Speaker 1: Hi there, thanks for joining us. This is a Q
Speaker 1: and a edition of Space Nuts. My name is Andrew Dunty.
Speaker 1: Coming up, we're going to look at a lot of issues,
Speaker 1: one involving dark matter. This question, though, comes about as
Speaker 1: a consequence of someone who wasn't real happy with a
Speaker 1: discussion we had recently, so we'll we'll certainly reinvestigate that.
Speaker 1: We'll also look at flawed mathematics. That sounds like my
Speaker 1: entire school career. We'll also be discussing black holes and
Speaker 1: gravity and energy in space. That's all coming up on
Speaker 1: this edition of Space Nuts fifteen seconds. Guidance is in
Speaker 1: channel ten nine ignition sequence Space Nuts or three.
Speaker 2: Two more review on.
Speaker 1: Space Nurse as can I reported Bills good and joining
Speaker 1: us again to sort all of this out is Professor
Speaker 1: Fred Watson.
Speaker 3: Hello Fred, Hello, I do let's get into those questions? Eh, Yes,
Speaker 3: let's just hit the nail on the head and start.
Speaker 3: And this first question comes about as a consequence of
Speaker 3: us answering a previous question. And I think we've kind
Speaker 3: of put Kevin's nose out of joint just slightly, I
Speaker 3: might say, though he's used a word that I think
Speaker 3: is probably not in keeping with the way you deal
Speaker 3: with things spread, I would never ever accuse you of
Speaker 3: being glip. However, that said, Kevin does have issue with
Speaker 3: the dark matter question. Now, so that I don't mash
Speaker 3: Kevin's question up, I have prepared it with an AI
Speaker 3: voice so that it comes out clean and.
Speaker 1: Unadulterated, if you like. So, let's see what the issue
Speaker 1: is and see if we can pick at the pieces
Speaker 1: and put it back together again. This is from Kevin.
Speaker 4: In your four hundred and twenty eighth episode. I was
Speaker 4: saddened by your response to a listener question asking if
Speaker 4: space time itself might be dark matter. I found your
Speaker 4: emphatic and almost glib No. Just doesn't fit with your
Speaker 4: regular open mindedness. I have asked similar questions before in
Speaker 4: other forums and received the same dismissive no response without
Speaker 4: any depth of thinking about the question. For starters, we
Speaker 4: don't yet know what space time actually is, but if
Speaker 4: it can be distorted, it has some aspect of a
Speaker 4: substance to it, and if it is a form of substance,
Speaker 4: why should it not be considered as a candidate for
Speaker 4: dark matter. It is everywhere, it is transparent to em
Speaker 4: it is weakly interacting it can be distorted, which means
Speaker 4: what that it becomes more dense in some areas than others.
Speaker 4: So what if areas that are denser have a positive
Speaker 4: gravitational effect compared to average background space, you might see clumping.
Speaker 4: So what if areas that are less dense have a
Speaker 4: repulsive gravitational effect compared to average background.
Speaker 3: Space, you might see voids.
Speaker 4: I'm not saying space time is dark matter, but dark
Speaker 4: matter is not actually a thing that has been discovered yet.
Speaker 4: Variable density space time maybe all that is needed to
Speaker 4: explain the gravitation anomalies that we observed, and I think
Speaker 4: it deserves a more open minded level of exploring than
Speaker 4: a simple dismissal. What I'd like to know is how
Speaker 4: would you test it as hypothesis? Has anyone done said testing?
Speaker 4: Has it been exhaustively ruled out by whom? How did
Speaker 4: they do that? Otherwise? Brilliant show. Kevin from Melbourne.
Speaker 1: Okay, Kevin, thank you very much. I hope you don't
Speaker 1: mind me using AI to put that question out there.
Speaker 1: I just wanted to make sure it was intact, because
Speaker 1: you obviously are very serious about this issue, and you
Speaker 1: have had problems in the past getting a straight answer,
Speaker 1: and you put a lot of thought into it. I
Speaker 1: give you credit for that. So, Fred, how can we
Speaker 1: sort of discuss this question with a more robust approach.
Speaker 3: By getting somebody who's more of a specialist in dark
Speaker 3: matter physics and cosmology than me as as a commentator.
