Feb. 24, 2025

Black Holes, Light Speed & Oceanic Exoplanets: #498 - Diving Deep into Your Space Queries

Black Holes, Light Speed & Oceanic Exoplanets: #498 - Diving Deep into Your Space Queries

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Space Nuts Episode 498: Reflections in Space, Holographic Theories, and Liquid Planets
Join Andrew Dunkley and Professor Jonti Horner in this engaging Q&A edition of Space Nuts, where they tackle some of the most thought-provoking questions from our listeners. From the possibility of seeing our own reflection in space to the intriguing theory of a holographic universe, and the concept of entirely liquid exoplanets, this episode is packed with fascinating insights that will expand your understanding of the cosmos.
Episode Highlights:
- Seeing Our Reflection in Space: Tony's question sparks a discussion on the challenges of capturing a reflected image of the Milky Way galaxy. Jonti explains the complexities of gravitational lensing and how light behaves in the presence of massive objects, revealing why a clear reflection is beyond reach.
- The Holographic Universe: Charles asks about the theory that suggests we might live in a holographic universe. Andrew and Jonti delve into the philosophical implications of this theory, touching on string theory and the nature of reality, while pondering the boundaries between science and philosophy.
- Black Holes and Light: David's inquiry leads to an exploration of light's behavior around black holes. The duo discusses whether a black hole can accelerate light beyond its speed, clarifying the fundamental principles of light speed and gravitational effects.
- Liquid Exoplanets: Duncan raises the intriguing possibility of an entirely liquid exoplanet. Jonti shares insights into the conditions necessary for such a planet to exist, the role of atmospheric pressure, and how it relates to the formation of planets in our universe.
For more Space Nuts, including our continually updating newsfeed and to listen to all our episodes, visit our website. Follow us on social media at SpaceNutsPod on Facebook, X, YouTube Music Music, Tumblr, Instagram, and TikTok. We love engaging with our community, so be sure to drop us a message or comment on your favorite platform.
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Stay curious, keep looking up, and join us next time for more stellar insights and cosmic wonders. Until then, clear skies and happy stargazing.
00:00 - Introduction to the episode and topics
02:15 - Discussion on seeing our reflection in space
10:30 - Exploring the holographic universe theory
18:00 - Insights into black holes and light behavior
26:45 - The concept of entirely liquid exoplanets
30:00 - Closing thoughts
✍️ Episode References
Gravitational Lensing Explained
https://www.space.com/gravitational-lensing
Holographic Universe Theory
https://www.sciencedirect.com/science/article/pii/S0370157317303410
Liquid Exoplanets Research
https://www.nature.com/articles/s41550-020-1170-5

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WEBVTT

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Hello again, thanks for joining us. This is a Cuan

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edition of Space Nuts. This is where the audience asks

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us questions and we refer to somebody else. And in

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today's episode, we are going to talk about whether or

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not we can see our own reflection in space. That's

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a question from Tony. Are we living in a holographic universe?

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Charles wants to know, David is asking about black holes

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versus light who wins that war? And duncan liquid planets?

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Are there any out there? We'll find out on this

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episode of Space Nuts fifteen, Channel ten nine Ignition Squench

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Space Nuts NI or three two Space Nuts as and

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I reported Neil's goods. And joining us to sort all

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of that out is Professor John ty Horner from the

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University of Southern Queensland. Hi, Johnny, how you doing. I'm good.

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It's feels like second since we last spoke.

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Absolutely time flies when you're having fun. I think this.

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Let's muck in, as they say in your part of

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the world. Let's go to our first question. This one

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comes from Honey. Hi, guys, Given the cosmoss has black holes,

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gravity waves, gravitational lensing, light echoes, and dust cloud reflections,

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any chance we could ever see a reflection of our

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Milky Way galaxy. Love the show, Tony from Marrickville, which

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is a suburb of Sydney. Thanks Tony. What are your thoughts, Johnny.

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I think that's a short I'm sure a long answer

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to this. I think the short answer is I can

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think of nowhere that we could get a resolved image,

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you know, so we're not going to get something like

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a mirror held up to reality where we get a

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beautiful picture of the Milky Way galaxy reflected back to us.

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The different phenomena that can bend light and change its

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direction are often ly to the amount of mass, So

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you've got a black hole or a star or something

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like that. And under Einstein's series of general relativity, the

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idea is that mass curve space, so like tries to

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go in what it thinks is a straight, direct, straight line,

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but because the space is curved, it gets deflected by

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following the shortest path through the curve space. So that's

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how you get gravitational lensing. How you get light being bent.

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Now like traveling really really quickly, so nearly all the

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time that deflection is relatively small. You're not talking about

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light changing through ninety degrees. You talk about it changing

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through a few degrees at most, and that kind of

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you could link to the idea of the escape velosity.

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In order to get it changing through a really substantial direction,

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you'd have to be very close into a black hole

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or something like that. And at that point you're almost

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falling into the black hole and everything is doomed. So

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you need to set up a really unusual set of

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circumstances for some light from the Milky Way to be

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bent by let's say three four degrees by one source,

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and then go to one other source and be bent

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again and again and again. That chain of events would

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probably get only a tiny time a little bit. So

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I think you could imagine a scenario where there are

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packets of light photons from the Milky Way that get

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back to the Milky Way and that mechanism, but there'd

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be barely any and we wouldn't really be able to

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detect them if there were any at all. If there

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were dust clouds near the Milky Way, some of the

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light from the Milky Way would reflect off them. And

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this is like the beautiful reflection nebulae we see Paul

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Dotta through our galaxy the things that we get fabulous

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asher photos off. Now, I was imaging doing some master

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of photography a few months ago, the larger and the

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small Magellanic clouds, and learning a new photograph processing tool

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that friends of mine who were incredibly gifted ATTERA photographers

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taught me how to use, and playing with that and

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stretching and bending and fiddling. There's a persistent feature around

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the Magellanic cloud that looks like dust that appears to

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be structured that I thought was I've overdone it on

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the image, And then I looked at a different image

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and the same structures were there at the same time.

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So there's clearly dust and gas that has been stripped

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off the large magilanic cloud by the Milky Way that

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is illuminated enough that it is brighter than the background

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pitch black of the sky for my camera to pick

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it up. That means that there is light hitting that

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and bouncing back to us to see it, and some

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fraction of that light will be light from the Milky Way.

