Space Nuts Q&A Edition #470 - Universe Enigmas and Titan's Mysteries
Join Andrew Dunkley and Professor Fred Watson in this captivating Q&A episode of Space Nuts, where they explore the cosmic questions posed by our curious audience. From the mysteries of a universe without black holes to the peculiar atmosphere of Saturn's moon Titan, this episode is brimming with fascinating insights and astronomical discussions.
Episode Highlights:
- Universe Without Dark Matter and Energy: Delve into the possibilities of a universe devoid of dark matter, dark energy, and black holes. Explore the implications for galaxy formation and the cosmic web, and ponder the nature of dark energy's role in the universe's expansion.
- Energy Loss and the Universe's Age : Investigate the concept of energy loss in the universe and the methods used to calculate its age. Discover why uranium's half-life isn't the key to unlocking the universe's timeline and how the Hubble constant plays a role.
- Early Universe Surprises: Question the surprises of finding ancient cosmic structures in the early universe. Examine how galaxy formation models are continually refined and the potential revelations from the Square Kilometre Array.
- Titan's Unique Atmosphere : Unravel the mystery of Titan's dense atmosphere and compare it to Mars' inability to retain one. Consider the possible factors contributing to Titan's atmospheric retention and the role of cryovolcanism.
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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 - This is a Q and A edition of Space Nuts
01:53 - Dark matter and dark energy are at the forefront of modern day cosmology
09:10 - How much of the universe's energy is kind of like gone
12:30 - Uranium was created in supernova explosions after the universe was formed
13:33 - Using half life of uranium or lithium to calculate age of the universe is sinful
15:33 - Ben Harding asks: Should we be surprised that galaxies formed so quickly
21:39 - How did Saturn's moon Titan accumulate its thick nitrogen atmosphere
26:45 - Andrew Dunkley: Thanks to everyone who's sending questions for Space Nuts
Episode link: https://play.headliner.app/episode/24127741?utm_source=youtube
00:00:00 --> 00:00:02 hi there thanks for joining us on a Q&A
00:00:02 --> 00:00:04 edition of Space Nuts Andrew Dunley here
00:00:04 --> 00:00:06 your host great to have your company in
00:00:06 --> 00:00:08 this episode we are going to talk about
00:00:09 --> 00:00:11 a universe without black holes dark
00:00:11 --> 00:00:13 matter or dark energy what would it be
00:00:13 --> 00:00:16 like yeah probably completely different
00:00:16 --> 00:00:19 might exist at all don't know uh We've
00:00:19 --> 00:00:21 also got a question about uh loss of
00:00:21 --> 00:00:24 energy and the age of the universe uh
00:00:24 --> 00:00:26 Another Universe question the early
00:00:26 --> 00:00:28 Universe uh and all the matter and the
00:00:28 --> 00:00:31 stars and things and and why we get so
00:00:31 --> 00:00:32 surprised when we discover something
00:00:32 --> 00:00:34 that's old because it's all been there
00:00:34 --> 00:00:36 from the very beginning it's a good
00:00:36 --> 00:00:38 question and Titan's atmosphere has come
00:00:38 --> 00:00:41 up uh from one of our audience members
00:00:41 --> 00:00:43 so we'll answer all of those questions
00:00:43 --> 00:00:47 today on Space Nuts 15 seconds guidance
00:00:47 --> 00:00:53 is internal 10 9 ignition sequence start
00:00:53 --> 00:00:58 Space Nuts 5 4 3 2 1 2 3 4 5 5 4 3 2 1
00:00:58 --> 00:01:02 Space Nuts as night report it feels good
00:01:02 --> 00:01:05 and he's back again for more can't
00:01:05 --> 00:01:07 believe it it's Professor Fred Watson
00:01:07 --> 00:01:10 astronomer La FR I can't believe it hi
00:01:10 --> 00:01:12 there how you doing
00:01:12 --> 00:01:15 Andrew Well you yeah thank you you're
00:01:15 --> 00:01:17 looking well too in fact I would I would
00:01:17 --> 00:01:20 go as far as saying that since you left
00:01:20 --> 00:01:22 the public service you seem a lot you
00:01:22 --> 00:01:26 seem a lot less tense a
00:01:26 --> 00:01:28 lot uh it's really interesting uh
00:01:28 --> 00:01:32 because I don't have to scan uh my you
00:01:32 --> 00:01:35 know my um government laptop every
00:01:35 --> 00:01:37 morning to see what meetings I've got
00:01:37 --> 00:01:39 during the day and that makes the day a
00:01:39 --> 00:01:41 lot more relaxed I do still have
00:01:41 --> 00:01:43 meetings but they're under a lot better
00:01:43 --> 00:01:47 control yeah yeah yeah well that's good
00:01:47 --> 00:01:50 that's good shall we um tackle some
00:01:50 --> 00:01:52 questions well let's attempt it let's
00:01:52 --> 00:01:55 see all right uh let's go to our first
00:01:55 --> 00:01:57 one that comes from Reynold or he may
00:01:57 --> 00:02:01 pronounce it Renault uh how would our
