28
  Speaker 1: going to answer a question about space telescopes. Now that's
• 0:31
  Speaker 1: right up, Fred Zali. He knows everything there is to
• 0:35
  Speaker 1: know about space. Telee's written books about these things, so
• 0:38
  Speaker 1: this is going to be a good question. And a
• 0:42
  Speaker 1: question has come up about whether or not Olympus mons
• 0:45
  Speaker 1: might make a good staging point for a space elevator.
• 0:49
  Speaker 1: We will answer all of that on this episode of Space.
• 0:53
  Speaker 2: Nuts fifteen, Channel ten nine ignition sequence Space Nuts or
• 1:02
  Speaker 2: three two one Space Nurse.
• 1:07
  Speaker 1: And I report it meels good and it feels good
• 1:11
  Speaker 1: to have his one and only self, professor've Fred's on
• 1:15
  Speaker 1: Astronomer at Large back in the chair.
• 1:16
  Speaker 3: Hello Fred, Hello, hello here, all ready to go, fresh and.
• 1:23
  Speaker 1: Well?
• 1:23
  Speaker 3: Slept, yeah, sort tough weird.
• 1:27
  Speaker 1: Night last night. I actually went to sleep fast, didn't
• 1:31
  Speaker 1: I only woke up kind of once once, which is
• 1:34
  Speaker 1: a new world record. And then I woke up at
• 1:39
  Speaker 1: five eighteen am and that was it. My body went
• 1:43
  Speaker 1: out that we're done binget up, go and watch something
• 1:46
  Speaker 1: on television because I'm not you know, I don't want
• 1:48
  Speaker 1: to go to sleep it ever again. So here we go.
• 1:52
  Speaker 1: Who knows what will happened tonight. Sleep is a weird thing.
• 1:56
  Speaker 1: We need it, and yet our bodies sometimes refused to comply. Yeah, yeah,
• 2:02
  Speaker 1: it is.
• 2:02
  Speaker 3: It's bizarre.
• 2:03
  Speaker 1: It's a strange thing. Shall we answer some questions? I
• 2:08
  Speaker 1: thought that was it. Well, I was just going to say, Fred,
• 2:11
  Speaker 1: why can't I sleep?
• 2:13
  Speaker 3: Let's answer some questions?
• 2:15
  Speaker 1: Okay? Our first one comes from Ben. He says Ben here.
• 2:19
  Speaker 1: It's good because I thought he was Ben too, the
• 2:21
  Speaker 1: Aussie and Chicago with a few new questions. In your
• 2:24
  Speaker 1: Last Question podcast, you mentioned about how eighty percent of
• 2:28
  Speaker 1: matter is missing or not visible to us, and it
• 2:31
  Speaker 1: made me think, how do we know or measure that
• 2:35
  Speaker 1: amount in the first place. I know a lot of
• 2:37
  Speaker 1: science is about measuring what we didn't find in results,
• 2:41
  Speaker 1: but I'm curious about how they came to that eighty
• 2:44
  Speaker 1: percent dark matter number. And secondly, for a smaller question,
• 2:49
  Speaker 1: if you could pick the next large telescope to be launched,
• 2:53
  Speaker 1: what would it be and why I'd personally love to
• 2:55
  Speaker 1: see a new larger Hubble type telescope with all the
• 2:59
  Speaker 1: advances we've applied to it that we've learned from the
• 3:02
  Speaker 1: James Webb Space Telescope. Thanks again for the great podcast.
• 3:06
  Speaker 1: Thank you, Ben. Great to hear from you. I hope
• 3:08
  Speaker 1: all is well in Chicago, home of the Bears, Chicago Bears. Right,
• 3:15
  Speaker 1: So it's a matter of matter, and he's saying, we
• 3:20
  Speaker 1: know there's eighty percent of the universe made up of
• 3:23
  Speaker 1: dark matter or thereabout. How do we know that?
• 3:29
  Speaker 3: We actually the way that we get the you know,
• 3:34
  Speaker 3: the accurate figures is quite interesting because it involves work
• 3:40
  Speaker 3: of the kind that wasn't possible before astronomers started using
• 3:44
  Speaker 3: fiber optics in their telescopes. And that's what I did.
• 3:49
  Speaker 3: Was one of the pioneers of fiber optics in astronomy.
• 3:53
  Speaker 3: The systems that we built back in the eighties the
• 3:56
  Speaker 3: nineteen eighties have now evolved into Mars machines which are
• 4:01
  Speaker 3: fully automated. The organization that I worked for has just
• 4:07
  Speaker 3: delivered one to Chile, which will position two four hundred
• 4:11
  Speaker 3: fibers in fifty seven seconds. And each one of those
• 4:15
  Speaker 3: fibers can be aligned with a target star or galaxy,
• 4:20
  Speaker 3: and that's the way you collect lots of information about
• 4:23
  Speaker 3: very large numbers of galaxies and about their velocities, what
• 4:27
  Speaker 3: we call their red shifts. So we'll get to that
• 4:30
  Speaker 3: in a minute, because that's how we are so certain
• 4:33
  Speaker 3: about these numbers, because of the ability to do that,
• 4:35
  Speaker 3: to measure these very large numbers of galaxies what we
• 4:38
  Speaker 3: call large girl surveys. But the story starts back in
• 4:43
  Speaker 3: nineteen thirty three with Fritz Vicki, the man who famously
• 4:48
  Speaker 3: called some of his colleagues not just bastards, they were
• 4:52
  Speaker 3: spherical bustards. The reason for that was that they were
• 4:56
  Speaker 3: bustards whichever way you looked at them. That's why call
• 4:59
  Speaker 3: them spherical beasts. Astronomers love him, Yeah, I'm sure they do.
