Nuclear Power in Space, SETI from the Moon & the Hubble Tension Unravelled | Space Nuts:...

WEBVTT
Kind: captions
Language: en

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Hello again. Thank you for joining us.


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This is Space Nuts. My name is Andrew


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Dunley. If you've never heard of Space


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Nuts, where have you been for the last


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10 years? Uh good to have you along if


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you're a first timer and everybody else


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who's been with us for eons. Uh today on


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the show, we will be talking about uh a


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a really interesting and some might


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think scary development, nuclear space


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policies. I don't think they're talking


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about, you know, weapons of mass


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destruction, but they are talking about


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power supply systems. Uh we're also


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going to look at SETI from the far side


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of the moon because uh that's the best


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place to listen for alien civilizations


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because well, Earth is very noisy. But


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the far side of the moon, you can't hear


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a thing except the aliens apparently.


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And oh no, the Hubble tension debate is


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siming simmering again. We will get into


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all of that on this uh this episode of


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Space Nuts.


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>> 15 seconds. Guidance is internal. 10 9g


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Ignition sequence start.


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>> Space nuts.


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>> 5 4 3 2 1 2 3 4 5 5 4 3 2 1


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>> Space Nuts.


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>> Astronauts report. It feels good.


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>> And joining us to nuke a few stories is


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Professor Fred Watson, astronomer at


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large. Hello, Fred. Hello, Andrew.


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Lovely to uh hear your voice and see


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your face.


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>> It's my my voice is still a little bit


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down like that. I could do an Elvis song


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as a backing vocal.


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>> You could. Yeah.


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>> Yeah. Way on down.


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>> Well, we So, at the end of the show, you


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definitely need to say thank you very


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much.


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>> Thank you very much.


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>> Uh yeah, it's that's what happens when I


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get a cold. My voice just goes down


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deep. When I first started in radio, I


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did Midnight to Dawns in the days where


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they didn't automate it. Everything


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Everything was live


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>> and around 4 in the morning when I used


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to get really really tired, my voice


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would just naturally go down there and


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and it was really weird because um it


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wasn't my natural voice, but um at the


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moment it's it's enjoying that part of


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the spectrum. So


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>> yes, hopefully it'll get better soon. I


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don't like the feeling, I must say.


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>> No, you wouldn't.


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>> Anyway, we battle on, don't we? No point


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getting all


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>> that's, you know,


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>> we do in space nuts. We come rain or


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shine or absence or whatever, we keep


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going.


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>> We do. Speaking of battling on nuclear


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energy. Uh


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uh this this is a a policy that's just


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been announced by the Pentagon and the


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Department of Energy and they've kind of


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dragged NASA into it. They said, "Hey,


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NASA, we want you to build us a couple


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of power stations, and they've got to be


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nuclear, and they got to be ready by


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2028."


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How about it?


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>> Yeah, that's more or less it. It's a


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six-page policy document. Uh, its title


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is NSTM-3.


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uh which is to direct a parallel and


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mutually reinforcing design uh set of


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design competitions by NASA and the


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defense department to enable and I'm


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quoting here to enable near-term


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demonstration and use of low to midpower


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space reactors in orbit and on the lunar


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surface and prepare to deploy high power


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reactors in the 2030s. Uh I'm quoting


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here from uh uh from people who who are


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closely involved with this. For this to


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work, it has to be a collaboration


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between multiple government agencies.


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Well, that's that's a novel idea, isn't


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it?


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>> Yes.


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>> Um, that's the way


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>> that'll work.


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>> Yeah.


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>> That's the way that we do the right R&D


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and get the right tools in place for


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these events to unfold over the next few


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years.


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>> Yeah.


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>> Yes. So, um, that's right. So the bottom


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line is NASA


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is directed to start work within 30 days


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on a midpower space reactor generating


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at least 20 kW of power with a variant


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that can operate on the lunar surface.


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He calls for the agency to work with


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multiple companies on reactor designs,


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including for a low power system that


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produces as little as 1 kilowatt if


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doing so offers lower cost and schedule


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risk. This is um it's a White House uh


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release that I'm quoting from here. So,


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it's uh it's definitely the official


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thing.


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>> Yeah. Wow. Should we be surprised by


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this though?


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>> No. No, we shouldn't. I mean, actually,


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we did get um was it Jared Isaacman, the


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uh the new relatively new head of NASA,


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who I think we covered this uh quite a


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few months ago, talked about the idea of


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uh using a 100 kow nuclear reactor on


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the lunar surface. that raises a few


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eyebrows. But it looks as though this is


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the first step in in um in expediting


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that to start small, maybe even the


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smallest 1 kilowatt. It'll run an


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electric fire uh and uh and um keep


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going upwards. Uh there's a interesting


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uh disparity in the sort of urgency of


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this though because um the next


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paragraph of the White House release


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says the policy calls on the defense


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department to provide a briefing to the


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White House in 90 days on potential uses


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and payloads for space nuclear systems


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of varying power levels. The Pentagon


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will in the first year of the policy use


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its space nuclear funding to support


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NASA's efforts, then conduct its own


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competition for space nuclear power


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systems. I get the feeling here that


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there's going to be too many fingers in


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the pie and too many people deciding


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which companies are going to get the,


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you know, going to get the contracts to


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do this.


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the the options for nuclear power these


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days are so much more


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uh available and and simple like you can


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make very small nuclear power stations


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now you you can you can build one that's


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that's small enough just to service a


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town these days you don't need these big


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complex


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>> setups anymore so it it probably is the


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logical way to go even though when you


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say the word nuclear everybody sort runs


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for the hills. Not that that would save


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them, but um it's not as big and scary


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as people


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envvisage, but um it it's it's got bad


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press for a long long time. So whenever


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you talk about nuclear power station or


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look what happened in Australia um we're


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so scared of it, we've never done it.


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And people think of three mile three


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mile island and churn bill


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>> uh and uh yes and the bottom line is


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that if things go wrong you have a very


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big environmental problem uh and that


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would look at Fukushima yeah with the um


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earthquake and the t and the and the


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tsunami. Yeah,


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>> that's a mess.


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>> Yes. So uh it is scary I think. Um


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but but well so I grew up in a country


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that uh pioneered nuclear power with the


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US and there are several nuclear power


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stations. Uh I used to live not very far


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from one actually at Torres in Scotland.


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>> Is it is that right? Yes. I think it's


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Torres. Uh and um look it everybody just


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regarded it as a normal power station.


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It was very much a low-key thing. Uh and


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and you you see statistics like there's


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more radiation comes from the natural


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emissions from rocks in the UK. If you


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go down to Cornwall, the rocks are


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basically radioactive there.