00:02:01 --> 00:02:03 universe behave without black holes dark
00:02:03 --> 00:02:06 matter and dark energy at what phase did
00:02:06 --> 00:02:10 Dark Matter and dark energy appear
00:02:10 --> 00:02:13 That's a double Bunger what do you think
00:02:13 --> 00:02:15 FR yeah I think it's a profound question
00:02:15 --> 00:02:18 um and you know it's at the Forefront of
00:02:18 --> 00:02:24 modern day cosmology um so uh we think
00:02:24 --> 00:02:27 that it was the dark matter that really
00:02:27 --> 00:02:30 uh caused the
00:02:30 --> 00:02:34 the ability of the universe to form
00:02:34 --> 00:02:38 galaxies uh well stars and galaxies uh
00:02:38 --> 00:02:40 because uh what we think happened was
00:02:40 --> 00:02:44 that the Dark Matter came first uh and U
00:02:45 --> 00:02:46 sort of coales into what we call the
00:02:46 --> 00:02:48 cosmic web this kind of honeycomb
00:02:48 --> 00:02:53 structure of sheets of of Dark Matter uh
00:02:53 --> 00:02:56 which attracted the hydrogen that at
00:02:56 --> 00:02:59 that stage pervaded the universe uh to
00:03:00 --> 00:03:01 form a similar structure because the
00:03:01 --> 00:03:03 hydrogen collapsed
00:03:03 --> 00:03:06 gravitationally uh uh to to to sort of
00:03:06 --> 00:03:07 mimic the underlying Dark Matter
00:03:07 --> 00:03:11 structure and then excuse me during that
00:03:11 --> 00:03:14 collapse many stars were formed star
00:03:14 --> 00:03:16 formation took place uh galaxies formed
00:03:16 --> 00:03:19 because the Stars you know they they all
00:03:19 --> 00:03:22 formed in these large Blobs of matter
00:03:22 --> 00:03:24 and we see that today we still see when
00:03:24 --> 00:03:26 you look at a structure of where
00:03:26 --> 00:03:28 galaxies lie in today's Universe you
00:03:28 --> 00:03:30 find that they make up the sonicone
00:03:30 --> 00:03:33 uh which basically mimics what we see in
00:03:33 --> 00:03:35 the cosmic microwave background
00:03:35 --> 00:03:36 radiation which we think is the
00:03:36 --> 00:03:39 precursor of those galaxies that's the
00:03:39 --> 00:03:41 sound waves going through the early
00:03:41 --> 00:03:44 universe so um we think that without
00:03:44 --> 00:03:46 Dark Matter the universe would be very
00:03:46 --> 00:03:48 different uh and wouldn't have this
00:03:48 --> 00:03:50 underlying web and maybe galaxies and
00:03:50 --> 00:03:53 stars wouldn't have formed that's really
00:03:53 --> 00:03:57 interesting so uh now dark
00:03:57 --> 00:04:01 energy no I was going to say so um if
00:04:01 --> 00:04:04 Dark Energy was the driving force and it
00:04:04 --> 00:04:07 didn't exist would our universe have
00:04:07 --> 00:04:09 formed at all
00:04:09 --> 00:04:12 anyway well yeah dark energy is the the
00:04:12 --> 00:04:14 different thing it's it's the Dark
00:04:14 --> 00:04:18 Matter sorry yeah so so that that yes
00:04:18 --> 00:04:20 dark matter we think would is what
00:04:20 --> 00:04:22 allowed galaxies to form out the
00:04:22 --> 00:04:25 universe itself might have formed uh we
00:04:25 --> 00:04:27 don't really understand the Big Bang
00:04:27 --> 00:04:28 well enough to
00:04:28 --> 00:04:32 know just where it all came from
00:04:33 --> 00:04:35 but um we might have had a universe
00:04:35 --> 00:04:38 devoid of Dark Matter uh just full of
00:04:38 --> 00:04:40 cold hydrogen and not really doing
00:04:40 --> 00:04:43 anything so that's pretty boring for the
00:04:43 --> 00:04:46 universe and dark energy really is a
00:04:46 --> 00:04:47 property of the
00:04:47 --> 00:04:51 expansion uh of the universe so it's
00:04:51 --> 00:04:54 telling us that space itself has energy
00:04:54 --> 00:04:58 um so I think the second part of uh of
00:04:58 --> 00:05:00 rol's question is
00:05:00 --> 00:05:02 at what phase did Dark Matter and dark
00:05:02 --> 00:05:04 energy appear so we think Dark Matter
00:05:04 --> 00:05:07 appeared right at the beginning now Dark
00:05:07 --> 00:05:09 Energy was probably always there this is
00:05:09 --> 00:05:12 a Hot Topic in cosmology uh but we think
00:05:12 --> 00:05:16 it's only manifested itself um in the
00:05:16 --> 00:05:19 last five or 600 sorry the last five or
00:05:19 --> 00:05:21 six billion years in other words about
00:05:21 --> 00:05:24 half the age of the universe uh uh and
00:05:24 --> 00:05:27 we think that's probably because Dark
00:05:27 --> 00:05:28 Matter Dark Energy might have been there
00:05:28 --> 00:05:32 all the time but it didn't have enough
00:05:32 --> 00:05:35 uh energy to cause the universe's
00:05:35 --> 00:05:38 expansion to accelerate which is how we
00:05:38 --> 00:05:41 see Dark Energy uh it didn't have enough
00:05:41 --> 00:05:43 energy early on because the galaxies and
00:05:43 --> 00:05:45 stars the galaxies themselves were too
00:05:45 --> 00:05:47 close together and their Mutual
00:05:48 --> 00:05:50 gravitational pull was enough to sort of
00:05:50 --> 00:05:53 slow down the dark energy and and hide
