Source:
https://www.spreaker.com/episode/450-dark-matter-debate-flawed-maths-spinning-black-holes--61307718
This episode of Space Nuts is brought to you by Incogni...looking after your online privacy with no hassles. To check out our special Space Nuts deal, visit https://www.incogni.com/spacenuts
Join Andrew Dunkley and Professor Fred Watson in this thought-provoking Q&A episode of Space Nuts, where they tackle intriguing questions from our listeners about dark matter, flawed mathematics, black holes, and more.Episode Highlights:- Dark Matter Debate: Kevin from Melbourne challenges the Timms on their previous discussion about dark matter, questioning whether SpaceTime itself could be the elusive substance.
- Flawed Mathematics: Simon wonders if the breakdown of models at the extremes of the universe is due to our mathematics being flawed. Could our system of mathematics be misaligned with the real world?
- Black Holes and Spin: Isaac from Brisbane, aged nine, asks how black holes spin if they take up no Space and why spin affects Space.
- Gravity and Space: Isaac's dad inquires about how gravity bends Space and thus bends light traveling past it.
- Energy in Space: Rusty from Donnybrook speculates about harnessing the energy of Space and the potential for one g drives to revolutionise Space travel.
- 00:00:00 - This is a q and a edition of Space Nuts
- 00:01:05 - Kevin from Melbourne asks whether spacetime itself might be dark matter
- 00:07:22 - Is it possible that breakdown of models is due to our mathematics being flawed
- 00:11:38 - Simon: I just finished watching a science fiction series called dark matter
- 00:13:01 - Why do black holes spin if they take up no space
- 00:15:11 - Isaac's dad wants to know how gravity bends space
- 00:16:56 - Fred and Andrew: Soon we'll harness the energy of space itself
- 00:18:39 - If we could achieve one g drive, it would make travel around the solar system pretty schmick
- 00:24:16 - Space Nuts podcast available at Apple Podcasts, Spotify, iHeartRadio
For more Space Nuts, including our continually updating newsfeed, visit our website at https://www.spacenutspodcast.com. Follow us on social media at SpaceNutsPod on facebook, X, YouTube Music, and TikTok. We love engaging with our community, so be sure to drop us a message or comment on your favourite platform. For more Space and Astronomy News Podcasts, visit our HQ at https://www.bitesz.com Become a supporter of this podcast: https://www.spreaker.com/podcast/space-nuts/support.Stay curious, keep looking up, and join us next time for more stellar insights and cosmic wonders. Until then, clear skies and happy stargazing.
00:00:00 --> 00:00:02 hi there thanks for joining us this is a
00:00:02 --> 00:00:05 Q&A edition of Space Nuts my name is
00:00:05 --> 00:00:08 Andrew Dunley coming up uh we're going
00:00:08 --> 00:00:10 to look at a lot of issues one involving
00:00:10 --> 00:00:14 dark matter um this question though uh
00:00:14 --> 00:00:17 comes about as a consequence of someone
00:00:17 --> 00:00:20 who wasn't real happy with a a
00:00:20 --> 00:00:22 discussion we had recently so we'll uh
00:00:22 --> 00:00:26 we'll um certainly reinvestigate that uh
00:00:26 --> 00:00:28 we'll also look at flawed mathematics
00:00:28 --> 00:00:31 that sounds like my entire School career
00:00:31 --> 00:00:33 uh we'll also be discussing black holes
00:00:33 --> 00:00:35 and gravity and energy in space that's
00:00:35 --> 00:00:38 all coming up on this edition of Space
00:00:38 --> 00:00:43 Nuts 15 seconds guidance is internal 10
00:00:43 --> 00:00:48 9 ignition sequence start Space Nuts 5 4
00:00:48 --> 00:00:53 3 2 1 2 3 4 5 5 4 3 2 1 Space Nuts as
00:00:53 --> 00:00:55 the nuts report it feels good and
00:00:55 --> 00:00:58 joining us again to sort all of this out
00:00:58 --> 00:01:01 is Professor Fred Watson hello Fred
00:01:01 --> 00:01:04 hello Andrew um let's get into those
00:01:04 --> 00:01:07 questions eh yes uh let's just let's
00:01:07 --> 00:01:09 just hit the nail on the head and start
00:01:09 --> 00:01:12 and uh this first question uh comes
00:01:12 --> 00:01:14 about as a consequence of us uh
00:01:14 --> 00:01:17 answering a previous question and I I
00:01:17 --> 00:01:19 think we've kind of put Kevin's nose out
00:01:19 --> 00:01:22 of joint just slightly I might say
00:01:22 --> 00:01:25 though he's he's used a word that I I
00:01:25 --> 00:01:29 think is probably not in keeping with uh
00:01:29 --> 00:01:31 the way you do deal with things spread I
00:01:31 --> 00:01:33 would never ever accuse you of being
00:01:33 --> 00:01:37 glip however that said uh Kevin does
00:01:37 --> 00:01:40 have issue with the dark M matter
