Archived Insights: Gravitational Waves, Earth's Fate, and Dark Energy
In this special episode of Space Nuts , hosts Andrew Dunkley and Professor Fred Watson take a trip down memory lane, revisiting some of the most compelling questions from their Q&A sessions. This episode features discussions on gravitational waves produced by the Big Bang, a thought-provoking "what if" scenario regarding the Earth's fate if the Sun never dies, and a deep dive into the enigmatic nature of dark energy.
Episode Highlights:
- Gravitational Waves and the Big Bang: Andrew and Fred tackle a listener's inquiry about whether the Big Bang generated gravitational waves and how these might be detected alongside the cosmic microwave background radiation.
- The Fate of Earth: A "what if" question explores the implications of an immortal Sun and how Earth's environment might evolve, leading to fascinating speculations about tidal locking and atmospheric changes.
- Time and Dark Energy: The hosts discuss a listener's theory proposing a connection between time and dark energy, addressing the complexities of cosmic expansion and the role of gravity in shaping our understanding of the 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.
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Episode link: https://play.headliner.app/episode/30776545?utm_source=youtube
00:00:00 --> 00:00:01 While the world takes a little bit of a
00:00:01 --> 00:00:03 rest over the Christmas New Year period,
00:00:03 --> 00:00:05 we thought we would, too. But we're not
00:00:05 --> 00:00:07 going to leave you hanging. We've dug
00:00:07 --> 00:00:10 into the archives and found a few of the
00:00:10 --> 00:00:13 biggest episodes of recent times. So,
00:00:13 --> 00:00:15 sit back and enjoy those. And we'll be
00:00:15 --> 00:00:18 back with new episodes of Space Nuts
00:00:18 --> 00:00:19 probably in the middle of January. See
00:00:20 --> 00:00:22 you then. Space Nuts. Hi there. Thanks
00:00:22 --> 00:00:25 for joining us. This is Space Nuts Q&A.
00:00:25 --> 00:00:28 My name is Andrew Dunley, your host. And
00:00:28 --> 00:00:30 coming up on this episode, we got a
00:00:30 --> 00:00:32 question about gravitational waves and
00:00:32 --> 00:00:34 the big bang. We're also going to uh
00:00:34 --> 00:00:36 look at a what if question. Love the
00:00:36 --> 00:00:39 what if questions. Uh which is asking
00:00:39 --> 00:00:41 about the life of Earth. Not life on
00:00:42 --> 00:00:45 Earth, the life of Earth if the sun
00:00:45 --> 00:00:49 never died. Interesting uh angle. And
00:00:49 --> 00:00:52 we're also going to look at uh time and
00:00:52 --> 00:00:55 dark energy. That's all coming up on the
00:00:55 --> 00:00:58 Q&A edition of Space Nuts.
00:00:58 --> 00:01:03 >> 15 seconds. Guidance is internal. 10 9
00:01:03 --> 00:01:05 Ignition sequence start.
00:01:05 --> 00:01:05 >> Space Nuts.
00:01:05 --> 00:01:08 >> 5 4 3 2
00:01:08 --> 00:01:10 >> 1 2 3 4 5 5 4 3 2 1
00:01:10 --> 00:01:12 >> Space Nuts.
00:01:12 --> 00:01:14 >> Astronauts report. It feels good.
00:01:14 --> 00:01:16 >> And joining me once again is Professor
00:01:16 --> 00:01:17 Fred Watson, astronomer at large. Hello
00:01:17 --> 00:01:18 Fred.
00:01:18 --> 00:01:20 >> Hi Andrew. How are you doing?
00:01:20 --> 00:01:22 >> I'm doing as much as I can.
00:01:22 --> 00:01:24 >> Good. Good. Good, good to be Q&A with
00:01:24 --> 00:01:25 you.
00:01:25 --> 00:01:28 >> Yes, you too. Um, shall we get stuck
00:01:28 --> 00:01:29 straight in?
00:01:29 --> 00:01:30 >> Why not? Yes, why not?
00:01:30 --> 00:01:32 >> All right. Uh, our first question comes
00:01:32 --> 00:01:35 I'm not sure if it's Bo or Boa. I'll
00:01:35 --> 00:01:36 have to listen more carefully. Here we
00:01:36 --> 00:01:38 go.