00:05:53 --> 00:05:56 its effect so we think Dark Energy might
00:05:56 --> 00:05:58 always have been there the big question
00:05:58 --> 00:06:01 is how it evolved uh because for about
00:06:01 --> 00:06:04 the last 20 years the thinking has been
00:06:04 --> 00:06:06 that it's a constant that uh it's a
00:06:06 --> 00:06:09 property of you know uh the same amount
00:06:09 --> 00:06:12 of dark energy per unit volume of space
00:06:12 --> 00:06:14 per cubic centimeter if you like of
00:06:14 --> 00:06:17 space uh that uh so it's said that in
00:06:18 --> 00:06:19 other words the dark energy is
00:06:19 --> 00:06:20 proportional to the volume of space so
00:06:20 --> 00:06:23 as the space expands with the expansion
00:06:23 --> 00:06:26 of the universe you get more Dark Energy
00:06:26 --> 00:06:27 but the thinking now is that maybe
00:06:28 --> 00:06:29 that's not quite true there might be
00:06:29 --> 00:06:33 slight Evolution effect over time uh
00:06:33 --> 00:06:34 which is still being
00:06:34 --> 00:06:37 explored so uh and the another piece of
00:06:37 --> 00:06:39 his question was you know a universe
00:06:39 --> 00:06:41 devoid of black
00:06:41 --> 00:06:44 holes um what would what would that be
00:06:44 --> 00:06:46 like
00:06:46 --> 00:06:49 uh yeah we we think black holes are a
00:06:49 --> 00:06:52 natural consequence of of the formation
00:06:52 --> 00:06:56 of stars and galaxies uh without a
00:06:56 --> 00:06:58 universe without black holes might not
00:06:58 --> 00:07:01 be that different because
00:07:01 --> 00:07:03 until 40 or 50 years ago we thought the
00:07:03 --> 00:07:06 universe didn't have black holes yeah
00:07:06 --> 00:07:09 that's true uh and and it's only by a
00:07:09 --> 00:07:11 lot of Fairly detailed and careful
00:07:11 --> 00:07:12 research that we've discovered that
00:07:12 --> 00:07:15 they're black holes everywhere uh so yes
00:07:15 --> 00:07:17 an interesting question um I don't know
00:07:17 --> 00:07:19 that the consequences there would there
00:07:19 --> 00:07:21 would be a lot less high energy events
00:07:21 --> 00:07:23 going on in the universe we wouldn't see
00:07:23 --> 00:07:26 quazar for a start quazar are powered by
00:07:26 --> 00:07:27 black holes they're delinquent galaxies
00:07:27 --> 00:07:30 with a black hole at their Center
00:07:30 --> 00:07:34 H okay um but if you didn't have any of
00:07:34 --> 00:07:38 that any of the the black or dark stuff
00:07:38 --> 00:07:40 um you might just have a universe that's
00:07:40 --> 00:07:43 full of hydrogen looking pretty boring I
00:07:43 --> 00:07:46 suppose there might be the the odd
00:07:46 --> 00:07:48 reactionary event that would create
00:07:48 --> 00:07:50 something but yeah wouldn't be wouldn't
00:07:50 --> 00:07:53 be much to look at it' be
00:07:53 --> 00:07:56 boreville yes well um it would be
00:07:56 --> 00:07:58 boreville because without the formation
00:07:58 --> 00:08:00 of stars in Galaxy is well in particular
00:08:00 --> 00:08:02 stars without the formation of stars you
00:08:02 --> 00:08:04 don't get the heavy elements all you get
00:08:04 --> 00:08:06 is a universe with hydrogen helium a
00:08:07 --> 00:08:08 little bit of lithium and a couple of
00:08:08 --> 00:08:11 other things and that's it uh so uh it
00:08:11 --> 00:08:13 would be a very boring place and talking
00:08:13 --> 00:08:17 of that um that is the one of the main
00:08:17 --> 00:08:19 targets of the square kilometer array
00:08:19 --> 00:08:22 because cold hydrogen actually radiates
00:08:22 --> 00:08:25 in low fre well relatively low frequency
00:08:26 --> 00:08:29 radio waves uh and the square kilometer
00:08:29 --> 00:08:31 R is going to be able to look so far
00:08:31 --> 00:08:33 into space in other words so far back in
00:08:33 --> 00:08:36 time that it can see the Dark Ages when
00:08:36 --> 00:08:38 the first stars have not yet come into
00:08:38 --> 00:08:40 being and all there was was cold
00:08:40 --> 00:08:42 hydrogen so they buil a map that cold
00:08:42 --> 00:08:44 hydrogen and see whether it does
00:08:44 --> 00:08:46 actually fall on the cosmic web as we
00:08:47 --> 00:08:50 believe it did fascinating fascinating
00:08:50 --> 00:08:52 uh Reynold the answer to your question
00:08:52 --> 00:08:53 was
00:08:53 --> 00:08:56 um it'd be a very different Universe
00:08:56 --> 00:08:57 without any of that stuff probably
00:08:57 --> 00:09:01 pretty boring and and it uh was probably
00:09:01 --> 00:09:02 always there at the beginning dark
00:09:02 --> 00:09:06 matter and dark energy perhaps as well
00:09:06 --> 00:09:09 um so yeah it's a great question thanks
00:09:09 --> 00:09:12 for sending it in our next question Fred
00:09:12 --> 00:09:14 comes from uh one of our regular
00:09:15 --> 00:09:16 although we haven't heard from him in a
00:09:16 --> 00:09:19 while sender's
00:09:19 --> 00:09:22 buddy that's his buddy
00:09:22 --> 00:09:25 again how much of