00:01:40 --> 00:01:42 question now so that I don't Mash
00:01:42 --> 00:01:46 Kevin's question up uh I have um
00:01:46 --> 00:01:48 prepared it with an AI voice so that it
00:01:48 --> 00:01:52 comes out clean and um unadulterated if
00:01:52 --> 00:01:55 you like so uh let's uh see what the
00:01:55 --> 00:01:58 issue is and see if we can um um pick it
00:01:58 --> 00:02:00 to pieces and put it back together again
00:02:00 --> 00:02:04 uh this is from Kevin in your 428th
00:02:04 --> 00:02:05 episode I was saddened by your response
00:02:05 --> 00:02:07 to a listener question asking if
00:02:07 --> 00:02:09 SpaceTime itself might be dark matter I
00:02:09 --> 00:02:12 found your emphatic and almost bli no
00:02:12 --> 00:02:14 just doesn't fit with your regular
00:02:14 --> 00:02:16 open-mindedness I have asked similar
00:02:16 --> 00:02:17 questions before in other forums and
00:02:17 --> 00:02:20 Reed the same dismissive no response
00:02:20 --> 00:02:21 without any depth of thinking about the
00:02:21 --> 00:02:24 question for starters we don't yet know
00:02:24 --> 00:02:26 what space time actually is but if it
00:02:26 --> 00:02:28 can be distorted it has some aspect of a
00:02:28 --> 00:02:30 substance to it and if it is a form of
00:02:30 --> 00:02:32 substance why should it not be
00:02:32 --> 00:02:33 considered as a candidate for Dark
00:02:33 --> 00:02:36 Matter it is everywhere it is
00:02:36 --> 00:02:37 transparent to em it is weakly
00:02:37 --> 00:02:39 interacting it can be distorted which
00:02:39 --> 00:02:42 means what that it becomes more dense in
00:02:42 --> 00:02:44 some areas than others so what if areas
00:02:44 --> 00:02:45 that are denser have a positive
00:02:45 --> 00:02:47 gravitational effect compared to average
00:02:47 --> 00:02:50 background space you might see clumping
00:02:50 --> 00:02:51 so what if areas that are less dense
00:02:51 --> 00:02:53 have a repulsive gravitational effect
00:02:53 --> 00:02:56 compared to average background space you
00:02:56 --> 00:02:58 might see voids I'm not saying space
00:02:58 --> 00:03:00 time is dark matter but dark matter is
00:03:00 --> 00:03:01 not actually a thing that has been
00:03:01 --> 00:03:04 discovered yet variable density space
00:03:04 --> 00:03:05 time may be all that is needed to
00:03:05 --> 00:03:07 explain the gravitation anomalies that
00:03:07 --> 00:03:09 we observed and I think it deserves a
00:03:09 --> 00:03:11 more open-minded level of exploring than
00:03:11 --> 00:03:13 a simple dismissal what I'd like to know
00:03:13 --> 00:03:15 is how would you test it as hypothesis
00:03:15 --> 00:03:18 has anyone done said testing has it been
00:03:18 --> 00:03:20 exhaustively ruled out by whom how did
00:03:20 --> 00:03:22 they do that otherwise brilliant show
00:03:23 --> 00:03:25 Kevin from Melbourne Okay Kevin thank
00:03:25 --> 00:03:27 you very much I hope you don't mind me
00:03:27 --> 00:03:28 using AI
00:03:28 --> 00:03:31 to put that question out there I just
00:03:31 --> 00:03:34 wanted to make sure it was intact
00:03:34 --> 00:03:35 because
00:03:35 --> 00:03:38 um you you obviously are very serious
00:03:39 --> 00:03:43 about this issue and you um have had
00:03:43 --> 00:03:45 problems in the past getting a straight
00:03:45 --> 00:03:47 answer and you put a lot of thought into
00:03:47 --> 00:03:51 it uh I I I give you credit for that so
00:03:51 --> 00:03:55 Fred um how can we sort of discuss this
00:03:55 --> 00:03:58 question with a with a a more robust
00:03:58 --> 00:04:00 approach
00:04:00 --> 00:04:02 by getting uh somebody who's more of a
00:04:02 --> 00:04:05 specialist in Dark Matter physics and
00:04:05 --> 00:04:07 cosmology than
00:04:07 --> 00:04:12 me um as um as a commentator I mean what
00:04:12 --> 00:04:15 I report on is what I understand from
00:04:15 --> 00:04:17 the work of my colleagues who uh work in
00:04:17 --> 00:04:20 this sort of field uh and there's
00:04:20 --> 00:04:24 certainly nothing I've heard and seen in
00:04:24 --> 00:04:25 the
00:04:25 --> 00:04:29 literature that would equate dark matter
00:04:29 --> 00:04:34 with SpaceTime um it is always regarded
00:04:34 --> 00:04:36 as something that exists within
00:04:36 --> 00:04:39 SpaceTime now there'll be there'll be
00:04:39 --> 00:04:42 very good reasons for that uh and
00:04:43 --> 00:04:46 um almost certainly uh if some of my
00:04:46 --> 00:04:47 friends and colleagues were sitting
00:04:48 --> 00:04:50 right here now they would be able to
00:04:50 --> 00:04:53 point us in the right direction as to
00:04:53 --> 00:04:55 why that is the case I haven't checked
00:04:55 --> 00:04:59 it the details myself but um nobody is