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Now I don't know enough about that there, but I've

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not been able to find much discussion online. Selves fascinated

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when I saw it on these photos repeatedly, but I

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would hazard that some of the light that is illuminating

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this gas and dust that is around the large Magilanic

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cloud is light from the Milky Way reflected back to us,

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but that isn't anywhere near enough to get an image.

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It's a bit like when you're looking on a really

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foggy day and the sky is really bright. You can't

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see an image of the sun from that light. You've

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just got a scattered at you in all directions. Help

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we lost all of the information. So I think we

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do get reflected light from the Milky wacoing back and

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things like that, but to actually get an image, a

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reflected image like you'd see the mirror, that to me

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is beyond the bounds of possibility. The nearest will get

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is finding galaxies that look very similar to our arm

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so they give us a perspective of what we would

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look like from the outside.

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Yeah, this is one of Fred's great wishes. If we

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were asked a question not so long ago, if you

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could do anything, if you could just take a spacecraft

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anywhere in the universe and look at something that you

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want to see, what would it be. And Fred's wish

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was to go outside of our galaxy so we could

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look at it and see exactly what shape it was.

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We have a pretty good idea, but we've never been

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able to image it. We don't know for sure if

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it's got the number of spiral arms that they assume

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it's got, or anything like that. So that was Fred's

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you know, if you could do anything at the snap

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of his fingers, looking at our galaxy from outside was

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one of his wishes, So Tony, unfortunately, no, we cannot

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see a reflection of our galaxy in any way or form.

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We probably are seeing light bounce back to us, as

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Johnny was explaining, from our own galaxy, but it certainly

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wouldn't give us an image. But thanks for the question.

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Great to hear from you. Our next question comes from Charles.

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This is a short, sweet, but rather difficult one to answer.

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What do you think of the theory that we live

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in a holographic universe? Now, this is something I've seen

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popping up time and time again in the popular press,

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and I suppose we should explain what a holographic universe

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is before we decide whether or not we live in one.

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Yeah, this is one of the ones that breaks my head.

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So your answer to this will be neither good or

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akura issispact, because this is far from our own expertise.

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Do my best. The holographic universe stuff is tied to

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string theory, is my understanding, and to me is at

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the point where you're bordering along the boundary between science

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and philosophy because you're starting to ask questions that we

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have no way of testing yet, and that's really hard. Now,

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this all ties down to very mathematical and very theoretical

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studies of the universe. I think getting back to about

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the nineteen nineties where people found that in some versions

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of the mass of string theory, you can get three

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dimensional stuff being represented in a two dimensional way without

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losing any data. And it's an answer to some of

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the issues to do with information and black holes. It's

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one of the things that led people to suggest that

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you can get information that does into black holes, is

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not lost, but might be stored in the event horizon

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and all these kind of things. Now, my understanding of

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it that you can tell by that explanation is kind

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of limited. It's not my area of expertise. It is

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called the holographic principle, and that leads to the idea

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of the holographic universe. So the idea that you can

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get essentially a two dimensional representation of all the data

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you need to have a three dimensional thing means that

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you could have, in some way a three dimensional appearing

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thing actually only be two dimensional a holograph essentially, So

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that's what the holograph is all about. And I don't

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fully understand that. You can tell by the explanation. It's

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interesting because it's become sufficiently rooted in popular consciousness. And

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this is a total turtle detail here, but one of

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the kinds of music I really like to listen to

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is a genre called symphonic metal, which is a bit bizarre.

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It's kind of operatic rock. If you think about the

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kind of stuff Queen we're doing, I'd go a little

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bit more rocky, a little bit more metal than that.

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It's like that, so you typically have an operatically trend

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soprano singing. The two biggest groups of that that I

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listened to quite a lot of groups called Nightwish and Epica.

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I might wish have done a couple of sigince sceened

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albums where they talk about the origin of life and

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philosophy and origin of species and all sorts of stuff.

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Like that.

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One of their tracks, which I try and get on

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the radio occasionally when I do a chat about asteroids,

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is a tribute to the great scientists Eugene Shoemaker, whose

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ashes were put onto a spacecraft to the moon, who

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discovered the comment that hit dup to back in nineteen

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ninety four. So that's might wish. But Epica have an

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album named the Holographic Principle, which they've always done slightly

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quirky projects as well. The fact that this concept, this

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thing that is at the very bound extreme bounds of

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theoretical physics and theoretical cosmology, has become sufficiently culturally embedded

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that rock groups and naming albums after it is kind

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of quirky for me. And it shows that it's not

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a totally brand new idea, because if it was certainly

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brand new, it wouldn't be in the popular consciousness. Yet

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it does make my head hurt. I will wholeheartedly and

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happily admit that this is not something where I'm an expert,

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you know, in any way, shape or form. There are

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very detailed discussions of it online. Even if you pull

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up the Wikipedia page. The Wikipedia page is pretty lengthy

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and links to a lot of references, talks about some

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of the discussions people have had about it, talks about

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information density, the people who've proposed all these ideas, and

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gives you links to other places. Now I know, certainly

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when I'm teaching, I have to tell people that Wikipedia

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is not the bill and end or it's a fluid resource.

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It's subject to change, and it's subject to being incorrect.

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But with a lot of these topics in the more

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theoretical parts of astrophysics or even fresterronomy as a whole,

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Wikipedia tends to be really pretty good because there's enough

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people out there who are really fascinated by the field

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that when they see something wrong, they'll fix it. The

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aerozont tend to hang around that one, so it tends

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to actually be a good first resource as long as

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it's not your only resource. And the article there about

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the holographic principle also links to these two albums by

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different groups that have had the same name that has

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a fairly lengthy discussion of a lot of the different

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ideas behind this, a few links to different types of

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theorems that are tied to this, and also a good

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list of twenty eight references and a couple of sources

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on top of that, including journal papers where if you

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really want to dive into this you can do will

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be very quickly apparent to you that by reading it

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to five minutes you already know more about it than

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I do. And then back to this sounds from point

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out every way in which I was wrong here, But

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that's my take on it. Now, with all that said,

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to get back to the question what do I think

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about the theory? I think I don't think about it

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very much because it makes my head hurt. But as

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I said, I think it gets to the point of philosophy.

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It's if there is something where you can make no

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testable measurement to differentiate between two different ideas, you're more

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in the bounds of philosophy than you are in the

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bounds of science. And it's a bit like that oldest

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of how do I know that anybody else actually exists?