00:09:25 --> 00:09:30 the energy of the universe is
00:09:30 --> 00:09:32 kind of like gone
00:09:32 --> 00:09:35 basically uh he never going to touch
00:09:35 --> 00:09:37 anything or is going to just continue
00:09:37 --> 00:09:40 forever like light or gravitational
00:09:40 --> 00:09:44 waves um plus maybe the potential of the
00:09:44 --> 00:09:46 energy of moving object I'm the
00:09:46 --> 00:09:49 universe's energy is tied up that way gu
00:09:49 --> 00:09:52 I got one one more question um is it
00:09:52 --> 00:09:53 possible to calculate the age of the
00:09:53 --> 00:09:56 Universe from the halflife of uranium or
00:09:56 --> 00:09:58 lithium all right guys keep up the good
00:09:58 --> 00:10:01 work love the
00:10:01 --> 00:10:03 thank you buddy uh that's uh two very
00:10:03 --> 00:10:07 very um good questions uh so we'll
00:10:07 --> 00:10:09 tackle them one at a time um he was
00:10:09 --> 00:10:12 asking about energy that's been lost in
00:10:12 --> 00:10:14 the universe I assume he means over the
00:10:14 --> 00:10:16 time the universe has
00:10:16 --> 00:10:20 existed um that there was a big bang
00:10:20 --> 00:10:22 everything expanded very quickly and
00:10:22 --> 00:10:25 then it slowed down now it's speeding up
00:10:25 --> 00:10:28 um there's a lot been happening over
00:10:28 --> 00:10:31 billions and billions of years is but is
00:10:31 --> 00:10:35 there energy loss in that
00:10:35 --> 00:10:39 process uh great question
00:10:39 --> 00:10:43 um one that I'm uh I'm thinking aloud
00:10:43 --> 00:10:48 Here Andrew uh so um so yeah the energy
00:10:48 --> 00:10:50 budget of the universe is is really
00:10:50 --> 00:10:53 interesting U because it sort of ties in
00:10:53 --> 00:10:55 with the mass of the universe as well
00:10:55 --> 00:10:57 you know mass as we know has an
00:10:57 --> 00:11:03 intrinsic energy um uh um buddy is
00:11:03 --> 00:11:07 talking about the kinetic energy of um
00:11:07 --> 00:11:08 moving
00:11:08 --> 00:11:12 objects uh and that's certainly an
00:11:12 --> 00:11:14 energy component but I think it is
00:11:14 --> 00:11:17 vanishingly small compared with the
00:11:17 --> 00:11:20 equivalent of the mass of the universe
00:11:20 --> 00:11:21 uh when you convert it to energy with E
00:11:21 --> 00:11:22 equals
00:11:22 --> 00:11:25 mc² so um most of the energy of the
00:11:25 --> 00:11:30 universe is tied up sorry most of the
00:11:30 --> 00:11:32 yeah so most of the energy of the
00:11:32 --> 00:11:36 Universe um Bing myself in a knot here
00:11:36 --> 00:11:39 if you if you regard mass as part of the
00:11:39 --> 00:11:41 mass energy budget of the universe and
00:11:41 --> 00:11:44 you draw a pie chart the stuff we can
00:11:44 --> 00:11:48 see uh is about 5% of that energy budget
00:11:48 --> 00:11:50 so that's all the mass equivalent the
00:11:50 --> 00:11:52 energy equivalent of all the mass in the
00:11:52 --> 00:11:56 universe uh and it's very very small
00:11:56 --> 00:11:58 compared with dark matter which is about
00:11:58 --> 00:12:02 five times bigger and then the rest
00:12:02 --> 00:12:06 which is 75 or 80 about 75% is dark
00:12:06 --> 00:12:09 energy so dark energy is by far the
00:12:09 --> 00:12:11 biggest energy content of the universe
00:12:11 --> 00:12:14 and the rest Almost Doesn't Matter um
00:12:14 --> 00:12:16 the you know it's it it is a incredible
00:12:16 --> 00:12:19 situation that we have that we the
00:12:19 --> 00:12:21 biggest energy component of the universe
00:12:21 --> 00:12:22 is something we actually don't
00:12:22 --> 00:12:24 understand uh it's making the universe
00:12:24 --> 00:12:28 expand ever more rapidly um so yeah
00:12:28 --> 00:12:32 really very very interesting um just
00:12:32 --> 00:12:36 moving on to uh uranium uranium's uh not
00:12:36 --> 00:12:38 something that you can use to to
00:12:38 --> 00:12:40 determine the age of the universe
00:12:40 --> 00:12:43 because it it was created in Supernova
00:12:44 --> 00:12:46 explosions which occurred after the
00:12:46 --> 00:12:48 universe was formed uh with think heavy
00:12:48 --> 00:12:53 elements like uranium uh are created uh
00:12:53 --> 00:12:55 within massive star either collisions
00:12:55 --> 00:12:58 neutron star collisions or massive
00:12:58 --> 00:12:59 supernate
00:12:59 --> 00:13:03 eruptions um you can use uranium
00:13:03 --> 00:13:06 obviously it has a half life uh and you
00:13:06 --> 00:13:07 can I think that might be one of the
00:13:07 --> 00:13:09 ways that you determine the age of the
00:13:09 --> 00:13:12 Earth actually uh when I think about it
00:13:12 --> 00:13:15 uh 4.6 billion years I think the age of
00:13:15 --> 00:13:20 of uh of the earth is partly due to our
00:13:20 --> 00:13:23 understanding of the radioactive decay
00:13:23 --> 00:13:26 of Isotopes like uranium so uh yes it's
00:13:26 --> 00:13:30 got a place in in cosmology but um not
00:13:30 --> 00:13:32 in regard to the Big Bang
