165: Twinkle Twinkle Very Old Star

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In fifteen seconds guidance journal and nine technician sequence spence nuts three to to space feels good hello and thank you for joining us on the space and that's podcast cast <hes> my name's andrew dunkley your host joining me as always professor fred watson astronomer <unk> afraid. Did i andrew. How are you sir all right. Thanks good to talk to you as always yes l. Now today we're going to try and tackle a few questions a little lighter about the big rip wormholes and an interesting sort of local one <hes> about wi fi interference from <hes> satellite intimate in in regard to the square kilometer awry. That's a really interesting question because they're alive or each other really <hes> but i got to talk about the oldest star in the we know universe that may have been discovered so that is exciting and long-haul space travel may be impossible because of brian damage now. I'm i'm assuming the brian damage happens after the long haul travellers started all we are suffering brian damage because we're thinking of going. I'm not sure which but we'll get to that a little lighter first of all fred this ancient star <hes> could be the oldest one ever discovered. Yes that's right the something of a rice going on with <hes> with this in the world of astronomy a damn australia is pretty well actually so i can remember back doc in the nineteen eighties when you know every week seemed we discovered the more distant objects will usually sells until the the record for the most distant object known to humankind humankind kept tumbling and a little bit like that with the oldest star. We say these things come up and then few months later. There's another one that's even older. It's mick jagger by the way i know a few role of yeah so the just to clarify we will one day be able to say well. Let me let me start. Let again when we look deep into the sky as you own. All our listeners know must've anyway euros looking back in time <hes> ah so you can imagine a situation where you're going to be looking back at really answering galaxies in fact there are so many she can see individual styles because of things like like gravitational lenzing which means that you are seeing stars very early. The history of the universe but we're talking about here is not bad. It's not the looking back in time. I'm tripping trick or trip which way you like it. It's not looking back in time trick. It is the ability to see stars in our neighborhood and which have evidence of being ancient and the way you pick that out is by initially is by <unk> style having strange colors and that's how the australian <hes> <unk> telescope run by strengthening national elite investigate siding spring observatory. They couldn't have them scott gripe for doing that because he got a whole array of filters can take images of the sky really detailed images of the sky looking through the different filters that allows scientists to say while he is a candidate for an all star but that's not enough what you then have to do is follow up with a big telescope one that will allow you to look at the spectrum of the style that the radio spectrum trim and to see this bach owed of information superimposed on the spectrum and it abaco really good analogy because when we look at the spectrum action style is exactly what we see the black lines on the barcode equate to what we call absorption lines essentially the thing bring excuse me fingerprints of different talents in the styles atmosphere so the most abundant element in the atmosphere ecstasies hydrogen because that's what the universality astounded offense and what happened in the very early universe there was nothing else actually was hailed as well but hot hydrogen helium were the only do things substantially that were there in the universe the tracks elements in a couple of other things that that's not pull to this context and the first generation of stars earliest wants to full would have basically not much more than hydrogen in spectrum probably been a failure because it was in the interiors of those stars that the other elements full <unk> the oxygen the cabin the iron all of all those things have full did site styles that first generation of stars would give rise to some of these heavier elements then because we believe the first generation towns were very massive they lived short lives measured intensive millions of years rather than billions of years like some at those massive styles would all have ended in a supernova explosion which blows the daybreak from which they have made at least atmosphere that debbie three from which the atmosphere is made out into the wild blue yonder which this guy's means the interstellar medium that the space between the stars what does kazan provides rule materials for subsequent generations of status to full house if they fade upon themselves and recreate accordingly so h generation of styles builds on what went before it and atmospheres are enriched by elise atoms that have been created in the previous previous generations of stars so if you want to find a very old star what you need to look for a something that's got very little in it other than other than hydrogen and helium very little spectrum and that's basically what has