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The only perception, the only existence I'm aware of is

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my own existence. I'm aware of my inner dialogue, and

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I'm aware of what I.

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See him perceive.

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And we implicitly assume that everybody we talk to is

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a being like us, but it could equally just be

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a convenient fiction. I could be entirely locked in my

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own head having all this is a kind of weird dream.

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I mean, I'd argue that this question is an example

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of the fact that I'm not just locking my own

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head and having a weird dream, because I would have

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never thought of this question myself. But you start getting

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to points where you are having an argument that is

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more one of philosophy than it is one of science.

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And for me, the thing that differentiates the two comes

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down to prediction and testing of theories. If you have

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a theory that is new, it should make testable predictions.

240
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And I'm not really sure because I'm not a theoretical

241
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cosmogis of theoretical physicist. If this doesn't, if it does,

242
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how they would work. So for me, then I come

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00:13:07.440 --> 00:13:09.399
back to kind of the Okhams Raiser thing. With a

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lack of knowledge, with a lack of expertise. The simplest

245
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explanation to me is just that we are in the universe.

246
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We see but it's really fascinating to look into this.

247
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It's important to do this kind of work. I'm just

248
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not qualified to do it. I don't have the expertise.

249
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Yeah, it sort of connects with another theory that we

250
00:13:28.200 --> 00:13:31.840
have created this universe in our own minds as a collective,

251
00:13:34.080 --> 00:13:37.399
with the physical existence of the universe is a manifestation

252
00:13:37.720 --> 00:13:41.399
of us. Yeah, I've heard that one before, which is.

253
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An interesting one. Tied tow it is simulation theory, which

254
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I've also seen musical albums. Then after, which is the

255
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idea that what we live in is a simulation, and

256
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it's extrapolating off More's law and similar laws about computing

257
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power increasing into the future, which is that whilst the

258
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universe is infinitely complex, the amount of computing how you

259
00:14:00.360 --> 00:14:03.600
would need to fully simulate a universe is not as

260
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high as you would think, particularly if you set up

261
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your code so you only simulate the bits that of

262
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being observed at a time. Yeah, you don't need to

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For example, if you were simulating the Earth and everything,

264
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you wouldn't need to simulate the surface of these extra

265
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planets we've discovered yet because we don't have the ability

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to see them, so you save a huge amount in processing.

267
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So that leads to this argument that you could set

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up a simulation with their quality of fidelity that we

269
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couldn't know the difference. Simulation theory then goes to one

270
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step further and says, if you can do that once,

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it's only a small step from being able to do

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something once to being able to do it many, many times.

273
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So therefore, statistically it becomes more likely that we live

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in a simulation rather than the real world, because there'll

275
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be millions of universes and only one of them will

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be real. And it's fascinating, it's really good fun. But

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again it's philosophy, because how do we test this unless

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we get to take the pill and step out of

279
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the matrix and see it for what it is. How

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you test between these things is really the child for

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me to make them into a really scientificness gosh, rather

282
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than philosophicalword.

283
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Yeah, the Matrix was a good film in a constructed

284
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universe and the reality was much more horrifying. But yeah,

285
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great question, and yeah, I think that's one that will

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be debated for years to come. Thanks Charles. This is

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Space Nuts Andrew Dunkley here with Professor John T. Horna.

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00:15:27.600 --> 00:15:29.240
Let's take a little break from the show to tell

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Now back to the show Space Nuts. Okay, Johnny, let's

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do some audio questions. And this one I thought we'd done,

324
00:17:32.920 --> 00:17:36.279
but I remember I did send it to you in name,

325
00:17:36.440 --> 00:17:38.160
but I sent you the wrong audio, so we did

326
00:17:38.200 --> 00:17:40.559
the other one. And so this is the question I

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00:17:40.680 --> 00:17:42.960
meant to send you a couple of weeks ago from David.

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00:17:43.160 --> 00:17:47.079
This is David from zagein Texas. I've got another question

329
00:17:47.079 --> 00:17:50.559
about Black Halls, just like all my other questions. I

330
00:17:50.720 --> 00:17:52.759
was listening to the latest episode and you were talking

331
00:17:52.839 --> 00:17:58.440
about late spinning around black Halls, and I was being

332
00:17:58.440 --> 00:18:00.920
able to see the f facts later than when the

333
00:18:01.880 --> 00:18:07.240
event actually happened. But that got me thinking, if the

334
00:18:07.400 --> 00:18:10.319
light goes around a black hole and then it starts

335
00:18:10.400 --> 00:18:15.720
to slowly get sucked in, would the additional gravity of

336
00:18:15.880 --> 00:18:19.279
the black hole pulling on the light increase the speed

337
00:18:19.359 --> 00:18:21.559
of the light any faster than the speed of light.

338
00:18:21.599 --> 00:18:22.359
Or even at all?

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00:18:23.279 --> 00:18:25.480
Because I know when a ballet dancer is spinning and

340
00:18:25.599 --> 00:18:29.400
she pulls her arms in, she spins faster. So would

341
00:18:29.480 --> 00:18:33.240
that effect be the same on light spinning around the

342
00:18:33.279 --> 00:18:37.920
black hole and then getting sucked in. I'm not really

343
00:18:37.960 --> 00:18:40.920
sure how that works with light, considering it has no mass,

344
00:18:41.119 --> 00:18:43.640
but I appreciate if you answer my question.

345
00:18:43.960 --> 00:18:47.799
Thank you. Good on you, David. I'm pretty sure ballerinas

346
00:18:47.799 --> 00:18:51.559
don't spin at the speed of light, but could be wrong.

347
00:18:52.319 --> 00:18:55.759
They do spin rather remarkably. Yeah, look, this is an

348
00:18:55.799 --> 00:18:59.960
interesting one. Light is the fastest thing in the universe,

349
00:19:00.240 --> 00:19:05.039
so I venture to say, and I think in conversations

350
00:19:05.119 --> 00:19:07.400
Fred and I have had in the past that nothing

351
00:19:07.480 --> 00:19:10.559
goes faster than the speed of light in a vacuum.

352
00:19:11.079 --> 00:19:15.039
So I would imagine the answer is probably know that

353
00:19:15.319 --> 00:19:17.640
the black hole can't make light go faster than the

354
00:19:17.680 --> 00:19:18.279
speed of light.