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>> Oh wow.


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>> There's radon in the atmosphere. Um but


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it's at a level that humans can


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tolerate. Humans have been tolerating it


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for hundreds of thousands of years. And


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uh that's Yeah. You're exposed to


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radiation every time you walk outside.


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>> Well, that's right. you are. Yes. So,


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um, so it it it's got to be treated with


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respect. Um, I I I think what freaks


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people out though as well is the idea of


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sticking a nuclear reactor on top of a


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rocket and then sending it into space.


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And there was an accident uh with a so


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just stepping back NASA has used their


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RTGS radioisotope thermal gener


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thermmoelectric generators. I think


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that's what it stands for. Uh on several


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spacecraft including the two Voyagers. I


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think the Pioneers have got it as well.


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Um the um Curiosity and


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um Perseverance both have RTG power


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supplies. Uh so so that's well you know


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a well trodden path but there was an


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accident. I think it might have been in


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the 80s with a spacecraft that was


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launched with something like an RTG on


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board and it did uh it went wrong. I


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can't remember the details, but I think


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it was Canada that took the the punch


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and there was a lot of radioactive


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debris that got spread over very very uh


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sparsely populated regions of Canada.


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>> Literal fallout.


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>> Yes, that's right. Yes, exactly. Falls


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out the sky. If I remember rightly, I'm


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I'm digging up things from the past


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year, but I think that's the case. And


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that that clearly freaks people out. If


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you've got a launch that doesn't work,


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uh what's going to happen? I imagine so.


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But, uh it certainly does ramp up the


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space race between the US and China. And


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you know, China's probably going to fall


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a bit behind here because I think they


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were trying to set up a coal fired power


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station on the moon. You know, it um


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>> might might slow them down a bit.


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>> Yeah, China's doing pretty well. They


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are doing


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>> sustainability. Yeah.


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>> Yeah, they are.


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>> But yeah, they do use a lot of coal


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still. Yeah,


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>> they do. They do. So, this is probably


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going to happen. And what other option


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would there be? That's the thing. I


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mean, some people will say, "No, put up


00:10:00.959 --> 00:10:04.790
solar energy systems, but um nuclear is


00:10:04.800 --> 00:10:07.670
probably a a much more efficient way of


00:10:07.680 --> 00:10:08.949
doing it."


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>> Yeah. Well, for a start, you've got the


00:10:10.399 --> 00:10:12.470
baseline load. You don't not worried


00:10:12.480 --> 00:10:14.310
about where the sun is in the sky.


00:10:14.320 --> 00:10:17.430
Correct. The idea of being at the south


00:10:17.440 --> 00:10:20.949
pole of the moon which is where the


00:10:20.959 --> 00:10:23.750
focus is in terms of uh our exploration


00:10:23.760 --> 00:10:27.509
of the moon uh is it it puts a different


00:10:27.519 --> 00:10:29.670
slant on it because it means that you


00:10:29.680 --> 00:10:32.790
are looking at a very low sun altitude


00:10:32.800 --> 00:10:35.110
in the sky. Uh the sun's coming in


00:10:35.120 --> 00:10:36.949
nearly horizontally the sunlight. Now


00:10:36.959 --> 00:10:40.790
that's not uh as bad a thing on the moon


00:10:40.800 --> 00:10:42.710
as it would be on the earth. The Earth,


00:10:42.720 --> 00:10:44.230
as the sun gets lower, it's going


00:10:44.240 --> 00:10:45.670
through a thicker and thicker layer of


00:10:45.680 --> 00:10:47.509
atmosphere. So, it's power is


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attenuated.


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>> On the moon, that doesn't happen because


00:10:50.640 --> 00:10:52.949
there ain't no atmosphere. But, it does


00:10:52.959 --> 00:10:55.430
bring challenges for your solar panels.


00:10:55.440 --> 00:10:56.790
You know, you've got to build arrays


00:10:56.800 --> 00:10:59.030
that are almost vertical. And if you're


00:10:59.040 --> 00:11:01.509
looking for a big structure, uh then


00:11:01.519 --> 00:11:04.310
it's uh it it becomes different slightly


00:11:04.320 --> 00:11:07.030
different engineering um issue. Plus,


00:11:07.040 --> 00:11:08.389
you've got to take all that stuff up


00:11:08.399 --> 00:11:11.509
there as well. You know, going up to the


00:11:11.519 --> 00:11:13.269
moon with arrays of solar panels in the


00:11:13.279 --> 00:11:15.430
spacecraft might not leave room for much


00:11:15.440 --> 00:11:17.509
else. Whereas a nuclear reactor of the


00:11:17.519 --> 00:11:18.949
kind that people are talking about will


00:11:18.959 --> 00:11:21.030
be relatively compact. I mean, the the


00:11:21.040 --> 00:11:25.509
RTG devices are I think it's is it 13 kg


00:11:25.519 --> 00:11:29.030
of uh of plutonium that they have in


00:11:29.040 --> 00:11:32.389
them and they're about the size of a you


00:11:32.399 --> 00:11:35.430
know a tea or something like that or


00:11:35.440 --> 00:11:36.949
>> a drinks. Yeah.


00:11:36.959 --> 00:11:39.509
>> Yeah. It it's it's much simpler than it


00:11:39.519 --> 00:11:42.310
was 20, 30, 40, 50 years ago.


00:11:42.320 --> 00:11:43.829
>> And of course, they're talking not only


00:11:43.839 --> 00:11:46.470
about the moon, but uh people on Mars,


00:11:46.480 --> 00:11:48.790
so they'll need power as well. Uh I know


00:11:48.800 --> 00:11:50.389
in the movie The Martian, they used


00:11:50.399 --> 00:11:52.870
solar panels, but Mars is bit further


00:11:52.880 --> 00:11:54.470
away, so the solar panels probably


00:11:54.480 --> 00:11:55.829
wouldn't be as efficient.


00:11:55.839 --> 00:11:56.710
>> Exactly.


00:11:56.720 --> 00:11:59.829
>> Uh nuclear power makes makes perfect


00:11:59.839 --> 00:12:02.230
sense. Although you know solar solar


00:12:02.240 --> 00:12:07.910
energy is quite um well used in space


00:12:07.920 --> 00:12:09.190
too used it.