happened with this particular style of gotta tell you what it's called od audrey <unk> crack six zero five four zero point one eight <unk> full three to three point one forgot that these prefixes s._m._s. so i gotta side again because it's just so up all the rest rest of it as a message just stunts sky scott probably so so that basically what we'd cup and that particular da whose name i'm not going to say again turns out to have virtually nothing in it other than hydrogen leland the one thing that isn't it which is kind of gay just to hold his <unk>. This is really the yardstick by which as old styles adjudged what is in it is iron and i am content as a measure of how earliest <hes> has appeared in the history of the the universe. This one has a nine content of one pop a fifty billion so it's very very spouse in iran dan in fact some people are describing as anemic which is very nice chemists resigned deficiency very anaemic style end of its iron content is record low that state the bottom line so that swap the published paper will say it's got a vitamin to describe describe them as ultra metal poor these they started a metal by the way to donovan is everything except tien-shan helium until that sounds bizarre <hes> <hes> but <hes> we think of even oxygen in combat and things like that as metals but the metal in the normal sense of the word at that that aside <hes> this is very very poor in on that places it in the record books as being at the moment they always known stop <unk> but what is this space in a couple of months of even older i suppose where is it do. We can we point. It's actually yes it. It's tim the milky way galaxy. It's actually in the halo of our galaxy that made that not the disk of the galaxy but there is a spherical. The family rarefied distribution of stars around the galaxy. We call it the halo that's where it is is about thirty five thousand light years away as the crow flies so <unk> a rather distant object but still in our galaxy and of great interest because it's an icon disalow nice coming from i think it's the law throughout thomas norlander who's from <hes> i think he's from the australian national university <hes> he <hes> he has this lovely quotation. Which is that's amount of iron one one party in fifty billion. It's like one drop of water olympic swimming swimming pool not a glass of water but one drop of water in olympics in class. Yea certainly isn't a name a star across they probably others at the <hes> <hes> this one's in our own system but <hes> could they be all the ones in other galaxies that we might never be able to catch onto. Yes that's true. I mean you know i guess we could look for these things also in <hes> nearest neighbour galaxies. I'm like at the andromeda galaxy <hes> it said it it is possible that when we get to the next generation have <unk> telescopes <unk> sorry the extremely large telescopes <hes> we will find that we can <unk> nearby by galaxy <unk> extent that we can do the measurement sell them and you can bet your life that they'll be really answered styles as well these styles. Are you know the styles that a a relatively small compared with the giants of the universe until they've been very stops with bending the hydrogen fuel. That's why there's still going strong after thirteen probably thirty billion years or so she that's a long time isn't it. I mean it is not to get your head around a stabbing banging existence for that long but then again the universe has been in existence for longer. So why are we surprised so that's the story of j. one six zero five four zero point one on its one four four three to three point one you do it yeah. Did you yeah so sadly it's not one of the first generation of styles but it probably belongs to the second generation the ones that were formed from the debris daybreak the generations very good fascinating all right bye but watch this space is for is set for it says because probably tell you about an older one in a couple of weeks time. You're listening to space nuts. Let's andrew dunkley fred watson parfait week ago spends nuts afraid a lot of people people have asked us about long haul travel and we're going to actually tackle <hes> one of those kinds of questions a little lighter <hes>. How can we do this. We talk the the the other day about <hes> long-haul travel and spice using perhaps <hes> solar sails <hes> but the the reality of sending people people long distance versus a small spacecraft is very very different venture and we certainly don't have the technology to fold space which is certainly something that is being considered in the realm of science fiction so if we're gonna send people long distance we're going to have to do it the old fashioned and why and now starting to look like that might be more difficult than we first thought yes that's right. I mean i think come come. It's fair to say that <hes> of the technological problems that face us intent of getting people for example two miles the radiation issue is the baps the most difficult to solve yet. You can provide your astronauts with an atmosphere. You can probably build a spacecraft that will <hes> will mimic the gravity by rotation by centrifugal fullest all of those do things but what you can't do easily without lots of shielding as stop the the subatomic particles getting