355
00:19:19.200 --> 00:19:21.759
It doesn't change the speed of light, it changes its direction.

356
00:19:23.599 --> 00:19:27.960
If you change the energy of light, because you can't

357
00:19:28.079 --> 00:19:30.400
change the speed, what you change is the frequency of

358
00:19:30.440 --> 00:19:33.359
the way of length. So if light is trying to

359
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escape from a mass, then you see a thing called

360
00:19:37.559 --> 00:19:41.119
gravitational redshift. So light coming up from the surface of

361
00:19:41.160 --> 00:19:44.200
the Sun will be red shifted at tony a little

362
00:19:44.240 --> 00:19:48.000
bit because it's escaping from the gravitational well of the Sun. Similarly,

363
00:19:48.000 --> 00:19:49.880
if it was falling inwards, so you expected to be

364
00:19:49.920 --> 00:19:52.319
slightly blue shifted. But it's a very very small and

365
00:19:52.400 --> 00:19:55.720
perceptible thing in terms of the speed of light being

366
00:19:55.759 --> 00:19:58.759
the fastest thing there results where all our models of

367
00:19:58.799 --> 00:20:02.680
the universe and everything's set. And Terry Pratchett, in one

368
00:20:02.720 --> 00:20:04.920
of the many discworld books that I love very well,

369
00:20:04.960 --> 00:20:07.599
made the point that darkness must travel faster than light.

370
00:20:08.160 --> 00:20:10.559
It's whenever you turn on a light, it was already dark.

371
00:20:11.599 --> 00:20:15.119
I think it's quite nice and poetic. But in reality

372
00:20:15.160 --> 00:20:17.119
it seems that the speed of light in all the

373
00:20:17.200 --> 00:20:20.240
models we have of the investent cosmologies is kind of

374
00:20:20.440 --> 00:20:24.440
inviolable speed limit of the universe. Now, it might be

375
00:20:24.559 --> 00:20:26.240
that when we have a chat in twenty years time

376
00:20:26.480 --> 00:20:28.880
that a change to tally, because that's how science works.

377
00:20:30.200 --> 00:20:32.599
But at the minute, the speed of light is a

378
00:20:32.680 --> 00:20:35.440
speed of light, and there is an implicit thing there

379
00:20:35.480 --> 00:20:37.039
that we never mentioned that we should do that. What

380
00:20:37.119 --> 00:20:38.920
we're actually talking about there is the speed of the

381
00:20:39.000 --> 00:20:42.079
light in the vacuum space. Yeah, so as soon as

382
00:20:42.079 --> 00:20:44.279
the light passes into a medium, it slows down, and

383
00:20:44.400 --> 00:20:48.119
that's why you get refraction. If light goes from air

384
00:20:48.440 --> 00:20:51.319
into water, the speed of light in water is slower

385
00:20:51.359 --> 00:20:53.680
than the speed of light in air. That's why you

386
00:20:53.799 --> 00:20:57.839
get the bending, the change of direction there. With black holes,

387
00:20:57.960 --> 00:21:00.920
what's actually happening is that the black hole bending space,

388
00:21:01.519 --> 00:21:03.519
and the light is following a straight path on a

389
00:21:03.599 --> 00:21:07.519
curved surface, so it appears to bend, which is subtly different.

390
00:21:08.160 --> 00:21:11.599
Essentially light falling into a black hole. If you could

391
00:21:11.640 --> 00:21:14.480
imagine being just outside the event horizon, so you're not

392
00:21:15.480 --> 00:21:19.680
dead and you're looking outwards, the things you were looking

393
00:21:19.720 --> 00:21:22.240
at would look a little bit bluer than they actually are,

394
00:21:22.640 --> 00:21:24.839
because light falling in is getting blue shifted as it

395
00:21:24.880 --> 00:21:28.960
comes towards you. Similarly, if you shone a yellow light

396
00:21:29.160 --> 00:21:31.440
or a green light laser, I've got one of those.

397
00:21:31.519 --> 00:21:33.720
When I do outreach sometimes to point the stars out.

398
00:21:34.039 --> 00:21:36.119
If I shown a green light laser out from near

399
00:21:36.160 --> 00:21:38.119
the event horizon of the black hole. The light would

400
00:21:38.119 --> 00:21:41.160
sile escape with some outside the event horizon, so they

401
00:21:41.279 --> 00:21:44.640
escape loss is lower than the sweed of light. There's

402
00:21:44.680 --> 00:21:48.519
an acceleration pulling back. The speed of the light cannot change,

403
00:21:48.559 --> 00:21:51.119
but the energy would change, so it would become gravitationally

404
00:21:51.200 --> 00:21:54.839
red shifted, so that green light laser would look redder

405
00:21:55.200 --> 00:21:58.200
to the observer where beyond the black hole than it

406
00:21:58.240 --> 00:22:00.480
would as it leaves in my hand where I'm in

407
00:22:00.519 --> 00:22:03.480
the shaddress frame for that. But the speed of light

408
00:22:03.559 --> 00:22:07.920
itself would not be changing caveat if the black hole's

409
00:22:07.960 --> 00:22:09.599
got a disc of material around it. If it's got

410
00:22:09.680 --> 00:22:12.200
material around it, then you're not moving through a perfect vacuum.

411
00:22:12.680 --> 00:22:14.359
So you would see a little bit of a change

412
00:22:14.400 --> 00:22:18.000
in speed there. But that is a different physical process

413
00:22:18.039 --> 00:22:22.160
for a different reason. But it's worth being complete.

414
00:22:22.200 --> 00:22:25.519
I guess, yes, Yes, I suppose. The other interesting thing

415
00:22:25.559 --> 00:22:28.880
about light, which we've talked about before, is that, as

416
00:22:28.920 --> 00:22:32.079
you said, it slows down in liquid, but light going

417
00:22:32.160 --> 00:22:34.400
through a glass slows down, but when it comes out

418
00:22:34.440 --> 00:22:37.480
the other side it speeds up again. Yes, and that's

419
00:22:37.559 --> 00:22:42.079
like the other direction. Yeah, yeah, So it's a tricky

420
00:22:42.160 --> 00:22:45.759
thing light because we take it for granted, we need it.

421
00:22:45.960 --> 00:22:49.400
It's something we've adapted to on this planet as human beings.

