The Search for Life on Venus: Uncovering Volcanic Activity | Space Nuts #344

[00:00:00] Hi there, thanks for joining us on this the latest edition of Space Nuts. I'm Andrew Dunkley your host. Great to have you company coming up today. We are going to look at volcanoes not on Earth, not on Mars but on Venus and it's starting to

[00:00:15] look like some of them might actually be active. Wow that's quite a thing and we've spoken before about the Ryugu asteroid samples of that were brought back to Earth and they've done some more analysis on them and some more

[00:00:31] revelations have been made. We'll also be answering questions about visible light energy, how slow can light go and matter and antimatter questions as well. That's all coming up on this edition of Space Nuts. Joining me to discuss all of that at length and we'll be finished in a

[00:01:07] couple of minutes is Professor Fred Watson, Astronomer Alarge. Thank you, what a great show that was. Thanks Andrew. Catch you next week. How are you Fred? Very well thank you. I'm coming to you from Hotel Rumi, Canberra which is

[00:01:25] where the lighting if people are watching on YouTube the lighting is less than optimal but you can probably see that it's me. The reason why I'm sitting here without headphones or anything like that is because my plans

[00:01:39] have changed. I was supposed to be going back home to Sydney yesterday after meetings at the Department of Industry and at Questacon, the science centre here in Canberra but I got my days wrong. I've just had a lightning flash

[00:01:53] there so I'm just gonna take myself off the mains just in case there's a power surge through the mains. It shouldn't have any effect because I've got a full charge on the battery on the laptop. The power charge of the phone as well. Better.

[00:02:13] So in fact I got my days wrong so all this is my fault but today at the National Press Club which is one of the main ways that what you might call government, in fact it is often government politicians use this a lot.

[00:02:31] It's sometimes other people who are in public life for one reason or another it's the voice that allows people to communicate their ideas and policies sometimes. So the National Press Club is a big gig. The National Press

[00:02:49] Club lunch is a very big deal and today at the National Press Club we have the NASA administrator Bill Nelson and his deputy Pam Melroy who we know because she wrote a lovely endorsement of Cosmic Chronicles when it

[00:03:10] came out and I've done the gig with her in the past and things like that. So it seemed like a good idea to try and get myself into that. Yes. My colleagues in the Department of Industry and the Space Agency actually, I think it's the

[00:03:22] Space Agency that I'm going with, they'll file me a ticket so I should be there at 11.30 this morning. How? I'm assuming we don't all get washed away by the rain I think is now falling outside. Yeah yeah but that's exciting what a great event.

[00:03:34] Of course the National Press Club is always broadcast on the ABC so people can tune in and watch that at lunchtime, our time. Yep. But yeah it's quite often the way that politicians get grilled and it's more

[00:03:56] attention leading up to a federal election but yeah it operates very regularly and always a source of news stories and information so yeah that'll be great that'll be really exciting. Maybe I'll be able to report on it

[00:04:12] next week or whenever. Perhaps. It is interesting as you said politicians use it for election policies. We are what three days out, two days out now from a state election. Yep yep. But I guess that doesn't count in the National Press Club because the Australian

[00:04:33] Capital Territory where the press club is is not New South Wales. No it's not and to be honest I really don't know which way the election is going to go this weekend. No. You could go either way. I guess it just depends on the mood of the

[00:04:47] electorate in the wake of COVID-19 but the sitting party is coming out of some turmoil with a few changes in the ranks forced upon them by unfortunate situations so it'll be interesting to see where it goes. I'm just not sure.

[00:05:06] Okay let's get down to business Fred and volcanoes on Venus we know they exist we know they're on earth we know they're on many planets Titan etc and moons but these ones are starting to look like they're just not sitting there dormant

[00:05:24] twiddling their thumbs there there's signs of activity that's pretty interesting. It is yeah I think this is a really exciting result so at present we know for certain that what we know for certain of two volcanically active bodies

[00:05:45] in the solar system one is our own planet and the other of course is EO Jupiter's little moon that's quite next quite near to Jupiter actually it's quite a big moon when you compare some of the other moons of Jupiter which are

[00:06:00] just rocks but he was stretched and squeezed by the gravitational attraction of Jupiter the tidal forces and so is very volcanically active in fact it's considered to be the most volcanically active. Did I say Titan? I thought Titan

