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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.
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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 (https://www.space.com/gravitational-lensing)
Holographic Universe Theory
https://www.sciencedirect.com/science/article/pii/S0370157317303410 (https://www.sciencedirect.com/science/article/pii/S0370157317303410)
Liquid Exoplanets Research
https://www.nature.com/articles/s41550-020-1170-5 (https://www.nature.com/articles/s41550-020-1170-5)
Become a supporter of this podcast: https://www.spreaker.com/podcast/space-nuts-exploring-the-cosmos--2631155/support (https://www.spreaker.com/podcast/space-nuts-exploring-the-cosmos--2631155/support?utm_source=rss&utm_medium=rss&utm_campaign=rss) .
Episode link: https://play.headliner.app/episode/25740562?utm_source=youtube
00:00:00 --> 00:00:01 hello again thanks for joining us this
00:00:01 --> 00:00:04 is a Q&A edition of Space Nuts this is
00:00:04 --> 00:00:06 where the audience asks us questions and
00:00:07 --> 00:00:10 we refer to somebody else and uh in
00:00:10 --> 00:00:12 today's episode we are going to talk
00:00:12 --> 00:00:14 about uh whether or not we can see our
00:00:14 --> 00:00:16 own reflection in space that's a
00:00:16 --> 00:00:19 question from Tony are we living in a
00:00:19 --> 00:00:22 holographic Universe Charles wants to
00:00:22 --> 00:00:24 know David is asking about black holes
00:00:24 --> 00:00:27 versus light who wins that war and
00:00:27 --> 00:00:30 Duncan liquid planets are there any out
00:00:30 --> 00:00:33 there we'll find out on this episode of
00:00:33 --> 00:00:36 Space Nuts 15 seconds guidance is
00:00:36 --> 00:00:41 internal 10 9 ignition sequence start
00:00:41 --> 00:00:47 Space Nuts 5 4 3 2 1 2 3 4 5 5 Space
00:00:47 --> 00:00:51 Nuts asut report feels good and joining
00:00:51 --> 00:00:53 us to sort all of that out is Professor
00:00:53 --> 00:00:55 jonty Horner from the University of
00:00:55 --> 00:00:58 Southern Queensland hi JY good afternoon
00:00:58 --> 00:01:00 how you doing I'm good it's feels like a
00:01:00 --> 00:01:03 second since we last spoke absolutely
00:01:03 --> 00:01:04 time flies when you're having fun I
00:01:04 --> 00:01:05 think that's
00:01:05 --> 00:01:09 say h let's um muck in as they say in
00:01:09 --> 00:01:11 your part of the world uh let's uh go to
00:01:11 --> 00:01:14 our first question this one comes from
00:01:14 --> 00:01:15 uh
00:01:15 --> 00:01:19 Tony um hi guys given the cosmos has
00:01:19 --> 00:01:20 black holes gravity waves uh
00:01:21 --> 00:01:24 gravitational lensing uh light echos and
00:01:24 --> 00:01:27 dust cloud Reflections any chance we
00:01:27 --> 00:01:29 could ever see a reflection of our Milky
00:01:29 --> 00:01:32 Way Galaxy love the show Tony from
00:01:32 --> 00:01:36 Merrickville which is a suburb of Sydney
00:01:36 --> 00:01:38 thanks Tony what are your thoughts jny I
00:01:38 --> 00:01:40 think there's a short answer a long
00:01:40 --> 00:01:41 answer to this I think the short answer
00:01:41 --> 00:01:44 is I can think of nowhere that we could
00:01:44 --> 00:01:46 get a resolved image you know so we're
00:01:46 --> 00:01:48 not going to get something like a mirror
00:01:48 --> 00:01:50 held up to reality where we get a
00:01:50 --> 00:01:52 beautiful picture of the Milky Way
00:01:52 --> 00:01:54 galaxy reflected back to us the
00:01:54 --> 00:01:56 different phenomena that can bend light
00:01:56 --> 00:01:57 and change its
00:01:57 --> 00:02:00 direction are often Le to the amount of
00:02:00 --> 00:02:03 mass so you've got a black hole or a
00:02:03 --> 00:02:07 star or something like that and under
00:02:07 --> 00:02:09 Einstein Ser general relativity the idea
00:02:09 --> 00:02:13 is that mass curve space so like tries
00:02:13 --> 00:02:15 to go in what it thinks is a straight
00:02:15 --> 00:02:17 straight line but because the space is
00:02:17 --> 00:02:19 curved it gets deflected by Falling the
00:02:19 --> 00:02:22 shortest path through the curved space
00:02:22 --> 00:02:23 so that's how you get gravitational
00:02:23 --> 00:02:26 lensing how you get light being bent now
00:02:26 --> 00:02:28 light's traveling really really quickly
00:02:28 --> 00:02:30 so nearly all the time that deflection
00:02:30 --> 00:02:32 is relatively small you're not talking
00:02:32 --> 00:02:34 about light changing through 90 degrees
00:02:34 --> 00:02:36 you're talking about it changing through
00:02:36 --> 00:02:39 a few degrees at most yeah and that kind
00:02:39 --> 00:02:41 of you could link to the idea of the
00:02:41 --> 00:02:43 skap Velocity in order to get it
00:02:43 --> 00:02:45 changing through a really substantial
00:02:45 --> 00:02:46 Direction you'd have to be very close
00:02:46 --> 00:02:49 into a black hole or something like that
00:02:49 --> 00:02:50 and at that point you're almost falling
00:02:50 --> 00:02:51 into the black hole and everything is
00:02:51 --> 00:02:54 doomed so you need to set up a
00:02:54 --> 00:02:57 really unusual set of circumstances for
00:02:57 --> 00:02:59 some light from the Milky Way to be bent
00:02:59 --> 00:03:01 by let's say three or four degrees by
00:03:01 --> 00:03:03 one source and then go to another source
00:03:03 --> 00:03:06 and be bent again and again and again
00:03:06 --> 00:03:08 that chain of events would probably get
00:03:08 --> 00:03:10 only a tiny tiny little bit so I think
00:03:10 --> 00:03:13 you could imagine a scenario where there
00:03:13 --> 00:03:16 are packets of light photons from the
00:03:16 --> 00:03:18 Milky Way that get back to the Milky Way
00:03:18 --> 00:03:19 and that mechanism but there'd be barely
00:03:19 --> 00:03:21 any and we wouldn't really be able to
00:03:21 --> 00:03:24 detect them if there were any at all if
00:03:24 --> 00:03:26 there were dust clouds near the Milky
00:03:26 --> 00:03:28 Way some of the light from the Milky Way
00:03:28 --> 00:03:29 would reflect off them and this is like
00:03:29 --> 00:03:32 the beautiful reflection nebuli we see
00:03:32 --> 00:03:35 all doed through our galaxy the things
00:03:35 --> 00:03:38 that we get fabul asra photos of now I
00:03:38 --> 00:03:40 was Imaging doing some asro photography
00:03:41 --> 00:03:42 a few months ago the large and the small
00:03:42 --> 00:03:43 maganic
00:03:43 --> 00:03:46 clouds and learning a new photograph
00:03:46 --> 00:03:48 processing tool that friends of mine who
00:03:48 --> 00:03:49 were incredibly gifted asra
00:03:49 --> 00:03:52 photographers taught me how to use and
00:03:52 --> 00:03:54 playing with that and stretching and
00:03:54 --> 00:03:55 bending and
00:03:55 --> 00:03:57 fiddling there's a persistent feature
00:03:57 --> 00:04:00 around the maganic cloud that looks like
00:04:00 --> 00:04:02 dust that appears to be structured that
00:04:02 --> 00:04:04 I thought was I've overdone it on the
00:04:04 --> 00:04:05 image and then I looked at a different