422
00:22:50.119 --> 00:22:52.240
If we would have venture to another planet with a

423
00:22:52.279 --> 00:22:57.200
different kind of star, it would be alien to us

424
00:22:57.279 --> 00:23:00.920
in more ways than we could imagine, because we are

425
00:23:01.119 --> 00:23:05.839
used to a medium sized star with a relatively right light.

426
00:23:06.039 --> 00:23:08.920
But if you went to a planet with a I

427
00:23:08.960 --> 00:23:13.000
don't know, a blue star, a bright blue star, the

428
00:23:13.160 --> 00:23:15.160
vegetation to be a different color because it would be

429
00:23:16.039 --> 00:23:20.359
having to do a different kind of photosynthesis. You'd see

430
00:23:20.440 --> 00:23:24.680
things differently. You know, there's all sorts of weird and

431
00:23:24.720 --> 00:23:28.000
wonderful things that light could do in other places. Just

432
00:23:28.119 --> 00:23:31.319
theory at the moment, but action.

433
00:23:32.880 --> 00:23:36.279
I've seen these articles about a small subset of women

434
00:23:36.319 --> 00:23:39.240
who have an extra set of cells detecting color in

435
00:23:39.240 --> 00:23:41.759
their eye, which gives them an incredibly more granular and

436
00:23:42.000 --> 00:23:47.400
fine ability to differentiate colors, so the visual equivalent of supertesters,

437
00:23:48.160 --> 00:23:51.359
and they can see something that to you or eye

438
00:23:51.359 --> 00:23:53.359
would just look like it's cirticle.

439
00:23:53.039 --> 00:23:54.519
And they can see the hues within that.

440
00:23:55.400 --> 00:23:58.400
Equally, you see these beautiful images of birds that look

441
00:23:58.599 --> 00:24:01.200
very dune and boring, to us, but then you see

442
00:24:01.200 --> 00:24:03.119
a visualization of what they would look like to one

443
00:24:03.160 --> 00:24:05.599
of the bird and they're incredibly colorful and vibrant because

444
00:24:05.599 --> 00:24:08.440
the birds are seeing frequencies that our eyes are not

445
00:24:09.079 --> 00:24:12.200
accustomed to. Similarly with bees and things like that, seeing

446
00:24:12.240 --> 00:24:15.920
into the ultra violet, and that will be accentuated for

447
00:24:16.640 --> 00:24:20.640
objects around, you know, planets, around the stars. You then

448
00:24:20.680 --> 00:24:22.960
get the other ties. I have had the pleasure of

449
00:24:23.000 --> 00:24:25.680
seeing a couple of total eclipses of the Sun, one

450
00:24:25.720 --> 00:24:27.680
of which I didn't actually see because it was cloudy

451
00:24:27.759 --> 00:24:29.680
and Cairnes in twenty twelve, but we saw the build

452
00:24:29.720 --> 00:24:33.000
up in the aftermath and the eclipse itself so soon.

453
00:24:33.480 --> 00:24:36.359
But there's this very weird Uncammi Valley period in the

454
00:24:36.440 --> 00:24:38.960
minutes just before and the minutes just after totality, where

455
00:24:39.000 --> 00:24:42.000
the Sun is a tiny little point because most of

456
00:24:42.039 --> 00:24:44.240
it's blocked by the Moon. So instead of having a disc,

457
00:24:45.240 --> 00:24:47.359
the Sun gets smaller and smaller until we've essentially got

458
00:24:47.400 --> 00:24:49.759
a single point of light shining nearly as bright as

459
00:24:49.799 --> 00:24:53.359
the sun, and shadows change and the behavior of shadows

460
00:24:53.440 --> 00:24:56.799
look different when you've got a single point, so rather

461
00:24:56.839 --> 00:24:59.720
than a few sorts of light, and that gives everything

462
00:24:59.759 --> 00:25:04.200
a very uncomfortable, slightly unusual feeling. You've got very cool

463
00:25:04.240 --> 00:25:07.799
effects like standing under a tree and all the leaves

464
00:25:07.839 --> 00:25:10.240
are blowing and all the gaps between the leaves act

465
00:25:10.240 --> 00:25:12.599
as pinhole cameras and you get images of the crescent

466
00:25:12.759 --> 00:25:14.519
Sun on the ground, which is spectacular.

467
00:25:14.920 --> 00:25:15.160
Wow.

468
00:25:15.559 --> 00:25:18.920
Incidentally, on the eclipse trip I went to for the

469
00:25:19.119 --> 00:25:22.400
Xmouth eclipse, a lot of people have a little pinhole

470
00:25:22.440 --> 00:25:25.279
cameras that they made to women's eclipse, and one person

471
00:25:25.400 --> 00:25:28.279
had a pack of jats, which are just an Australian

472
00:25:28.400 --> 00:25:31.720
cheese biscuit, and the poles in the biscuits were perfect

473
00:25:31.799 --> 00:25:35.759
pinhole cameras, and they had a snack, so when the

474
00:25:35.759 --> 00:25:38.839
eclips finished, nobody was hungry. It was absolutely brilliant and

475
00:25:38.880 --> 00:25:41.279
I'd never even thought of it, so you get all

476
00:25:41.319 --> 00:25:44.319
these weird effects in it. We take for granted very

477
00:25:44.480 --> 00:25:47.680
very much that our perception is actually what is out there,

478
00:25:48.319 --> 00:25:51.559
and this was brought home to me. I went to

479
00:25:51.680 --> 00:25:53.920
driving range with one of my PhD students. Obviously I

480
00:25:54.000 --> 00:25:56.720
don't play golf, and I'm particularly bad at it, but

481
00:25:56.839 --> 00:25:59.160
there's always this thing about what you perceive and how

482
00:25:59.240 --> 00:26:01.480
much of the area of your vision that you're actually

483
00:26:01.519 --> 00:26:03.759
actively updating, and how much of it is just auto

484
00:26:03.960 --> 00:26:06.960
generated by your brain best on all the information and

485
00:26:07.079 --> 00:26:09.759
you forget about that. But we actually are like our

486
00:26:09.799 --> 00:26:11.920
eyes are rastering across and we only see a tiny

487
00:26:11.960 --> 00:26:14.960
little bit of our vision. Are we seeing true updates?