00:13:32 --> 00:13:34 itself okay you also mentioned lithium
00:13:34 --> 00:13:37 same do I did yeah now lithium's not
00:13:37 --> 00:13:40 that's what I was just looking up um
00:13:40 --> 00:13:44 it's I think um I'm not aware of the
00:13:44 --> 00:13:46 radioactive properties of lithium let me
00:13:46 --> 00:13:47 put it that
00:13:47 --> 00:13:51 way okay yeah um well we know about its
00:13:51 --> 00:13:54 properties when it comes to energy use
00:13:55 --> 00:13:58 in on Earth and it's a dwindling
00:13:58 --> 00:14:00 resource they got to find something else
00:14:00 --> 00:14:02 eventually and I think they're they're
00:14:02 --> 00:14:05 working on sodium batteries uh there's
00:14:05 --> 00:14:07 plenty of that stuff around but um yeah
00:14:07 --> 00:14:10 um so so if you can't use the half life
00:14:10 --> 00:14:12 of uranium or lithium to calculate the
00:14:12 --> 00:14:13 age of the
00:14:13 --> 00:14:18 universe what do you use uh the first
00:14:18 --> 00:14:21 way it was worked out was simply by the
00:14:21 --> 00:14:24 measure measuring the Hubble constant
00:14:24 --> 00:14:25 which is the rate at which the universe
00:14:25 --> 00:14:27 is expanding if you invert the Hubble
00:14:27 --> 00:14:30 constant you get the time
00:14:30 --> 00:14:31 how long it's been expanding for you can
00:14:31 --> 00:14:35 basically use that simple number uh to
00:14:35 --> 00:14:37 work out when everything was Al together
00:14:37 --> 00:14:39 in one place but that assumes that the
00:14:39 --> 00:14:42 expansion has been uniform throughout
00:14:42 --> 00:14:44 and we don't believe that's the case now
00:14:44 --> 00:14:46 so you've got to modify it so these days
00:14:46 --> 00:14:47 it's a combination of looking at the
00:14:47 --> 00:14:50 distribution of galaxies in the universe
00:14:50 --> 00:14:53 plus our uh observations of the flash of
00:14:53 --> 00:14:56 the Big Bang uh which we could still see
00:14:56 --> 00:14:57 of course is a cosmic microwave
00:14:57 --> 00:15:00 background radiation and you can deduce
00:15:00 --> 00:15:02 from that how old the universe is
00:15:02 --> 00:15:03 because you know it was visible light
00:15:04 --> 00:15:05 when it left and it's now microwaves and
00:15:05 --> 00:15:08 that's a simple calculation as well yeah
00:15:08 --> 00:15:11 I suppose in terms of uh dwindling
00:15:11 --> 00:15:13 energy or lost energy in the universe
00:15:13 --> 00:15:14 you can you can look at I think we've
00:15:14 --> 00:15:16 spoken about it before you can look at
00:15:16 --> 00:15:20 photons which do die um especially if
00:15:20 --> 00:15:23 they hit something but that energy
00:15:23 --> 00:15:25 transfers into something else does it
00:15:25 --> 00:15:26 that's that's correct yeah so it's
00:15:26 --> 00:15:29 conserved that's right m there you go
00:15:29 --> 00:15:31 okay thank you buddy great to hear from
00:15:31 --> 00:15:34 you it's been a while hope you're well
00:15:34 --> 00:15:37 uh our next question comes from oh hang
00:15:37 --> 00:15:41 on a sec we've got to do this
00:15:41 --> 00:15:45 first and I feel fine Space Nuts there
00:15:45 --> 00:15:46 we go always got to Chuck one of those
00:15:46 --> 00:15:51 in uh Ben has sent us a question H and
00:15:51 --> 00:15:54 uh Ben asks in the early Universe it was
00:15:54 --> 00:15:57 physically much smaller but the total
00:15:57 --> 00:15:59 amount of matter SL energy was the same
00:15:59 --> 00:16:01 so everything was much closer together
00:16:01 --> 00:16:03 than now so wouldn't that make it much
00:16:03 --> 00:16:06 easier to build Stars galaxies and stuff
00:16:06 --> 00:16:09 uh even super massive black holes yet we
00:16:09 --> 00:16:11 are supposed to be surprised that these
00:16:11 --> 00:16:13 structures existed in the very early
00:16:13 --> 00:16:16 days why so I would be surprised if huge
00:16:16 --> 00:16:19 compact structures didn't form quickly
00:16:19 --> 00:16:21 as the ingredients were so readily
00:16:22 --> 00:16:25 available Ben Harding uh thank you Ben
00:16:25 --> 00:16:26 we've kind of been talking about that
00:16:26 --> 00:16:29 stuff um as a part of today today's
00:16:29 --> 00:16:32 program uh and yes you bring up an
00:16:32 --> 00:16:34 interesting point uh we we get excited
00:16:35 --> 00:16:37 when we find a primordial black hole or
00:16:37 --> 00:16:40 or or an ancient Galaxy that seems to
00:16:40 --> 00:16:42 you know almost be as old as the
00:16:42 --> 00:16:45 universe itself uh which has happened in
00:16:45 --> 00:16:48 recent times uh should we be surprised
00:16:48 --> 00:16:51 FR or is um been on to something look it
00:16:51 --> 00:16:53 was all there in the first place why are
00:16:53 --> 00:16:56 we getting you know super super excited
00:16:56 --> 00:17:00 about it so yeah so if our models of uh
00:17:00 --> 00:17:03 Galaxy formation were perfect and a
00:17:03 --> 00:17:05 perfect representation of reality then