00:12:09.200 --> 00:12:12.790
>> Um that's correct. Yes. Uh and um you


00:12:12.800 --> 00:12:14.150
know thinking of the different


00:12:14.160 --> 00:12:15.829
spacecraft the one that's got perhaps


00:12:15.839 --> 00:12:17.910
the most spectacular solar panels is the


00:12:17.920 --> 00:12:20.310
Lucy spacecraft which is on its way to


00:12:20.320 --> 00:12:23.670
the Trojan asteroids. Uh and that's got


00:12:23.680 --> 00:12:26.230
solar panels which are huge and that's


00:12:26.240 --> 00:12:28.470
because you're going out to the asteroid


00:12:28.480 --> 00:12:30.069
belt and beyond. actually going to the


00:12:30.079 --> 00:12:31.590
orbit of Jupiter which is where the


00:12:31.600 --> 00:12:34.550
Trojan asteroids hang out. Uh so you


00:12:34.560 --> 00:12:36.710
need big solar panels to collect all the


00:12:36.720 --> 00:12:37.350
energy.


00:12:37.360 --> 00:12:38.710
>> Yeah. The other problem with solar


00:12:38.720 --> 00:12:41.829
panels on Mars would be dust because


00:12:41.839 --> 00:12:44.069
>> it's it's a pretty grubby place.


00:12:44.079 --> 00:12:46.790
>> Yeah. That's what um probably brought an


00:12:46.800 --> 00:12:49.590
end to so Spirit and Opportunity both


00:12:49.600 --> 00:12:52.310
had solar panels. Uh and they there were


00:12:52.320 --> 00:12:54.790
certainly times when the amount of dust


00:12:54.800 --> 00:12:57.750
was stopping the power generation and


00:12:57.760 --> 00:13:00.310
that was cleared by uh willy-willies as


00:13:00.320 --> 00:13:02.069
they're called


00:13:02.079 --> 00:13:03.030
the


00:13:03.040 --> 00:13:05.350
>> dust devils that's right on Mars. Yeah.


00:13:05.360 --> 00:13:08.310
>> Fascinating. All right. So the um the


00:13:08.320 --> 00:13:10.470
directive has been put to NASA to start


00:13:10.480 --> 00:13:11.990
working on this.


00:13:12.000 --> 00:13:14.550
>> Uh and it comes from the White House. So


00:13:14.560 --> 00:13:16.629
um it's all systems go and they hope to


00:13:16.639 --> 00:13:19.190
have something operational as soon as


00:13:19.200 --> 00:13:22.069
2028. So they're not mucking around. In


00:13:22.079 --> 00:13:23.590
fact, I think NASA after this was


00:13:23.600 --> 00:13:25.110
released were given one month to get


00:13:25.120 --> 00:13:26.150
started.


00:13:26.160 --> 00:13:26.550
>> So,


00:13:26.560 --> 00:13:28.550
>> uh, that's exactly right. That's the 30


00:13:28.560 --> 00:13:29.829
days that I mentioned earlier.


00:13:29.839 --> 00:13:30.790
>> No mucking around.


00:13:30.800 --> 00:13:31.750
>> Get going.


00:13:31.760 --> 00:13:33.910
>> Yep. Uh, you can read all about it at


00:13:33.920 --> 00:13:36.230
spacnews.com.


00:13:36.240 --> 00:13:38.550
This is Space Nuts with Andrew Dunley


00:13:38.560 --> 00:13:43.509
and Professor Fred Watson.


00:13:43.519 --> 00:13:45.110
>> G. And I feel


00:13:45.120 --> 00:13:46.150
>> space nuts.


00:13:46.160 --> 00:13:47.990
>> Well, we mentioned the moon. We'll stick


00:13:48.000 --> 00:13:50.550
with the moon. This story though has


00:13:50.560 --> 00:13:52.710
nothing to do with people on the moon.


00:13:52.720 --> 00:13:54.790
It's got uh everything to do with people


00:13:54.800 --> 00:13:57.509
that are not on Earth or the moon or


00:13:57.519 --> 00:13:59.509
Mars for that matter. They uh they're


00:13:59.519 --> 00:14:01.670
out there somewhere. We're looking for


00:14:01.680 --> 00:14:03.430
them. We're talking about the search for


00:14:03.440 --> 00:14:06.389
extraterrestrial intelligence and the


00:14:06.399 --> 00:14:08.069
dark side of the moon, the far side of


00:14:08.079 --> 00:14:11.509
the moon is uh the best place to start


00:14:11.519 --> 00:14:13.189
looking.


00:14:13.199 --> 00:14:14.870
>> Uh that's right. So, we've been looking


00:14:14.880 --> 00:14:18.550
for this for 60 years. um and


00:14:18.560 --> 00:14:22.069
>> and using uh groundbased antennas here


00:14:22.079 --> 00:14:26.389
on planet earth uh which are very very


00:14:26.399 --> 00:14:29.110
capable um when once the square


00:14:29.120 --> 00:14:31.350
kilometer array observatory comes on


00:14:31.360 --> 00:14:33.990
stream towards the end of the decade uh


00:14:34.000 --> 00:14:37.590
we'll have the finest most capable radio


00:14:37.600 --> 00:14:41.110
telescope in the world uh which will not


00:14:41.120 --> 00:14:44.069
directly engage with SETI programs but


00:14:44.079 --> 00:14:45.910
it will


00:14:45.920 --> 00:14:48.550
uh have the sensitivity to detect well


00:14:48.560 --> 00:14:50.790
the thing that my colleagues tell me is


00:14:50.800 --> 00:14:52.790
it'll detect an airport radar at 50


00:14:52.800 --> 00:14:53.670
light years.


00:14:53.680 --> 00:14:53.990
>> Yeah.


00:14:54.000 --> 00:14:57.430
>> Uh so that's the kind of sensitivity uh


00:14:57.440 --> 00:15:00.470
that you're talking about. Um, but the


00:15:00.480 --> 00:15:02.150
main problem with groundbased with


00:15:02.160 --> 00:15:05.590
earthbased uh radio telescopes is that


00:15:05.600 --> 00:15:07.829
they're compromised by all the the


00:15:07.839 --> 00:15:10.550
cacophony of radio signals that


00:15:10.560 --> 00:15:12.470
surrounds us from your mobile phones,


00:15:12.480 --> 00:15:15.269
from broadcasts, from people like you


00:15:15.279 --> 00:15:17.590
and me doing this, going out into the


00:15:17.600 --> 00:15:18.389
ether,


00:15:18.399 --> 00:15:19.670
>> Wi-Fi routers,


00:15:19.680 --> 00:15:22.069
>> Wi-Fi, the whole thing, microwave ovens,


00:15:22.079 --> 00:15:24.949
it all provides this noisy radio


00:15:24.959 --> 00:15:27.030
background. And that's not getting any


00:15:27.040 --> 00:15:29.670
better with the um satellite mega


00:15:29.680 --> 00:15:31.509
constellations.