488
00:26:14.960 --> 00:26:17.880
And I've never really seen that demonstrated. And sois at

489
00:26:17.920 --> 00:26:19.680
the driving range, because if I hit a golf ball,

490
00:26:20.200 --> 00:26:21.920
and I often hit them very badly, but they go

491
00:26:22.039 --> 00:26:24.359
up in the air somewhere, and I can stand there

492
00:26:24.400 --> 00:26:26.839
and watch where it goes, and it's easy, and you

493
00:26:26.880 --> 00:26:29.079
can follow it all the way. The minute you look

494
00:26:29.119 --> 00:26:32.400
away and look back, you cannot find the ball exactly.

495
00:26:32.880 --> 00:26:35.559
It's astonishing, and you think when you're just looking at

496
00:26:35.559 --> 00:26:38.519
it's really obvious there's a ball. There is the yellow

497
00:26:38.640 --> 00:26:41.400
or white against the blue sky that target more obvious.

498
00:26:41.440 --> 00:26:43.839
Look away, totally lost it, even if you know where

499
00:26:43.880 --> 00:26:47.119
it was. And that's all down to how our brain

500
00:26:47.279 --> 00:26:49.880
is processing the day to were getting the ball is

501
00:26:49.920 --> 00:26:53.079
still there. The ball hasn't miraculously disappeared, and so all

502
00:26:53.160 --> 00:26:55.960
these kind of questions. I find it really fascinating that

503
00:26:56.000 --> 00:26:59.200
boundary between the perception of the reality and I wonder

504
00:26:59.319 --> 00:27:02.799
what we observe is of our own generation essentially.

505
00:27:03.079 --> 00:27:06.279
Yeah, it reminds me of that famous gorilla experiment. You're

506
00:27:06.279 --> 00:27:10.119
aware of that one. Yeah, that that is a very

507
00:27:11.279 --> 00:27:14.920
great It's a great example of what you think you

508
00:27:15.039 --> 00:27:19.079
see and what's really there. And I won't try and

509
00:27:19.160 --> 00:27:21.880
spoil it for anybody. You can see it on YouTube videos.

510
00:27:22.440 --> 00:27:25.119
Yeah, they do that in a lot of training for

511
00:27:25.200 --> 00:27:28.319
things like police officers, to talk about the funt that

512
00:27:28.400 --> 00:27:32.200
people who think they've witnessed something are inherently unreliable. And

513
00:27:32.680 --> 00:27:36.480
it's also what makes it very feasible for magicians and

514
00:27:36.680 --> 00:27:41.160
concerts and tricksters to trick you by taking your brain

515
00:27:41.200 --> 00:27:43.079
off somewhere else. You know. The whole slight of hump

516
00:27:43.119 --> 00:27:44.799
thing is all bother of this thing.

517
00:27:45.319 --> 00:27:49.440
Yeah, it's really remarkable. I could talk about this stuff forever.

518
00:27:49.519 --> 00:27:53.519
I really think that it's fascinating. But yeah, lovely question, David,

519
00:27:53.559 --> 00:27:56.680
and I hope that it covered you adequately as we

520
00:27:57.039 --> 00:27:59.559
strive to do here on space nuts. But no, black

521
00:27:59.599 --> 00:28:02.640
hole can't make light travel faster than light.

522
00:28:07.359 --> 00:28:08.079
Space nuts.

523
00:28:08.640 --> 00:28:11.680
Our final question comes from a regular cender in arat

524
00:28:11.920 --> 00:28:14.279
from the United Kingdom. Below.

525
00:28:14.400 --> 00:28:17.519
It is Duncan from Weymouth, in the UK yere again,

526
00:28:20.039 --> 00:28:23.680
just wondering is it possible to have an exoplanet that

527
00:28:23.960 --> 00:28:28.960
is entirely liquid, so it could just be like a

528
00:28:29.039 --> 00:28:34.480
global ocean, but with no solid core, just liquid all

529
00:28:34.519 --> 00:28:38.400
the way through. If it's not possible and it has

530
00:28:38.480 --> 00:28:41.519
to have a solid core, why is that?

531
00:28:42.279 --> 00:28:43.160
And also.

532
00:28:44.359 --> 00:28:47.240
How small could that solid core be?

533
00:28:47.519 --> 00:28:48.039
Could it be.

534
00:28:49.279 --> 00:28:54.039
Something the size of say Everest, or could it be

535
00:28:54.119 --> 00:28:57.960
even smaller or does it have to be something bigger,

536
00:28:58.839 --> 00:29:02.519
maybe the size of the moon. I don't know what

537
00:29:02.599 --> 00:29:05.039
are your thoughts on that and opinions?

538
00:29:05.599 --> 00:29:07.079
Do you have any actual answers?

539
00:29:07.119 --> 00:29:07.839
Does anyone know?

540
00:29:09.799 --> 00:29:13.559
Just wondering, prouds you could give us some answers with

541
00:29:13.720 --> 00:29:14.359
regards to that.

542
00:29:15.599 --> 00:29:19.319
Okay, thank you very much, keep up good work.

543
00:29:21.119 --> 00:29:23.160
And well until next time.

544
00:29:23.799 --> 00:29:26.160
Thank you, Duncan. I love this question because these are

545
00:29:26.200 --> 00:29:29.480
the sorts of things I wonder. And look, we've got

546
00:29:29.559 --> 00:29:32.880
examples of ice worlds in our Solar system. They are

547
00:29:33.200 --> 00:29:36.599
ice moons that they have a solid surface, and it's

548
00:29:36.799 --> 00:29:38.839
thought that they probably have a solid core, but in

549
00:29:38.960 --> 00:29:43.440
between oceans. But he's talking about an exoplanet that is

550
00:29:43.960 --> 00:29:46.440
pure liquid, just a big blob of water.

551
00:29:46.839 --> 00:29:51.160
Yes, it's a fabulous question, and again this can have

552
00:29:51.240 --> 00:29:53.799
a shot answering the one answer. The short answer is

553
00:29:54.440 --> 00:29:57.319
essentially no, but it's not for the reason you're thinking of.