00:17:05 --> 00:17:07 we wouldn't be
00:17:07 --> 00:17:09 surprised because the models will
00:17:09 --> 00:17:12 predict that uh but the models need
00:17:12 --> 00:17:16 fine-tuning um so those surprises are uh
00:17:16 --> 00:17:19 I think to to to be honest they're often
00:17:19 --> 00:17:22 beat up by the media including space
00:17:22 --> 00:17:28 knots um so so um it's it's there is
00:17:28 --> 00:17:30 there is a element of you know
00:17:30 --> 00:17:34 researchers who uh are the ones who put
00:17:34 --> 00:17:36 together models of the Way galaxies form
00:17:36 --> 00:17:39 and evolve um they're the ones who have
00:17:39 --> 00:17:41 in some ways had to rewrite their models
00:17:41 --> 00:17:44 they've had to tune the parameters uh we
00:17:44 --> 00:17:47 had um uh talk at the uh 50th
00:17:48 --> 00:17:49 anniversary of the Anglo stonan
00:17:49 --> 00:17:51 telescope that Symposium that I was uh
00:17:52 --> 00:17:54 chairing uh as the uh local organizing
00:17:54 --> 00:17:56 committee chair sorry science organizing
00:17:56 --> 00:17:59 committee chair not very long ago one of
00:17:59 --> 00:18:02 the talks was about exactly this and um
00:18:02 --> 00:18:04 the our that particular speaker said we
00:18:04 --> 00:18:06 shouldn't be surprised that these
00:18:06 --> 00:18:09 structures formed so early in the
00:18:09 --> 00:18:10 universe because the ingredients were
00:18:10 --> 00:18:15 there exactly as Ben says uh and um uh
00:18:15 --> 00:18:16 but you know there's a bit more to it
00:18:16 --> 00:18:19 than that you you've got to have the the
00:18:19 --> 00:18:20 gravitational pull that's provided by
00:18:20 --> 00:18:22 that Cosmic web structure that we were
00:18:22 --> 00:18:23 talking about a few minutes ago that
00:18:23 --> 00:18:26 needs to be in place as well uh and that
00:18:26 --> 00:18:28 must have formed very very early on in
00:18:28 --> 00:18:30 the history of the universe that's what
00:18:30 --> 00:18:33 we learn from the square kilometer array
00:18:33 --> 00:18:35 uh we might get surprises from the
00:18:35 --> 00:18:37 square kilometer array as well because
00:18:37 --> 00:18:39 we think there's at least you know at
00:18:39 --> 00:18:42 least a time of more than 100 million
00:18:42 --> 00:18:45 years when the universe went through the
00:18:45 --> 00:18:47 Dark Ages there were no stars shining
00:18:47 --> 00:18:49 now that might turn out to be an
00:18:49 --> 00:18:52 underestimate or an overestimate uh and
00:18:52 --> 00:18:54 it might surprise the theorists when we
00:18:54 --> 00:18:55 start to get the results from the square
00:18:55 --> 00:18:57 kilometer array which won't be too far
00:18:57 --> 00:18:59 down the track I don't think maybe
00:18:59 --> 00:19:01 I was about to ask you that
00:19:01 --> 00:19:03 um it can't be too long before they
00:19:04 --> 00:19:06 switch that on but uh it is still a
00:19:06 --> 00:19:11 while yeah it's 20 2028 or thereabouts
00:19:11 --> 00:19:13 yeah right but they will switch on bits
00:19:13 --> 00:19:16 of it beforehand so we might glean stuff
00:19:16 --> 00:19:18 it is an array so you know it's not just
00:19:18 --> 00:19:23 a single Telescope yes tell us um yeah
00:19:23 --> 00:19:26 very good thank you Ben and I think we
00:19:26 --> 00:19:29 basically answered it that um yes um
00:19:29 --> 00:19:31 because of modeling and it's not an
00:19:31 --> 00:19:34 exact science um these discoveries are
00:19:34 --> 00:19:37 quite surprising from time to time uh
00:19:37 --> 00:19:39 and and not all the stuff was there in
00:19:39 --> 00:19:42 the first place I suppose Fred because
00:19:42 --> 00:19:44 it a consequence of the big bang and
00:19:44 --> 00:19:47 that mix of materials that created more
00:19:47 --> 00:19:50 materials and new materials and new
00:19:50 --> 00:19:52 discoveries being made as a consequence
00:19:52 --> 00:19:53 of that I
00:19:53 --> 00:19:56 suppose yeah so I mean the modeling of
00:19:56 --> 00:20:01 the big Banks fairly pretty well sewn up
00:20:01 --> 00:20:04 uh and um it's within the first few
00:20:04 --> 00:20:06 minutes that you actually get atoms
00:20:06 --> 00:20:09 forming but they are hydrogen and helium
00:20:09 --> 00:20:12 uh and then you've got to wait a long
00:20:12 --> 00:20:15 time uh probably 100 million years
00:20:15 --> 00:20:18 before you started getting carbon and
00:20:18 --> 00:20:19 oxygen and the other things that are
00:20:19 --> 00:20:22 formed by the interior of stars and and
00:20:22 --> 00:20:24 that you know that's a fairly um
00:20:24 --> 00:20:28 coherent picture uh which as I said will
00:20:28 --> 00:20:31 be demonstrated we hope by the square
00:20:31 --> 00:20:33 kilometer array what will be a surprise
00:20:33 --> 00:20:37 there is if they when they analyze the
00:20:37 --> 00:20:39 signal coming from that that early gas
00:20:39 --> 00:20:41 if heavy elements were present in that