00:15:31.519 --> 00:15:35.030
I was in a meeting yesterday where which


00:15:35.040 --> 00:15:37.509
for it's a meeting of the um


00:15:37.519 --> 00:15:39.750
international astronomical union center


00:15:39.760 --> 00:15:42.069
for the protection of the dark and quiet


00:15:42.079 --> 00:15:45.670
sky from satellite interference. Uh and


00:15:45.680 --> 00:15:47.750
it was um you know one of the things


00:15:47.760 --> 00:15:50.629
that's raising anxiety is the idea of uh


00:15:50.639 --> 00:15:53.910
Elon Musk's million satellites for for


00:15:53.920 --> 00:15:57.670
um orbital data u orbital data centers


00:15:57.680 --> 00:16:00.069
and this mirror in the sky idea sunlight


00:16:00.079 --> 00:16:01.910
on demand that also has a million


00:16:01.920 --> 00:16:04.069
satellites with mirrors on it. That's


00:16:04.079 --> 00:16:05.749
that's more for the optical astronomers


00:16:05.759 --> 00:16:09.189
but it's all a concern. uh and it's it


00:16:09.199 --> 00:16:11.910
it basically is eroding our capability


00:16:11.920 --> 00:16:14.949
slowly but surely to detect uh faint


00:16:14.959 --> 00:16:17.670
extraterrestrial signals.


00:16:17.680 --> 00:16:21.350
Uh so that brings us to currently


00:16:21.360 --> 00:16:24.150
possibly the best place to do this sort


00:16:24.160 --> 00:16:27.030
of thing from which is the far side of


00:16:27.040 --> 00:16:33.350
the moon. Uh and um uh we have one uh


00:16:33.360 --> 00:16:36.310
spacecraft by we I mean humankind have


00:16:36.320 --> 00:16:38.470
one spacecraft on the far side of the


00:16:38.480 --> 00:16:42.870
moon. Uh it is China's Chang 4 uh which


00:16:42.880 --> 00:16:44.949
soft landed on the far side of the moon


00:16:44.959 --> 00:16:47.829
back in 2019. Can you believe it? It's


00:16:47.839 --> 00:16:49.110
been there.


00:16:49.120 --> 00:16:51.350
>> Uh this is seven years. It's quite


00:16:51.360 --> 00:16:56.710
extraordinary. Um but uh now that um


00:16:56.720 --> 00:16:59.350
spacecraft was not set up uh


00:16:59.360 --> 00:17:03.829
specifically for uh for looking for um


00:17:03.839 --> 00:17:05.750
SETI search for extraterrestrial


00:17:05.760 --> 00:17:08.949
intelligence but it's got a low


00:17:08.959 --> 00:17:12.150
frequency radio spectrometer on board uh


00:17:12.160 --> 00:17:15.189
that actually has been used to conduct


00:17:15.199 --> 00:17:17.909
the first ever SETI search from the


00:17:17.919 --> 00:17:22.309
lunar far side. Um and so the the goal


00:17:22.319 --> 00:17:26.309
uh the idea is to use that equipment


00:17:26.319 --> 00:17:29.830
which is designed to do natural sciences


00:17:29.840 --> 00:17:34.230
but to look for um those uh techno


00:17:34.240 --> 00:17:36.549
signatures uh technomarkers they're


00:17:36.559 --> 00:17:39.669
sometimes called uh which might suggest


00:17:39.679 --> 00:17:41.909
that you're getting a signal from an


00:17:41.919 --> 00:17:44.390
artificially generated source. And what


00:17:44.400 --> 00:17:47.909
you're really looking for are uh


00:17:47.919 --> 00:17:49.590
periodic


00:17:49.600 --> 00:17:52.310
um bursts of radiation with perhaps


00:17:52.320 --> 00:17:54.470
regular intervals


00:17:54.480 --> 00:17:57.669
um that are not easily explained


00:17:57.679 --> 00:18:00.390
>> by natural processes. And you've got got


00:18:00.400 --> 00:18:04.150
to think back to Joselyn Bell and her


00:18:04.160 --> 00:18:06.230
discovery of the first pulsar because


00:18:06.240 --> 00:18:09.830
that's what she saw. um narrow band um


00:18:09.840 --> 00:18:14.390
sorry uh narrow band in time signatures


00:18:14.400 --> 00:18:17.029
uh or bursts of radiation which we now


00:18:17.039 --> 00:18:18.549
know is the pulsar the kind of


00:18:18.559 --> 00:18:20.630
lighthouse beam of radiation from the


00:18:20.640 --> 00:18:22.789
pulsar sweeping round and passing the


00:18:22.799 --> 00:18:25.750
earth. Um she didn't know that then so


00:18:25.760 --> 00:18:28.549
she wrote little green men in her uh in


00:18:28.559 --> 00:18:31.190
on her chart record of very very famous


00:18:31.200 --> 00:18:35.750
words. Um so that's what basically uh


00:18:35.760 --> 00:18:39.270
the uh Changa um low frequency radio


00:18:39.280 --> 00:18:41.590
spectrometer has been looking for. Uh


00:18:41.600 --> 00:18:44.470
and it's things that um you know that


00:18:44.480 --> 00:18:46.950
speak of an artificially generated


00:18:46.960 --> 00:18:50.470
source. And so um what's what they've


00:18:50.480 --> 00:18:53.110
done uh the scientists working on this


00:18:53.120 --> 00:18:56.789
uh basically they built an algorithm


00:18:56.799 --> 00:18:59.669
uh that uh uh troll through the data


00:18:59.679 --> 00:19:03.110
looking for anything that might be


00:19:03.120 --> 00:19:07.669
artificial with no credible candidates


00:19:07.679 --> 00:19:10.390
revealed. Uh nothing that couldn't be


00:19:10.400 --> 00:19:13.190
explained either by you know natural


00:19:13.200 --> 00:19:18.630
phenomena or by instrument uh issues. Um


00:19:18.640 --> 00:19:20.710
there's a nice comment though from


00:19:20.720 --> 00:19:25.110
fizz.org who is carrying this story. Uh


00:19:25.120 --> 00:19:27.430
this is I'll quote this. This is not a


00:19:27.440 --> 00:19:29.909
failure. It is a beginning. As Carl Sean


00:19:29.919 --> 00:19:33.110
once put it, absence of evidence is not


00:19:33.120 --> 00:19:35.190
evidence of absence. Brilliant.


00:19:35.200 --> 00:19:36.150
>> Really good point.