554
00:29:57.359 --> 00:29:59.319
It's not to do with the car. It's a fact

555
00:29:59.359 --> 00:30:01.480
that must can be a liquid, and I'm aware of

556
00:30:01.559 --> 00:30:04.279
in the vacuum of space, so one of the surface

557
00:30:04.319 --> 00:30:06.279
of the liquid you will get evaporation and you would

558
00:30:06.319 --> 00:30:08.039
end up with an atmosphere, so you'd end up with

559
00:30:08.119 --> 00:30:11.440
a guessious shroud around it doesn't need to be much atmosphere,

560
00:30:11.480 --> 00:30:14.039
So technically it couldn't be entirely liquid because it would

561
00:30:14.039 --> 00:30:16.200
need to be gas around it for there to be

562
00:30:16.279 --> 00:30:20.839
sufficient pressure that the material on the surface can remain liquid.

563
00:30:21.640 --> 00:30:23.680
You could create something, of course, but you'd need it

564
00:30:23.920 --> 00:30:27.119
like a bubble around it, glass shell or whatever. The

565
00:30:27.240 --> 00:30:30.599
other reason that in a physical sense it would be

566
00:30:30.720 --> 00:30:34.359
very unlikely to have this is that the things that

567
00:30:34.519 --> 00:30:39.200
you form are made of everything that's around. Rocky planets

568
00:30:39.880 --> 00:30:42.920
don't capture the hydrogen and healingxerescape ve loss is too high,

569
00:30:42.960 --> 00:30:46.000
so the gravity is too weak. But when you're forming something,

570
00:30:46.039 --> 00:30:48.240
you're building a planet, you're building in of everything that

571
00:30:48.400 --> 00:30:51.039
is around, so that will include a lot of water

572
00:30:51.160 --> 00:30:53.240
if you're somewhere where the temperature is low enough fur

573
00:30:53.400 --> 00:30:55.720
water to become an icon to be a solid, but

574
00:30:55.720 --> 00:30:58.200
it will also include iron and nickel and dust and

575
00:30:58.839 --> 00:31:01.759
all the other stuff, And you're not going to have

576
00:31:01.799 --> 00:31:06.160
a situation where everything you form a planet from would

577
00:31:06.319 --> 00:31:09.799
all be liquid at the same conditions, so you'd always

578
00:31:09.880 --> 00:31:12.200
end up with some stuff sinking to the middle of solids.

579
00:31:13.400 --> 00:31:15.880
What you could imagine, though, is you could have a

580
00:31:16.599 --> 00:31:19.920
idealized situation. Let's say you could quarantine an area of

581
00:31:19.960 --> 00:31:24.440
space off and you could form something planet mass out

582
00:31:24.480 --> 00:31:27.920
of absolutely perfectly pure water ice so and nothing else

583
00:31:28.000 --> 00:31:32.720
but hydrogen and oxygen bound together. In that scenario, I

584
00:31:32.799 --> 00:31:35.480
could imagine you having a planet that is almost entirely

585
00:31:35.640 --> 00:31:39.720
liquid except for the atmosphere, which will be water vapor

586
00:31:40.000 --> 00:31:42.920
and would probably then quickly become an oxygen rich atmosphere

587
00:31:42.960 --> 00:31:46.119
because once you've got water vapor exposed to UV, it

588
00:31:46.200 --> 00:31:49.279
gets dissociated in hydrogen and oxygen blah blah blah that

589
00:31:49.640 --> 00:31:55.680
fappens there. You would then have a situation where, depending

590
00:31:55.720 --> 00:31:59.000
on the mass of the object, you could have an

591
00:31:59.039 --> 00:32:01.559
object liquid all the way through. If the object is

592
00:32:01.640 --> 00:32:06.039
too lower mass, you'd gradually lose it because if it's

593
00:32:06.079 --> 00:32:08.039
a low enough mass and it's going around the star,

594
00:32:08.799 --> 00:32:11.960
the stuff that's boiling off former gas will then be

595
00:32:12.079 --> 00:32:14.279
moving fast enough to escape, so the atmosphere will be

596
00:32:14.319 --> 00:32:16.480
stripped and the thing will essentially boil away, like if

597
00:32:16.519 --> 00:32:19.400
you leave a pan on the hob. I would imagine

598
00:32:19.440 --> 00:32:23.079
that there is also a range of sizes and masses

599
00:32:23.119 --> 00:32:25.240
where the pressure in the center gets so high that

600
00:32:25.359 --> 00:32:28.880
the water becomes ice again, even at high temperature, and

601
00:32:29.000 --> 00:32:31.480
we see this with Urinus and Nettune. There is certainly

602
00:32:31.640 --> 00:32:34.440
water ice in the interior of those, but it's a

603
00:32:34.519 --> 00:32:37.039
different phase of water ice to that we used, so

604
00:32:37.319 --> 00:32:39.720
I never really understood this. But there is an incredibly

605
00:32:39.759 --> 00:32:44.799
gifted Australian researcher called Helen maynad Caseley who last time

606
00:32:44.839 --> 00:32:46.759
I've not seen her for a few years, but she

607
00:32:46.880 --> 00:32:50.279
used to work down an anstole at in northern Sydney

608
00:32:50.400 --> 00:32:53.519
using devices like one bat doing X ray diffraction and

609
00:32:53.559 --> 00:32:56.880
stuff like this, and she discovered several new types of

610
00:32:57.000 --> 00:32:59.480
water ice because she was looking at what happens to

611
00:32:59.599 --> 00:33:03.640
water are temperatures and pressures very different to room temperature,

612
00:33:04.240 --> 00:33:06.240
and that can be really cold conditions lack on the

613
00:33:06.400 --> 00:33:09.200
icimins of Jupiter, or it can be really high pressures

614
00:33:09.319 --> 00:33:12.279
or both. And so it's fairly well established that if

615
00:33:12.319 --> 00:33:16.200
you increase the pressure water ice will remain solid at

616
00:33:16.279 --> 00:33:20.799
higher temperatures. That this boiling at one hundred and freezing

617
00:33:20.839 --> 00:33:24.039
at zero is a function of the current atmosphere pressure

618
00:33:24.119 --> 00:33:27.680
we have on Earth, and you change that and it changes. Yeah. Incidentally,

619
00:33:27.759 --> 00:33:30.079
that's why if you're a bit of a tea fishing idol,

620
00:33:30.160 --> 00:33:31.759
you cannot get a good cup of tea at high

621
00:33:31.799 --> 00:33:35.000
altitude because water boils are a low enough temperature that

622
00:33:35.240 --> 00:33:37.240
it makes them a cup of tea. You know. But

623
00:33:37.359 --> 00:33:40.000
people who went into the Himalayas grumbling about how terrible

624
00:33:40.039 --> 00:33:42.720
the tea was, and you're at high in altitude that

625
00:33:42.799 --> 00:33:46.839
the boiling point of water is reduced enough that and

626
00:33:47.200 --> 00:33:49.480
for people listening in America who aren't familiar with this,

627
00:33:49.640 --> 00:33:52.960
people particularly from the UK, are very obsessive about their tea.