00:04:05 --> 00:04:07 image and the same structures were there
00:04:07 --> 00:04:09 at the same time so there's clearly dust
00:04:09 --> 00:04:11 and gas that has been stripped off the
00:04:12 --> 00:04:15 large melanic Cloud by the Milky
00:04:15 --> 00:04:17 Way that is illuminated enough that it
00:04:18 --> 00:04:19 is brighter than the background pitch
00:04:19 --> 00:04:21 black of the sky for my camera to pick
00:04:21 --> 00:04:24 it up that means that there is light
00:04:24 --> 00:04:26 hitting that and bouncing back to us to
00:04:26 --> 00:04:29 see it and some fraction of that light
00:04:29 --> 00:04:32 will be light from the Milky Way now I
00:04:32 --> 00:04:33 don't know enough about that Deb I've
00:04:33 --> 00:04:35 not been able to find much discussion
00:04:35 --> 00:04:36 online cuz I was fascinated when I saw
00:04:36 --> 00:04:38 it on these photos
00:04:38 --> 00:04:41 repeatedly um but I would Hazard that
00:04:41 --> 00:04:43 some of the light that is Illuminating
00:04:43 --> 00:04:44 this gas and dust that is around the
00:04:44 --> 00:04:46 large maganic cloud is light from the
00:04:46 --> 00:04:49 Milky Way reflected back to us but that
00:04:49 --> 00:04:51 isn't anywhere near enough to get an
00:04:51 --> 00:04:54 image it's a bit like when you're
00:04:54 --> 00:04:55 looking on a really foggy day and the
00:04:55 --> 00:04:57 sky is really bright you can't see an
00:04:57 --> 00:04:59 image of the Sun from that light you
00:04:59 --> 00:05:01 just got light scattered at you in all
00:05:01 --> 00:05:03 directions yeah lost all of the
00:05:03 --> 00:05:05 information so I think we do get
00:05:06 --> 00:05:08 reflected light from the Milky Way going
00:05:08 --> 00:05:10 back and things like that but to
00:05:10 --> 00:05:12 actually get an image a reflected image
00:05:12 --> 00:05:15 like you see the mirror that to me is
00:05:15 --> 00:05:16 beyond the bounds of possibility the
00:05:17 --> 00:05:19 nearest we'll get is finding galaxies
00:05:19 --> 00:05:21 that look very similar to our own so
00:05:21 --> 00:05:23 they give us a perspective of what we
00:05:23 --> 00:05:25 would look like from the outside yeah
00:05:26 --> 00:05:28 this is one of Fred's great wishes if we
00:05:28 --> 00:05:31 were asked a question not so long ago uh
00:05:31 --> 00:05:32 you if you could do anything if you
00:05:32 --> 00:05:34 could just take a spacecraft anywhere in
00:05:34 --> 00:05:36 the universe and look at something that
00:05:36 --> 00:05:38 you want to see what would it be and and
00:05:38 --> 00:05:40 Fred's wish was to go outside of our
00:05:40 --> 00:05:43 galaxy so he could look at it and see
00:05:43 --> 00:05:46 exactly what shape it was we we have a
00:05:46 --> 00:05:48 pretty good idea but we've we've never
00:05:48 --> 00:05:50 been able to image it we don't know for
00:05:50 --> 00:05:52 sure if it's got the number of spiral
00:05:52 --> 00:05:54 arms that they assume it's got or
00:05:54 --> 00:05:58 anything like that um so that was Fred's
00:05:58 --> 00:06:00 you know if you could do anything just
00:06:00 --> 00:06:03 the snap of his fingers looking at our
00:06:03 --> 00:06:05 our galaxy from outside was was one of
00:06:05 --> 00:06:09 his wishes so Tony unfortunately no we
00:06:09 --> 00:06:12 cannot see a reflection of our galaxy in
00:06:12 --> 00:06:15 any way or form we probably are seeing
00:06:15 --> 00:06:18 light bounc back to us as jonty was
00:06:18 --> 00:06:21 explaining um from our own Galaxy but it
00:06:21 --> 00:06:24 certainly wouldn't give us an image but
00:06:24 --> 00:06:26 thanks for the question great to hear
00:06:26 --> 00:06:27 from you our next question comes from
00:06:28 --> 00:06:30 Charles this is a short sweet but uh
00:06:30 --> 00:06:33 rather difficult one to answer uh what
00:06:33 --> 00:06:35 do you think of the theory that we live
00:06:35 --> 00:06:38 in a holographic Universe now this is
00:06:38 --> 00:06:41 something I've seen popping up time and
00:06:41 --> 00:06:43 time again in the popular press and I
00:06:44 --> 00:06:45 suppose we should explain what a
00:06:45 --> 00:06:47 holographic universe is before we decide
00:06:47 --> 00:06:50 whether or not we live in one yeah and
00:06:50 --> 00:06:51 this is one of the ones that breaks my
00:06:51 --> 00:06:54 head so your answer to this will be
00:06:54 --> 00:06:58 neither um good or accurate I suspect
00:06:58 --> 00:06:59 because this is far from my a of EXP but
00:06:59 --> 00:07:02 I'll do my best the holographic Universe
00:07:02 --> 00:07:06 stuff is tied to string theory is my
00:07:06 --> 00:07:08 understanding and to me is at the point
00:07:08 --> 00:07:09 where you're bordering along the
00:07:10 --> 00:07:12 boundary between science and philosophy
00:07:12 --> 00:07:14 because you're starting to ask questions
00:07:14 --> 00:07:16 that we have no way of testing yet and
00:07:16 --> 00:07:19 that's really hard now this all ties
00:07:19 --> 00:07:21 down to very mathematical and very
00:07:21 --> 00:07:24 theoretical studies of the Universe I
00:07:24 --> 00:07:26 think getting back to about the 1990s
00:07:26 --> 00:07:29 where people found that in some versions
00:07:29 --> 00:07:33 of the mass of string theory you can get
00:07:33 --> 00:07:35 threedimensional stuff being represented
00:07:35 --> 00:07:37 in a two-dimensional way without losing
00:07:37 --> 00:07:39 any
00:07:39 --> 00:07:41 data um and it's an answer to some of
00:07:41 --> 00:07:43 the issues to do with information and
00:07:43 --> 00:07:44 black holes it's one of the things that
00:07:44 --> 00:07:47 led people to suggest that you can get
00:07:47 --> 00:07:49 information that goes into black holes
00:07:49 --> 00:07:50 is not lost but might be stored in the
00:07:50 --> 00:07:53 Event Horizon and all these kind of
00:07:53 --> 00:07:54 things now my understanding of it as you
00:07:54 --> 00:07:56 can tell by that explanation is kind of
00:07:56 --> 00:07:59 limited it's not my area of expertise it
00:07:59 --> 00:08:02 is called the holographic principle and
00:08:02 --> 00:08:04 that leads to the idea of the
00:08:04 --> 00:08:06 holographic universe so the idea that
00:08:06 --> 00:08:10 you can get essentially a
00:08:10 --> 00:08:13 two-dimensional representation of all
00:08:13 --> 00:08:14 the data you need to have a
00:08:14 --> 00:08:17 three-dimensional thing means that you
00:08:17 --> 00:08:18 could have in some
00:08:18 --> 00:08:22 way a three-dimensional appearing thing
00:08:22 --> 00:08:24 actually only be twood dimensional a
00:08:24 --> 00:08:26 holograph essentially so that's what the
00:08:26 --> 00:08:28 holograph is all about and I'm I fully
00:08:28 --> 00:08:30 understand that you can tell by the
00:08:30 --> 00:08:33 explanation it's interesting it's become
00:08:33 --> 00:08:36 sufficiently rooted in popular
00:08:36 --> 00:08:38 Consciousness and this is a turtle
00:08:38 --> 00:08:40 turtle um detour here but one of the
00:08:40 --> 00:08:42 kinds of music I really like to listen