00:19:36.160 --> 00:19:38.230
>> I I got I had a lot of time for Carl


00:19:38.240 --> 00:19:41.750
Sean, very wise man and um yeah, he uh


00:19:41.760 --> 00:19:43.510
he did a lot for astronomy


00:19:43.520 --> 00:19:46.310
>> during his time. But um that's a valid


00:19:46.320 --> 00:19:48.870
point and and I suppose you and I have


00:19:48.880 --> 00:19:50.710
spoken about it in the past. The big


00:19:50.720 --> 00:19:53.750
problem is distance. There might there


00:19:53.760 --> 00:19:55.510
might be civilizations out there that


00:19:55.520 --> 00:19:57.350
are advanced and capable of


00:19:57.360 --> 00:19:59.110
communication, but they're so far away


00:19:59.120 --> 00:20:01.190
we will never hear from them.


00:20:01.200 --> 00:20:05.590
>> Maybe that Yeah. Um that's right. Uh and


00:20:05.600 --> 00:20:07.510
you know, and time is the other issue.


00:20:07.520 --> 00:20:09.350
It's a needle in a hay stack both in


00:20:09.360 --> 00:20:11.430
distance and in time because you've got


00:20:11.440 --> 00:20:13.669
to hit your civilization just at the


00:20:13.679 --> 00:20:14.549
right time.


00:20:14.559 --> 00:20:15.029
>> Yes.


00:20:15.039 --> 00:20:18.230
>> Uh when they are technologically enough


00:20:18.240 --> 00:20:20.789
to have airport radar, for example, uh


00:20:20.799 --> 00:20:22.710
but haven't wiped themselves out because


00:20:22.720 --> 00:20:24.870
of the loonies that they've generated.


00:20:24.880 --> 00:20:26.710
You're more you're more likely to get a


00:20:26.720 --> 00:20:29.909
um a tick tock of some kid doing a


00:20:29.919 --> 00:20:32.789
stupid rap song. That's probably that's


00:20:32.799 --> 00:20:35.669
what you'll get from from an


00:20:35.679 --> 00:20:38.390
extraterrestrial intelligence. Um what


00:20:38.400 --> 00:20:42.390
what I wonder is with the far side of


00:20:42.400 --> 00:20:44.710
the moon, yes, it's radio silent, but


00:20:44.720 --> 00:20:47.110
does it cover enough of the spectrum of


00:20:47.120 --> 00:20:50.390
the universe to to pick up something or


00:20:50.400 --> 00:20:52.950
is or is it fairly narrow in its its


00:20:52.960 --> 00:20:53.750
scope?


00:20:53.760 --> 00:20:55.909
>> Uh do you mean uh in terms of direction


00:20:55.919 --> 00:20:56.470
or


00:20:56.480 --> 00:20:58.230
>> Yeah. being able to pick something up?


00:20:58.240 --> 00:21:00.870
Is it got like a wide array? I mean the


00:21:00.880 --> 00:21:03.909
far side of the moon um you know if you


00:21:03.919 --> 00:21:05.990
plunk something on the equator of the


00:21:06.000 --> 00:21:09.110
moon on the far side over a month you


00:21:09.120 --> 00:21:11.110
cover the entire sky. No


00:21:11.120 --> 00:21:15.750
>> uh if your Yeah. If your um if your uh


00:21:15.760 --> 00:21:18.630
equipment is broadband enough and all


00:21:18.640 --> 00:21:20.710
the seti stuff is it's got a very wide


00:21:20.720 --> 00:21:22.950
range of spectral of frequencies.


00:21:22.960 --> 00:21:25.350
Although they do tend to to concentrate


00:21:25.360 --> 00:21:29.510
on uh what we call the 21 cm line. This


00:21:29.520 --> 00:21:31.990
is the frequency the specific frequency


00:21:32.000 --> 00:21:34.950
that's radiated by cold hydrogen.


00:21:34.960 --> 00:21:37.110
>> Uh and they do tend to concentrate on


00:21:37.120 --> 00:21:39.110
that because everybody in the universe


00:21:39.120 --> 00:21:43.430
will be aware of that 21 cm uh uh


00:21:43.440 --> 00:21:45.750
wavelength because that's called


00:21:45.760 --> 00:21:48.470
hydrogen which is the same everywhere.


00:21:48.480 --> 00:21:51.669
>> Yeah, makes sense. All right. Uh


00:21:51.679 --> 00:21:54.710
fascinating story. Um nothing yet but


00:21:54.720 --> 00:21:56.549
that doesn't mean that doesn't mean


00:21:56.559 --> 00:21:58.789
it'll always be nothing. So


00:21:58.799 --> 00:22:01.110
>> it's not um evidence of absence. That's


00:22:01.120 --> 00:22:01.990
right.


00:22:02.000 --> 00:22:04.070
>> Exactly. You can read all about it as


00:22:04.080 --> 00:22:08.149
Fred said at the fizz physf.org


00:22:08.159 --> 00:22:10.310
website. This is Space Nuts. Andrew


00:22:10.320 --> 00:22:15.270
Dunley here with Professor Fred Watson.


00:22:15.280 --> 00:22:17.510
>> Okay, we checked all four systems and


00:22:17.520 --> 00:22:18.149
with the


00:22:18.159 --> 00:22:19.669
>> Space Nuts.


00:22:19.679 --> 00:22:22.950
>> Our final story, Fred, uh brings us back


00:22:22.960 --> 00:22:25.750
to that old debate about the Hubble


00:22:25.760 --> 00:22:28.230
tension. Now, the Hubble tension is


00:22:28.240 --> 00:22:30.310
measured in two different ways, and they


00:22:30.320 --> 00:22:32.230
come up with two different answers, and


00:22:32.240 --> 00:22:35.110
that's troubled people for a while.


00:22:35.120 --> 00:22:36.870
Although, we did a story not so long ago


00:22:36.880 --> 00:22:39.029
that suggested, hang on a minute, the


00:22:39.039 --> 00:22:41.909
differences aren't that significant. So,


00:22:41.919 --> 00:22:44.549
they're probably both right if you allow


00:22:44.559 --> 00:22:47.669
for the u you know, the the variables.


00:22:47.679 --> 00:22:49.830
But this story is saying, "Hang on a


00:22:49.840 --> 00:22:52.149
minute. We we think there's a better


00:22:52.159 --> 00:22:53.830
way."