• 5:06
  Speaker 3: I usually turned that down a bit and make it
• 5:09
  Speaker 3: wrap bags. But for this show, I can reckon. I
• 5:12
  Speaker 3: could quote him about him, it isn't quote.
• 5:15
  Speaker 1: Therefore it's a quote. Yeah, part of it's a part
• 5:18
  Speaker 1: of history.
• 5:19
  Speaker 3: It is indeed part of history. But what he was
• 5:23
  Speaker 3: doing was measuring cluster of galaxies actually in the Northern Hemisphere,
• 5:26
  Speaker 3: consolation of Coma Baronesses, the Coma Cluster, a very rich
• 5:30
  Speaker 3: cluster of galaxies, and he figured out that the he
• 5:33
  Speaker 3: was measuring the motions of all the galaxies and when
• 5:36
  Speaker 3: he looked at it, they're all going too fast for
• 5:39
  Speaker 3: the gravity of what he could see to hold onto them.
• 5:43
  Speaker 3: So if all that was there was what all he
• 5:46
  Speaker 3: could see, then this cluster should have evaporated gazillions of
• 5:50
  Speaker 3: years ago, and it hasn't. And he was the person
• 5:53
  Speaker 3: who coined the term dark matter. He said, there's something
• 5:57
  Speaker 3: there that we can't see. The astronomy basically ignored it
• 6:01
  Speaker 3: because it was just too hard to get your head around.
• 6:04
  Speaker 3: There's obviously something wrong, we don't know what it is.
• 6:06
  Speaker 3: We'll go and do something else. And it wasn't until well,
• 6:10
  Speaker 3: actually there was an Australian who in nineteen seventy Ken
• 6:13
  Speaker 3: Freeman A and U still a good friend, He figured
• 6:19
  Speaker 3: out that galaxies were rotating too fast for what was
• 6:23
  Speaker 3: in them to hold them together, and that again was
• 6:27
  Speaker 3: largely ignored that nineteen seventy result until VERA. Reuben basically
• 6:33
  Speaker 3: did the same thing, but worked out that in order
• 6:36
  Speaker 3: for galaxies to stay together and not fly apart as
• 6:39
  Speaker 3: they rotate, they must all be enveloped in a sort
• 6:43
  Speaker 3: of sphere or halo as we call it, of something
• 6:46
  Speaker 3: we call dark matter, and that in nineteen seventy eight
• 6:49
  Speaker 3: was the start of the modern era of dark matter.
• 6:52
  Speaker 3: And so you can actually use those those measurements to
• 6:56
  Speaker 3: make a crude estimate of what's missing. You know that
• 6:59
  Speaker 3: you can say, use something called the virial theorem, which
• 7:02
  Speaker 3: I've thought about for a long time, but that's what
• 7:04
  Speaker 3: lets you weigh things by their motion. So you can
• 7:07
  Speaker 3: weigh the dark matter by the motion of galaxies in
• 7:11
  Speaker 3: a cluster, for example. You can then weigh what you
• 7:15
  Speaker 3: can see because you know roughly how much stars weigh,
• 7:19
  Speaker 3: and the stars are what you can see in the
• 7:20
  Speaker 3: gas two, and then you can divide one by the
• 7:22
  Speaker 3: other end you do get this sort of eighty ish percent.
• 7:26
  Speaker 3: But the way that it's done today, as I've said,
• 7:31
  Speaker 3: it involves these very large scale surveys of galaxies and
• 7:35
  Speaker 3: their positions and velocities in you know, as much of
• 7:38
  Speaker 3: the universe as you can see, very very large scale
• 7:41
  Speaker 3: surveys involving millions of galaxies. And when you do that,
• 7:44
  Speaker 3: you can make statistical deductions that tell you that the
• 7:48
  Speaker 3: universe is made of something like seventy percent dark energy,
• 7:52
  Speaker 3: about twenty percent dark matter, about five percent normal matter,
• 7:56
  Speaker 3: most of which is hydrogen. So that comes from the
• 7:59
  Speaker 3: large scale surveys, and it's because the positions of galaxies
• 8:04
  Speaker 3: are actually determined by the gravitational forces.
• 8:07
  Speaker 1: That they feel.
• 8:08
  Speaker 3: And you know, that's the key to understanding dark matter
• 8:11
  Speaker 3: and dark energy, to see how these forces stuck up.