Speaker 3: I mean, what I report on is what I understand
Speaker 3: from the work of my colleagues who work in this
Speaker 3: sort of field. And there's certainly nothing I've heard and
Speaker 3: seen in the literature that would equate dark matter with
Speaker 3: space time. It is always regarded as something that exists
Speaker 3: within space time. Now there'll be there'll be very good
Speaker 3: reasons for that, and almost certainly if some of my
Speaker 3: friends and colleagues were sitting right here now, they would
Speaker 3: be able to point us in the right direction as
Speaker 3: to why that is the case. I haven't checked the
Speaker 3: details myself, but nobody is making that such. Yes, it is.
Speaker 3: It's almost universally accepted as being a sub atomic particle
Speaker 3: of some kind which exists within space time that we
Speaker 3: haven't yet detected. I'm sorry if I sounded glid, but
Speaker 3: it wasn't. Certainly wouldn't have been my intention, and dismissive.
Speaker 3: Isn't something I like to be described as either because
Speaker 3: you know, we normally, we normally exactly keep an open
Speaker 3: mind about many of these issues. And part of that
Speaker 3: open mindedness is because I'm not a specialist in the field.
Speaker 3: I'm reporting on what, you know, what my colleagues, not
Speaker 3: just one of them, but many of them are saying, so, yeah,
Speaker 3: let's keep it, keep it in mind. I will explore
Speaker 3: it a little bit further, the idea that Jody's going
Speaker 3: to get involved as well. I'll explore the reasons why
Speaker 3: we don't consider it to be part of space until
Speaker 3: later date.
Speaker 1: Okay, No, that's fair enough.
Speaker 3: I mean, thanks for your comments.
Speaker 1: Yeah, and look, I appreciate his frustration because he's obviously
Speaker 1: tried to get answers on this and may not have
Speaker 1: liked the way we approached it at that particular time.
Speaker 1: But it is an area that is under heavy investigation.
Speaker 1: Everyone is looking at. Even one or two episodes ago,
Speaker 1: we talked about a particular search for dark matter that
Speaker 1: came up with nothing, And that doesn't mean it doesn't exist.
Speaker 1: In fact, we know it exists. They just haven't found
Speaker 1: it within certain parameters, and so they'll be looking bigger.
Speaker 1: But that particular equipment hasn't actually been built yet, so
Speaker 1: the frustration continues. So we hopefully are not a long
Speaker 1: way off figuring out dark matter. But right now there's
Speaker 1: lots small questions than there are answers, and it's I
Speaker 1: supposed to watch this space scenario, but no. We appreciate
Speaker 1: you passing on your thoughts, Kevin, and hopefully we will
Speaker 1: be able to come up with some more information moving
Speaker 1: forward once we've looked into it through the respective experts.
Speaker 1: Let's move on to our next question. This comes from
Speaker 1: Simon and he says, hi, is it possible that the
Speaker 1: breakdown of models at extremes of the universe is due
Speaker 1: to our mathematics being flawed rather than the models? For example,
Speaker 1: fluid dynamic models of real world scenarios rely on imaginary numbers.
Speaker 1: Might our system of mathematics be slightly misaligned with the
Speaker 1: real world? Thank you, Simon. I think we've kind of
Speaker 1: talked about the mathematics being off in respect to some
Speaker 1: things in the past, and even Einstein consider is the
Speaker 1: model of relativity is probably not right, even though we
Speaker 1: can't prove it wrong. So it is a good question
Speaker 1: to ask, and the answer is yeah, probably somewhere along
Speaker 1: the line, then the numbers don't stack up.
Speaker 3: Yeah. I think it's an interesting you know Simon's postulate
Speaker 3: about particularly about imaginary numbers, which is we call them
Speaker 3: complex numbers. They have a real and an imaginary component.
Speaker 3: Why is it imaginary because it's the square root of
Speaker 3: minus one, which doesn't exist. But it's an incredibly useful
Speaker 3: tool in so many fields of science and engineering too.