00:08:42 --> 00:08:44 to is a genre called symphonic metal
00:08:44 --> 00:08:47 which is bit bizarre it's kind of
00:08:47 --> 00:08:49 operatic Rock if you think about the
00:08:49 --> 00:08:51 kind of stuff Queen were doing and got a
00:08:51 --> 00:08:53 little bit more Rocky a little bit more
00:08:53 --> 00:08:54 metal and that's like that so you
00:08:54 --> 00:08:56 typically have an operatically Trend
00:08:56 --> 00:08:59 soprano singing the two biggest groups
00:08:59 --> 00:09:01 of that that I listen to quite a lot are
00:09:01 --> 00:09:04 groups called Nightwish and EPA and
00:09:04 --> 00:09:05 Nightwish have done a couple of science
00:09:05 --> 00:09:07 sced albums where they talk about the
00:09:08 --> 00:09:10 origin of life and philosophy and Origin
00:09:10 --> 00:09:12 of Species and all sorts of stuff like
00:09:12 --> 00:09:14 that one of their tracks which I try and
00:09:14 --> 00:09:15 get on the radio occasionally when I do
00:09:15 --> 00:09:18 a chat about asteroids is a tribute to
00:09:18 --> 00:09:21 the great scientist Eugene Shoemaker who
00:09:21 --> 00:09:23 whose ashes were put onto a spacecraft
00:09:23 --> 00:09:25 to the Moon who discovered the comic
00:09:25 --> 00:09:28 that hit Jupiter back in 1994 so that's
00:09:28 --> 00:09:32 might wish Epica have an album named the
00:09:32 --> 00:09:33 holographic
00:09:33 --> 00:09:35 principle which they've always done
00:09:35 --> 00:09:38 slightly quirky projects as well the
00:09:38 --> 00:09:41 fact that this concept this thing that
00:09:41 --> 00:09:43 is at the very bound extreme bounds of
00:09:43 --> 00:09:46 theoretical physics and theoretical
00:09:46 --> 00:09:49 cosmology has become sufficiently
00:09:49 --> 00:09:51 culturally embedded that rock groups are
00:09:51 --> 00:09:55 naming albums after it is kind of quirky
00:09:55 --> 00:09:58 for me and it shows that it's not a
00:09:58 --> 00:10:00 totally brand new idea it's if it was
00:10:00 --> 00:10:01 certainly brand new it wouldn't be in
00:10:01 --> 00:10:04 the popular Consciousness yet it does
00:10:04 --> 00:10:07 make my head hurt I will wholeheartedly
00:10:07 --> 00:10:09 and happily admit that this is not
00:10:09 --> 00:10:12 something where I'm an expert you know
00:10:12 --> 00:10:14 in any way shape or form there are very
00:10:14 --> 00:10:16 detailed discussions of it online even
00:10:16 --> 00:10:19 if you pull up the Wikipedia page the
00:10:19 --> 00:10:22 Wikipedia page is pretty lengthy and
00:10:22 --> 00:10:24 links to a lot of references talks about
00:10:24 --> 00:10:25 some of the discussions people have had
00:10:25 --> 00:10:28 about it talks about information density
00:10:28 --> 00:10:30 the people whove proposed OS all these
00:10:30 --> 00:10:33 ideas um gives you links to other places
00:10:33 --> 00:10:35 now I know certainly when I'm teaching I
00:10:35 --> 00:10:36 have to tell people that Wikipedia is
00:10:36 --> 00:10:38 not the be and
00:10:38 --> 00:10:40 Endor it's a fluid resource it's subject
00:10:40 --> 00:10:42 to change and it's subject to being
00:10:42 --> 00:10:44 incorrect but with a lot of these topics
00:10:44 --> 00:10:47 in the more theoretical parts of
00:10:47 --> 00:10:49 astrophysics or even for astronomy as a
00:10:49 --> 00:10:50 whole Wikipedia tends to be really
00:10:50 --> 00:10:52 pretty good because there's enough
00:10:52 --> 00:10:54 people out there who are really
00:10:54 --> 00:10:56 fascinated by the field that when they
00:10:56 --> 00:10:58 see something wrong they'll fix it the
00:10:58 --> 00:10:59 errors don't tend to hang around that
00:10:59 --> 00:11:01 one so it tends to actually be a good
00:11:01 --> 00:11:02 first resource so long as it's not your
00:11:02 --> 00:11:05 only resource and the article there
00:11:05 --> 00:11:07 about the holographic principle also
00:11:07 --> 00:11:09 links to these two albums by different
00:11:09 --> 00:11:11 groups that have had the same name but
00:11:12 --> 00:11:14 has a fairly lengthy discussion of a lot
00:11:14 --> 00:11:16 of the um different ideas behind this a
00:11:16 --> 00:11:19 few links to different types of theorems
00:11:19 --> 00:11:22 that are tied to this and also a good
00:11:22 --> 00:11:24 list of 28 references and a couple of
00:11:24 --> 00:11:26 results on top of that including Journal
00:11:26 --> 00:11:28 papers where if you really want to dive
00:11:28 --> 00:11:32 into this can do um will be very quickly
00:11:32 --> 00:11:34 apparent to you that by reading it for
00:11:34 --> 00:11:35 five minutes you already know more about
00:11:35 --> 00:11:37 it than I do and then listen back to
00:11:37 --> 00:11:39 this answer from point out every way in
00:11:39 --> 00:11:42 which I was wrong here but that's my
00:11:42 --> 00:11:45 take on it now with all that said to get
00:11:45 --> 00:11:46 back to the question what do I think
00:11:46 --> 00:11:48 about the theory I think I don't think
00:11:48 --> 00:11:50 about it very much because it makes my
00:11:50 --> 00:11:52 head hurt but as I say I think it gets
00:11:52 --> 00:11:54 to the point of philosophy it's if there
00:11:54 --> 00:11:57 is something where you can make no
00:11:57 --> 00:11:59 testable measurement to differentiate
00:11:59 --> 00:12:01 between two different ideas you're more
00:12:01 --> 00:12:02 in the bounds of philosophy than you are
00:12:02 --> 00:12:06 in the bounds of Science and it's a bit
00:12:06 --> 00:12:07 like that old chest of how do I know
00:12:07 --> 00:12:09 that anybody else actually exists the
00:12:10 --> 00:12:12 only perception the only existence I'm
00:12:12 --> 00:12:14 aware of is my own existence I'm aware
00:12:15 --> 00:12:17 of my inner dialogue and I'm aware of
00:12:17 --> 00:12:19 what I see and perceive and we
00:12:19 --> 00:12:21 implicitly assume that everybody we talk
00:12:21 --> 00:12:24 to is a being like us but it could
00:12:24 --> 00:12:26 equally just be a convenient fiction and
00:12:26 --> 00:12:28 I could be entirely locked in my own
00:12:28 --> 00:12:30 head having all this is a kind of weird
00:12:30 --> 00:12:32 dream I mean I'd argue that this
00:12:32 --> 00:12:33 question is a good example of the fact
00:12:33 --> 00:12:35 that I'm not just lock in my own head
00:12:35 --> 00:12:36 and having a weird dream because I would
00:12:36 --> 00:12:37 have never thought of this question
00:12:37 --> 00:12:41 myself but you start getting to points
00:12:41 --> 00:12:44 where you are having an argument that is
00:12:44 --> 00:12:46 more one of philosophy than it is one of
00:12:46 --> 00:12:48 Science and for me the thing that
00:12:48 --> 00:12:51 differentiates the two comes down to
00:12:51 --> 00:12:53 prediction and testing of theories if
00:12:53 --> 00:12:56 you have a theory that is new it should
00:12:56 --> 00:12:58 make testable predictions and I'm not
00:12:58 --> 00:13:00 really sure because I'm not a
00:13:00 --> 00:13:02 theoretical cosmologist or a theoretical