00:04:59 --> 00:05:03 making suggestion uh it is uh it's
00:05:03 --> 00:05:06 almost universally accepted as being uh
00:05:06 --> 00:05:09 a a subatomic particle of some kind
00:05:09 --> 00:05:12 which exists within SpaceTime uh that we
00:05:12 --> 00:05:16 haven't yet detected um I and I'm sorry
00:05:16 --> 00:05:18 if I sounded glit but it wasn't
00:05:18 --> 00:05:19 certainly wouldn't have been my
00:05:19 --> 00:05:21 intention and um dismissive isn't
00:05:21 --> 00:05:24 something I like to be described as
00:05:24 --> 00:05:27 either uh because um you know we we
00:05:27 --> 00:05:30 normally um we normally exactly keep an
00:05:30 --> 00:05:32 open mind about many of these issues and
00:05:32 --> 00:05:35 part of that open-mindedness is because
00:05:35 --> 00:05:37 I'm not a specialist in the field I'm
00:05:37 --> 00:05:39 reporting on what you know what my
00:05:39 --> 00:05:42 colleagues not just one of them but many
00:05:42 --> 00:05:45 of them uh are saying so uh yeah let's
00:05:45 --> 00:05:48 let's um keep it keep it in mind uh I
00:05:48 --> 00:05:50 will explore it a little bit further the
00:05:50 --> 00:05:52 idea that Jord is going to get involved
00:05:52 --> 00:05:55 as well there we'll go uh I'll I'll
00:05:55 --> 00:05:58 explore the reasons why um we don't
00:05:58 --> 00:06:01 consider it to be part of space time um
00:06:01 --> 00:06:04 at a later date okay no that's fair
00:06:04 --> 00:06:06 enough thanks thanks for your comments
00:06:06 --> 00:06:09 Kevin yeah and um look I I appreciate
00:06:09 --> 00:06:11 his frustration because he's obviously
00:06:11 --> 00:06:13 tried to get answers on this and uh may
00:06:13 --> 00:06:16 not have liked the way we approached it
00:06:16 --> 00:06:19 at that particular time but it is an
00:06:19 --> 00:06:23 area that is under heavy investigation
00:06:23 --> 00:06:25 indeed yeah everyone is looking at it
00:06:25 --> 00:06:27 even one or two episodes ago we talked
00:06:27 --> 00:06:30 about uh a a particular search for dark
00:06:31 --> 00:06:34 matter that came up with nothing MH uh
00:06:34 --> 00:06:35 and that doesn't mean it doesn't exist
00:06:35 --> 00:06:38 in fact we we know it exists they just
00:06:38 --> 00:06:39 haven't found it within certain
00:06:40 --> 00:06:42 parameters and so they'll be looking
00:06:42 --> 00:06:44 bigger but that particular equipment
00:06:44 --> 00:06:48 hasn't actually been built yet so uh the
00:06:48 --> 00:06:51 the the frustration continues so um yeah
00:06:51 --> 00:06:54 it we're we're hopefully not a long way
00:06:54 --> 00:06:57 off figuring out dark matter but right
00:06:57 --> 00:07:00 now there's there's lots more questions
00:07:00 --> 00:07:04 than there are answers and it's it's um
00:07:04 --> 00:07:05 I suppose it to watch this space
00:07:05 --> 00:07:10 scenario but um no we appreciate you um
00:07:10 --> 00:07:11 passing on your thoughts Kevin and
00:07:11 --> 00:07:13 hopefully we'll be able to uh come up
00:07:13 --> 00:07:16 with some more information moving
00:07:16 --> 00:07:18 forward once we've uh We've looked into
00:07:18 --> 00:07:21 it through the respective
00:07:21 --> 00:07:23 experts uh let's move on to our next
00:07:23 --> 00:07:27 question this comes from Simon and uh he
00:07:27 --> 00:07:29 says Hi is it possible that the
00:07:29 --> 00:07:31 breakdown of models at extremes of the
00:07:31 --> 00:07:34 universe is due to our mathematics being
00:07:34 --> 00:07:36 flawed rather than the models for
00:07:37 --> 00:07:40 example fluid Dynamic uh models of real
00:07:40 --> 00:07:43 world scenarios rely on imaginary
00:07:43 --> 00:07:45 numbers might our system of mathematics
00:07:45 --> 00:07:48 be slightly misaligned with the real
00:07:48 --> 00:07:50 world thank you
00:07:51 --> 00:07:53 Simon I think we've kind of talked about
00:07:53 --> 00:07:56 the mathematics being off uh in respect
00:07:56 --> 00:07:58 to some things in the past and even
00:07:58 --> 00:08:02 Einstein considers the model of
00:08:02 --> 00:08:05 Relativity is probably not right even
00:08:05 --> 00:08:08 though we can't prove it wrong so it is
00:08:08 --> 00:08:10 a good question to ask and the answer is
00:08:10 --> 00:08:12 yeah probably somewhere along the line
00:08:12 --> 00:08:15 that the numbers don't stack up yeah I I
00:08:15 --> 00:08:17 think it's an interesting you know
00:08:17 --> 00:08:20 Simon's postulate about particularly
00:08:20 --> 00:08:24 about imaginary numbers um which
00:08:24 --> 00:08:27 is uh we call them complex numbers they
00:08:27 --> 00:08:29 have an a real and and an imagin
00:08:29 --> 00:08:32 component why is it imaginary because