Speaker 3: Your aerodynamics relies on the imaginary numbers, so it's imaginary
Speaker 3: numbers that keep you plane in the air. Could could
Speaker 3: that understanding be flawed? Yes? I think it could. And
Speaker 3: again I think, you know, we are pretty open minded
Speaker 3: about this idea. What breaks down our physics in the
Speaker 3: extreme situations that I think Simon's referring to things like,
Speaker 3: you know, how do you deal with the way the
Speaker 3: universe behaved immediately after the Big Bang, where you've got
Speaker 3: temperatures and pressures that we've got no physical experience of
Speaker 3: in terms of working out how they would behave, and
Speaker 3: they become what we call highly nonlinear. That means that
Speaker 3: they behave in a way that is actually really hard
Speaker 3: to predict. And so that's saying that our physical models
Speaker 3: are not are not robust enough, not necessarily that the
Speaker 3: mathematics is not robust enough, but it is an interesting conjecture.
Speaker 3: I yeah, I think Simon's point is well made. Might
Speaker 3: our system of mathematics be slightly misaligned with the right
Speaker 3: real world? Well, in extreme cases it probably is. When
Speaker 3: you think about, you know, the temperature immediately after the
Speaker 3: Big Bang.
Speaker 1: Well, yeah, that's a good point. I mean it's no
Speaker 1: easy remedy though, is this? No?
Speaker 3: I mean there are people who are modeling those scenarios
Speaker 3: where you do have these extremes, and they're probably relying
Speaker 3: on relatively conventional mathematics, although yes, the other they will
Speaker 3: involve complex numbers and all the rest of it. But
Speaker 3: I yeah, I think it gets weirdest. Actually, it gets
Speaker 3: weirder in the quantum world, where we've got all kinds
Speaker 3: of interesting notions that do rely heavily on mathematics, superposition, entanglement,
Speaker 3: all of these things, and they rely on particular types
Speaker 3: of mathematics Hilbert spaces and things of that sort, which
Speaker 3: are well understood. I have to say, but to you know,
Speaker 3: to the uneducated, and I include myself in that, because
Speaker 3: mathematics was my achilles heel at university nearly cost me
Speaker 3: my degree. The I think they look these things look
Speaker 3: like mathematics gone wrong, if I can put it that way,
Speaker 3: but they haven't. They we'll understood. So the misalignment with
Speaker 3: the real world, I think it's possible. But in many ways,
Speaker 3: the mathematics is all we've got to rely on, so
Speaker 3: we just keep plodding on with what we know.
Speaker 1: Yeah, you mentioned superposition. I've just finished watching a science
Speaker 1: fiction series called Dark Matter, right, and they the goal
Speaker 1: of the main character, the scientist, that was the whole
Speaker 1: story was built around. His aim was to achieve superposition
Speaker 1: so they could travel into dimensionally. It was brilliantly done.
Speaker 1: Brilliantly done. They obviously had to work out how to
Speaker 1: make it a convincing storyline for those who are so
Speaker 1: into science fiction and science for that matter, to make
Speaker 1: it plausible, and they did a great job. It's a
Speaker 1: brilliant story, brilliant series. Really enjoyed it. Won't spoil it
Speaker 1: by telling you how it ended, but I doubt there
Speaker 1: will be a sequel because it did end, and it
Speaker 1: did end well. I thought, Okay, was it cool to
Speaker 1: dark Matter? Dark Dark Matter? And I think it was
Speaker 1: on Netflix. I can't remember now, But yeah, terrific series.
Speaker 1: Really enjoyed it and just so you know they could
Speaker 1: have well they did. It got so very confusingly complicated
Speaker 1: towards the end, but yeah, that's what made it so interesting.
Speaker 1: Thank you, Simon, And our next question coming up in
Speaker 1: a moment. Let's take a break from the show to
Speaker 1: tell you about our sponsor in Cogny, and I'll be
Speaker 1: giving you a special space nuts Url, so you can
Speaker 1: get up to sixty percent off in Cogni. But first,
Speaker 1: what's incognit all about. It's a way of cleaning up
Speaker 1: your online presence and reducing the risk of your personal
Speaker 1: information being sold to unscrupulous people via the dark web,
Speaker 1: or just via a hacker who's trying to fleece you
Speaker 1: or other people. It's also a great way to reduce
Speaker 1: spam emails and spam phone calls, reduce the risk of
Speaker 1: identity theft, which is big business these days. I think
Speaker 1: most significantly, it greatly reduces your risk of being scammed
Speaker 1: and that is just such a viral thing that's happening
Speaker 1: around the world at the moment. So how does all
Speaker 1: this work? Well, it's simple. All you have to do
Speaker 1: is sign up to in Cogni. Give them permission to
Speaker 1: act on your behalf and they'll do the rest. They'll
Speaker 1: trawl the Internet and remove your personal information from the web.