• 8:15
  Speaker 1: It's so hard to comprehend because when you say that
• 8:18
  Speaker 1: five percent of the universe is made up of stars, planets,
• 8:22
  Speaker 1: and gas, and you look out into space and see
• 8:26
  Speaker 1: so many stars, so many other things, and yet you're
• 8:30
  Speaker 1: only saying five percent of what is out there, it's
• 8:33
  Speaker 1: it's mindblow, that's right.
• 8:36
  Speaker 3: I mean some of that that figure of five percent
• 8:40
  Speaker 3: is that when you look at it as a fraction
• 8:42
  Speaker 3: of the mass and energy budget and energy and matter,
• 8:45
  Speaker 3: you know they're interchangeable equals mc squared, and so it's
• 8:49
  Speaker 3: when you do that something you realize that, yes, seventy
• 8:53
  Speaker 3: percent of the mass energy budget of the universe is
• 8:56
  Speaker 3: dark energy, twenty percent is dark matter, five percent thereabouts
• 9:02
  Speaker 3: is his normal matter. But most of that normal matter
• 9:05
  Speaker 3: is invisible to us because most of it's just cold hydrogen.
• 9:09
  Speaker 3: The you know, the materials that make up the planets,
• 9:12
  Speaker 3: in particular, the the you know, the normal elements that
• 9:16
  Speaker 3: we see around us on Earth. There's a vanishingly small
• 9:20
  Speaker 3: fraction of that that represents you know, their fraction within
• 9:24
  Speaker 3: the universe.
• 9:25
  Speaker 1: Yeah, all right, so that covers these eighty percent question.
• 9:28
  Speaker 1: But he asks a question about what will be the
• 9:32
  Speaker 1: next large telescope to be launched. What would you like
• 9:36
  Speaker 1: it to be?
• 9:38
  Speaker 3: Yeah, that's an interesting question. I mean, the thing that
• 9:40
  Speaker 3: I'm looking forward to, and we'll see it online within
• 9:44
  Speaker 3: the next probably two years, is the ELT, the extremely
• 9:48
  Speaker 3: large telescope down in Chile that's going to be visible
• 9:50
  Speaker 3: light telescope with a mirror thirty nine meters in diameter,
• 9:58
  Speaker 3: and it will be able to observe because it's got
• 10:01
  Speaker 3: this very sophisticated adaptive optic system that effectively puts it
• 10:06
  Speaker 3: above the atmosphere. It is.
• 10:11
  Speaker 1: It will have.
• 10:12
  Speaker 3: Twenty times the resolution of the Hubble telescope. So if
• 10:16
  Speaker 3: you've thought the Hubble images that you see have find
• 10:19
  Speaker 3: detail in them, wait till you see what's going to
• 10:21
  Speaker 3: come from the ELT, because it'll be twenty times better.
• 10:24
  Speaker 3: And the reason why that's my favorite big telescope is
• 10:28
  Speaker 3: that its cost has been almost since the beginning estimated
• 10:33
  Speaker 3: at one point three billion euros and it still is.
• 10:36
  Speaker 3: It's on budget and pretty well on time. And remember
• 10:40
  Speaker 3: the James Web Telescope costs ten billion dollars to build, launch,
• 10:45
  Speaker 3: and you know, and keep it going. As soon as
• 10:50
  Speaker 3: you put things into space, their price tag goes up enormously,
• 10:55
  Speaker 3: which is why I'm a big fan of ground based astronomy,
• 10:57
  Speaker 3: especially when we now have sites like so Amazonas in
• 11:01
  Speaker 3: northern Chile, which is where the ELT will be. Who's
• 11:05
  Speaker 3: who's uh, you know, whose clarity and atmospheric stability you
• 11:11
  Speaker 3: can hone with that adaptive opsic system that the telescope's
• 11:15
  Speaker 3: got to be fitted with. So that's that's what I'm
• 11:19
  Speaker 3: looking out for next. I don't think you need to
• 11:21
  Speaker 3: launch anything else into space to get anywhere near what
• 11:23
  Speaker 3: the ELT will do.
• 11:25
  Speaker 1: Very exciting. Yeah, I heard they're going to have a
• 11:28
  Speaker 1: visitors center at the el T, but the only thing
• 11:31
  Speaker 1: on the menu will be BLT. So sorry had they
• 11:36
  Speaker 1: do that joke? It just you know my brain doesn't
• 11:39
  Speaker 1: let me stop something. No, I don't. Thank you Ben
• 11:45
  Speaker 1: for the question. Great to hear from you. Let's talk
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• 13:12
  Speaker 1: I'm going to do a bit of a switcheroo here
• 13:14
  Speaker 1: because we were already talking about telescopes, and we've got
• 13:17
  Speaker 1: a question about telescopes, so we might just jump straight
• 13:19
  Speaker 1: to that one. Hi, Fred and Andrew. Just wondering if
• 13:23
  Speaker 1: Fred can shed some light pun fully intended on telescopes
• 13:28
  Speaker 1: and the different types of light they can detect. I
• 13:31
  Speaker 1: was recently thinking about how the James web Space telescope
• 13:34
  Speaker 1: uses mirrors to observe infra red light but not visible light,
• 13:38
  Speaker 1: while Hubble also uses mirrors for visible light yet can't
• 13:41
  Speaker 1: really see infra red. That got me wondering how mirrors, detectors,
• 13:46
  Speaker 1: and telescope design all come together or don't for different wavelengths.