00:13:02 --> 00:13:04 physicist if this does and if it does
00:13:04 --> 00:13:07 how they would work so for me then I
00:13:07 --> 00:13:08 come back to kind of the okam draer
00:13:08 --> 00:13:10 thing with a lack of knowledge with a
00:13:10 --> 00:13:12 lack of expertise the simplest
00:13:12 --> 00:13:14 explanation to me is just that we are in
00:13:14 --> 00:13:16 the universe we
00:13:16 --> 00:13:18 see but it's really fascinating to look
00:13:18 --> 00:13:19 into this it's important to do this kind
00:13:19 --> 00:13:22 of work I'm just not qualified to do it
00:13:22 --> 00:13:24 I don't have the expertise yeah it sort
00:13:24 --> 00:13:28 of connects with another theory that we
00:13:28 --> 00:13:30 have created this universe in their own
00:13:30 --> 00:13:34 minds as a collective uh we you know the
00:13:34 --> 00:13:36 physical existence of the universe is a
00:13:36 --> 00:13:40 manifestation of us yeah um I've I've
00:13:40 --> 00:13:42 heard that one before which is an
00:13:42 --> 00:13:43 interesting one tied to it is simulation
00:13:43 --> 00:13:45 Theory which I've also seen musical
00:13:45 --> 00:13:47 albums named after which is the idea
00:13:47 --> 00:13:49 that what we live in is a simulation and
00:13:49 --> 00:13:52 it's extrapolating off Mo's law and
00:13:52 --> 00:13:53 similar laws about computing power
00:13:53 --> 00:13:56 increasing into the future which is that
00:13:56 --> 00:13:58 whilst the universe is infinitely
00:13:58 --> 00:14:00 complex amount of computing power you
00:14:00 --> 00:14:03 would need to fully simulate a universe
00:14:03 --> 00:14:05 is not as high as you would think
00:14:05 --> 00:14:06 particularly if you set up your code so
00:14:06 --> 00:14:08 you only simulate the bits that have
00:14:08 --> 00:14:10 been observed at a time you know you
00:14:11 --> 00:14:12 don't need to for example if you were
00:14:12 --> 00:14:13 simulating the Earth and everything you
00:14:13 --> 00:14:15 wouldn't need to simulate the surface of
00:14:16 --> 00:14:17 these exop planets we've discovered yet
00:14:17 --> 00:14:19 because we don't have the ability to see
00:14:19 --> 00:14:20 them so you serve a huge amount in
00:14:20 --> 00:14:22 processing so that leads to this
00:14:22 --> 00:14:24 argument that you could set up a
00:14:24 --> 00:14:26 simulation with the quality of fidelity
00:14:26 --> 00:14:29 that we couldn't know the difference
00:14:29 --> 00:14:31 simulation Theory then goes to one step
00:14:31 --> 00:14:33 further and says if you can do that once
00:14:33 --> 00:14:35 it's only a small step from being able
00:14:35 --> 00:14:36 to do something once to being able to do
00:14:36 --> 00:14:38 it many many towns so therefore
00:14:38 --> 00:14:40 statistically it becomes more likely
00:14:40 --> 00:14:42 that we live in a simulation rather than
00:14:42 --> 00:14:44 the real world because there'll be
00:14:44 --> 00:14:45 millions of universes and only one of
00:14:45 --> 00:14:47 them will be real and it's fascinating
00:14:48 --> 00:14:49 it's really good fun but again it's
00:14:49 --> 00:14:51 philosophy because how do we test this
00:14:51 --> 00:14:53 unless we get to take the pill and step
00:14:53 --> 00:14:55 out of the Matrix and see it for what it
00:14:55 --> 00:14:59 is how you test between these things is
00:14:59 --> 00:15:01 really the challenge for me to make them
00:15:01 --> 00:15:03 into a really scientific discuss rather
00:15:03 --> 00:15:06 than a philosophical one yeah uh The
00:15:06 --> 00:15:09 Matrix was a good film in in a
00:15:09 --> 00:15:12 constructed universe and the reality was
00:15:12 --> 00:15:15 much more horrifying but uh yeah great
00:15:15 --> 00:15:18 question and um yeah I think that's one
00:15:18 --> 00:15:20 that'll be de debated for years to come
00:15:20 --> 00:15:23 thanks Charles this is Space Nuts uh
00:15:23 --> 00:15:26 Andrew Dunley here with Professor jonty
00:15:26 --> 00:15:28 hona let's take a little break from the
00:15:28 --> 00:15:32 show tell you about our sponsor incog
00:15:32 --> 00:15:35 now have you heard of incog this is
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00:15:44 --> 00:15:47 show notes but I hear you asking why do
00:15:47 --> 00:15:48 I need
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00:15:58 --> 00:16:00 priv information and it could be in the
00:16:00 --> 00:16:02 hands of people who shouldn't have it or
00:16:02 --> 00:16:05 may soon be could be getting pedal on
00:16:05 --> 00:16:07 the on the dark web as well or maybe you
00:16:07 --> 00:16:09 just don't like the idea of your private
00:16:10 --> 00:16:12 information floating around online now
00:16:12 --> 00:16:15 you could try to remember every website
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00:16:17 --> 00:16:19 dot and in a couple of years you might
00:16:19 --> 00:16:22 have made a dent in it but that's pretty
00:16:22 --> 00:16:25 unlikely let's be real so why not get
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00:16:44 --> 00:16:47 money stolen that is the worst feeling
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00:16:48 --> 00:16:51 happened to me right now incog is
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00:17:02 --> 00:17:05 out at incog
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00:17:16 --> 00:17:21 SPAC nuts that's
00:17:21 --> 00:17:24 incognet now back to the
00:17:24 --> 00:17:28 show and I feel fine Space Nuts okay um
00:17:28 --> 00:17:31 Johny Let's uh do some audio questions
00:17:31 --> 00:17:33 and this one I I thought we'd done but I
00:17:33 --> 00:17:36 remember I did send it to you in name
00:17:36 --> 00:17:38 but I sent you the wrong audio so we did
00:17:38 --> 00:17:40 the other one and so this is the
00:17:40 --> 00:17:41 question I meant to send you a couple of
00:17:41 --> 00:17:43 weeks ago from David this is David from
00:17:44 --> 00:17:45 zagen
00:17:45 --> 00:17:47 Texas uh I got another question about
00:17:47 --> 00:17:49 black holes just like all my other
00:17:49 --> 00:17:51 questions I was listening to the latest
00:17:51 --> 00:17:54 episode and you were talking about light
00:17:54 --> 00:17:58 spinning around black holes um andless
00:17:58 --> 00:18:00 being able to see the the effects later
00:18:00 --> 00:18:02 than when the the event actually
00:18:03 --> 00:18:07 happened but that got me thinking if the
00:18:07 --> 00:18:09 light goes around the black hole and
00:18:09 --> 00:18:12 then starts to slowly get sucked
00:18:12 --> 00:18:15 in would the additional gravity of the
00:18:15 --> 00:18:18 black hole pulling on the light increase
00:18:18 --> 00:18:20 the speed of the light any faster than
00:18:20 --> 00:18:23 the speed of light or even at all
00:18:23 --> 00:18:24 because I know when a ballet dancer is
00:18:25 --> 00:18:26 spinning and she pulls her arms in she
00:18:26 --> 00:18:30 spins faster so so would that effect be
00:18:30 --> 00:18:33 the same on light spinning around the