Speaker 1: The stuff that can be found on search engines, public websites,
Speaker 1: even private databases. It's all easily accessible. And let's face it,
Speaker 1: are you really going to be able to clean up
Speaker 1: the entire world wide web of your personal information by yourself?
Speaker 1: Right now? In Cogni is offering a significant discount for
Speaker 1: space Nuts listeners, up to sixty percent off and that
Speaker 1: comes with a thirty day money back guarantee. Just go
Speaker 1: to Incogni dot com slash space nuts that's I Ncogni,
Speaker 1: incogni dot com slash space nuts to find out more.
Speaker 1: And they have special prices for students and graduates as well.
Speaker 1: Make your personal information much harder to find online with
Speaker 1: in Cogny. Check out all their plans today at incogny
Speaker 1: dot com slash space nuts. Now back to the show.
Speaker 1: We're old on space Nuts and that's a moment this right,
Speaker 1: This one's from Isaac on the Gold. It is from Brisbane,
Speaker 1: actually in Australia. Isaac is nine years old. He said,
Speaker 1: I have two questions, how do black holes spin if
Speaker 1: they take up no space? And why does spin affect space?
Speaker 1: And his dad's got a question as well. My dad
Speaker 1: asks how does gravity bend space and thus bend light
Speaker 1: traveling past it? Isaac in Brisbane, nine years old. Great
Speaker 1: to hear from your Isaac. Thanks for sending your questions
Speaker 1: in why do black holes spin? I think someone else
Speaker 1: asked a similar question percently.
Speaker 3: We covered this not very long ago. Yeah, and so
Speaker 3: what you've got to think about is how black black
Speaker 3: holes are formed. If you have a star which is
Speaker 3: more than you know, ten times the mass of the Sun,
Speaker 3: something like that, gets to the end of its life,
Speaker 3: the nuclear propulsion system of the star stops until gravity
Speaker 3: takes over and the star collapses or its core collapses
Speaker 3: to become a black hole. So what you've got is
Speaker 3: a star that is going to be spinning. It will
Speaker 3: rotate because everything is rotating or evolving, and as it rotates,
Speaker 3: the spin will get faster because of the conservation of
Speaker 3: angular momentum. So spin is conserved. So even when the
Speaker 3: black hole becomes something that, as Isaac says, takes up
Speaker 3: no space, it's still spinning. Even though it is a
Speaker 3: single point. It's still spinning because it's the original style
Speaker 3: that collapsed to form. It was spinning, so that spin
Speaker 3: gets imparted to the black hole.
Speaker 1: So it's just inheriting basically.
Speaker 3: Yes, that's right. It's a good way of putting it,
Speaker 3: an inherited spin. I think I've got that as well.
Speaker 3: So and Isaac's dad wants to know how gravity bend space.
Speaker 3: We all want to know that actually, because it's what
Speaker 3: we know is how much in bend space. We do
Speaker 3: understand the mechanics of what happens when you put mass there.
Speaker 3: You can you can accurately predict just how and how
Speaker 3: much space will be bent, but why does it happens.
Speaker 3: It's the effect of gravity. That's the phenomenon we call gravity,
Speaker 3: and at that level we really don't understand it very well.
Speaker 1: Yeah, this is the thing. We know dark matter exists.
Speaker 1: We can't prove it yet. We know gravity exists, but
Speaker 1: we don't know about how it exists, in the way
Speaker 1: it exists, and whether or not it's a subatomic particle
Speaker 1: called a graviton.
Speaker 2: Yeah.
Speaker 1: I mean, we know a lot of things that exist,
Speaker 1: but we don't know much about why they exist and
Speaker 1: how they exist.
Speaker 3: Yeah, I suppose what you could say, is that we
Speaker 3: know extremely accurately. And this was you know, one of
Speaker 3: your answers to that last question. Relativity works like a dream.