• 13:52
  Speaker 1: Could you please walk us through the various types of
• 13:55
  Speaker 1: telescopes optical, infra red, radio all the way to gamma
• 13:58
  Speaker 1: and explain what kinds of light they detect, how they
• 14:00
  Speaker 1: do it, and why each telescope can only be used
• 14:04
  Speaker 1: in certain ways. Absolutely loved the show. May Your Reign,
• 14:08
  Speaker 1: May You Reign Supreme for many years to come. Cheese Ash,
• 14:12
  Speaker 1: Thank you Ash, and he just wants to know everything
• 14:16
  Speaker 1: you've ever written down a bed telescopes read.
• 14:19
  Speaker 3: Yeah, there's a book on it. I recommend USh hunted out.
• 14:23
  Speaker 3: It's called Stargaz's Other Life and Times of the Telescope.
• 14:26
  Speaker 3: It's the first big, thick book that I wrote, and
• 14:30
  Speaker 3: are still one of my favorites because even though it's
• 14:33
  Speaker 3: slightly out of date. It opens by talking about what
• 14:36
  Speaker 3: used to be called OWL, the overwhelmingly Large telescope, which
• 14:40
  Speaker 3: was actually the precursor of the ELT. We were just
• 14:43
  Speaker 3: talking about there. But when they were proposing OWL, which
• 14:49
  Speaker 3: had an overwhelmingly large mirror of one hundred meters in diameter,
• 14:52
  Speaker 3: and then they realized it also had an overwhelmingly large
• 14:55
  Speaker 3: price tag, which is why it came down to thirty
• 14:57
  Speaker 3: nine meters. And that's fine, because that's still.
• 15:00
  Speaker 1: An extremely big telescope. Anyway.
• 15:02
  Speaker 3: That's the plug over, that's the advert over. So basically,
• 15:08
  Speaker 3: telescopes have sort of got the same ingredients no matter
• 15:13
  Speaker 3: what they're observing, and that is something to gather at
• 15:17
  Speaker 3: the radiation, and whether that's very short wavelength radiation like
• 15:21
  Speaker 3: gamma rays or long wavelength radiation like radio waves, you've
• 15:26
  Speaker 3: got something to gather the radiation and either focus it
• 15:30
  Speaker 3: in some way or at least concentrate it, and then something.
• 15:33
  Speaker 1: To detect it. And it's usually the.
• 15:36
  Speaker 3: Detectors that are perhaps the most waveband critical, because you
• 15:42
  Speaker 3: need different detectors, for example, to detect visible lights from
• 15:47
  Speaker 3: the ones that you would use to detect infra red light.
• 15:52
  Speaker 3: And again it depends on the infrared wavelength. So I
• 15:57
  Speaker 3: guess starting right short wavelength end with gamma ray and
• 16:03
  Speaker 3: X ray detectors. They are almost the same sort of
• 16:07
  Speaker 3: technology as are used in medical imaging, but to focus
• 16:11
  Speaker 3: them you've got to have very special technologies. My recollection
• 16:16
  Speaker 3: of gamma ray telescopes and things might have changed a
• 16:19
  Speaker 3: little bit here, but they made mirrors which were called
• 16:24
  Speaker 3: grazing incidence mirrors, which looked more like a piece of
• 16:28
  Speaker 3: origami than a reflector that you'd imagine, but they did
• 16:32
  Speaker 3: focus the light to provide that thing. And then you
• 16:35
  Speaker 3: go to ultraviolet. The hubble is sensitive to ultraviolet lights
• 16:40
  Speaker 3: and that for that it needed a very precise mirror.
• 16:43
  Speaker 3: And we all know that the mirror was made very precisely,
• 16:46
  Speaker 3: but to the wrong prescription for reasons that we went
• 16:50
  Speaker 3: time to go into. So once again, you know the
• 16:53
  Speaker 3: detector is sensitive to ultraviolet radiation. In fact, they've got
• 16:56
  Speaker 3: wide band quite wideband detectors. Hubble detect long wavelength ultraviolet
• 17:03
  Speaker 3: whole of the visible and also the short wavelength infrared
• 17:07
  Speaker 3: what we call the near infrared, and its mirror and
• 17:10
  Speaker 3: detectors are capable of doing that. When you go up
• 17:13
  Speaker 3: to the James Web, you're right, that's tuned for infrared light,
• 17:17
  Speaker 3: and that means your tolerances on the accuracy of the
• 17:20
  Speaker 3: mirror are slightly less because infrared light's got a longer wavelength,
• 17:25
  Speaker 3: and you know, how accurate your mirror needs to be
• 17:30
  Speaker 3: made is dependent on the wavelength. The longer the wavelength,
• 17:33
  Speaker 3: the more relaxed you can be about the shape of
• 17:36
  Speaker 3: the mirror. So Web telescope is slightly more relaxed, although
• 17:41
  Speaker 3: still to very high tolerances. But the detectors are the
• 17:44
  Speaker 3: thing that really render it not suitable for visible light.