[00:06:15] was but it's EO. Yes that's right Titan actually you're not wrong because there's evidence of cryo volcanoes on Titan. I knew there was something that yeah in the freezing cold slosh that's right so you're not you're

[00:06:28] not off the mark but EO is certainly the most volcanic one but Venus kind of since the Magellan spacecraft which was in orbit around Venus 30 years ago since it because Venus has got this huge atmosphere thick clouds so a huge

[00:06:51] atmosphere it's just a normal atmosphere but he's very thick high density a hundred times the pressure of our atmosphere here on Earth and I'm essentially opaque so that you can't see the surface directly. Magellan to

[00:07:08] combat that was equipped with the very accurate radar system so you know this sort of radar that allows you to map the terrain beneath and give you topographical information like hill heights and all the rest of it and so

[00:07:24] that's why we've got really good maps of Venus' surface and my recollection from the statistics is that what we know about that is that Venus has the most volcanoes of any object in the solar system. Wow. We believe we've believed

[00:07:43] until now it was volcanically dormant these come from an ancient period when Venus was much more geologically active than it is today. Until now. Yeah. What's happened Andrew is it's actually a scientist at the University of Alaska Robert Tarrick who's a planetary scientist and he's published a

[00:08:05] paper which comes out so has come out this week at the 54th lunar planetary science conference in Houston and what he's detected is a particular volcanic vent that's changed its shape and the reason why it can do that is that when

[00:08:27] Magellan was flying over Venus and doing its mapping it actually did certainly for some parts of Venus it did three cycles between 1991 and 1992 and something like 42% of the planet was imaged or radar imaged more than more than more than once at least twice so that's what allowed this

[00:09:01] scientist to trail dot to troll through the data and look at differences between the two sets of images I think they're about eight months apart if I remember rightly from the paper so and yes Professor Herrick has realised that one

[00:09:24] particular crazier and he's actually one of the biggest it's a mountain called Mart MAAT Mons Mons is just mount and it's very close to Venus's equator and the the essence of his argument was that if you were going to look for

[00:09:48] activity today you would look at the biggest volcanoes and you might also think about looking on the equator which is you know where you experience well tidal forces and centrifugal forces and all of that stuff yeah not

[00:10:02] that probably makes much difference but you're looking and it's got this lovely comment about his search through the data it was a search for a needle in a haystack without any guarantee that there was a needle there and he says and he said if

[00:10:19] you were if you're going to bet on where the most likely place for an eruption to occur on Venus this would it this will be it is the the tallest volcano on the planet and sure enough he's realised that there's an area which is

[00:10:36] the sort of summit it's the crater summit of of Mart Mons which is about nearly two and a half kilometers wide and and about eight kilometers is in height that mountain isn't it that you're saying incredible that's right big mountain

[00:10:58] but but it that that area had doubled in size over the eight months wow and what he's suggesting is maybe there's um well let me let me quote sir professor Herrick the most reasonable interpretation of that data is that there has been an eruption that has come up

[00:11:18] and changed the shape of the vent and filled it so it looks like a lava lake that has spilled up to near the rim and in fact he's uh he's goes on to say on earth there's never

[00:11:32] been as far as I know a volcanic event that is changed by multiple kilometers without an eruption occurring somewhere nearby yeah so I don't think that's probably fair enough and what he's suggesting oh there is a there is another aspect to this because apparently there's a

[00:11:50] an area in the radar images that's near the vent in fact downstream from the vent that's brighter in the later images and that suggests a rougher surface bright usually means rough when you're looking at radar images and professor Herrick says this suggests that perhaps a new flow of

[00:12:08] lava has formed but he said there was a caveat with that because they can't actually rule out the possibility that that particular observation was an artifact of the viewing end which is different

[00:12:22] between the two but that's been ruled out for the main observation okay it's yeah so it's quite extraordinary are we you know if this is the case and it seems pretty obvious that it is

[00:12:35] with volcanic activity on venus what's causing the volcanic activity is it tectonics because they don't have tectonics on mars we do on earth and that's got a lot to do with what is happening

[00:12:47] beneath the surface and moving all that magma around what's the story on venus so I think you and I um probably a year or so ago Andrew had a story that was again from Magellan data uh and it

[00:13:03] was looking at sort of linear features on the surface of Mars um and this is different it wasn't recording any changes or anything but it was suggesting that the particular layout of these features could be due to low-level tectonic activity that you were getting perhaps some