00:22:53.840 --> 00:22:57.430
>> Yes, that's right. uh in exactly that


00:22:57.440 --> 00:23:00.870
it's all about so le let's just uh


00:23:00.880 --> 00:23:03.990
backtrack what is the Hubble tension uh


00:23:04.000 --> 00:23:07.909
so the expansion rate of the universe


00:23:07.919 --> 00:23:10.950
basically is a number that we was first


00:23:10.960 --> 00:23:13.990
measured by Edwin Hubble back in 1929


00:23:14.000 --> 00:23:15.830
um he got the wrong answer because he


00:23:15.840 --> 00:23:17.669
was only looking at a very small number


00:23:17.679 --> 00:23:19.830
of galaxies but it it comes about


00:23:19.840 --> 00:23:23.110
because as you look at galaxies


00:23:23.120 --> 00:23:25.430
in the wider universe


00:23:25.440 --> 00:23:29.110
uh they get um their velocity away from


00:23:29.120 --> 00:23:32.789
us is bigger the further away they are


00:23:32.799 --> 00:23:34.549
and that comes about when you've got a


00:23:34.559 --> 00:23:36.390
universe that's expanding. That's the


00:23:36.400 --> 00:23:38.630
natural assumption and we've believed


00:23:38.640 --> 00:23:43.190
that ever since. Yeah. Excuse me. So, so


00:23:43.200 --> 00:23:44.789
um got a bit of Hubble tension in my


00:23:44.799 --> 00:23:47.909
chest there. Um so that's how it's


00:23:47.919 --> 00:23:50.390
normally measure measured the Hubble


00:23:50.400 --> 00:23:52.070
constant


00:23:52.080 --> 00:23:55.350
this number which is in slightly bizarre


00:23:55.360 --> 00:23:58.470
units. It's in mega par kilometers/s per


00:23:58.480 --> 00:24:02.310
mega par sec. Kilometers/s is the


00:24:02.320 --> 00:24:05.909
recession speed of a galaxy. A mega parc


00:24:05.919 --> 00:24:09.669
is uh is it 3.26 I can never remember


00:24:09.679 --> 00:24:12.710
the name. Million light years. Uh it's


00:24:12.720 --> 00:24:14.710
the it's the units that astronomers use


00:24:14.720 --> 00:24:17.430
for measuring distance parex and it's a


00:24:17.440 --> 00:24:21.110
million parex. So um kilometers/s per


00:24:21.120 --> 00:24:24.630
mega parc tells you how the velocity of


00:24:24.640 --> 00:24:27.750
a g galaxy increases with distance and


00:24:27.760 --> 00:24:29.669
that's the result of the expansion of


00:24:29.679 --> 00:24:31.990
the universe. So the hub constant tells


00:24:32.000 --> 00:24:34.789
you how fast the universe is expanding.


00:24:34.799 --> 00:24:35.909
Now,


00:24:35.919 --> 00:24:39.190
>> now you can you the normal way of doing


00:24:39.200 --> 00:24:41.750
this is uh and it's actually why the


00:24:41.760 --> 00:24:44.310
Hubble telescope was created and why it


00:24:44.320 --> 00:24:47.350
got its name. Uh we excuse me. We


00:24:47.360 --> 00:24:49.750
measure the brightness.


00:24:49.760 --> 00:24:51.750
Sorry, I've got my got my tension back


00:24:51.760 --> 00:24:53.750
there.


00:24:53.760 --> 00:24:55.430
If you want to cut this bit out, Hugh,


00:24:55.440 --> 00:24:58.710
you're more than welcome to.


00:24:58.720 --> 00:25:02.950
Um it's it's fine now. uh the uh the the


00:25:02.960 --> 00:25:05.269
tension comes about. So no, let me step


00:25:05.279 --> 00:25:08.149
back again. The uh measure the way it's


00:25:08.159 --> 00:25:10.789
measured is you build up a sort of


00:25:10.799 --> 00:25:12.789
distance scale ladder. So the direct


00:25:12.799 --> 00:25:15.590
measurement of star distances in outer


00:25:15.600 --> 00:25:18.310
space comes about by the parallax


00:25:18.320 --> 00:25:20.230
method. As the earth goes around the


00:25:20.240 --> 00:25:23.909
sun, we see stars uh apparently changing


00:25:23.919 --> 00:25:26.549
their position with relative to very


00:25:26.559 --> 00:25:28.630
distant background stars. And that


00:25:28.640 --> 00:25:30.950
change in position you can measure uh


00:25:30.960 --> 00:25:33.430
and in fact it's that that gives the


00:25:33.440 --> 00:25:35.510
parseek its name. It's a parallax of one


00:25:35.520 --> 00:25:38.789
arcsec is what it's short for. And so


00:25:38.799 --> 00:25:41.110
that's a direct geometrical way of


00:25:41.120 --> 00:25:43.350
measuring the distance to certain stars.


00:25:43.360 --> 00:25:45.669
If you can do that to stars whose


00:25:45.679 --> 00:25:48.230
intrinsic brightness you know and these


00:25:48.240 --> 00:25:50.789
are typically sephied variable stars


00:25:50.799 --> 00:25:52.789
then you can extend it because you know


00:25:52.799 --> 00:25:54.950
their brightness uh their intrinsic


00:25:54.960 --> 00:25:56.710
brightness how much uh light they


00:25:56.720 --> 00:25:59.190
radiate then you can look at how faint


00:25:59.200 --> 00:26:01.750
they are further and further on um and


00:26:01.760 --> 00:26:03.590
that's the that's how we started off


00:26:03.600 --> 00:26:08.549
because Hubble um measured um in fact in


00:26:08.559 --> 00:26:11.190
1923 used these variable stars to


00:26:11.200 --> 00:26:12.950
measure the distance of the Andromeda


00:26:12.960 --> 00:26:14.630
galaxy. Once again, he got it a bit


00:26:14.640 --> 00:26:17.190
wrong by today's standards, but uh that


00:26:17.200 --> 00:26:18.710
was when we realized that galaxies


00:26:18.720 --> 00:26:20.630
weren't little things frutling around in


00:26:20.640 --> 00:26:23.190
our own milky way. They are very distant


00:26:23.200 --> 00:26:26.789
objects. So that's the basic process and


00:26:26.799 --> 00:26:29.830
that has now been uh basically


00:26:29.840 --> 00:26:33.350
elaborated by additional things which


00:26:33.360 --> 00:26:36.230
involve supernovi, the exploding stars,


00:26:36.240 --> 00:26:39.350
all sorts of other uh cosmic phenomena.