• 17:48
  Speaker 3: It's definitely got infrared sensitive detectors. It's also got a
• 17:54
  Speaker 3: gold coating and that's so that rather than an aluminium
• 17:59
  Speaker 3: or silver coating like a visible light telescope would have,
• 18:01
  Speaker 3: it's got a gold coating because gold reflects in for
• 18:04
  Speaker 3: red light better and then you get up to radio
• 18:07
  Speaker 3: waves and you're talking about often dishes, and you know
• 18:11
  Speaker 3: a dish is just a big mirror, but one that's
• 18:15
  Speaker 3: as I said before, it doesn't have to be as
• 18:17
  Speaker 3: accurate as the mirror on a visible light telescope because
• 18:20
  Speaker 3: the wavelength is longer. And that's why we see these
• 18:23
  Speaker 3: much bigger, bigger telescopes for radio waves.
• 18:26
  Speaker 1: You get the.
• 18:27
  Speaker 3: Same sensitivity to detail with a bigger dish than you
• 18:33
  Speaker 3: do with visible light with a smaller dish. That's cause
• 18:35
  Speaker 3: that sensitive to details proportional to the wavelength. But the
• 18:39
  Speaker 3: detectors are quite different. In radio telescopes. They use often
• 18:44
  Speaker 3: very sophisticated technologies where they're actually measuring the waveform itself,
• 18:49
  Speaker 3: which you don't do with visible light what are called
• 18:52
  Speaker 3: heterodyne receivers and things of that sort. So that's walking
• 18:55
  Speaker 3: through the various types of telescopes, as you've suggested, is
• 19:00
  Speaker 3: from another bit to the question how they do it? Well,
• 19:03
  Speaker 3: I've explained that why each telescope can only be used
• 19:06
  Speaker 3: in certain ways.
• 19:06
  Speaker 1: Yeah, yeah, I guess the question he asks prompt a
• 19:10
  Speaker 1: question in my mind or a suggestion that you really
• 19:13
  Speaker 1: could not build a single telescope that could do absolutely
• 19:17
  Speaker 1: everything you'd want to do on all spectrums.
• 19:21
  Speaker 3: That's correct. There is a device which in fact is
• 19:27
  Speaker 3: only used really in the microwave region.
• 19:29
  Speaker 1: Of the spectrum.
• 19:31
  Speaker 3: But it's called a bolometer, and a bolometer is something
• 19:34
  Speaker 3: that is basically detect stuff, but it's insensitive to wavelengths.
• 19:39
  Speaker 3: So in a sense, a bolometer, a perfect bilometer, will
• 19:42
  Speaker 3: be able to detect all wavelengths. Now, the reality is
• 19:45
  Speaker 3: you can't do that, but that's the notion behind a bilometer,
• 19:49
  Speaker 3: and what it means is that for microwave astronomy, the
• 19:54
  Speaker 3: bolometer gives you a very wide range of wavelengths to cover.
• 19:58
  Speaker 1: So when you banning to build a telescope, do you
• 20:03
  Speaker 1: have an objective in mind before you build it? Or
• 20:05
  Speaker 1: do you build it and then think, well, what come.
• 20:08
  Speaker 2: O you do?
• 20:08
  Speaker 3: Is no, it's definitely the other way around. You you
• 20:12
  Speaker 3: start off with the science case, what are the questions
• 20:14
  Speaker 3: that we really think are the most urgent questions to answer?
• 20:19
  Speaker 3: And you've got things like, you know, the nature of
• 20:22
  Speaker 3: dark energy, the nature of dark matter, are there any
• 20:26
  Speaker 3: living organisms anywhere else in the universe? All the questions
• 20:28
  Speaker 3: that you and I talk about on the show are
• 20:31
  Speaker 3: the ones that scientists are still intrigued by, and there
• 20:33
  Speaker 3: are many others as well, the details of the way
• 20:35
  Speaker 3: galaxies interact with the environments. What about all these young
• 20:40
  Speaker 3: galaxies that seem to be more mature than we think
• 20:44
  Speaker 3: they should be at you know, when the universe is
• 20:47
  Speaker 3: only a couple hundred millionaiears or questions like that. They're
• 20:50
  Speaker 3: all the ones that would go into the science case
• 20:52
  Speaker 3: for a project. But there is always the background that
• 20:56
  Speaker 3: you're going to find things out that you simply did
• 20:59
  Speaker 3: not expect to find out, So that's usually added into
• 21:02
  Speaker 3: the science case, the stuff that we just don't expect,
• 21:06
  Speaker 3: serendipitous discovering. There's been so many of those made by
• 21:10
  Speaker 3: the world's great telescopes.
• 21:12
  Speaker 1: Yeah, thank you, Ash. That's a great question, and I
• 21:15
  Speaker 1: could tell Fred was excited about it. I'm just going
• 21:17
  Speaker 1: to go I'm going to go back to Ben's question
• 21:19
  Speaker 1: about you know, what do you want the next big
• 21:22
  Speaker 1: thing in telescopes to be. I've thought of one. I
• 21:24
  Speaker 1: want to see the f WST in Fred Watson Space telescope.