Speaker 3: Everything is so precise, following the rules that Einstein laid
Speaker 3: out in nineteen fifteen. So that describes gravity incredibly well,
Speaker 3: incredibly accurately. But it is still only a description of gravity.
Speaker 3: It's not an understanding of how gravity arises. And so yes,
Speaker 3: we still have big mysteries.
Speaker 1: Though relatively speaking. Indeed, Yes, thanks Isaac, great to hear
Speaker 1: from you. Please send us questions again. I always love
Speaker 1: to hear from our younger listeners. And finally we have
Speaker 1: a question from our old mate Rusty. I believe Rusty
Speaker 1: is from Donnie Brook.
Speaker 2: Gooday, Fred and Andrew and all you space nuts. It's
Speaker 2: Rusty and Donny Roop, Western Australia. It seems to me
Speaker 2: that soon, and that may be in astronomical terms, we'll
Speaker 2: be able to harness the energy of space itself. We
Speaker 2: know there's a lot of energy in space. It has
Speaker 2: most of it if you look at the expanding universe
Speaker 2: and dark energy. But when we do harness the energy
Speaker 2: energy of space, we should be able to crank up
Speaker 2: one g drives and that allow us to go anywhere
Speaker 2: we like with swop over halfway, so the first half
Speaker 2: of the whege is accelerating at one g and the
Speaker 2: second half is decelerating at one G.
Speaker 1: A funny thing happens.
Speaker 3: The crew.
Speaker 2: To them seem to be traveling faster than the speed
Speaker 2: of light, so that they would go to Andromeda under
Speaker 2: these circumstances.
Speaker 3: In thirty crew years.
Speaker 2: So just wondering what Fred and Andrew, what your priorities
Speaker 2: would be once we do develop this drive both for
Speaker 2: the Solar System.
Speaker 1: And in the wider universe. Thank you, Oh Rusty, just
Speaker 1: put us right there in the middle of it. What
Speaker 1: would our priorities be over to you, Fred.
Speaker 3: Well, I've kind of said this before, and it's something
Speaker 3: that almost you know, rust is almost hinted by referring
Speaker 3: to a trip to Andromeda. The Andromeda galaxy. The view
Speaker 3: of our own galaxy from the outside is what I'd
Speaker 3: really like to see. Love to know how close our
Speaker 3: models are, just to make sure you got the color right,
Speaker 3: the color, how many spiral arms it's got? You know what?
Speaker 3: Don't we know that? No, not really. We think it's
Speaker 3: a forearm spiral, which is quite unusual. So you know,
Speaker 3: there's a there's a bar across the middle what we
Speaker 3: call a bar in the galaxy, not one you lean
Speaker 3: up against, but one that you you know, a bit
Speaker 3: like a rod or something like that. That's that's made
Speaker 3: of stars. And from each end of the bar, it
Speaker 3: looks as though there are two spiral arms that emerge.
Speaker 3: And that's based on mapping that we can do from
Speaker 3: the inside of the galaxy. But just imagine what it
Speaker 3: would look like if you're on the outside of it.
Speaker 1: Yeah, yeah, that's a great Yeah. I'd never contemplate a depth.
Speaker 1: To be honest, I know I have mentioned it before.
Speaker 1: I'd probably go further. I'd probably like to sort of
Speaker 1: get right away from our rum I suppose galactic cluster
Speaker 1: and look at the whole thing. I mean, I don't
Speaker 1: know how to explain it, but I'd like to be
Speaker 1: able to have in my view Andromeda and the Milky
Speaker 1: Way and whatever else is in the vicinity. You know,
Speaker 1: I'm assuming there are great voids between galaxy clusters, and
Speaker 1: I'd like to get out into one of them looking
Speaker 1: back at our galaxy cluster. I suppose that's what I'm saying.
Speaker 1: I think that would be fascinating just to see it
Speaker 1: all in one.
Speaker 3: Yes, yes, I think so. We're the Milky Way and
Speaker 3: the Andromeda Galaxy are the two biggest members of what
Speaker 3: we call the local Group, which is about thirty galaxies thereabouts.