00:26:39.360 --> 00:26:42.630
And that's the basis of what this story


00:26:42.640 --> 00:26:45.430
is about because


00:26:45.440 --> 00:26:49.190
uh that technology has now been


00:26:49.200 --> 00:26:53.110
absolutely refined to the nth degree uh


00:26:53.120 --> 00:26:57.110
by the scientists who are uh who are u


00:26:57.120 --> 00:27:00.470
uh basically reporting this work. Uh


00:27:00.480 --> 00:27:02.470
it's a study in astronomy and


00:27:02.480 --> 00:27:04.470
astrophysics one of the leading journals


00:27:04.480 --> 00:27:07.269
actually a European journal. uh and the


00:27:07.279 --> 00:27:10.230
these scientists have spent a lot of


00:27:10.240 --> 00:27:14.310
time getting uh the answer right from


00:27:14.320 --> 00:27:15.990
this method what we call the distance


00:27:16.000 --> 00:27:19.669
ladder or the distance scale by invoking


00:27:19.679 --> 00:27:23.110
objects of all kinds and so they have


00:27:23.120 --> 00:27:24.950
produced a number for the Hubble


00:27:24.960 --> 00:27:28.870
constant which has a very very small


00:27:28.880 --> 00:27:33.669
error in fact they quote it as 7350


00:27:33.679 --> 00:27:37.110
kilometers/s per megap par sec plus or


00:27:37.120 --> 00:27:38.710
minus.0


00:27:38.720 --> 00:27:41.190
sorry 0.81


00:27:41.200 --> 00:27:44.149
kilometers/s per mega par sec. So


00:27:44.159 --> 00:27:46.149
they're talking about something that's


00:27:46.159 --> 00:27:49.909
either somewhere between 72.0 and 74


00:27:49.919 --> 00:27:54.070
sorry 72.5 and 74.5 thereabouts which is


00:27:54.080 --> 00:27:58.070
a very very tight uh estimate of this


00:27:58.080 --> 00:27:59.909
velocity.


00:27:59.919 --> 00:28:02.230
Uh so what's the tension about


00:28:02.240 --> 00:28:05.350
>> until somebody debunks them?


00:28:05.360 --> 00:28:08.630
>> Yeah. Uh it well it's true. Um I do


00:28:08.640 --> 00:28:11.350
remember um back in the 70s and I've


00:28:11.360 --> 00:28:13.669
told you this before, Andrew, there were


00:28:13.679 --> 00:28:16.310
two schools of thought. Both offering


00:28:16.320 --> 00:28:18.149
measurements with very tight error


00:28:18.159 --> 00:28:20.070
limits. One of which said that the


00:28:20.080 --> 00:28:22.070
number was 50 and the other which said


00:28:22.080 --> 00:28:24.230
the number was 100. Yeah. And lo and


00:28:24.240 --> 00:28:25.590
behold, when we when the Hubble


00:28:25.600 --> 00:28:27.190
telescope gave us the right answer, it


00:28:27.200 --> 00:28:28.710
was basically at the average of those


00:28:28.720 --> 00:28:31.269
two around about 75. It's now been


00:28:31.279 --> 00:28:31.830
refined.


00:28:31.840 --> 00:28:33.110
>> It's kind of what they're doing with


00:28:33.120 --> 00:28:34.789
this, isn't it?


00:28:34.799 --> 00:28:36.549
>> A little bit, although they're they're


00:28:36.559 --> 00:28:40.310
really giving tight very tight um


00:28:40.320 --> 00:28:42.710
estimates based on everything that we


00:28:42.720 --> 00:28:43.830
can observe, right?


00:28:43.840 --> 00:28:46.389
>> Uh whereas the previous this with it the


00:28:46.399 --> 00:28:48.070
difference between 50 and 100 and that


00:28:48.080 --> 00:28:50.070
was a kind of hollow tension. We didn't


00:28:50.080 --> 00:28:51.750
call it that, but that's sort of what it


00:28:51.760 --> 00:28:55.590
was. that uh was based on uh just


00:28:55.600 --> 00:28:58.389
individ individual measurements from you


00:28:58.399 --> 00:29:00.389
know their own particular school of


00:29:00.399 --> 00:29:02.149
thought. One was galaxies, one was


00:29:02.159 --> 00:29:03.750
supernovi or something. I can't remember


00:29:03.760 --> 00:29:05.110
how it worked. I can't remember the


00:29:05.120 --> 00:29:06.630
details. Probably could if I thought


00:29:06.640 --> 00:29:09.029
about it. Uh but this brings them all


00:29:09.039 --> 00:29:11.750
together to get this super accurate


00:29:11.760 --> 00:29:14.870
so-called value of 73.5.


00:29:14.880 --> 00:29:17.430
So the tension is that there is another


00:29:17.440 --> 00:29:21.029
way of uh determining the Hubble


00:29:21.039 --> 00:29:23.909
constant and it involves uh observing


00:29:23.919 --> 00:29:25.510
the cosmic microwave background


00:29:25.520 --> 00:29:27.830
radiation. That's the radiation that we


00:29:27.840 --> 00:29:29.350
see from the big bang. We're looking


00:29:29.360 --> 00:29:32.870
back 13.8 billion years to see that


00:29:32.880 --> 00:29:34.549
what's sometimes called the afterglow of


00:29:34.559 --> 00:29:36.149
the Big Bang. It's really still the


00:29:36.159 --> 00:29:37.590
light of the Big Bang that you can see


00:29:37.600 --> 00:29:39.190
because you're looking so far back in


00:29:39.200 --> 00:29:39.830
time.


00:29:39.840 --> 00:29:40.230
>> Yeah.


00:29:40.240 --> 00:29:42.389
>> And that gives us a different number.


00:29:42.399 --> 00:29:45.750
You can you can look at the um it's


00:29:45.760 --> 00:29:47.190
what's called the power spectrum. The


00:29:47.200 --> 00:29:48.789
the the cosmic microwave background


00:29:48.799 --> 00:29:51.110
radiation has these tiny tiny


00:29:51.120 --> 00:29:53.269
fluctuations and by tiny I mean the


00:29:53.279 --> 00:29:55.750
amount fluctuations in temperature. You


00:29:55.760 --> 00:29:56.870
can measure the temperature of the


00:29:56.880 --> 00:29:59.590
radiation and they they form in little


00:29:59.600 --> 00:30:01.990
blobs and we think that's where the


00:30:02.000 --> 00:30:03.909
galaxies came from. The the cooler parts


00:30:03.919 --> 00:30:06.230
were where galaxies formed. The warmer


00:30:06.240 --> 00:30:09.909
parts were not. Uh, and so this the


00:30:09.919 --> 00:30:11.590
microwave background radiation when you


00:30:11.600 --> 00:30:13.750
when you look at it, it looks like it


00:30:13.760 --> 00:30:16.310
looks like a p a wallpaper pattern. Uh,


00:30:16.320 --> 00:30:17.750
which is why I sometimes call it the


00:30:17.760 --> 00:30:19.590
cosmic wallpaper. Partly because it's


00:30:19.600 --> 00:30:21.190
behind everything else just like the


00:30:21.200 --> 00:30:22.630
wallpaper in a room is behind


00:30:22.640 --> 00:30:23.269
everything.


00:30:23.279 --> 00:30:23.510
>> Yeah.