• 21:31
  Speaker 1: That's that's what I am said of that. Yeah, on
• 21:34
  Speaker 1: the side of that, thank you, well, you're a pioneer
• 21:37
  Speaker 1: in fiber optics. I mean, it makes sense to me
• 21:39
  Speaker 1: that you should have one named after you.
• 21:42
  Speaker 3: I always think the reason for my hairstyle is because
• 21:46
  Speaker 3: I worked in fiber optics. Because the individual follicules got
• 21:50
  Speaker 3: jealous of all these thin strands of material that I
• 21:53
  Speaker 3: was playing with and they all just fell out.
• 21:55
  Speaker 1: Yeah, they gave her. Yeah, so now we can't beat that.
• 21:57
  Speaker 1: See later, friends, We're going somewhere else. Thanks Ash for
• 22:03
  Speaker 1: the question. This is Space Nuts with Andrew Dunkley and
• 22:06
  Speaker 1: Professor Fred Watson, a Q and A edition. Let's tell
• 22:11
  Speaker 1: you about our sponsor in Cogny. Now, if you've been
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• 23:40
  Speaker 1: here the lambage space nuts. Next question comes from somebody else, Hi,
• 23:48
  Speaker 1: Fred Andrew. Gravity is described by Einstein's theories as the
• 23:52
  Speaker 1: bending of space time in the presence of massive objects. Great,
• 23:56
  Speaker 1: Why then, does physics discuss the hype anthetical graviton as
• 24:01
  Speaker 1: a force carrier for gravity? What would a graviton look
• 24:05
  Speaker 1: like were we to discover it or discover its existence?
• 24:09
  Speaker 1: And why is it needed at all in the context
• 24:12
  Speaker 1: of Einstein's theory? Thanks keep up the good work. Love
• 24:15
  Speaker 1: the show Russ from StarBridge in the UK Stourbridge it is.
• 24:21
  Speaker 3: That's right, it's in the Midlands, StarBridge. I think I
• 24:24
  Speaker 3: remember rightly. I mean, yes, it's a good question, and
• 24:32
  Speaker 3: that's kind of hard to know how to how to
• 24:36
  Speaker 3: start it because there's so much to say. So, yes,
• 24:40
  Speaker 3: general relativity exactly as ros says, is that space time
• 24:45
  Speaker 3: bends or there is says space time bends when you've
• 24:50
  Speaker 3: got matter there. And all the evidence is that general
• 24:55
  Speaker 3: relativity is absolutely on the money. It's you know, it
• 24:59
  Speaker 3: meets predictions with such a higher level of accuracy that
• 25:04
  Speaker 3: it's almost mind blowing. If I remember rightly, I think
• 25:07
  Speaker 3: it's one part in tenth to the eighteen or something
• 25:10
  Speaker 3: like that that it's been proven to work for. So
• 25:14
  Speaker 3: that's great. But the physicists who look at the other
• 25:20
  Speaker 3: end of the size scale, the ones who are interested
• 25:24
  Speaker 3: in quantum mechanics and you know, particle physics subatomic particles,
• 25:32
  Speaker 3: they say that all forces and here we're talking about
• 25:38
  Speaker 3: gravity in the Newtonian sense that it's a force have
• 25:43
  Speaker 3: have a particle that carries them. And so you know,
• 25:47
  Speaker 3: we've got the photon for electromagnetic force, we've got the
• 25:52
  Speaker 3: various force carriers for the strong and weak nuclear forces,
• 25:58
  Speaker 3: and we've also got now the Higgs field, the Higgs boson.
• 26:04
  Speaker 3: So what they're saying is that because gravity works that way,
• 26:08
  Speaker 3: there should be a boson that carries gravity, and that's
• 26:12
  Speaker 3: the idea of a hypothetical graviton. And my suspicion as
• 26:17
  Speaker 3: to how that links with relativity comes from the description
• 26:26
  Speaker 3: of the Higgs boson that I think we might have
• 26:29
  Speaker 3: talked about a few weeks ago. So the Higgs boson
• 26:34
  Speaker 3: is I think somebody asked about, you know, how do
• 26:37
  Speaker 3: you reconcile the Higgs boson with something that gives all
• 26:40
  Speaker 3: the other forces their mass, because that's what the boson does.
• 26:45
  Speaker 3: And the bottom line is that what you're really talking
• 26:48
  Speaker 3: about is the Higgs field, which is something like they
• 26:52
  Speaker 3: usually talk about syrup or molasses, and as the particles
• 26:56
  Speaker 3: move through it, they get resistance because they're, you know,
• 27:00
  Speaker 3: because they're in this sticky stuff, and that gives them
• 27:03
  Speaker 3: the effect of mass. It's not an analogy that thrills me,
• 27:09
  Speaker 3: I have to say, but it kind of gets the idea.