628
00:33:53.000 --> 00:33:54.680
But to make tea you need the water to be

629
00:33:54.799 --> 00:33:57.880
on a rolling boil at one hundred degrees c. Well

630
00:33:58.319 --> 00:34:00.640
for many kinds of black teas, green tea, and white

631
00:34:00.640 --> 00:34:03.440
t it's called the temperature. But when you make tea

632
00:34:03.519 --> 00:34:07.319
with lukewarm water. That is wrong. That just doesn't work,

633
00:34:07.359 --> 00:34:09.280
and you get a very different behavior. And it's to

634
00:34:09.360 --> 00:34:10.679
do with the chemistry of what goes on.

635
00:34:12.280 --> 00:34:13.880
Yeah, that's fascinating.

636
00:34:14.119 --> 00:34:18.719
Yeah, comes into this mm HM, which would ly to

637
00:34:18.800 --> 00:34:20.840
if we ever found a planet that was pure water

638
00:34:21.239 --> 00:34:23.679
and was liquid all the way through, that to me

639
00:34:23.760 --> 00:34:26.320
will be evidence of the builders of Magra, thea from

640
00:34:26.440 --> 00:34:28.280
double Sadoms, you know, it would be evidence that this

641
00:34:28.519 --> 00:34:31.239
was a constructed entity rather than something that form naturally.

642
00:34:31.760 --> 00:34:31.960
Bis.

643
00:34:32.039 --> 00:34:34.400
The contamination is the simplest way of saying you wouldn't

644
00:34:34.400 --> 00:34:36.760
get a purely liquid planet. You can get a planet

645
00:34:36.800 --> 00:34:39.639
that is more liquid than anything else. And we have

646
00:34:39.760 --> 00:34:42.800
suspicions that there are these high seeing worlds its ocean planets,

647
00:34:43.800 --> 00:34:46.119
and the reasoning there is that water is actually one

648
00:34:46.159 --> 00:34:48.400
of the most common things in the universe. You've got

649
00:34:48.440 --> 00:34:50.480
the most common atom with hydrogen, You've got the third

650
00:34:50.519 --> 00:34:52.519
mass common atom with oxygen. You put them together, you

651
00:34:52.599 --> 00:34:56.480
get water, ice or liquid water or water vapor. So

652
00:34:56.559 --> 00:34:59.559
you can imagine planets that have more water than anything else,

653
00:34:59.639 --> 00:35:02.840
that are a huge oceans with a coal underneath them

654
00:35:03.519 --> 00:35:06.199
that are ice and then liquid and ic again like

655
00:35:06.280 --> 00:35:08.840
we see without the moves, but getting something that is

656
00:35:08.960 --> 00:35:11.639
liquid from the surface to the car has those problems,

657
00:35:11.679 --> 00:35:14.639
one of contamination, one of you would need an atmosphere

658
00:35:14.679 --> 00:35:16.159
to have the pressure to remain liquid.

659
00:35:17.360 --> 00:35:20.480
Fascinating. Yeah, I love that question, Duncan. So the answer

660
00:35:20.559 --> 00:35:24.639
is probably no, but not far off in some respects.

661
00:35:24.760 --> 00:35:28.079
But it might take a megastructure of some kind to

662
00:35:29.079 --> 00:35:33.719
create a water world, although Kevin Costner did find one apparently,

663
00:35:34.400 --> 00:35:34.840
but only the.

664
00:35:34.880 --> 00:35:36.960
Costs of going that film the film We're outrageous.

665
00:35:37.000 --> 00:35:39.719
So yes, yes, yes they're trying to get it all

666
00:35:39.800 --> 00:35:42.800
back with a theme park, I think, but yes, Thank

667
00:35:42.840 --> 00:35:44.960
you Duncan. Always good to hear from you. You've always

668
00:35:45.000 --> 00:35:47.440
got some great ideas and if you would like to

669
00:35:47.480 --> 00:35:50.719
send us some questions please do via our website, space

670
00:35:50.840 --> 00:35:53.679
nuts podcast dot com, space nuts dot io and have

671
00:35:53.760 --> 00:35:55.400
a look around while you're there. Check out the shop,

672
00:35:55.519 --> 00:35:58.719
check out out around all the other things, and don't

673
00:35:58.719 --> 00:36:00.920
forget to click the AMA at the top, which is

674
00:36:00.960 --> 00:36:05.719
where you send your questions text or audio versions. Thank you, Johnny,

675
00:36:05.840 --> 00:36:06.559
that was great fun.

676
00:36:06.800 --> 00:36:08.559
It's a pleasure. It's always good to start. Thank you

677
00:36:08.559 --> 00:36:08.960
for having me.

678
00:36:09.480 --> 00:36:11.840
Oh no, my pleasure. We'll catch up with you next time.

679
00:36:12.159 --> 00:36:15.079
Professor John T. Horner from the University of Southern Queensland.

680
00:36:16.039 --> 00:36:17.000
Hugh couldn't be.

681
00:36:17.159 --> 00:36:19.159
With us today. I don't know what he's been up to,

682
00:36:19.280 --> 00:36:22.079
but I do know about today. Apparently he was using

683
00:36:22.119 --> 00:36:26.079
a telescope to try and see his own reflection. He's

684
00:36:26.119 --> 00:36:29.599
still going. He's been doing it for days apparently. And

685
00:36:29.760 --> 00:36:31.599
from me Andrew Uncley, thanks for your company. Catch you

686
00:36:31.639 --> 00:36:33.880
on the very next episode of Space Nuts. Bye bye.

687
00:36:35.360 --> 00:36:40.400
You'll be listening to the Space Nuts podcast available at

688
00:36:40.440 --> 00:36:45.679
Apple Podcasts, Spotify, iHeartRadio, or your favorite podcast player.

689
00:36:45.920 --> 00:36:48.679
You can also stream on demand at bides dot com.

690
00:36:49.239 --> 00:36:53.159
This has been another quality podcast production from nights dot Com.
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