00:08:32 --> 00:08:34 it's the square root of minus one uh
00:08:34 --> 00:08:39 which doesn't exist um so uh but it's a
00:08:39 --> 00:08:42 incredibly useful tool in so many fields
00:08:42 --> 00:08:46 of science um and Engineering too uh
00:08:46 --> 00:08:49 your aerodynamics relies on imaginary
00:08:49 --> 00:08:50 numbers so it's imaginary numbers that
00:08:50 --> 00:08:55 keep you pling in the air um could could
00:08:55 --> 00:08:58 that understanding be flawed yes I think
00:08:58 --> 00:09:00 it could and again I think you know we
00:09:00 --> 00:09:02 we are pretty open-minded about this
00:09:02 --> 00:09:07 idea um what breaks down our
00:09:07 --> 00:09:11 physics um in the extreme situations
00:09:11 --> 00:09:13 that I think Simon's referring to things
00:09:13 --> 00:09:17 like you know how do you deal with um uh
00:09:17 --> 00:09:19 the way the universe behaved immediately
00:09:19 --> 00:09:21 after the big bang where you've got
00:09:21 --> 00:09:23 temperatures and pressures that we've
00:09:23 --> 00:09:26 got no physical experience of uh in
00:09:26 --> 00:09:29 terms of working out how how they would
00:09:29 --> 00:09:30 behave
00:09:30 --> 00:09:32 uh and they become what we call highly
00:09:32 --> 00:09:34 nonlinear that means that they they
00:09:34 --> 00:09:36 behave in a way that is actually really
00:09:36 --> 00:09:40 hard to predict uh and so um that's
00:09:40 --> 00:09:42 saying that our physical models are are
00:09:42 --> 00:09:47 not are not uh robust enough um uh not
00:09:47 --> 00:09:49 necessarily that the mathematics is not
00:09:49 --> 00:09:50 robust enough uh but it is an
00:09:50 --> 00:09:56 interesting conjecture um I yeah I I I
00:09:56 --> 00:09:59 think Simon's point is well made uh
00:09:59 --> 00:10:00 might system of mathematics be slightly
00:10:00 --> 00:10:02 misaligned with the real world well in
00:10:02 --> 00:10:04 extreme cases it probably is when you
00:10:04 --> 00:10:07 think about you know the temperature
00:10:07 --> 00:10:10 immediately after the big bag well yeah
00:10:10 --> 00:10:13 that's a that's a good point um I mean
00:10:13 --> 00:10:15 it's no easy remedy though is
00:10:16 --> 00:10:21 there um no um I mean uh there are
00:10:21 --> 00:10:22 people who are
00:10:22 --> 00:10:24 modeling those scenarios where you do
00:10:24 --> 00:10:26 have these extremes and they're probably
00:10:26 --> 00:10:28 relying on relatively conventional
00:10:28 --> 00:10:31 mathematics although yes you know they
00:10:31 --> 00:10:33 they will involve complex numbers and
00:10:33 --> 00:10:37 all the rest of it but I I think it it
00:10:37 --> 00:10:39 gets weirdest actually it gets
00:10:39 --> 00:10:43 weirder uh in um in the quantum world
00:10:43 --> 00:10:47 where we've got uh all kinds of uh
00:10:47 --> 00:10:49 interesting Notions that do rely heavily
00:10:49 --> 00:10:51 on mathematics superposition
00:10:51 --> 00:10:54 entanglement all of these things um and
00:10:54 --> 00:10:56 they rely on particular types of
00:10:56 --> 00:10:58 mathematics Hilbert spaces and things of
00:10:58 --> 00:10:59 that sort
00:10:59 --> 00:11:00 which
00:11:00 --> 00:11:04 are uh well understood I have to say but
00:11:04 --> 00:11:07 to you know to the uneducated and I
00:11:07 --> 00:11:10 include myself in that um because
00:11:10 --> 00:11:13 mathematics was my Achilles heel at
00:11:13 --> 00:11:16 University uh nearly cost me my degree
00:11:16 --> 00:11:20 uh the um the the I think they look
00:11:20 --> 00:11:22 these things look like mathematics gone
00:11:22 --> 00:11:24 wrong if I can put it that way but they
00:11:24 --> 00:11:27 haven't they're well understood so um
00:11:27 --> 00:11:29 the misalignment with the real world uh
00:11:29 --> 00:11:33 I I I think it's possible um but in many
00:11:33 --> 00:11:35 ways the mathematics is all we've got to
00:11:35 --> 00:11:37 rely on so we just keep plooding on with
00:11:37 --> 00:11:40 what we know yeah you mentioned
00:11:40 --> 00:11:41 superposition I've just finished
00:11:41 --> 00:11:43 watching a science fiction series called
00:11:43 --> 00:11:45 Dark Matter right
00:11:45 --> 00:11:50 and uh they the goal of the the main
00:11:50 --> 00:11:53 character the the scientist that was the
00:11:53 --> 00:11:56 the the whole story was built around uh
00:11:56 --> 00:11:59 his aim was to achieve superposition
00:11:59 --> 00:12:02 so so he could travel interdimensionally
00:12:02 --> 00:12:06 it was it was uh it was brilliantly done
00:12:06 --> 00:12:08 brilliantly done they they they
00:12:08 --> 00:12:11 obviously had to work out how to make it