• 27:13
  Speaker 3: And the only time the Higgs boson itself appears is
• 27:17
  Speaker 3: when you've got something a collision between particles. So the
• 27:21
  Speaker 3: Higgs field is the main thing. But if you collide
• 27:25
  Speaker 3: particles together, you get this thing that emerges from the
• 27:29
  Speaker 3: Higgs field, which is called the Higgs boson, and that
• 27:32
  Speaker 3: can be measured, which it was in twenty twelve. And
• 27:35
  Speaker 3: my guess is that the graviton would be something like it.
• 27:38
  Speaker 3: It would be a boson, It would emerge from the
• 27:41
  Speaker 3: gravity field, and maybe would emerge when there were collisions
• 27:45
  Speaker 3: in particle accelerators, but we have no evidence for it yet.
• 27:49
  Speaker 3: So I think, you know, Russ, I think that's the
• 27:53
  Speaker 3: bottom line, that, like the search for the Higgs boson,
• 27:57
  Speaker 3: one day, the Higgs search for the graviton will basically
• 28:01
  Speaker 3: cough up the goods and and well we'll understand it,
• 28:05
  Speaker 3: perhaps in a similar way to the way we understand
• 28:07
  Speaker 3: the Higgs boson. That you need to actively create a
• 28:11
  Speaker 3: boson from the Higgs field. So maybe you need to
• 28:14
  Speaker 3: create a graviton from the gravity field, which we're used
• 28:18
  Speaker 3: to talking about.
• 28:18
  Speaker 1: And some kind of particle to account for dark matter,
• 28:21
  Speaker 1: and so well that's.
• 28:23
  Speaker 3: Right, yes, yeah, the dark matter would probably be a
• 28:26
  Speaker 3: fermi on, a thing that you know is a matter
• 28:29
  Speaker 3: particle rather than a forced particle.
• 28:31
  Speaker 1: Okay, gotcha, fair enough, all right, So where does a
• 28:35
  Speaker 1: light particle fit in that?
• 28:38
  Speaker 3: That's the photon, yes, gravitation, it's the electromagnetic particle. That's
• 28:42
  Speaker 3: probably the best understood of the sub atomic particles because.
• 28:46
  Speaker 1: We use it all the time.
• 28:48
  Speaker 3: We're using it as we speak.
• 28:50
  Speaker 1: Ah, it's very it's very handy. That's very handy. I've
• 28:54
  Speaker 1: found it quite useful for reason it could.
• 28:58
  Speaker 3: You probably find the strong and we nuclear force is
• 29:01
  Speaker 3: quite useful as well, because they stop you falling to bits.
• 29:05
  Speaker 1: That's a good one. I keep that in mind.
• 29:07
  Speaker 3: Yeah, I think that's even more useful than photop Really,
• 29:10
  Speaker 3: the problem with all of this spread is none of
• 29:12
  Speaker 3: it gives me anything to work with to improve my
• 29:15
  Speaker 3: golf game. So yeah, well you've got to start with
• 29:21
  Speaker 3: the notion that five irons dot float and once you've
• 29:24
  Speaker 3: got bus that step, then.
• 29:27
  Speaker 1: You're getting some book plugs in today.
• 29:30
  Speaker 3: That's one for you.
• 29:32
  Speaker 1: Thank you very much, thank you, russ. I hope we
• 29:35
  Speaker 1: covered that. I think we did, not sure, but anyway,
• 29:38
  Speaker 1: it's a work in progress. We'll call it that. Our
• 29:41
  Speaker 1: final question today comes from Robert. He said, Hi, my
• 29:45
  Speaker 1: friends down under, I live in Arcerreri, Iceland, and I'm
• 29:50
  Speaker 1: very much looking forward to the eclipses this year in
• 29:54
  Speaker 1: the western part of Iceland. However, your recent fabulous show
• 29:59
  Speaker 1: regarding Olympus on Mars, would this make a perfect candidate
• 30:03
  Speaker 1: for a space elevator. That comes from Robert. Hello Robert,
• 30:08
  Speaker 1: thanks for sending your question in our carea. You've been there,
• 30:12
  Speaker 1: I have, yes.
• 30:12
  Speaker 3: I sent you some photographs so you could see what
• 30:15
  Speaker 3: it's like. We should put them up on the website.
• 30:18
  Speaker 1: We could post them on in the space nets podcast group.
• 30:21
  Speaker 3: That nice nice one of the main street Money and
• 30:25
  Speaker 3: me in the main street in Aker area. We were
• 30:26
  Speaker 3: there at this time last year, actually, Robert, so I'm
• 30:32
  Speaker 3: sorry I didn't know you then, else we'd have looked
• 30:34
  Speaker 3: you up. But we had a great time there. It
• 30:36
  Speaker 3: was part of our Iceland tour which was not the
• 30:40
  Speaker 3: best for weather, so we didn't see any Roory, but
• 30:43
  Speaker 3: certainly experienced some really fabulous landscapes up in the northwest
• 30:48
  Speaker 3: of Iceland. It was the first our first visit up
• 30:51
  Speaker 3: to the northwest. We spent a lot of time in
• 30:53
  Speaker 3: the south on previous trips. But yeah, Akai is such
• 30:56
  Speaker 3: a stunning place, beautiful scenery, They.
• 31:00
  Speaker 1: Love the cathedrals, don't they in Iceland churches you, they're amazing.