00:18:33 --> 00:18:35 black hole and then getting sucked
00:18:35 --> 00:18:38 in um I'm not really sure how that works
00:18:38 --> 00:18:41 with light considering it has no Mass
00:18:41 --> 00:18:43 but I appreciate if youall answer my
00:18:43 --> 00:18:46 question thank you good on you David uh
00:18:46 --> 00:18:48 I'm pretty sure ballerinas don't spin at
00:18:48 --> 00:18:49 the speed of light
00:18:49 --> 00:18:53 but could be wrong uh they do spin
00:18:53 --> 00:18:55 rather remarkably uh yeah look this is
00:18:55 --> 00:18:59 an interesting one um light is the fast
00:18:59 --> 00:19:01 thing in the universe I venture to say
00:19:01 --> 00:19:05 and I think in conversations Fred and I
00:19:05 --> 00:19:07 have had in the past that nothing goes
00:19:07 --> 00:19:10 faster than the speed of light in a
00:19:10 --> 00:19:13 vacuum so I would imagine the answer is
00:19:13 --> 00:19:16 probably no that the black hole can't
00:19:16 --> 00:19:18 make light go faster than the speed of
00:19:18 --> 00:19:20 light it doesn't change the speed of
00:19:20 --> 00:19:23 light it changed its direction and if
00:19:23 --> 00:19:26 you change the energy of
00:19:26 --> 00:19:28 light because you can't change the speed
00:19:28 --> 00:19:30 what you change is the frequency and the
00:19:30 --> 00:19:33 wavelength so if light is trying to
00:19:33 --> 00:19:37 escape from a mass then you see a thing
00:19:37 --> 00:19:39 called gravitational red shift so light
00:19:39 --> 00:19:42 coming up from the surface of the sun
00:19:42 --> 00:19:44 will be red shifted a tiny little bit
00:19:44 --> 00:19:45 because it's escaping from the
00:19:45 --> 00:19:47 gravitational well of the sun similarly
00:19:48 --> 00:19:49 if it was falling inwards you'd expect
00:19:49 --> 00:19:51 it to be slightly blue shifted but it's
00:19:51 --> 00:19:54 a very very small imperceptible thing um
00:19:54 --> 00:19:55 in terms of the speed of light being the
00:19:55 --> 00:19:57 fastest thing there is that's where all
00:19:58 --> 00:19:59 our models of the Universe and
00:19:59 --> 00:20:02 Everything sits and Terry praet in one
00:20:02 --> 00:20:04 of the many bqu world books that I love
00:20:04 --> 00:20:06 very well made the point that Darkness
00:20:06 --> 00:20:08 must travel faster than light because
00:20:08 --> 00:20:09 whenever you turn on light it was
00:20:09 --> 00:20:12 already dark I think is quite nice and
00:20:12 --> 00:20:15 poetic but in reality it seems that the
00:20:15 --> 00:20:17 speed of light in all of the models we
00:20:17 --> 00:20:20 have of the inves cosmology is this kind
00:20:20 --> 00:20:21 of
00:20:21 --> 00:20:23 inviolable speed limit of the universe
00:20:23 --> 00:20:25 now might be that when we have a chat in
00:20:25 --> 00:20:27 20 years time that a change to tell
00:20:27 --> 00:20:29 because that's how science works
00:20:29 --> 00:20:32 works but at the minute the speed of
00:20:32 --> 00:20:34 light is a speed of light and there is
00:20:34 --> 00:20:35 an implicit thing there that we never
00:20:35 --> 00:20:37 mentioned that we should do that what
00:20:37 --> 00:20:38 we're actually talking about there is
00:20:38 --> 00:20:40 the speed of the light in the vacuum of
00:20:40 --> 00:20:42 space yeah so as soon as light passes
00:20:42 --> 00:20:44 into a medium it slows down and that's
00:20:44 --> 00:20:47 why you get refraction if light goes
00:20:47 --> 00:20:50 from air into water the speed of light
00:20:50 --> 00:20:51 in water is slower than the speed of
00:20:51 --> 00:20:54 light in air that's why you get the
00:20:54 --> 00:20:56 bending the change of Direction there
00:20:56 --> 00:20:59 with black HS what's actually happening
00:20:59 --> 00:21:01 is that the black hole is bending space
00:21:01 --> 00:21:03 and the light is following a straight
00:21:03 --> 00:21:05 path on a curved surface so it appears
00:21:05 --> 00:21:08 to bend which is subtly different
00:21:08 --> 00:21:10 essentially light falling into a black
00:21:10 --> 00:21:12 hole if you could imagine being just
00:21:12 --> 00:21:16 outside the Event Horizon so you're not
00:21:16 --> 00:21:18 dead and you're looking outwards the
00:21:18 --> 00:21:20 things you were looking at would look a
00:21:20 --> 00:21:22 little bit Bluer Than they actually are
00:21:22 --> 00:21:24 because light falling in is getting blue
00:21:24 --> 00:21:26 shifted as it comes towards you
00:21:26 --> 00:21:29 similarly if you sha a yellow light or a
00:21:29 --> 00:21:31 green light laser I've got one of those
00:21:31 --> 00:21:33 when I do Outreach sometimes to point
00:21:33 --> 00:21:35 the stars out if I sh a green light
00:21:35 --> 00:21:36 laser out from Near The Event Horizon of
00:21:37 --> 00:21:38 the black ho the light would still
00:21:38 --> 00:21:40 Escape be some outside the Event Horizon
00:21:40 --> 00:21:42 so the escape Velocity is lower than the
00:21:42 --> 00:21:45 speed of light there's an acceleration
00:21:45 --> 00:21:47 pulling back the speed of the light
00:21:47 --> 00:21:49 cannot change but the energy would
00:21:49 --> 00:21:50 change so it would become
00:21:50 --> 00:21:52 gravitationally red shifted so that
00:21:52 --> 00:21:55 green light laser would look redder to
00:21:55 --> 00:21:57 The Observer Way Beyond the black hole
00:21:57 --> 00:21:59 than it would as it leaves in my hand
00:22:00 --> 00:22:01 where I'm in the shared rest frame for
00:22:01 --> 00:22:04 it but the speed of light itself would
00:22:04 --> 00:22:05 not be
00:22:05 --> 00:22:08 changing cavat if the black hole's got a
00:22:08 --> 00:22:09 disc of material around it if it's got
00:22:09 --> 00:22:10 material around it then you're not
00:22:10 --> 00:22:12 moving through a perfect vacuum so you
00:22:12 --> 00:22:14 would see a little bit of a change in
00:22:14 --> 00:22:17 speed there but that is a different
00:22:17 --> 00:22:19 physical process for a different
00:22:19 --> 00:22:22 reason but it's worth being complete I
00:22:22 --> 00:22:24 guess yes yes I suppose so uh the other
00:22:24 --> 00:22:26 interesting thing about light which
00:22:26 --> 00:22:29 we've talked about before is that as you
00:22:29 --> 00:22:31 said it slows down in liquid but light
00:22:31 --> 00:22:33 going through a glass slows down but
00:22:33 --> 00:22:35 when it comes out the other side it
00:22:35 --> 00:22:37 speeds up again yes and that's what it
00:22:37 --> 00:22:40 bends back in the other direction yeah
00:22:40 --> 00:22:43 yeah so it's a it's a tricky thing light
00:22:43 --> 00:22:45 it because we take it for granted we
00:22:45 --> 00:22:47 need it it's uh something we've adapted
00:22:47 --> 00:22:50 to on this planet as human beings uh if
00:22:50 --> 00:22:51 we were to venture to another planet
00:22:51 --> 00:22:54 with a different kind of star
00:22:54 --> 00:22:58 um it would be alien to us in more ways
00:22:58 --> 00:23:01 than we could imagine because we are
00:23:01 --> 00:23:04 used to a mediumsized star with a