[00:13:22] sort of division into crustal plates now as we as as we get to know did I say Mars there when I'm at venus caravan anyway well talking about Mars I'm talking about venus um so the um that these

[00:13:36] crustal plates may actually be moving and I guess all of this is going to be food for thought yeah or the veritas mission which you and I have talked about um which is a NASA mission

[00:13:51] there's also a an e-submission called Envision which I think both of those will have much more detailed radar capabilities uh they apparently they're not scheduled for launch until the early 2030s

[00:14:07] was that thunder I just heard yes wow yeah she's thunder it's quite loud outside so we've got the whole thing today yeah we were the wrong place the wrong time at a thunderstorm it could get

[00:14:20] any better wow so it's uh yeah that that veritas mission unfortunately has been pushed back and probably won't be launched until oh 2028 at the earliest but probably 2031 is the year they're looking at now so we're gonna have to be very patient to get the backup data

[00:14:41] but gee and you know the other pity about venus is we can't see a damn thing we just wouldn't it be great if we could actually do what we do on um on mars and have an all-mars

[00:14:53] spacecraft that can take high resolution photos but all we get all we get is cloud yes well that's right the clouds themselves are really interesting though you know with their sulfuric acid aerosols

[00:15:05] and things like that yeah but but you're right um I should I just putting a plug for um a former colleague of mine who sadly no longer with us David Allen he used the Anglo-Australian telescope at Cunabara, Brunney, New South Wales though

[00:15:21] I used to be a strong marine charge of uh back in probably the early 1990s maybe 1980s late 1980s but he actually used an infrared camera on that telescope to demonstrate that he could detect the surface of venus in infrared radiation

[00:15:41] but I think it was more of a glimpse than anything just a region of the clouds where the where the transparency was a bit higher than it is elsewhere but got an infrared signal that

[00:15:52] could only have been the surface because of its temperature okay all right well we'll watch with interest and uh we will hopefully learn more about the volcanic activity of venus in the not too distant future this is Space Nuts with Andrew Dunkley and Professor Fred Watson

[00:16:10] let's take a short break from the show to talk about our sponsor NordVPN now I've told you about NordVPN many times I use them myself in fact I use everything that they offer at the moment

[00:16:22] I did a bit of an upgrade the other day and very very happy indeed I love it smart thinking because I don't have to you know worry about remembering passwords and if I go to a website that

[00:16:35] has a username and password that I haven't used for a while and I can't remember it it automatically is ready to give me the information so it's really fantastic that way and it works on my Windows machine uh it works on my iPhone it works on my iPad

[00:16:51] I don't have to think about it it is the world's leading virtual private network by reputation and has been backed by many many big corporations that you know very well they use advanced security and privacy features that protect you from online threats

[00:17:09] and they've announced the launch of their latest version of NordVPN which is in the form of an app for Windows which I'm experienced with now you can even integrate it with your Windows

[00:17:20] computer so that when you log onto the computer you don't have to sign into Nord you can get Windows to do it for you so they they integrate really really well there are quick connect buttons

[00:17:32] in the system and Nord is committed to use the privacy and security it's very much evident in their strict no-log policies and they don't collect and store your data either if you're

[00:17:43] worried about that so have a go and check it out because it's it's trusted by millions of users around the world including me and it's a robust system and they've got servers in over 60 countries

[00:17:58] and I've tested the speed with my Nord VPN and I'm getting lightning speeds on my devices I pay for a 50-20 plan on my home computer and the other day through Nord I got 52 megapits

[00:18:12] per second download which you know it's above what I was paying for so pretty impressive stuff now if you'd like to take advantage of the offer that's available to SpaceNuts listeners it's really simple just go to NordVPN.com slash SpaceNuts that's NordVPN.com slash SpaceNuts

[00:18:32] click on the button get the deal you won't be disappointed now back to the show 0G and I feel fine. SpaceNuts. Okay Fred let's move on from volcanoes on Venus to asteroids that have very interesting things that we're learning including the the one that had a return sample

[00:18:55] brought back to Earth it's been analysed and that is RyuGu and I did see a lot of these news stories popping up this morning because they've made another pretty startling discovery in this regard

[00:19:07] too. That's right I've got the the Nature Communications paper in front of me now it's is titled Uracil in the carbonaceous asteroid 162173 RyuGu and there's a very long list of authors most of whom as you might expect are Japanese names they because it's not all of them but