through the skin of the spice guy and it it particularly pertains delong holes buys fly exactly as you say so just looking at what we've done in humans bags flags so far most of the experience ab- astronauts and you know the medicine that is it's been done with astronauts relate to scientists either in the international space station or its predecessors like beer in the policies and things like that those are long long duration spaceflight but the very much in the local environment at all of those astronauts who protected to allow <unk> by the natives favor of the earth they basically the magnetic shielding the s. The s magnetism builds around the the planet so certainly the international space station. He's well within so i'm traveled to the moon of course meant astronauts left out that protective detectives zone around the us but that direction was not that much more than a week you know of the older of seven into ten days and that means that dosages of the subatomic particles were relatively low. Oh i'm so we you know we don't have any direct experience of plunking people in the middle of nowhere and watch what happens when they radiated by two specific sources one is the solar wind you know this wind of subatomic particles <hes> ah basically electrons protons electrons from the some but the other really may be more dangerous one as the in the what's called the cosmic ray flux of cosmic rays actually come from alexey another galaxies that not from the sun itself their background subatomic particles that come from a source is actually the not well defined. You know that they are we're within our galaxy probably a lot of stuff that results from a neutral stuff that results from bass black holes from supernova all of that stuff is floating around and we are irradiated where they actually cosmic rays were would i think they will i measured before the first world war aw by scientists using balloons to see you know to to record what happened so the cosmic ray flux and particularly the high energy cosmic cosmic ray flux is something that we i guess recognized for a long time as putting long-haul astronauts at risk but now some work has been done by scientists actually they're both the two scientists who publish this work they both the university of california irvine and they both <hes> basically involved with radiation oncology that says specialism and it's work they have done in looking at it's relatively low doses the kind of things that you might find you know irradiate astronauts traveling to mas but of alone periods of time and of course astronauts they've used my says <hes> basically as as substitutes had as we do so they did this six months they basically exposed mice to low level neutron radiation for six months so then look at the at the neurons in the brains in particular laser the salads that essentially still memories and things of that sort and concluded. It's not a two while they concluded that they worked great while ago fine structure in the neurons iran's has been damaged. Maybe some of the connections have as well so the there were clearly you know that studies of course after after the irradiation tested device to to find out in behavioral tubs how so how how they were coping this they say the outcome about beheshti studies demonstrated that mice exposed to neutrons for six months at trouble with learning adapting acting installing memories for example these mice were less likely to be interested in a new toy that being placed in that testing compared with a toy that had already seen before the control mice the other hand would take much more time to explode in utility than the old toy similar tests but what was was also really interesting is that the irradiated mice demonstrated a social problems much more likely to avoid <unk> social interactions at difficulty dissociating forgetting adverse event that happened in the past the the space radiation induced changes ages that increased anxiety levels so they essentially believe that they've replicated what would happen to human huma brian in spice and they believe that they could this could significantly impact once again quoting network could significantly impact the ability of astronauts responded under distress or in unexpected situations and what they've done wrong. They kind of you know translate those findings into what that might mean in human terms. They say we estimate in a crew of five astronauts traveling to mazda back we would expect to at least one member to display severe via deficits in cognitive function by the time they returned to us thaddeus scary. Very scary could be all of them. Couldn't it says statistically one in five but you could actually go the other way. Yeah that's right. They qualify qualify that by saying. This is just one study. The results must be replicated but it does raise the sobering possibility. The galactic cosmic radiation exposure asia represents a significant obstacle today's space travel and once again our coal on science fiction to provide the answer and in the movie resigns. They wrap their heads in aluminium foil that that there it is. Why did they think of that. What is going uh on if you want to follow up on this the u._s. Addition of the <unk> compensation astronauts brands is subject to long lasting damage due to lotus does