00:12:11 --> 00:12:14 a convincing storyline for those who are
00:12:14 --> 00:12:18 so into science fiction and science for
00:12:18 --> 00:12:20 that matter to make it plausible and
00:12:20 --> 00:12:22 they did a great job it's a brilliant
00:12:22 --> 00:12:25 story brilliant series really enjoyed it
00:12:25 --> 00:12:28 won't uh won't uh spoil it by telling
00:12:28 --> 00:12:30 you how it ended but there I doubt
00:12:30 --> 00:12:32 there'll be a sequel because it did end
00:12:32 --> 00:12:36 okay and it did end well I thought right
00:12:36 --> 00:12:38 okay what was it called again Dark
00:12:38 --> 00:12:40 Matter Dark Matter okay Dark Matter uh
00:12:40 --> 00:12:43 and I think it was on Netflix can't
00:12:43 --> 00:12:46 remember now but um yeah terrific series
00:12:46 --> 00:12:49 really enjoyed it uh and just so you
00:12:49 --> 00:12:52 know they could have well they did it it
00:12:52 --> 00:12:55 got so very confusingly complicated
00:12:55 --> 00:12:58 towards the end but um yeah that's what
00:12:58 --> 00:13:01 made it so interesting yeah uh thank you
00:13:01 --> 00:13:04 Simon and our next question coming up in
00:13:04 --> 00:13:05 a
00:13:05 --> 00:13:07 moment let's take a break from the show
00:13:07 --> 00:13:10 to tell you about our sponsor in cogny
00:13:10 --> 00:13:12 and I'll be giving you a special Space
00:13:12 --> 00:13:17 Nuts URL so you can get up to 60% off
00:13:17 --> 00:13:21 incog but first what's incog all about
00:13:21 --> 00:13:23 uh it's a way of cleaning up your online
00:13:23 --> 00:13:25 presence and reducing the risk of your
00:13:25 --> 00:13:27 personal information being sold to
00:13:27 --> 00:13:30 unscrupulous people via the dark web or
00:13:30 --> 00:13:33 just via a hacker who's trying to fleece
00:13:33 --> 00:13:36 you or other people it's also a great
00:13:36 --> 00:13:39 way to reduce spam emails and spam phone
00:13:39 --> 00:13:42 calls reduce the risk of identity theft
00:13:42 --> 00:13:45 which is Big Business these days I think
00:13:45 --> 00:13:48 most significantly it greatly reduces
00:13:48 --> 00:13:51 your risk of being scammed and that is
00:13:51 --> 00:13:54 just such a viral thing that's happening
00:13:54 --> 00:13:57 around the world at the moment so how
00:13:57 --> 00:13:59 does all this work well it's
00:13:59 --> 00:14:02 simple all you have to do is sign up to
00:14:02 --> 00:14:04 incog give them permission to act on
00:14:04 --> 00:14:06 your behalf and they'll do the rest
00:14:06 --> 00:14:08 they'll troll the internet and remove
00:14:08 --> 00:14:11 your personal information from the web
00:14:11 --> 00:14:13 the stuff that can be found on search
00:14:13 --> 00:14:16 engines public websites even private
00:14:16 --> 00:14:19 databases it's all easily accessible and
00:14:19 --> 00:14:21 let's face it are you really going to be
00:14:21 --> 00:14:23 able to clean up the entire worldwide
00:14:23 --> 00:14:26 web of your personal information by
00:14:26 --> 00:14:30 yourself right now in COG is offering a
00:14:30 --> 00:14:32 significant discount for Space Nuts
00:14:32 --> 00:14:35 listeners up to 60% off and that comes
00:14:35 --> 00:14:39 with a 30-day money back guarantee just
00:14:39 --> 00:14:42 go to incog
00:14:42 --> 00:14:44 docomo that's in
00:14:44 --> 00:14:59 NC in cog.org
00:14:59 --> 00:15:02 line with incog check out all their
00:15:02 --> 00:15:06 plans today at incog
00:15:06 --> 00:15:10 docomo now back to the
00:15:10 --> 00:15:14 show Space Nuts and that's a moment uh
00:15:14 --> 00:15:18 this one this one's from um
00:15:18 --> 00:15:21 Isaac uh on the gold this is from
00:15:21 --> 00:15:24 Brisbane actually in um in Australia uh
00:15:24 --> 00:15:27 Isaac is 9 years old he said I have two
00:15:27 --> 00:15:29 questions how do black hole
00:15:29 --> 00:15:32 spin if they take up no space and why
00:15:32 --> 00:15:35 does spin affect
00:15:35 --> 00:15:38 space um and and his dad's got a
00:15:38 --> 00:15:41 question as well my dad asked how does
00:15:41 --> 00:15:43 gravity bend space and thus bend light
00:15:43 --> 00:15:48 traveling past it uh Isaac in Brisbane 9
00:15:48 --> 00:15:49 years old great to hear from you Isaac
00:15:49 --> 00:15:51 thanks for sending your questions in why
00:15:51 --> 00:15:54 do black holes spin I think someone else
00:15:54 --> 00:15:56 asked a similar question recently we
00:15:56 --> 00:15:58 covered this not very long ago yeah um
00:15:58 --> 00:16:00 and so what what you've got to think
00:16:00 --> 00:16:02 about is how black black holes are
00:16:02 --> 00:16:07 formed if you have um a star which is
00:16:07 --> 00:16:10 more than you know 10 times the mass of