[00:19:29] most of them because it's a Japanese spacecraft that brought back that sample and maybe I might I might just read the abstract of that paper at least some of it because it's not gobbledygook like so many of these asteroids sorry so many of these research paper abstracts are

[00:19:54] it starts off the pristine sample from near Earth carbonaceous asteroid 162173 RyuGu collected by the Hayabusa 2 spacecraft enabled us to analyse the pristine extraterrestrial material without uncontrolled exposure to the Earth's atmosphere and biosphere and of

[00:20:13] course that's what you get with meteorites Andrea they lie on the surface of the earth yeah and so you can't rule out contamination and so the abstract goes on to say the initial analysis team for the soluble organic matter reported the detector detection of a wide

[00:20:29] variety of organic molecules including racemic amino acids in the RyuGu sample here we report the detection of uracil one of the four nucleobases in ribonucleic acid at RNA yeah in aqueous extract from RyuGu samples and it goes on to look at the details

[00:20:55] and the suggestion is that what we've got here is a component of RNA now RNA is not DNA but it's one of the molecules the sort of enabling molecules that's very important

[00:21:11] living organisms on earth so this amino acid is a bit of a tracer once again that these complex organic molecules were able to form probably in the depths of space in cold molecular clouds and then condense onto primitive asteroids like RyuGu that's one reason why this asteroid was

[00:21:33] chosen for for the mission because it's a carbonaceous asteroid it's probably one of the earliest types of object formed in the as the solar system was forming and it's got this uracil in

[00:21:45] now I'm not an organic chemist by any means but I think it's a pretty exciting result just a caveat again there I believe that uracil has also been detected in meteorite samples

[00:21:58] yeah but as I was just saying because meteorites land on the ground and sometimes lie there for quite a long time it can't rule I believe it's also found in the uracil bunny the one that keeps on going

[00:22:19] sorry that was just so awful I had to do it oh my gosh yeah the dad jokes are sick yeah we did a whole bunch of them on the radio the other day and I haven't I haven't stopped

[00:22:28] hearing about it because it was the answer to my quiz question the origin of dad jokes all right okay they date way back to 1987 who was the original dad though well that's a thing yeah they were defined in 1987 I'm sure they

[00:22:46] existed a lot further back than that yeah yeah but what a great what a great coming back from due to uracil to uracil yeah a great result very very interesting this if our listeners and watchers want to

[00:23:04] catch up a little bit on it there is a really interesting article on the conversation by Trevor Ireland who's a professor of the School of Earth and Environmental Scientist in the University of Queensland and so his article really captures the excitement of that and

[00:23:21] it gives all the details for anybody who's interested in organic chemistry and he also has a link to the original paper as well I suppose to the question that comes up with a discovery like this in the

[00:23:30] previous discoveries as a consequence of an analysis of the samples from RyuGu is what does it mean for planets like ours that have advanced life is this like you know would you call RyuGu like

[00:23:45] a seed pod or something like that and asteroids like it have perhaps been responsible for creating the opportunity for life to exist on this and perhaps other planets yep I think that's a really good analogy quite extraordinary actually there's a little

[00:24:02] post-cript here which I meant to mention and it's Trevor Ireland's paper that's reminded me of it so amino acids which if I understand things correctly go towards proteins those amino acids that are produced by life processes on earth there's a thing let me just

[00:24:30] step back there's a thing called chirality do you know about this we had a comment whether I've ever talked about this before but I've always thought it was really interesting knowing my memory

[00:24:38] we probably have but it's not coming through it's about the way complex molecules are put together and many of these so the amino acids can be put together in either a left-handed way or a right

[00:24:54] handed way it's just the you know the structure of the molecules okay think about your left hand in your right hand they're symmetric and some of these molecules are so you can put them together

[00:25:06] either one way and it's called left-handed or right-handed that is the chirality chirality is whether it's left or right-handed and all amino acids produced by life processes on earth are left handed wow however the ones that come from the RyuGu samples are equally both right-handed

[00:25:29] and left-handed and so what Trevor Allen draws from this I think it's probably you know the view of experts in this field it indicates the molecules found on RyuGu are not signs of life because

[00:25:43] they've got this equal distribution of left and right handed if you found they were all left-handed like life is on earth yeah maybe you'd start thinking a bit more deeply about it