the conversation the station website is one of the best online facilities really getting down and dirty into some deep meaningful staff. I go go to the website so often. There's always something interesting and they really doing a great in-depth analysis. It's fantastic absolutely relate largely because you actually answered two or three questions that were formulating in my mind while you were talking because i was going to say you know we're protected by the magnetosphere. We don't go out beyond much except to go to the moon and back and we were only at their awake. So why haven't we tested along whole trip sending someone at for months and then coming back over losing so it's a two month trip justice say what it's like probably a good thing we didn't yeah i. I think that's right so that's another problem. We need to solve. Yeah i mean. I think you know you just have to send about that with some aluminium. Uh <unk> aluminium foil just wrap that stuff around here. It is in a good sorry which movie was in the movie movie signs they will. They silly lally medium hat said that the island's couldn't read their minds sir yeah but you know it will protect you from all that other stuff as as well good that put it in microwave oven on the phone and i might mention please as forgive me for forgetting your nine but we got a message on facebook the other day from someone who is looking at becoming a doctor but specializing in space ice and wanted us to actually talk about some of the afflictions that astronauts might face. Oh she'll be fascinated to have heard that particular problem. That's a new problem but there how many many others likely issue with <hes> with damage to the is refugee caused muscle wastage is a big issue as well as just the list is rather along. Isn't it fred. It is specs petain's alive and well. It's a career that i think in the in the spice while it was probably pretty competitive to get into about. It's <hes> yeah it it. It's very very interesting. Research is being done to the melting well worth pursuing because again at night people going forward board because this is just going to get bigger and bigger imagine okay you're listening to the space nuts podcast with nutty professor for watson and the nuttier the andrew dunkley space nuts now fred to the question question what's board <hes> which is way we put all questions except it's virtual and we we're gonna try and tackle a few today and hopefully get the truth without interruption from one man. Do the cat who is in your presence right now so hopefully you'll silo but <hes> jim carrey on. It's not like grandchildren walking on your tell you that much now first question comes from a west from wiz smith highways if the universe is infinite all. We really don't know how big it is. How can we categorically say there's not auden enough matter for a big crunch with the discovery of new galaxies blackhall's etc and we don't completely understand doc energy. Oh doc matter for that matter <hes> who's to say that the universe went stop expanding and reversed itself it starts at some point respectfully with smith now we have kind of touched on this before but but <hes> it is worth sort of looking into that <hes> potential crunch i mean when i was a kid that was the the belief that the universe would expand like a like a rubber balloon and ridge boy where it will go and crush back in on itself an author was going to happen the next day but now we think it's not gonna do that at all but they are. Obviously people like me who wonder why it went well. It's a great thing you talk to <hes> to to to to ask. Let me just congress is saying this in the i think we've said this before about a brunch. Mitts who was is one of the co discoverers of energy that the accelerated expansion of the universe he always used to refer to the the big crunch has gone up gabe <hes> which which is the big bang backwards out. Get is the the advocate boring that one is a good one but look wise. He's right on the money and we can't say categorically that there is not enough massive for big crunch because of you know all we can say is is the uh we look within the observable universe now. The expansion is accelerating their horizons to the universe band which we can't see and things like the cosmic microwave background radiation. That's one of them stuff stuff like that as well but the fundamental reasons why we can't see the whole universe and indeed we don't know whether there is a whole universe we we eat may be infinite is west suggests one of the things that has been suggested. Is that what we see in our accelerated expansion is just one little blob bob a much much bigger universe. Which is you know somebody <unk> which are in a state of expansion some probably in a state of slowing down on expansion as as distinct from accelerating expansion <hes> but we can't detect those and so you've got to you know whatever you make a statement about what the universe might do abilities caveats to it <hes> the evidence at the moment is that sunday's vows the universe we can observe is concerned it is it is expanding more rapidly than it was five billion years ago so that's all all we can say we can't rule out a big crunch because you know exactly the reasons that wednesday suggested so. I can't rule out a big papa no we we