00:23:04 --> 00:23:06 relatively bright light but if you went
00:23:06 --> 00:23:09 to a a planet with a uh I don't know a a
00:23:09 --> 00:23:13 blue star a bright blue star the
00:23:13 --> 00:23:14 vegetation would be a different color
00:23:14 --> 00:23:16 because it would be having to do a
00:23:16 --> 00:23:17 different kind of
00:23:18 --> 00:23:21 photosynthesis um you'd see things
00:23:21 --> 00:23:23 differently uh you know there's all
00:23:23 --> 00:23:25 sorts of weird wonderful things that
00:23:25 --> 00:23:28 light could do on in other places just
00:23:28 --> 00:23:31 Theory the moment
00:23:31 --> 00:23:35 buttion I I've seen these articles about
00:23:35 --> 00:23:36 a small subset of women who have an
00:23:36 --> 00:23:39 extra set of cells detecting color in
00:23:39 --> 00:23:40 their eye which gives them an incredibly
00:23:40 --> 00:23:43 more granular and fine ability to
00:23:43 --> 00:23:45 differentiate colors they're like
00:23:45 --> 00:23:47 they're the visual equivalent of super
00:23:47 --> 00:23:50 tasters and they can see something that
00:23:50 --> 00:23:52 to you or I would just look like it's
00:23:52 --> 00:23:54 certain color they can see the Hues
00:23:54 --> 00:23:56 within that you equally you see these
00:23:56 --> 00:23:58 beautiful images of birds that look very
00:23:58 --> 00:24:01 done and boring to us but then you see a
00:24:01 --> 00:24:02 visualization of what they would look
00:24:02 --> 00:24:03 like to another bird and they're
00:24:03 --> 00:24:05 incredibly colorful and vibrant because
00:24:05 --> 00:24:07 the birds are seeing frequencies that
00:24:07 --> 00:24:10 our eyes are not accustomed to similarly
00:24:10 --> 00:24:12 with bees and things like that seeing
00:24:12 --> 00:24:14 into the ultraviolet and that will be
00:24:14 --> 00:24:18 accentuated for objects around you know
00:24:18 --> 00:24:20 planets around other stars you then get
00:24:20 --> 00:24:22 The Oddities I have had the pleasure of
00:24:22 --> 00:24:24 seeing a couple of turtle eclipses of
00:24:24 --> 00:24:26 the sun one of which I didn't actually
00:24:26 --> 00:24:28 see because it was cloudy in cans in
00:24:28 --> 00:24:30 2012 but we saw the buildup and the
00:24:30 --> 00:24:32 aftermath and the eclipse itself's
00:24:32 --> 00:24:34 awesome but there's this very weird
00:24:34 --> 00:24:36 uncanny valley period in the miniatur
00:24:36 --> 00:24:38 before and the miniaturist after
00:24:38 --> 00:24:41 totality where the sun is a tiny little
00:24:41 --> 00:24:42 point because most of it's blocked by
00:24:42 --> 00:24:45 the moon so instead of having a disc the
00:24:45 --> 00:24:46 sun gets smaller and smaller until
00:24:46 --> 00:24:48 you've essentially got a single point of
00:24:48 --> 00:24:49 light shining nearly as bright as the
00:24:49 --> 00:24:52 sun and shadows change and the behavior
00:24:52 --> 00:24:54 of Shadows look
00:24:54 --> 00:24:56 different when you've got a single point
00:24:56 --> 00:24:58 source rather than a few source of light
00:24:58 --> 00:25:01 and that gives everything a very
00:25:01 --> 00:25:03 uncomfortable slightly unusual feel
00:25:03 --> 00:25:05 you've got very cool effects like
00:25:05 --> 00:25:07 standing under a tree and all the leaves
00:25:07 --> 00:25:09 are blowing and all the gaps between the
00:25:09 --> 00:25:11 leaves act as pinhole cameras and you
00:25:11 --> 00:25:13 get images of the Cresent sun on the
00:25:13 --> 00:25:15 ground which is spectacular wow
00:25:15 --> 00:25:17 incidentally on the eclipse trip I went
00:25:17 --> 00:25:20 to um for the exmouth eclipse one of a
00:25:20 --> 00:25:22 lot of people have a little pinhole
00:25:22 --> 00:25:23 cameras that they made to image the
00:25:23 --> 00:25:26 eclipse and one person had a pack of
00:25:26 --> 00:25:28 jats which are just an Australian cheese
00:25:28 --> 00:25:30 biscuit and the poles in the biscuits
00:25:31 --> 00:25:33 were perfect pinhole
00:25:33 --> 00:25:35 cameras and they had a snack so when the
00:25:35 --> 00:25:37 equp finished nobody was hungry it was
00:25:37 --> 00:25:39 absolutely brilliant and I'd never even
00:25:39 --> 00:25:41 thought of it so you get all these Weir
00:25:41 --> 00:25:44 effects and it we take for granted very
00:25:44 --> 00:25:46 very much that our perception is
00:25:46 --> 00:25:48 actually what is out there yeah and this
00:25:49 --> 00:25:51 was brought home to me I went to driving
00:25:51 --> 00:25:53 range with one of my PhD students on I
00:25:53 --> 00:25:55 don't play golf and I'm particularly bad
00:25:55 --> 00:25:57 at it but there's always this thing
00:25:57 --> 00:25:59 about what you perceive and how much of
00:25:59 --> 00:26:01 the area of your vision that you're
00:26:01 --> 00:26:02 actually actively updating and how much
00:26:02 --> 00:26:04 of it is just autogenerated by your
00:26:04 --> 00:26:07 brain based on Old information and you
00:26:07 --> 00:26:09 forget about that but we actually are
00:26:09 --> 00:26:11 like our eyes are rasling across and we
00:26:11 --> 00:26:13 only see a tiny little bit of our vision
00:26:13 --> 00:26:15 are we seeing true updates and I've
00:26:15 --> 00:26:17 never really seen that demonstrated
00:26:17 --> 00:26:18 until I was at the driving range because
00:26:18 --> 00:26:20 if I hit a golf ball and I often hit
00:26:20 --> 00:26:22 them very badly but they go up in the
00:26:22 --> 00:26:24 air somewhere and I can stand there and
00:26:24 --> 00:26:26 watch where it dos and it's easy and you
00:26:26 --> 00:26:28 can follow it all the way the minute you
00:26:28 --> 00:26:31 look away and look back you cannot find
00:26:31 --> 00:26:33 the ball exactly it's astonishing and
00:26:33 --> 00:26:35 you think when you're just looking at it
00:26:35 --> 00:26:37 it's really obvious there's a ball there
00:26:37 --> 00:26:39 it's yellow or white against the Blue
00:26:39 --> 00:26:42 Sky can't get more obvious Look Away
00:26:42 --> 00:26:43 totally lost it even if you know where
00:26:43 --> 00:26:46 it was and that's all down to how our
00:26:46 --> 00:26:48 brain is processing the data we're
00:26:48 --> 00:26:50 getting the ball's still there the ball
00:26:50 --> 00:26:52 hasn't miraculously disappeared and so
00:26:53 --> 00:26:55 all these kind of questions I find it
00:26:55 --> 00:26:56 really fascinating that boundary between
00:26:56 --> 00:26:58 the perception and the reality
00:26:58 --> 00:27:01 how much of what we observe is of our
00:27:01 --> 00:27:03 own generation essentially yeah it
00:27:03 --> 00:27:05 reminds me of that famous gorilla
00:27:05 --> 00:27:08 experiment you aware of that one yeah um
00:27:08 --> 00:27:12 that that is a very great it's a great
00:27:12 --> 00:27:15 example of of what you think you see and
00:27:15 --> 00:27:18 what's really there and uh I won't try
00:27:18 --> 00:27:20 and spoil it for anybody you can see it
00:27:20 --> 00:27:22 on
00:27:22 --> 00:27:24 YouTube they do that in a lot of