[00:25:56] yeah I say you're telling me I was wrong actually but anyway no no I'm not no because no the seed pods they're not they're not seed pods of life they're seed pods of the of the you know the

[00:26:07] building the building blocks of life that way so it's a case of hits to earth just add water oh yeah that's right and a few other complex view of the things too just you know to chuck

[00:26:21] into the mix yeah I think the creator reminds me of my childhood we just I'd get a jar and I just put stuff in it to see what happens nearly blew myself up one day because I added honey to powdered

[00:26:34] chlorine and it turned into a blasted bomb I got picked it up and the jar was really hot almost burning hot and I didn't know what it was doing at the time I was an idiot but yeah I guess that's

[00:26:53] that's how these things happen and that's possibly our life evolved on this planet just some kind of weird mix that was just right yes accidental reactions there's I mean people have talked about this in detail and that's certainly part of the story but another part that I've always

[00:27:12] found interested is interesting in you need sort of fatty molecules as well lipids because what you want is to have these fatty molecules that can provide a kind of envelope in other words a cell

[00:27:28] wall within which these reactions can take place so that you actually confine them they're not just reactions taking place in a in an amorphous blob of something you've got them confined within a cell and that's you know the way people think maybe cells originated speaking of which I

[00:27:47] saw an article last week that suggested that by 2050 more than 50% of the world's population will be obese I know that's got nothing to do with RyuGoo but you were talking about fatty molecules and just popped into my head that's quite a staggering statistic when you think about it

[00:28:05] it is yes and they've released a report on the data and suggested that the world needs to do something about it and that's probably true but can we expect more revelations from RyuGoo going

[00:28:19] forward I think yeah I think we probably can I think we should watch this space there's I don't think they're gonna find DNA in it or anything like that wouldn't that be a shock that would be

[00:28:30] a shock yes quite extraordinary all right more to come on RyuGoo but as Fred said if you want to chase that story up it's on the conversation.com website three two one space nuts oh gosh this

[00:28:48] we're traveling along at a rate of knots Fred um but it is question time we've got uh three questions to deal with today two audio questions and a text question uh we will firstly hear from

[00:29:01] Renny who is asking us about visible light energy hi this is Renny Trow from West Hills California thank you for answering my last question I have another one that's been bothering me the question

[00:29:19] has to do with the visible light coming out of the sun if at all possible in simple terms what creates these light particles and how do these particles have enough energy to travel across the

[00:29:33] universe to an observer's eye and why can't we mimic this energy to propel our rockets that would carry our robotic space explorers wow that's a that's a lot that's a big question um so I

[00:29:49] suppose in a couple of parts what creates the light particles initially and and that's a it's a fantastic question um which has a pretty neat answer uh Andrew the sun um well the sun yeah so

[00:30:06] deep in the sun's core and this is way below you know the levels that we can see um let's let's look at the uh what we can see the sun what we what we see is something called the photosphere

[00:30:18] uh which is essentially the the the kind of boundary of the sun beyond below which you can't see yeah now the sun's a ball of gas uh but the photosphere is uh that that almost what you might

[00:30:32] call the light emitting surface it's it's where the radiation actually escapes from this ball of gas but that radiation has had a long and tumultuous journey because deep in the sun's interior that's the core it's where the nuclear reactions are taking place that power the sun

[00:30:51] and as you know the main reaction is turning hydrogen into helium and that process actually gives you a slight mass loss if I remember rightly the sun loses is it six million

[00:31:05] tons per second of mass it's something like that it sounds like a lot it is yes and when you you know when you multiply that by uh c squared the speed of light squared to get the energy

[00:31:16] loss you could see that there's a huge amount of energy being created yeah and that energy is in the form of electromagnetic electromagnetic radiation in fact it's gamma rays it's high energy gamma

[00:31:27] rays that are created in the interior of the sun um but the density there is so high that a gamma ray photon emitted by a nuclear reaction doesn't get very far before it hits something else and then it's scattered off and that process repeatedly happens throughout the

[00:31:48] sun's interior uh the photons are getting scattered from other other um nuclei atomic nuclei and eventually from other atoms uh and that scattering reduces their energy so as the sun as the radiation gets finally to the surface of the sun it's coming out as visible light

[00:32:11] there are gamma rays as well but they're at a much lower level the predominant radiation is visible light but this is the the great thing Andrew um that process that scattering process takes in the region of 200 000 years yeah that's incredible and it's it is um i in fact