00:20:41 --> 00:20:44 early primordial gas then we really have
00:20:44 --> 00:20:46 to start rewriting the
00:20:46 --> 00:20:48 textbooks uh because at the moment we
00:20:48 --> 00:20:50 don't think there were any so there's a
00:20:50 --> 00:20:51 there's a challenge for the square
00:20:51 --> 00:20:53 kilometer a and that would probably win
00:20:53 --> 00:20:56 a Nobel Prize a discovery like that yeah
00:20:56 --> 00:20:58 I I imagine so uh so Ben's basically
00:20:58 --> 00:21:01 asked his question a few years too early
00:21:01 --> 00:21:04 yes that's right so um if if a Nobel
00:21:04 --> 00:21:06 Prize came from that it would please me
00:21:06 --> 00:21:08 enormously because I'm on record in
00:21:08 --> 00:21:10 Hansard as having promised the
00:21:10 --> 00:21:12 government that the square kilometer
00:21:12 --> 00:21:16 array would win a Nobel
00:21:16 --> 00:21:19 Prize oh day yeah that was a few years
00:21:19 --> 00:21:22 AG that was yeah I'm just going to write
00:21:22 --> 00:21:24 a note because we're going to follow
00:21:24 --> 00:21:24 that
00:21:25 --> 00:21:29 up okay thanks Ben
00:21:29 --> 00:21:32 okay we checked all four systems and it
00:21:32 --> 00:21:36 space Nets and our final question today
00:21:36 --> 00:21:38 comes from uh
00:21:38 --> 00:21:42 Yan hello space nuts this is Yan from
00:21:42 --> 00:21:45 The Forest of doston at Sweden as we all
00:21:45 --> 00:21:47 know Saturn's moon Titan is a very
00:21:47 --> 00:21:51 special place so here is my question how
00:21:51 --> 00:21:54 did Titan become so special how did it
00:21:54 --> 00:21:56 accumulate its thick nitrogen atmosphere
00:21:56 --> 00:21:59 and all its meeting and eating
00:21:59 --> 00:22:01 there are dozens of moons of outer
00:22:01 --> 00:22:04 planets but only Titan has an atmosphere
00:22:04 --> 00:22:06 what is it about Titan that made it
00:22:06 --> 00:22:09 become different from all the other
00:22:10 --> 00:22:13 moons and another related question it is
00:22:13 --> 00:22:15 often said that Mars is too small to
00:22:15 --> 00:22:18 retain an atmosphere in the long term
00:22:18 --> 00:22:21 the Titan is even smaller how come Titan
00:22:21 --> 00:22:24 can retain an atmosphere when Mars
00:22:24 --> 00:22:27 cannot thanks for a great
00:22:27 --> 00:22:30 show uh thank you y uh great to hear
00:22:30 --> 00:22:33 from somebody in Sweden and gee that
00:22:33 --> 00:22:36 were great questions um that especially
00:22:36 --> 00:22:39 that last part comparing Mars who that
00:22:39 --> 00:22:40 couldn't hold an atmosphere to Titan
00:22:40 --> 00:22:43 that's smaller that can hold an
00:22:43 --> 00:22:45 atmosphere uh and how did Titan get its
00:22:45 --> 00:22:46 atmosphere in the first place because
00:22:46 --> 00:22:47 it's
00:22:47 --> 00:22:50 Unique I think that was a reasonably
00:22:50 --> 00:22:53 good paraphrasing of paraphrases it very
00:22:53 --> 00:22:55 well yeah and I can paraphrase the
00:22:55 --> 00:22:58 answer which is basically I don't know
00:22:58 --> 00:23:01 um homework time yeah I think we will do
00:23:01 --> 00:23:03 some homework on this but it's a great
00:23:03 --> 00:23:07 question uh yens uh and
00:23:07 --> 00:23:09 I just thinking about it you know with
00:23:10 --> 00:23:13 Mars um the obvious difference between
00:23:13 --> 00:23:14 Mars and
00:23:14 --> 00:23:18 Titan uh is that Mars well Mars is
00:23:18 --> 00:23:21 bigger than Titan but Mars is much
00:23:21 --> 00:23:24 closer to the Sun uh and so while it's
00:23:24 --> 00:23:27 not in the goldilock zone it's it's um
00:23:27 --> 00:23:29 near enough to the Sun that we think the
00:23:29 --> 00:23:31 sun's radiation by that I mean the
00:23:31 --> 00:23:34 subatomic particles has helped to strip
00:23:34 --> 00:23:39 off the atmosphere from Mars um uh which
00:23:39 --> 00:23:42 uh is you know some of it some of it is
00:23:42 --> 00:23:44 water vapor that's frozen frozen out a
00:23:44 --> 00:23:47 lot of that but a lot of it was
00:23:47 --> 00:23:49 dissociated uh into uh well the water
00:23:50 --> 00:23:51 was certainly dissociated into hydrogen
00:23:51 --> 00:23:54 and oxygen and the hydrogen's just gone
00:23:54 --> 00:23:57 into space um yeah likewise probably
00:23:57 --> 00:23:59 some of the carbon dioxide side it's so
00:23:59 --> 00:24:01 I I think it's there's a temperature
00:24:01 --> 00:24:04 difference there but once you get to
00:24:04 --> 00:24:07 Jupiter now ganim is bigger than Titan
00:24:07 --> 00:24:09 and ganim doesn't have a scar of an
00:24:09 --> 00:24:12 atmosphere there's nothing there at all
00:24:12 --> 00:24:14 uh so it's a really interesting question
00:24:14 --> 00:24:17 why Titan should have that thick
00:24:17 --> 00:24:20 atmosphere um and I I'm not you know an
00:24:20 --> 00:24:22 expert on planetary science but I will
00:24:22 --> 00:24:24 take that one on notice because I think