• 31:05
  Speaker 1: The one, the one we saw in Reguvi just bleue
• 31:08
  Speaker 1: my mind.
• 31:08
  Speaker 3: That's right, that's that's the classic one. That is such
• 31:12
  Speaker 3: an elegant building. And indeed there's church in that curre
• 31:15
  Speaker 3: area is lovely as well.
• 31:16
  Speaker 1: It is. Yeah, well you've got a photo of that one. Yeah,
• 31:18
  Speaker 1: I'll post that to it. What was that question again?
• 31:22
  Speaker 2: Oh?
• 31:22
  Speaker 1: Yeah, as a good platform for a space elevator.
• 31:30
  Speaker 3: Yes, there's a kind of problem because to make a
• 31:36
  Speaker 3: space elevator stable, it has to start off from a
• 31:42
  Speaker 3: point on the equator of whatever world you're trying to
• 31:46
  Speaker 3: get up into space. Fright, and Olympus Mons, i'm told,
• 31:52
  Speaker 3: is at latitude eighteen degrees north. In fact, it's eighteen
• 31:56
  Speaker 3: degrees thirty nine minutes north, which is not the equator
• 31:59
  Speaker 3: of Mars. So you'd have problems with it. It would
• 32:03
  Speaker 3: need to stretch and shrink and I think would probably
• 32:06
  Speaker 3: shake itself to pieces. So I think you've got to
• 32:10
  Speaker 3: have the equator. So that's a bit sad because Olympus Mods,
• 32:15
  Speaker 3: as Robert is hinting at, is, you know, it's high
• 32:20
  Speaker 3: enough that you kind of already already held. Well you're
• 32:24
  Speaker 3: already yeah, you're already on the way of your space elevator.
• 32:27
  Speaker 3: So a nice idea, very nice idea, but I don't
• 32:30
  Speaker 3: think it would work.
• 32:31
  Speaker 1: That's a pity. Well, I suspect that the space elevator
• 32:36
  Speaker 1: concepts probably not even going to happen. It just sounds
• 32:40
  Speaker 1: like it's too expensive, too hard, and there are easy
• 32:42
  Speaker 1: ways to do things.
• 32:44
  Speaker 3: Yeah, well that's right. Reusable boosters is the way to
• 32:47
  Speaker 3: do it, and as we talked about in the last show,
• 32:49
  Speaker 3: that's now basically the normal way of getting into space.
• 32:54
  Speaker 1: Very much so, Robert, great to hear from you. Enjoy
• 32:56
  Speaker 1: those eclipses later this year. Yeah, that very exciting in Iceland.
• 33:01
  Speaker 1: If you can get there, it be a lot of
• 33:04
  Speaker 1: fun too. So Robert, hopefully we answered your question was
• 33:08
  Speaker 1: an easy one, as it turns out, and that brings
• 33:11
  Speaker 1: us to an end. Don't forget. If you've got questions
• 33:12
  Speaker 1: for us, please send them in. We're actually quite desperately
• 33:16
  Speaker 1: short of questions, so send them to us via our
• 33:19
  Speaker 1: website space nuts podcast dot comspacenuts dot io, or just
• 33:23
  Speaker 1: do a search for space Nuts Podcast on your favorite
• 33:26
  Speaker 1: search engine. Click on the AMA button that is, ask
• 33:29
  Speaker 1: me anything and send your text and audio questions in
• 33:32
  Speaker 1: with your name and location. We would really love to
• 33:35
  Speaker 1: hear from you. Fred. We're all done. Thank you so much.
• 33:38
  Speaker 1: It was good fun today.
• 33:40
  Speaker 3: It's been great.
• 33:41
  Speaker 1: It's never fun any other time, but it was good
• 33:43
  Speaker 1: fun today.
• 33:45
  Speaker 3: I love connecting with our listeners, especially when they're in
• 33:49
  Speaker 3: places like our Cary.
• 33:51
  Speaker 1: Yeah. Yeah, what an amazing place. See you soon, Fred
• 33:55
  Speaker 1: Chess for no. Professor Fredwart's an astronomer at large part
• 33:58
  Speaker 1: of the team here a Space Nuts and thanks to
• 34:02
  Speaker 1: here in the studio works really hard, but he couldn't
• 34:05
  Speaker 1: be with us today. He got on a space elevator
• 34:07
  Speaker 1: and he thought he'd be back in time, but some
• 34:09
  Speaker 1: kid pushed all the buttons, so he was very angry. Anyway,
• 34:15
  Speaker 1: he sent me a text and from me Andrew Dunkley,
• 34:18
  Speaker 1: thanks for your company. We'll catch you on the next
• 34:20
  Speaker 1: episode of Space Nuts. Bye bye. You'll be listening to
• 34:24
  Speaker 1: the Space Nuts podcast available at Apple Podcasts, Spotify, iHeartRadio,
• 34:31
  Speaker 1: or your favorite podcast player. You can also stream on
• 34:35
  Speaker 1: demand at bytes dot com. This has been another quality
• 34:38
  Speaker 1: podcast production from nights dot com.