[00:32:34] i think i think i wrote about it in one of the books i can't remember which one uh and i i'll check the best value it's really a guess people people are it's an estimate not so much a guess

[00:32:44] a guesstimate perhaps is the right word um somewhere between 170 000 and a million years is what what the figure is so it's in the region does that actually mean the light hitting us now

[00:32:56] was created before the dawn of humanity uh well it means it means it's our distant ancestors tell him yes that's right you know it's not not i think we we place kind of recognizable humans

[00:33:12] at about two million years ago right something like that's pretty close and it may even be more than that so it is pretty close um what you know it's it's interesting isn't it that it takes

[00:33:24] maybe two or three hundred thousand years for light to get from the center of the sun to the edge and then eight minutes to get that 150 million kilometers to us um so yes it's a fascinating

[00:33:36] thing so that's and that's how the radiation kind of is created René um you wanted to know how does it travel so far once it gets out and that's because excuse me light is excuse me

[00:33:52] electromagnetic radiation doesn't have a limit to how far it will go um what limits it in in realities you know the intensity eventually would get so low that it's uh undetectable by any means

[00:34:05] that we might have access to but it goes on forever unlike um the two fundamental forces which relate to atoms which only have a very short range the stronger weak nuclear forces the two other fundamental forces gravitation and electromagnetic radiation effectively go

[00:34:23] infinitely but at very low levels because it's an inverse square rule it means that when it goes twice as far its intensity drops by four four times i have another theory René if

[00:34:37] you're in jail for 200 000 years you want to get as far away as you can when you get out yeah that's that's a good analogy though and how do we harness this power to uh you know reach

[00:34:51] speeds that will get us uh traveling into the cosmos i think um was this last question it was it was how do we how do we create uh artificial sunlight i guess to uh to propel

[00:35:03] solar sands along and that's exactly what the breakthrough star shop project's all about it's using uh he's trying to demonstrate the idea of using lasers to uh to propel a solar sail vehicle to proximate centauri or point two light years away yeah so people are thinking

[00:35:21] about it René it's uh it's a great question fabulous thanks René hope we answered it adequately let's move on to our next question from Fenton yeah hello Frédéric

[00:35:34] this is Fenton calling you from Minnesota in the U.S. I would mention off the top that I really like your show because you can hear people questions from many different countries i think that's really great. Henry here's my question it's anti-matter time so there is more matter

[00:35:56] than anti-matter in the universe how much more what are the relative amounts of anti-matter and matter so question number two is it conceivable that there's another solar system someplace that's made of anti-matter

[00:36:18] question number three uh what would happen if we tried to shake hands with an anti-matter person okay thanks i enjoy it hope you like the question bye bye love the question thank you Fenton so yeah there's more matter than anti-matter he suggests how much more

[00:36:39] um i'm sorry i can't remember the fractions but it's overwhelmingly um matter is the the dominant by very large quantities the dominant type of matter in our part of the universe not just the solar system but probably our whole galaxy and maybe even our

[00:37:00] our local group and the the local cluster of galaxies it's all matter and by the way just the reminder that anti-matter is just like matter but the the subatomic particles have the opposite charge they're left handed yeah they're left handed except it's a bit different so let's

[00:37:20] just forget that you're right that's molecules um so they've got the opposite electrical charge so electrons have an anti-matter equivalent called positrons uh which have a positive electronic charge a positive charge to them so um uh we we do know that anti-matter is created in some

[00:37:43] nuclear reactions and i read a story quite recently from one of the accelerators and i don't can't remember whether it was the large andron collider or one of the accelerators in the united states but they have an anti-matter factory which produces tiny tiny amounts

[00:38:01] of this stuff because you know you can't let it touch matter because the two annihilate with the production of the high-energy photon um once again gamma rays and so that's actually one

[00:38:14] of the ways that people look for anti-matter deep in the universe because if you have matter and anti-matter annihilating you get a gamma ray with a particular spectrum signal it's got a particular energy um and i'm not sure you know whether there's evidence of cause of anti-matter

[00:38:33] in some galaxies for example but that's the way that scientists look for it so uh Fenton's question about whether it could be another solar system yeah made of anti-matter is not it's not it's not ruled out um we simply don't know there may be other parts of the

[00:38:51] universe which have a bigger concentration of matter of anti-matter than matter um it may well be unlikely because at one point the universe was falling in one place and i should just add