Speaker 3: The next biggest one is the Triangular Galaxy, and then
Speaker 3: there's lots of small stuff. But we're part of a
Speaker 3: bigger cluster. I think it's a Virgo cluster that we're
Speaker 3: part of. I'm shocking it not remembering that that we're
Speaker 3: a little bit of that. It was certainly one of
Speaker 3: the bigger galaxy clusters we're part of as well. So
Speaker 3: you want to get right outside that and see what
Speaker 3: it looks like and be able to point to our
Speaker 3: Milky Way and say that's fled. Yeah.
Speaker 1: Yeah, I mean that's probably very un exciting to most people.
Speaker 1: I'm sure others have thought, oh, okay, well, if I
Speaker 1: could get a one G drive, what I would do
Speaker 1: is this, Maybe they can let us know. But you know,
Speaker 1: if we get achieved one G drive, it would make
Speaker 1: travel around the Solar System pretty schmick, wouldn't It is?
Speaker 3: It's it is. It's a nice concept because you you
Speaker 3: do two things. You give your spacecraft a long period
Speaker 3: of constant acceleration. But if you make it one G,
Speaker 3: then you've you've also provided your spacecraft with artificial gravity.
Speaker 3: So it means that everybody you know can stand upright
Speaker 3: on the bottom of the spacecraft as it's accelerating. Yeah,
Speaker 3: the end away from the the end of away from them, sorry,
Speaker 3: the way the end away from the point a bit
Speaker 3: that the bottom of your capsule that the acceleration would
Speaker 3: would mean that you were you were actually kept there
Speaker 3: exactly the same weight as you have on Earth. And
Speaker 3: then if you switched it around to slow down at
Speaker 3: the other end of your trip, you'd have one G
Speaker 3: also decelerating it. It's a really neat idea, if ever
Speaker 3: it can be made to work.
Speaker 1: Do you think it could work?
Speaker 3: Yes, well it could, but the main issue is sustaining
Speaker 3: it for a long period. That's why it's something that
Speaker 3: we haven't done yet.
Speaker 1: Maybe ion drive engines.
Speaker 3: That sort of thing. That's why that's the kind of
Speaker 3: thing that people think of.
Speaker 1: Yeah, could be interesting. Thank you, Rusty. As always you
Speaker 1: you pulled one out of the big black box. It's
Speaker 1: he's always got a bit of a curve ball for us.
Speaker 1: Has Rusty nice to hear from you. That is the
Speaker 1: end of this particular episode. If you would like to
Speaker 1: ask questions of Fred by all means, go to our
Speaker 1: website spacenuts podcast dot com. Spacenuts dot io is the
Speaker 1: other url. I'll both take you to the same place.
Speaker 1: You just click on the tab at the top and
Speaker 1: when you go in there, it gives you the option
Speaker 1: to send us a text or audio question.
Speaker 3: If you've got a.
Speaker 1: Device with a microphone, it's as easy as saying, Hi,
Speaker 1: I'm Fred from Sydney and I want to know and
Speaker 1: awhere you go. And if you're not named Fred, you
Speaker 1: can send us questions to just tell us who you
Speaker 1: are and where you're from, and we'd love to hear
Speaker 1: from you, especially if you've contemplated sending a question and
Speaker 1: you've been a bit reluctant. There are no dumb questions
Speaker 1: in astronomy and space science, so yeah, please please do
Speaker 1: get onto our website and send us some questions asap.
Speaker 1: We're done, Fred, thank you very much.
Speaker 3: You're welcome. It's always a pleasure, Andrew, and we'll talk
Speaker 3: again to we will possibly in the next few days.
Speaker 1: Who knows. That's Professor Fred Wartson, astronomer at large here
Speaker 1: in the studio, is just being here in the studio today. Actually,
Speaker 1: I think he's been the guy who picks up the
Speaker 1: kids from school. Hugh in the studio and from me
Speaker 1: Andrew and Unkley, thanks for your company. We'll catch you
Speaker 1: again real soon on another episode of Space Nuts. Bye bye.
Speaker 3: To the Space Nuts podcast.
Speaker 1: Available at Apple Podcasts, Spotify, iHeartRadio, or your favorite podcast player.
Speaker 1: You can also stream on demand at bides dot com.
Speaker 4: This has been another quality podcast production from nights dot com.