00:30:23.520 --> 00:30:25.510
>> Uh, but it's also got these patterns. So


00:30:25.520 --> 00:30:27.590
you can use those patterns to make


00:30:27.600 --> 00:30:30.470
another estimate of the uh Hubble


00:30:30.480 --> 00:30:33.190
constant. And the answer that you get is


00:30:33.200 --> 00:30:37.269
67 kilometers/s per mega parse which is


00:30:37.279 --> 00:30:41.029
well outside the error band of the sort


00:30:41.039 --> 00:30:43.350
of traditional method.


00:30:43.360 --> 00:30:47.430
>> And so I think what the direction this


00:30:47.440 --> 00:30:50.789
is going in is so as you and I have


00:30:50.799 --> 00:30:53.350
spoken about before people have done a


00:30:53.360 --> 00:30:55.990
lot of work to try and look for where


00:30:56.000 --> 00:30:57.750
we've gone wrong here because these two


00:30:57.760 --> 00:30:59.350
numbers should give you the same answer


00:30:59.360 --> 00:31:02.070
but they don't. that they don't.


00:31:02.080 --> 00:31:04.230
>> And so now people are turning it upside


00:31:04.240 --> 00:31:06.470
down and saying maybe the fact that they


00:31:06.480 --> 00:31:08.389
don't give the same answer is telling us


00:31:08.399 --> 00:31:09.830
something about the physics of the


00:31:09.840 --> 00:31:12.950
universe that we don't know


00:31:12.960 --> 00:31:14.470
>> or we're just not accounting for


00:31:14.480 --> 00:31:16.230
everything we need to put into the


00:31:16.240 --> 00:31:16.789
formula.


00:31:16.799 --> 00:31:19.350
>> Yeah. Yeah. There's that too. And but I


00:31:19.360 --> 00:31:21.590
think that's so as time goes on people


00:31:21.600 --> 00:31:23.750
are ticking off all those things


00:31:23.760 --> 00:31:25.590
>> uh simply because there's a lot more


00:31:25.600 --> 00:31:28.070
work being done on this on this topic.


00:31:28.080 --> 00:31:30.310
So the Hubble tension could turn out to


00:31:30.320 --> 00:31:34.870
be uh the gateway into new physics that


00:31:34.880 --> 00:31:37.029
might tell us about dark matter and dark


00:31:37.039 --> 00:31:39.029
energy and all the other dark stuff that


00:31:39.039 --> 00:31:41.990
we we think about. Yeah. So it's it's


00:31:42.000 --> 00:31:45.669
potentially uh something that I think uh


00:31:45.679 --> 00:31:47.110
scientists everywhere will keep an eye


00:31:47.120 --> 00:31:50.470
on. Uh but it is really um really in


00:31:50.480 --> 00:31:52.310
many ways getting quite exciting that


00:31:52.320 --> 00:31:54.470
this Hubble tension is not going away.


00:31:54.480 --> 00:31:56.310
>> No, definitely not. It's come up a few


00:31:56.320 --> 00:31:58.149
times in the last 10 years that we've


00:31:58.159 --> 00:32:00.149
been doing this. So, they keep looking


00:32:00.159 --> 00:32:01.990
at it and that's and very good reasons


00:32:02.000 --> 00:32:04.549
to do so. Uh, for the record, a mega


00:32:04.559 --> 00:32:07.029
parseek is approximately 3.26 million


00:32:07.039 --> 00:32:08.470
lighty years. I think that's what you


00:32:08.480 --> 00:32:09.029
said.


00:32:09.039 --> 00:32:10.710
>> That is what I said. Yeah. I could never


00:32:10.720 --> 00:32:13.029
remember. I think it's 3.26. I told


00:32:13.039 --> 00:32:14.630
>> that's what I found. Yes.


00:32:14.640 --> 00:32:16.950
>> Yeah. Very good. All right. Uh,


00:32:16.960 --> 00:32:18.549
hopefully they've finally cracked the


00:32:18.559 --> 00:32:21.190
Hubble tension debate. Uh, I guess we'll


00:32:21.200 --> 00:32:22.710
find out if they keep coming up with


00:32:22.720 --> 00:32:25.029
different numbers in in the future, but


00:32:25.039 --> 00:32:26.549
uh, you can look it up at daily


00:32:26.559 --> 00:32:29.190
galaxy.com or you can read the published


00:32:29.200 --> 00:32:32.630
paper at astronomy and astrophysics.


00:32:32.640 --> 00:32:34.149
Fred, that brings us to the end of the


00:32:34.159 --> 00:32:36.389
program. Thank you so much.


00:32:36.399 --> 00:32:38.389
>> A great pleasure, Andrew. Uh, we've


00:32:38.399 --> 00:32:41.110
covered some great topics today and, uh,


00:32:41.120 --> 00:32:42.630
it's always a delight.


00:32:42.640 --> 00:32:44.310
>> Yeah, it's very, very, you know, a few


00:32:44.320 --> 00:32:46.470
different types of stories this time


00:32:46.480 --> 00:32:48.630
around, which we like. We'll catch you


00:32:48.640 --> 00:32:50.389
on the next one, Fred.


00:32:50.399 --> 00:32:52.710
>> Uh, I guess we will. Yes, sounds good.


00:32:52.720 --> 00:32:54.389
>> Professor Fred Watson, astronomer at


00:32:54.399 --> 00:32:56.070
large. And thanks to Hugh in the studio.


00:32:56.080 --> 00:32:58.389
He couldn't be with us today because he


00:32:58.399 --> 00:33:03.110
caused a bit of hubby tension at home


00:33:03.120 --> 00:33:04.630
and he's been sent to the naughty


00:33:04.640 --> 00:33:06.710
corner. Uh, don't forget to visit us


00:33:06.720 --> 00:33:09.909
online or um visit us on social media


00:33:09.919 --> 00:33:11.590
and don't forget to send us your


00:33:11.600 --> 00:33:13.509
comments and questions via our website,


00:33:13.519 --> 00:33:15.830
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00:33:15.840 --> 00:33:19.509
or spacenuts.io. io and uh leave reviews


00:33:19.519 --> 00:33:21.830
from your favorite podcasting platform


00:33:21.840 --> 00:33:23.990
in the meantime. From me, Andrew Dunley,


00:33:24.000 --> 00:33:24.950
thanks for your company. We'll see you


00:33:24.960 --> 00:33:27.110
on the very next episode of Space Nuts.


00:33:27.120 --> 00:33:27.990
Bye-bye.


00:33:28.000 --> 00:33:29.029
>> Space Nuts.


00:33:29.039 --> 00:33:31.110
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00:33:33.360 --> 00:33:36.310
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