[00:39:04] that it's a puzzle uh actually as to why this is something that troubles cosmologists why the universe when it was created why there was an imbalance a slight imbalance between matter and anti-matter uh because if there'd been a perfect match of matter and anti-matter in the

[00:39:23] early universe then the universe would have been completely made of energy uh there wouldn't have been any matter at all because it would all have annihilated if there was a perfect match one to the other in that case Fred it wouldn't matter oh

[00:39:40] uh are they getting better as you go yeah i'm small i'm smoldering today certainly not on fire well uh just don't annihilate yourself with the someone else will do that yes um yeah they might anyway uh so uh yes so there could be other regions of the

[00:40:02] universe that made of anti-matter but we don't know okay uh and yeah if you shake hands with somebody you're in big trouble so uh so an anti-matter person walks in your doorway there behind

[00:40:11] you andrew keep well away keep well yeah do not touch although they probably get destroyed by anything they touched wouldn't they well the atmosphere would destroy them already so we're

[00:40:22] pretty safe so yeah thank you okay thank you fenton and uh hope you're well in minnesota and i hope it's getting warmer uh one final question this one comes from emma in brisbane uh hi fred and

[00:40:36] andrew i love your podcast i have a question regarding the speed of light never had one of those before uh what is the slowest light can travel through a medium could i go faster than

[00:40:46] light in that medium uh how would i achieve this run fast uh would i then be able to say that i've gone faster than light i wouldn't be able to say that i've gone faster than the maximum speed of

[00:40:58] light but i would have gone faster than light at a speed i need help finishing my bucket list thanks emma um what is the slowest the slowest that light can travel and i did mention a week or

[00:41:13] two ago that there have been some experiments done and they've actually managed to stop light then dead in its tracks so everybody has now achieved faster than life speed that's right

[00:41:25] basically true exactly right um it so just to clarify that it's the speed of light in a vacuum that's the ultimate speed limit 300 000 kilometers per second so that's the one you can never go

[00:41:40] faster but as soon as light passes through glass or water or any transparent medium it slows down by a significant amount and that's why we have the phenomenon of refraction because the light is is changing its speed um so um but yes you're absolutely right andrew modern physics

[00:41:59] some modern physics experiments uh with laser light uh and really quite interesting media that they're passing the light through i think what you're doing is trying to trap photons among subatomic particles i'm not directly across that but i i do recall that there is you know

[00:42:21] that the record has been dropping over the last few years that light has been traveling at a few centimeters per second rather than a few few hundred thousand kilometers per second yeah uh and and eventually somebody's managed to create a stationary photon uh so uh yes everybody has

[00:42:39] traveled faster than the speed of light so you can cross that off your bucket list then yeah more great to you yep let me just you go to love big brisbane yes indeed yeah lovely city i love

[00:42:48] brisbane hate their football team but love brisbane um actually they've got two football teams now because we've got a new one started this year it's uh they've won they've won their first

[00:42:57] three games as it turns out the dolphins so uh they're off to a flying start uh thank you uh reny uh thank you phantom thank you emma and uh that brings us to the end of a show don't uh

[00:43:10] our show this week and don't forget to visit our website because that's where you can send us questions click on the AMA tab uh where you can send us text or audio questions or just

[00:43:18] click on the send us your voice message on the right hand side and don't forget to tell us who you are where you're from and how many dogs you own and what they eat for breakfast we want

[00:43:28] to know everything uh you can also visit the astronomy daily newsletter on our website the space nuts shop is there and if you want to learn about how to support space nuts whether

[00:43:40] it's to buy us a cup of coffee or to go the whole hog and become a patron now you can do that too and thank you uh to our patrons who um are such wonderful supporters of the podcast we

[00:43:53] so much appreciate it fred uh thank you so much we're going to wrap it up and we'll catch you on the very next episode sounds great undrew all the best and thanks again for a great show stay

[00:44:05] dry and avoid politicians in canberra at all costs no they're good people yeah thanks fred fred what's an astronomer at large and thanks to hu in the studio who got us uh out live at the

[00:44:19] very last second this morning i didn't give him more than a moment's notice so well done hu retrained and from me andrew definitely andrew directly thanks for your company we look forward to your company again on the next episode of space nuts bye bye

[00:44:43] spotify i heart radio or your favorite podcast player you can also stream on demand at bite.com this has been another quality podcast production from bites.com