come or a big rip. Whatever look what we it's white scientists particularly cosmology symptoms. They sometimes sound wishy washy because he's saying well. You know the best information we have at the moment is this this and this but that really is only say it econ sign anything categorically berkeley about a big crunch but stands what we're saying is. The expansion is ongoing and accelerating. That's correct so that's taught we know definitively but we don't know categorically now the essay next next taiwa the <hes> the ways hopefully that will help you sleep. It not now <hes> moving right along. I've been wondering a lot about half. Humans will travel to other solar all the systems <hes> while i wanted brian so when meta and i know that the regular rocket y y cut it would take thousands of years to get at i've heard <hes> people talk about wormholes and all same kind of odd the whole idea my question to you is is there any scientific backing the worm halls exist and and if there is is it a possible maine's of transportation as technology gets better in the next few hundred thousand years sincerely western minds oregon u._s._a. Thanks western austin went holes. Yeah no this you know there are theoretical entity but they come completely without any evidence of a you know the practical nature the was so in the seventies when people were looking at the physics of black holes it was realized is that you could you could <unk> equations. You could just reverse the sign of time if you've got negative time <hes> the physical <unk> seem to work and you end up with white hills rather than black holes. A dentist suggestion was made that if you've got you know to these things back to back whether they were wide tells a black holes might fulda web hall which essentially linked unrelated parts of the universe but there's no observational evidence whatsoever for this an even if the was they extremities of gravitational distortion that you get anywhere near a black hole a such that it's it's very hard to see any technology in the next ten thousand years probably the code of conduct so my guess is that we are stuck with conventional prevention methods they might however allow us to do interstellar travel bowl rapidly than the current regime of chemical rockets sits at which really made for the nearest style. He's talking about sixty thousand years of slow but if he can augment that with light sale technology under essentially projects looking at that <hes> including me we spoke about last week by the way not reminds me. We were gonna ed what the big news item was about did put it on facebook and i and i must confess a little bit of my reaction. Action was a bit all all i were announcing was that they did it and it worked any work but they actually monies to steer and in fact to put the spacecraft into a high robot which you know it's it is quite big news yeti city so it's possible that ally mando yeah mondays. It's big not actually if you go. The furniture is just about loud. You know anyway so like cell technologies. Oh jeez promising in terms of certainly would small spacecraft accelerating things to a significant fraction of the speed of lines until there is this a project breakthrough star shells which is an initiative of the russian billionaire yuri milner donna funded by your email which is to look at the possibilities of sending a very small space craft and by small main sentiment olvera thereabouts <hes> to the nearest star proxima centauri with a light sail powered by a laser either on the authority of the c._b._s. Yes that's all doing at. The moment is looking the <unk>. I haven't seen a find where he pulled on that but you can tell that people are thinking of the existed so it may be that the technologies that we could employ but women hos doesn't like what about folding space it in a sense and stats. It's related to him. Also they was a paper which read is probably about twenty thirty years ago now which was published <hes> i think in the u._k. Astronomical journal where somebody looked at the physics of the wolf driving stop track which involves folded bags and very quickly rounded the conclusion that you need more than the entire energy budget of the universe to make it work so everybody kinda lost interest after them to understandable okay so probably not western unfortunately no the states. I might find something else else now final question today hi andrew and fred i got i do not dive this time. A first time albert longtime listener wall reading one of the regular manufacturing monthly newsletters who how exciting i came across a story about a western australian minister for original donald development alana mckinnon switching on the national broadband network in australia western australia's midwest for those who died the national broadband broadband network is at high speed internet service and in some areas in remote country. It has to be fed by a wireless signal. I presume the midwest this includes areas just south of the region encompassing lee square kilometer orion other radio astronomy projects so that rise in questions actions in relation to the technologies used for the wireless broadband network which bring advanced technologies remote pharma's given the sky 'sensitive sensitive isn't putting powerful wireless base stations one