00:24:24 --> 00:24:25 that's worth following up just to find
00:24:25 --> 00:24:28 out it's such a great question and it's
00:24:28 --> 00:24:30 a you know it's glaringly obvious why is
00:24:30 --> 00:24:33 this body in the outer solar system why
00:24:33 --> 00:24:35 is it clung on to an atmosphere that is
00:24:35 --> 00:24:40 thick and murky um uh when uh we've got
00:24:40 --> 00:24:45 a similar sized object ganim uh not that
00:24:45 --> 00:24:49 far nearer to the inner solar system uh
00:24:49 --> 00:24:51 in orbit around Jupiter uh that doesn't
00:24:51 --> 00:24:53 have any sign of an atmosphere like that
00:24:53 --> 00:24:56 so that is one I'll come back to and
00:24:56 --> 00:24:59 thank you for the question okay uh just
00:24:59 --> 00:25:00 throwing it out there could it be
00:25:00 --> 00:25:03 something to do with the volatility of
00:25:03 --> 00:25:07 Titan uh it's it's um it's volcanic is
00:25:07 --> 00:25:09 it not and it's throwing up a lot of
00:25:09 --> 00:25:12 these um nasty smelly gases and could it
00:25:12 --> 00:25:14 constantly be renewing its atmosphere
00:25:15 --> 00:25:18 which genid cannot perhaps these are the
00:25:18 --> 00:25:21 Cry Cry of volcanoes uh we think it's a
00:25:21 --> 00:25:23 mixture of water and ammonia that comes
00:25:23 --> 00:25:26 up from them uh and not you know not
00:25:26 --> 00:25:28 what the kind of thing that we imagine
00:25:28 --> 00:25:30 when we think of a terrestrial volcano
00:25:30 --> 00:25:32 uh so the volcanoes are coming up from
00:25:32 --> 00:25:34 the ocean layer beneath the ice of Titan
00:25:34 --> 00:25:37 because Titan surface is solid ice as we
00:25:37 --> 00:25:40 believe is ganin uh so it's a such a
00:25:40 --> 00:25:45 contrast I mean in a sense uh my first
00:25:45 --> 00:25:48 thought about this was well gas giants
00:25:48 --> 00:25:50 are uh you know they they they grow
00:25:50 --> 00:25:54 their gassiness because they've got a um
00:25:54 --> 00:25:56 massive core that's been built up by by
00:25:56 --> 00:25:59 the um uh
00:25:59 --> 00:26:01 fact that that they're beyond the ice
00:26:01 --> 00:26:03 line so ice has formed and they've got
00:26:03 --> 00:26:08 probably got an icy core uh and whether
00:26:08 --> 00:26:11 you can apply the same argument to Titan
00:26:11 --> 00:26:13 I'm not sure uh I need to check on that
00:26:13 --> 00:26:16 so uh yeah thanks for the question and
00:26:16 --> 00:26:18 we'll we'll have a look at it I'm gonna
00:26:18 --> 00:26:22 put an my notes we'll we'll put it pin
00:26:22 --> 00:26:24 in that one uh and try and come back to
00:26:24 --> 00:26:27 it in a in a later episode but uh great
00:26:27 --> 00:26:28 question yeah it's very very good and
00:26:28 --> 00:26:30 hope all is well in Sweden although
00:26:30 --> 00:26:32 you're you're heading into the colder
00:26:32 --> 00:26:35 month so I won't be visiting for a while
00:26:35 --> 00:26:37 well we will we'll be there next not
00:26:37 --> 00:26:40 next month but the month after we'll be
00:26:40 --> 00:26:44 oh wonderful for Arctic tour yeah
00:26:44 --> 00:26:47 excellent okay um that's it for today
00:26:47 --> 00:26:49 thanks to everyone who send in questions
00:26:49 --> 00:26:51 don't forget you can send us questions
00:26:51 --> 00:26:55 as well via our website space nuts.i
00:26:55 --> 00:26:58 just uh click on the AMA link up the top
00:26:58 --> 00:27:00 and and send us your questions through
00:27:00 --> 00:27:02 that and have a look around while you're
00:27:02 --> 00:27:04 there particularly the Space Nuts shop
00:27:04 --> 00:27:06 or the Space Nuts supporter button if
00:27:06 --> 00:27:09 you want to push that uh what it does is
00:27:09 --> 00:27:11 as soon as you push that button it sends
00:27:11 --> 00:27:14 out a Trojan and empties your bank bank
00:27:14 --> 00:27:17 account no it doesn't no no it doesn't
00:27:17 --> 00:27:20 don't even joke about that no it
00:27:20 --> 00:27:21 shouldn't
00:27:21 --> 00:27:25 really good grief no it doesn't um it's
00:27:25 --> 00:27:25 purely
00:27:26 --> 00:27:29 voluntary um thanks Fred as always great
00:27:29 --> 00:27:31 great to chat and great questions again
00:27:31 --> 00:27:33 this week well they just they're
00:27:33 --> 00:27:35 terrific questions yeah thank you very
00:27:35 --> 00:27:38 much everybody thanks Andrew no worries
00:27:38 --> 00:27:40 catch you soon Professor Fred Watson
00:27:40 --> 00:27:42 astronomer at large and thanks to H in
00:27:42 --> 00:27:43 the studio for telling me about the
00:27:43 --> 00:27:45 troan horse problem we've been having no
00:27:45 --> 00:27:48 no I'm kidding again no he didn't
00:27:48 --> 00:27:50 although he's working on it and from me
00:27:50 --> 00:27:51 Andrew Dunley thanks for your company
00:27:51 --> 00:27:53 we'll catch you on the very next episode
00:27:53 --> 00:27:57 of Space Nuts see you then bye-bye Space
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