00:27:24 --> 00:27:26 training for things like police officers
00:27:26 --> 00:27:28 and stuff to talk about the fact people
00:27:28 --> 00:27:29 who think they've witnessed something
00:27:29 --> 00:27:32 are inherently unreliable yeah and it's
00:27:32 --> 00:27:35 also what makes it very feasible for
00:27:35 --> 00:27:38 magicians and concerts and tricksters to
00:27:38 --> 00:27:41 trick you by taking your brain off
00:27:41 --> 00:27:42 somewhere else you know the whole slight
00:27:42 --> 00:27:44 of hand thing is all born of this same
00:27:44 --> 00:27:47 thing yeah yeah it is it's really
00:27:47 --> 00:27:49 remarkable I could talk about this stuff
00:27:49 --> 00:27:51 forever I really find it fascinating but
00:27:51 --> 00:27:53 uh yeah lovely question David and I hope
00:27:54 --> 00:27:56 that it um covered you adequately as we
00:27:57 --> 00:27:59 strive to do here on B nuts but no black
00:27:59 --> 00:28:06 hole can't make light travel faster than
00:28:06 --> 00:28:09 light Space Nuts our final question
00:28:09 --> 00:28:12 comes from a regular Cendera from um the
00:28:12 --> 00:28:15 United Kingdom hello Duncan from
00:28:15 --> 00:28:17 Waymouth in the UK here
00:28:18 --> 00:28:21 again um just wondering is it possible
00:28:21 --> 00:28:26 to have an exoplanet that is entirely
00:28:26 --> 00:28:29 liquid so it could just be like a global
00:28:29 --> 00:28:34 ocean but with no solid core just liquid
00:28:34 --> 00:28:35 all the way
00:28:35 --> 00:28:38 through if it's not possible and it has
00:28:38 --> 00:28:39 to have a solid
00:28:39 --> 00:28:43 core why is that and
00:28:43 --> 00:28:47 also how small could that solid core be
00:28:47 --> 00:28:51 could it be something the size of say
00:28:51 --> 00:28:55 Everest or could it be even smaller or
00:28:55 --> 00:28:58 does it have to be something bigger
00:28:58 --> 00:29:01 maybe the size of the moon I I don't
00:29:01 --> 00:29:04 know um what are your thoughts on that
00:29:04 --> 00:29:06 and opinions um do you have any actual
00:29:06 --> 00:29:09 answers does anyone know um just
00:29:09 --> 00:29:12 wondering perhaps you could give us some
00:29:13 --> 00:29:16 answers with regards to that okay thank
00:29:16 --> 00:29:20 you very much uh keep up the good work
00:29:20 --> 00:29:24 um and uh well until next time thank you
00:29:24 --> 00:29:25 Duncan I love this question because
00:29:25 --> 00:29:27 these are the sorts of things I wonder
00:29:27 --> 00:29:30 yeah uh and and look we've got examples
00:29:30 --> 00:29:32 of ice worlds in our solar system they
00:29:32 --> 00:29:35 are ice moons they have a solid surface
00:29:35 --> 00:29:37 and and it's thought that they probably
00:29:37 --> 00:29:40 have a solid core but in between oceans
00:29:41 --> 00:29:43 but he's talking about an exoplanet that
00:29:43 --> 00:29:46 is pure liquid just a Big Blob of water
00:29:47 --> 00:29:50 yes it's a fabulous question and again
00:29:50 --> 00:29:52 this can have a short answer in the long
00:29:52 --> 00:29:54 answer the short answer is essentially
00:29:55 --> 00:29:57 no but it's not for the reason you're
00:29:57 --> 00:29:58 thinking of it's not to do with the core
00:29:58 --> 00:30:00 it's the fact that nothing can be a
00:30:00 --> 00:30:02 liquid that I'm aware of in the vacuum
00:30:02 --> 00:30:04 of space so on the surface of the liquid
00:30:04 --> 00:30:06 you will get evaporation and you would
00:30:06 --> 00:30:07 end up with an atmosphere so you'd end
00:30:07 --> 00:30:10 up with a gasier shroud around it
00:30:10 --> 00:30:11 doesn't need to be much atmosphere so
00:30:11 --> 00:30:13 technically it couldn't be entirely
00:30:13 --> 00:30:14 liquid because it would need to be gas
00:30:14 --> 00:30:16 around it for there to be sufficient
00:30:16 --> 00:30:18 pressure that the material on the
00:30:18 --> 00:30:21 surface can remain liquid you could
00:30:22 --> 00:30:23 create something of course but you'd
00:30:23 --> 00:30:25 need it like a bubble around it glass
00:30:25 --> 00:30:28 shell or whatever yeah the other reason
00:30:28 --> 00:30:30 that in a physical sense it would be
00:30:30 --> 00:30:33 very unlikely to have this is that the
00:30:33 --> 00:30:35 things that you form are made of
00:30:35 --> 00:30:38 everything that's around um rocky
00:30:38 --> 00:30:40 planets don't capture the hydrogen and
00:30:41 --> 00:30:42 helium their escape velocity is too high
00:30:42 --> 00:30:45 so the gravity is too weak but when
00:30:45 --> 00:30:46 you're forming something you're building
00:30:46 --> 00:30:47 a planet you're building it of
00:30:47 --> 00:30:49 everything that is around so that will
00:30:50 --> 00:30:51 include a lot of water if you're
00:30:51 --> 00:30:52 somewhere where the temperature's low
00:30:52 --> 00:30:54 enough for water to become an ice and to
00:30:54 --> 00:30:56 be a solid but it'll also include iron
00:30:56 --> 00:30:59 and nickel and dust and all the other
00:31:00 --> 00:31:02 stuff and you're not going to have a
00:31:02 --> 00:31:04 situation where everything you form a
00:31:04 --> 00:31:07 planet from would all be liquid at the
00:31:07 --> 00:31:10 same conditions so you'd always end up
00:31:10 --> 00:31:12 with some stuff sinking to the middle of
00:31:12 --> 00:31:14 solids what you could imagine though is
00:31:14 --> 00:31:17 you could have a idealized situation
00:31:17 --> 00:31:19 let's say you could quarantine an area
00:31:19 --> 00:31:22 of space off and you could form
00:31:22 --> 00:31:25 something Planet Mass out of absolutely
00:31:25 --> 00:31:28 perfectly pure water ice so nothing else
00:31:28 --> 00:31:30 but hydrogen and oxygen bound together
00:31:30 --> 00:31:33 in that scenario I could imagine you
00:31:33 --> 00:31:36 having a planet that is almost entirely
00:31:36 --> 00:31:38 liquid except for the atmosphere which
00:31:38 --> 00:31:40 would be water vapor and would probably
00:31:40 --> 00:31:42 then quickly become an oxygen-rich
00:31:42 --> 00:31:44 atmosphere because once you've got water
00:31:44 --> 00:31:47 vapor exposed to UV it gets dissociated
00:31:47 --> 00:31:48 into hydrogen and oxygen blah blah blah
00:31:48 --> 00:31:52 all stive happens there you would then
00:31:52 --> 00:31:55 have a situation where depending on the
00:31:55 --> 00:31:57 mass of the object
00:31:57 --> 00:31:59 you could have a an object liquid all
00:31:59 --> 00:32:02 the way through if the object is too low
00:32:02 --> 00:32:05 a mass you'd gradually lose it because
00:32:05 --> 00:32:07 if it's of a low enough mass and it's
00:32:07 --> 00:32:09 going around the star the stuff that's
00:32:09 --> 00:32:11 boiling off for a gas will then be
00:32:12 --> 00:32:13 moving fast enough to escape so the
00:32:13 --> 00:32:14 atmosphere will be stripped and the
00:32:14 --> 00:32:16 thing will essentially boil away like if
00:32:16 --> 00:32:18 you leave a pan on the hob I would
00:32:18 --> 00:32:21 imagine that there is also a range of
00:32:21 --> 00:32:23 sizes and masses where the pressure in