00:16:10 --> 00:16:12 the Sun something like that gets to the
00:16:12 --> 00:16:15 end of its life the
00:16:15 --> 00:16:18 the nuclear propulsion system of the
00:16:18 --> 00:16:22 star stops until gravity takes over and
00:16:22 --> 00:16:25 the star collapses or it its core
00:16:25 --> 00:16:29 collapses to become a black hole so um
00:16:29 --> 00:16:31 what you've got is a star that is is
00:16:31 --> 00:16:33 going to be spinning it will rotate
00:16:33 --> 00:16:36 because everything is rotating or
00:16:36 --> 00:16:39 evolving uh and uh as it rotates uh the
00:16:39 --> 00:16:42 spin will get faster because of the
00:16:42 --> 00:16:45 conservation of angular momentum uh so
00:16:45 --> 00:16:48 spin is conserved so even when the black
00:16:48 --> 00:16:52 hole becomes something that as as Isaac
00:16:52 --> 00:16:55 says takes up no space um it's still
00:16:55 --> 00:16:59 spinning even though it is a single
00:16:59 --> 00:17:01 Point uh it's still spinning because
00:17:01 --> 00:17:03 it's the original Star that collapsed to
00:17:03 --> 00:17:05 form it was spinning so that spin gets
00:17:06 --> 00:17:08 imparted to the black H so it's just
00:17:08 --> 00:17:10 inherited basically it's yes that's
00:17:10 --> 00:17:11 right it's a good way of putting it an
00:17:11 --> 00:17:15 inherited spin um think think I've got
00:17:15 --> 00:17:18 that as well uh so and um Isaac's dad
00:17:18 --> 00:17:20 wants to know how gravity bend space we
00:17:20 --> 00:17:23 all want to know that actually yeah uh
00:17:23 --> 00:17:27 because um it's what we know is is how
00:17:27 --> 00:17:29 much it bent space we do understand
00:17:29 --> 00:17:32 the mechanics of uh what happens when
00:17:32 --> 00:17:35 you put Mass there you you can you can
00:17:35 --> 00:17:36 accurately
00:17:36 --> 00:17:40 predict just how and how much um space
00:17:40 --> 00:17:44 will be bent but why does it happen it's
00:17:44 --> 00:17:47 a it's the effect of gravity that's the
00:17:47 --> 00:17:49 phenomenon we call gravity and at that
00:17:49 --> 00:17:52 level we really don't understand it very
00:17:52 --> 00:17:54 well yeah this is the thing we know Dark
00:17:54 --> 00:17:57 Matter exists we can't prove it yet uh
00:17:57 --> 00:17:59 we know gravity exists but we don't know
00:17:59 --> 00:18:03 much about how it exists in the way it
00:18:03 --> 00:18:04 exists and whether or not it's a
00:18:04 --> 00:18:07 subatomic particle called a
00:18:07 --> 00:18:09 graviton yeah I mean we know a lot of
00:18:09 --> 00:18:11 things that exist but we don't know much
00:18:11 --> 00:18:15 about why they exist and how they exist
00:18:15 --> 00:18:17 yeah I I suppose what you could say is
00:18:17 --> 00:18:19 that we know extremely accurately and
00:18:19 --> 00:18:21 this was you know one of your answers to
00:18:21 --> 00:18:25 that last question relativity works like
00:18:25 --> 00:18:29 a dream everything is so precise h uh
00:18:29 --> 00:18:30 following the rules that Einstein laid
00:18:31 --> 00:18:31 out in
00:18:31 --> 00:18:36 1915 um uh so that describes gravity
00:18:36 --> 00:18:39 incredibly well incredibly accurately
00:18:39 --> 00:18:41 but it is still only a description of
00:18:41 --> 00:18:43 gravity it's not an understanding of how
00:18:43 --> 00:18:46 gravity arises yeah uh and so yes we
00:18:46 --> 00:18:49 still we still have big Mysteries there
00:18:49 --> 00:18:53 relatively speaking indeed yes thanks
00:18:53 --> 00:18:55 Isaac uh great to hear from you please
00:18:55 --> 00:18:57 uh send us questions again always love
00:18:57 --> 00:19:01 to hear from our younger listeners uh
00:19:01 --> 00:19:04 and finally we have a question from our
00:19:04 --> 00:19:06 old mate Rusty I believe Rusty's from
00:19:07 --> 00:19:08 Donny
00:19:08 --> 00:19:11 Brook good day Fred and Andrew and all
00:19:11 --> 00:19:14 you space nuts it's Rusty and Donny
00:19:14 --> 00:19:15 Brook West in
00:19:15 --> 00:19:20 Australia it seems to me that soon and
00:19:20 --> 00:19:23 that may be in astronomical terms will
00:19:23 --> 00:19:27 be able to harness the energy of space
00:19:27 --> 00:19:29 itself we know this's there's a lot of
00:19:29 --> 00:19:30 energy in
00:19:30 --> 00:19:34 space it has most of it if you look at
00:19:34 --> 00:19:36 the expanding universe
00:19:36 --> 00:19:40 and and dark energy but U when we do
00:19:40 --> 00:19:42 harness the energy energy of space we
00:19:42 --> 00:19:47 should be able to crank up a 1G
00:19:47 --> 00:19:51 drivve H that allow us to go anywhere we
00:19:51 --> 00:19:54 like with
00:19:54 --> 00:19:58 uh a swap over halfway