hundred or two hundred kilometers away potentially a risk. How close is too close. How big is the sign for a billion dollar l. international project. How does the sky deal with noise from such sources. Is there a no fly zone for drains and other industrial oregon cultural aircraft that are mobile sources of our if noise dogs and cats living together who shot j on cain to hear thoughts. That's from justin availble melvin. Thank you yet and you know that's a fantastic question is right on the money and i think just in santa's of he's got some handle on the technology so i can direct him strikes to the <hes> to the whole season it can which is the web page a. which relates exactly to this there is a web page on our website that let's see <hes> department of industry innovation signs one of their web pages called australian radio quiet zone w way and that is all about the essentially the exclusion zone full the <unk> radio frequency interference in the square kilometer array and it's quite extensive that website entree gives details of not just the area that's covered which actually is is more the five hundred kilometers in diameter. It's a large area centered on a point which is about three hundred and fifty kilometres northeast of gerald carrollton which is the radio quiet zone and that is actually covered by a whole lot of legislative regulatory regulatory policy instruments that actually set up the legalities of what you can and can't do that so that they they include things like the midwest radio quiet zone frequency band plan that <unk> frequencies he can operate them the assignment licensing instructions instructions that i think that's all part of the structure in particular at their things like radio communications <unk> plus licenses for satellite phone c._b. Radio <unk> potential devices as well as a radio telescope mineral resource management area. All of these things are already already in place. That's in the zone which is out to seventy kilometers <unk> <unk> out his own beyond that to one hundred fifty kilometers tomatoes and then there's something called the coordination zones which go out to two hundred sixty kilometers radius so you talk about five hundred kilometers all told <unk> quick look italy's when this question came up and of course the the the thing about radio transmissions that are used for communications and things like that. They're very specific frequencies on that big gaps in those frequency bands which are the ones that are interested interesting radio astronomers and that's why these things that have been tallied with one another. I know from talking to astronomers at the murchison jason radio astronomy observatory that one of the problems that they have notwithstanding all this stuff is that the telescopes are so sensitive the <unk> radio interference from reflections from the mood if you've got communication signals which are thousands of kilometers from the telescope they still effectively finding their way to the telescope because of <unk> basically because of reflections from the moon so it. It is a very difficult issue. It's kind of similar you know to the problems we have in optical astronomy where a lot yellowish in yeah yeah but i'm just a suggestion that just how she goes has a website because the details of that need particular how interacts with things like high speed <unk> high-speed road onto the n._b._a. What about the no-fly zones and drawings implying polling places well covered. It's all covered justin at it doesn't mean it will stop stuff from getting discount but at least i've come up with a formula that will reduce the amount of interference in eh them to define the little green men whatever else was at the <hes> in the long term all <hes> an answer to justin's other question a was kristen shifted he shot j._r. He didn't ask that question i just i hope you'll just just huma a andrew. He gets like this giant time happens after i've spent a lot of time in space summers and could be taste better be. It'll probably a lot of time in the space between my e-z <hes> one more thing before we go for it. We have to shout out to our patrons ends again. <hes> fantastic people and the numbers are growing. We now have thirty three patrons who <hes> supporting podcast and we really appreciate them. <hes> <hes> putting up a few dollars each month to to cape is on the national broadband network because it's don expensive but <hes> yeah fantastic. Thank you and don't forget to follow us on facebook. We put a lot of information on our facebook page so do research for the space nets podcast on facebook and follow us and like ass staffan often share with your friends that would be that would be fantastic. <hes> get the word and get a bigger bigger bigger audience because it's good for my ego. <hes> i think fred has always it's fantastic right fan and <hes> look forward to talking to you again very very soon sounds great andrew thank. You have a good weeks fixings u._2. Fred watson astronomer at large and thank you feel company again this week and we will join your next time on another edition office space nuts to the spice nuts podcast subscribe to the podcast on institure or your favorite podcast distributor. This is another gas production from dot com.

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