00:32:23 --> 00:32:26 the center gets so high that the water
00:32:26 --> 00:32:27 becomes ice again even at High
00:32:27 --> 00:32:30 temperature and we see this with Uranus
00:32:30 --> 00:32:32 and netrun there is certainly Water Ice
00:32:32 --> 00:32:34 in the interior of those but it's a
00:32:34 --> 00:32:36 different phase of water Riz to that
00:32:36 --> 00:32:37 we're used to I I never really
00:32:37 --> 00:32:39 understood this but there is an
00:32:39 --> 00:32:41 incredibly gifted Australian researcher
00:32:41 --> 00:32:44 called Helen Menard kley who last time I
00:32:44 --> 00:32:46 saw I've not seen her for a few years
00:32:46 --> 00:32:49 but she used to work down at ano at um
00:32:49 --> 00:32:51 in Northern Sydney using devices like
00:32:51 --> 00:32:53 wbat doing X-ray defraction and stuff
00:32:53 --> 00:32:56 like this and she discovered several new
00:32:56 --> 00:32:58 types of Water Ice she was looking at
00:32:58 --> 00:33:01 what happens to water at temperatures
00:33:01 --> 00:33:03 and pressures very different to room
00:33:03 --> 00:33:05 temperature and that can be really cold
00:33:05 --> 00:33:07 conditions lack on the icy M of Jupiter
00:33:07 --> 00:33:09 or it can be really high pressures or
00:33:09 --> 00:33:11 birth and so it's fairly well
00:33:11 --> 00:33:13 established that if you increase the
00:33:13 --> 00:33:16 pressure water ice will remain solid at
00:33:16 --> 00:33:17 higher
00:33:17 --> 00:33:20 temperatures that this boiling at 100
00:33:20 --> 00:33:22 and freezing at zero is a function of
00:33:22 --> 00:33:24 the current atmosphere pressure we have
00:33:24 --> 00:33:25 on Earth and you change that and it
00:33:25 --> 00:33:28 changes yeah incidentally that that's
00:33:28 --> 00:33:30 why if you're a bit of a tea fish inard
00:33:30 --> 00:33:31 you cannot get a good cup of tea at high
00:33:31 --> 00:33:34 altitude because water boils at a low
00:33:34 --> 00:33:35 enough temperature that it makes him a
00:33:35 --> 00:33:38 cup of tea you know people who went into
00:33:38 --> 00:33:39 the Himalayas grumbling about how
00:33:39 --> 00:33:41 terrible the tea was and you're at high
00:33:41 --> 00:33:43 enough altitude that the boiling point
00:33:43 --> 00:33:47 of water is reduced enough that um and
00:33:47 --> 00:33:48 for people listening in America who
00:33:48 --> 00:33:50 aren't familiar with this people
00:33:50 --> 00:33:51 particularly from the UK are very
00:33:51 --> 00:33:53 obsessive about their tea but to make
00:33:53 --> 00:33:54 tea you need the water to be on a
00:33:54 --> 00:33:58 rolling boil at 100° C for for many
00:33:58 --> 00:34:00 kinds of black teas green tea and white
00:34:00 --> 00:34:02 tea it's a colder temperature but when
00:34:02 --> 00:34:05 you make tea with lukewarm water that is
00:34:06 --> 00:34:07 wrong that just doesn't work and you get
00:34:07 --> 00:34:09 a very different behavior and it's to do
00:34:09 --> 00:34:11 with the chemistry of what goes
00:34:11 --> 00:34:17 on yeah that's fascinating yeah into
00:34:17 --> 00:34:19 this which would lead to if we ever
00:34:19 --> 00:34:21 found a planet that was pure water and
00:34:21 --> 00:34:23 was Liquid all the way through that to
00:34:23 --> 00:34:25 me would be evidence of the Builders of
00:34:25 --> 00:34:27 magra from double saddens you know would
00:34:27 --> 00:34:29 be evidence that this was a constructed
00:34:29 --> 00:34:30 entity rather than something that form
00:34:30 --> 00:34:33 naturally F contamination is the
00:34:33 --> 00:34:34 simplest way of saying you wouldn't get
00:34:34 --> 00:34:36 a purely Liquid Planet you can get a
00:34:36 --> 00:34:38 planet that is more liquid than anything
00:34:38 --> 00:34:40 else and we have suspicions that there
00:34:40 --> 00:34:43 are these hean World desertion planets
00:34:43 --> 00:34:45 and the reasoning there is that water is
00:34:45 --> 00:34:46 actually one of the most common things
00:34:46 --> 00:34:48 in the universe you've got the most
00:34:48 --> 00:34:50 common atom with hydrogen you've got the
00:34:50 --> 00:34:51 third most common atom with oxygen you
00:34:51 --> 00:34:53 put them together you get water ice or
00:34:53 --> 00:34:56 liquid water or water vapor so you can
00:34:56 --> 00:34:58 imagine planets have more water than
00:34:58 --> 00:35:01 anything else that are huge oceans with
00:35:01 --> 00:35:04 a core underneath them that are ice and
00:35:04 --> 00:35:06 then liquid then ice again like we see
00:35:06 --> 00:35:08 with out mes but getting something that
00:35:08 --> 00:35:10 is liquid from the surface to the core
00:35:10 --> 00:35:13 has those problems one of contamination
00:35:13 --> 00:35:14 and one of you would need an atmosphere
00:35:14 --> 00:35:16 to have the pressure to remain
00:35:16 --> 00:35:18 liquid fascinating yeah love that
00:35:18 --> 00:35:20 question Duncan uh so the answer is
00:35:20 --> 00:35:24 probably no but um not far off in some
00:35:24 --> 00:35:26 respects but uh yeah it might take a
00:35:26 --> 00:35:29 mega structure of some kind to create a
00:35:29 --> 00:35:32 water world although um Kevin cner did
00:35:32 --> 00:35:35 find one yeah appar the cost of going
00:35:35 --> 00:35:37 there to film the film we outrageous so
00:35:37 --> 00:35:39 yes yes they're trying to get it all
00:35:39 --> 00:35:41 back with a theme park I think but um
00:35:41 --> 00:35:44 yes thank you Duncan always good to hear
00:35:44 --> 00:35:45 from you you've always got some great
00:35:45 --> 00:35:47 ideas uh and if you would like to send
00:35:47 --> 00:35:50 us some questions please do via our
00:35:50 --> 00:35:52 website Space Nuts podcast.com SPAC
00:35:52 --> 00:35:54 nuts. and have a look around while
00:35:54 --> 00:35:55 you're there check out the shop check
00:35:55 --> 00:35:58 out our all the other things uh
00:35:58 --> 00:36:00 and don't forget to click the AMA thing
00:36:00 --> 00:36:01 at the top which is where you send your
00:36:02 --> 00:36:05 questions text or audio versions um
00:36:05 --> 00:36:07 thank you johy that was great fun it's a
00:36:07 --> 00:36:08 pleasure it's always good to chat thank
00:36:08 --> 00:36:10 you for having me oh no my pleasure
00:36:10 --> 00:36:12 we'll catch up with you next time
00:36:12 --> 00:36:13 Professor jonty Horner from the
00:36:13 --> 00:36:15 University of Southern Queensland uh
00:36:15 --> 00:36:18 Hugh couldn't be with us today I don't
00:36:18 --> 00:36:20 know what he's been up to but I do know
00:36:20 --> 00:36:22 about today apparently he was using a
00:36:22 --> 00:36:24 telescope to try and see his own
00:36:24 --> 00:36:26 reflection he's still going he's been
00:36:26 --> 00:36:29 doing it for days apparently uh and from
00:36:29 --> 00:36:31 me Andrew Dunley thanks for your company
00:36:31 --> 00:36:32 catch you on the very next episode of
00:36:32 --> 00:36:35 Space Nuts bye-bye Space Nuts you been
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