00:19:58 --> 00:20:00 so the first half of the voyage is
00:20:00 --> 00:20:03 accelerating at 1G and the second half
00:20:03 --> 00:20:06 is decelerating at 1G a funny thing
00:20:06 --> 00:20:08 happens the
00:20:08 --> 00:20:12 crew uh to them seem to be traveling
00:20:12 --> 00:20:14 faster than the speed of light so that
00:20:14 --> 00:20:17 they would go to Andromeda under these
00:20:17 --> 00:20:20 uh circumstances in 30 crew
00:20:20 --> 00:20:24 years so uh just wondering what Fred and
00:20:24 --> 00:20:27 Andrew what your priorities would be
00:20:27 --> 00:20:29 once we do develop this
00:20:29 --> 00:20:31 both for the solar system and in The
00:20:31 --> 00:20:31 Wider
00:20:31 --> 00:20:36 Universe thank you oh Rusty just put us
00:20:36 --> 00:20:39 right there in the middle of it
00:20:39 --> 00:20:43 um what would our priorities be um oh
00:20:43 --> 00:20:46 you Fred well I've kind of said this
00:20:46 --> 00:20:49 before and it's um something that almost
00:20:49 --> 00:20:53 you know rust's almost hinted at by
00:20:53 --> 00:20:55 referring to a trip to Andromeda the
00:20:55 --> 00:20:59 Andromeda galaxy uh the
00:20:59 --> 00:21:00 the view of our own Galaxy from the
00:21:00 --> 00:21:02 outside is what I'd really like to see
00:21:02 --> 00:21:05 I'd love to know how close our models
00:21:05 --> 00:21:07 are just to make sure you got the color
00:21:07 --> 00:21:09 right the color how many spiral arms
00:21:09 --> 00:21:12 it's got uh you know what what don't we
00:21:12 --> 00:21:15 know that no not really we think it's a
00:21:15 --> 00:21:19 forarm spiral which is quite unusual um
00:21:19 --> 00:21:21 so to you know there's a there's a bar
00:21:21 --> 00:21:23 across the middle what we call a bar in
00:21:23 --> 00:21:24 the Galaxy not one you lean up against
00:21:25 --> 00:21:27 but one that you uh uh you know a bit
00:21:27 --> 00:21:29 like a a Rod or something like that
00:21:29 --> 00:21:31 that's that's made of stars and from
00:21:31 --> 00:21:33 each end of the bar it looks as though
00:21:33 --> 00:21:36 there are two spiral arms that emerge
00:21:36 --> 00:21:38 and that's based on mapping that we can
00:21:38 --> 00:21:39 do from the inside of the Galaxy but
00:21:39 --> 00:21:41 just imagine what it would look like if
00:21:41 --> 00:21:44 you were on the outside of it yeah yeah
00:21:44 --> 00:21:46 that's a great yeah I i' never
00:21:47 --> 00:21:48 contemplated that to be honest I know
00:21:48 --> 00:21:51 you've mentioned it before I I'd
00:21:51 --> 00:21:54 probably go further I'd probably like to
00:21:54 --> 00:22:00 um sort of get right away from our
00:22:00 --> 00:22:04 um I suppose Galactic cluster and and
00:22:04 --> 00:22:08 look at the whole thing I mean I don't
00:22:08 --> 00:22:11 know how to explain it but um yeah i'
00:22:11 --> 00:22:13 I'd like to be able to have in my view
00:22:13 --> 00:22:16 Andromeda and the Milky Way and whatever
00:22:16 --> 00:22:20 else is in the vicinity you know um I'm
00:22:20 --> 00:22:22 assuming there are great voids between
00:22:22 --> 00:22:25 Galaxy clusters yeah and I'd like to get
00:22:25 --> 00:22:27 out into one of them looking back at our
00:22:27 --> 00:22:29 galaxy clusters I suppose that's what
00:22:29 --> 00:22:31 I'm saying I think that would be
00:22:31 --> 00:22:35 fascinating just to see it all in
00:22:35 --> 00:22:38 one yes yes that's so I think um so
00:22:38 --> 00:22:41 we're me um the Milky Way and the
00:22:41 --> 00:22:43 Andromeda galaxy are the two biggest
00:22:43 --> 00:22:45 members of what we call the local group
00:22:45 --> 00:22:48 uh which is about 30 galaxies there
00:22:48 --> 00:22:50 thereabouts and the next biggest one is
00:22:50 --> 00:22:52 the triangulum Galaxy uh and then
00:22:53 --> 00:22:55 there's lots of small stuff but we're
00:22:55 --> 00:22:58 part of a bigger um cluster I think it's
00:22:58 --> 00:23:01 the Virgo cluster that we're part of I I
00:23:01 --> 00:23:03 I'm shocking at not remembering that uh
00:23:04 --> 00:23:05 that we're a little bit of that it was
00:23:05 --> 00:23:06 certainly one of the bigger Galaxy
00:23:07 --> 00:23:08 clusters we're part of as well so you
00:23:08 --> 00:23:11 want to get right outside that and see
00:23:11 --> 00:23:13 what it looks like and be able to point
00:23:13 --> 00:23:15 to our Milky Way and say that's
00:23:15 --> 00:23:18 F that's F yeah I mean that's probably
00:23:18 --> 00:23:20 very unexciting to most people I'm sure
00:23:20 --> 00:23:23 others have um thought oh okay well if I
00:23:23 --> 00:23:25 could get a 1G Drive what I would do is
00:23:25 --> 00:23:29 this um maybe they can let us know but
00:23:29 --> 00:23:32 uh you know if we could achieve 1G drive
00:23:32 --> 00:23:34 it would make travel around the solar
00:23:34 --> 00:23:36 system pretty Schmick wouldn't it it
00:23:36 --> 00:23:38 would is um it's
00:23:38 --> 00:23:42 um it is it's a nice concept because you
00:23:42 --> 00:23:44 you do two things you you give you
00:23:44 --> 00:23:48 spacecraft a long period of constant
00:23:48 --> 00:23:50 acceleration but if you make it 1G then
00:23:50 --> 00:23:52 you've you've also provided your
00:23:52 --> 00:23:55 spacecraft with artificial gravity um so
00:23:55 --> 00:23:57 it means that everybody can you know can
00:23:57 --> 00:23:59 stand up right on the bottom of the
00:23:59 --> 00:24:02 spacecraft as it's accelerating yeah the
00:24:02 --> 00:24:05 end away from the uh the end away from
00:24:05 --> 00:24:06 the sorry the the end away from the
00:24:07 --> 00:24:11 pointy bit uh the um the bottom of your
00:24:11 --> 00:24:14 capsule uh that the acceleration would
00:24:14 --> 00:24:16 would mean that you were you were
00:24:16 --> 00:24:18 actually kept there at the exactly the
00:24:18 --> 00:24:20 same weight as you have on Earth and
00:24:20 --> 00:24:22 then if you switched it round to slow
00:24:22 --> 00:24:24 down at the other end of your trip you'd
00:24:24 --> 00:24:27 have one G uh also decelerating you it's
00:24:27 --> 00:24:30 it's a really neat idea if ever it can
00:24:30 --> 00:24:32 be made to work do you think it could
00:24:32 --> 00:24:37 work uh yes well it could um but the
00:24:37 --> 00:24:39 main issue is sustaining it for a long
00:24:39 --> 00:24:41 period that's why it's something that we
00:24:41 --> 00:24:42 haven't done
00:24:42 --> 00:24:46 yet maybe ey on Drive engines or sort of
00:24:46 --> 00:24:47 thing that's right that's the kind of
00:24:47 --> 00:24:50 thing that people think of yeah could be
00:24:50 --> 00:24:52 interesting thank you Rusty as always
00:24:52 --> 00:24:54 you you pulled one out of the uh the big
00:24:54 --> 00:24:57 black box it's um he's always got a bit
00:24:57 --> 00:25:00 of a curve ball Forest has Rusty uh nice
00:25:00 --> 00:25:04 to hear from you uh that uh is the end
00:25:04 --> 00:25:06 of this particular episode uh if you
00:25:06 --> 00:25:09 would like to ask our questions of Fred
00:25:09 --> 00:25:11 uh by all means go to our website Space
00:25:11 --> 00:25:14 Nuts podcast.com SPAC nuts.i is the
00:25:14 --> 00:25:16 other URL they'll both take you to the
00:25:17 --> 00:25:20 same place you just click on the AMA tab
00:25:20 --> 00:25:23 at the top and when you go in there it
00:25:23 --> 00:25:24 gives you the option to send us a text
00:25:24 --> 00:25:26 or audio question if you've got a device
00:25:26 --> 00:25:29 with a microphone to as easy as saying
00:25:29 --> 00:25:32 hi I'm Fred from Sydney and I want to
00:25:32 --> 00:25:35 know uh and Away you go try that um and
00:25:35 --> 00:25:38 if you're not named Fred you can send us
00:25:38 --> 00:25:39 questions too just tell us who you are
00:25:40 --> 00:25:43 and where you're from uh and we'd love
00:25:43 --> 00:25:45 to hear from you especially if you
00:25:45 --> 00:25:46 contemplated sending a question and
00:25:46 --> 00:25:48 you've been a bit reluctant there are no
00:25:48 --> 00:25:50 dumb questions in astronomy and space
00:25:50 --> 00:25:54 science so yeah please please do um get
00:25:54 --> 00:25:56 on to our website and send us some
00:25:56 --> 00:25:58 questions ASAP
00:25:58 --> 00:26:01 we're done Fred thank you very much uh
00:26:01 --> 00:26:03 you're welcome it's uh always a pleasure
00:26:03 --> 00:26:06 Andrew and we'll talk again soon we will
00:26:06 --> 00:26:10 possibly in the next few days who knows
00:26:10 --> 00:26:11 uh that's Professor Fred Watson
00:26:11 --> 00:26:13 astronomer at large here in the studio
00:26:13 --> 00:26:16 is just being here in the studio today
00:26:16 --> 00:26:18 actually I think he's being um the guy
00:26:18 --> 00:26:20 who picks up the kids from school here
00:26:20 --> 00:26:23 in the studio and from me Andrew Dunley
00:26:23 --> 00:26:24 thanks for your company we'll catch you
00:26:24 --> 00:26:26 again real soon on another episode of
00:26:26 --> 00:26:29 Space Nuts bye-bye Space Nuts you'll be
00:26:29 --> 00:26:32 listening to the Space Nuts
00:26:32 --> 00:26:35 podcast available at Apple podcasts
00:26:35 --> 00:26:38 Spotify ihart radio or your favorite
00:26:38 --> 00:26:40 podcast player you can also stream on
00:26:41 --> 00:26:43 demand at bites.com this has been
00:26:43 --> 00:26:46 another quality podcast production from
00:26:46 --> 00:26:48 bites.com