00:01:38 --> 00:01:40 >> Hello, Fred and Andrew. Is Bo here from
00:01:40 --> 00:01:43 Melbourne? I hope you're well. I have a
00:01:43 --> 00:01:46 question for you, and it is not about
00:01:46 --> 00:01:48 dark energy, nor it is about dark
00:01:48 --> 00:01:50 matter, but it is about gravitational
00:01:50 --> 00:01:54 waves. It's a straightforward question.
00:01:54 --> 00:01:56 Did the big bang produce gravitational
00:01:56 --> 00:01:59 waves? As we understand it,
00:01:59 --> 00:02:01 gravitational waves are generated when
00:02:01 --> 00:02:03 two massive bodies such as neutron stars
00:02:03 --> 00:02:06 and black holes collided each other and
00:02:06 --> 00:02:08 cause that ripple in the fabric of
00:02:08 --> 00:02:10 spacetime.
00:02:10 --> 00:02:14 But when the universe as just began uh
00:02:14 --> 00:02:17 in infinite density and so forth when it
00:02:17 --> 00:02:20 came into existence via the big bang did
00:02:20 --> 00:02:23 it produce gravitational waves or echoes
00:02:23 --> 00:02:26 and can we detect those echoes in space
00:02:26 --> 00:02:28 and time very much like the cosmic
00:02:28 --> 00:02:30 microwave background radiation that we
00:02:30 --> 00:02:33 see today. Anyway, I hope that makes
00:02:33 --> 00:02:35 sense. I'd love to hear your answer.
00:02:35 --> 00:02:36 Thank you very much.
00:02:36 --> 00:02:38 >> Thank you Boa. Um that's a good
00:02:38 --> 00:02:40 question. I you know we talk about the
00:02:40 --> 00:02:41 big bang a lot. We get a lot of
00:02:42 --> 00:02:46 questions about it. Uh and I mean it was
00:02:46 --> 00:02:51 a a massive event. We don't know why. We
00:02:51 --> 00:02:55 don't know a lot but uh we know we can
00:02:55 --> 00:02:57 see that it happened through the cosmic
00:02:57 --> 00:02:58 microwave background radiation that's
00:02:58 --> 00:03:02 still evident today. But gravitational
00:03:02 --> 00:03:06 waves would I mean if the universe
00:03:06 --> 00:03:07 didn't exist at the moment of the big
00:03:08 --> 00:03:10 bang and was being created as a
00:03:10 --> 00:03:12 consequence of that
00:03:12 --> 00:03:14 I'm not sure gravitational waves could
00:03:14 --> 00:03:16 have happened the way we understand them
00:03:16 --> 00:03:20 with other events in our universe. So um
00:03:20 --> 00:03:24 yeah I'm not sure about this one. So um
00:03:24 --> 00:03:27 the the thing is Andrew um the yes the
00:03:27 --> 00:03:30 universe was created in that instant uh
00:03:30 --> 00:03:35 of the big bang um and so you're right
00:03:35 --> 00:03:37 um you know in the conventional theory
00:03:37 --> 00:03:40 standard Einsteinian physics we we
00:03:40 --> 00:03:42 imagine that time and space didn't exist
00:03:42 --> 00:03:45 before the big bang so uh you've got to
00:03:45 --> 00:03:47 create some space for your gravitational
00:03:47 --> 00:03:50 waves to go through uh which is kind of
00:03:50 --> 00:03:53 thinking yeah and so um And so yes,
00:03:54 --> 00:03:56 there was the instant of the big bang
00:03:56 --> 00:03:59 that created this singularity in time
00:03:59 --> 00:04:03 and space followed by this period was it
00:04:03 --> 00:04:06 10us 33 of a second something like that
00:04:06 --> 00:04:09 in duration uh which we call the period
00:04:09 --> 00:04:12 of inflation when the when the expansion
00:04:12 --> 00:04:16 really took hold uh and it you know the
00:04:16 --> 00:04:18 universe went from the size of a
00:04:18 --> 00:04:20 football to the size of a galaxy in
00:04:20 --> 00:04:24 something like 10 theus 33 a second and
00:04:24 --> 00:04:28 uh the thinking is and I'm actually
00:04:28 --> 00:04:30 dragging this up from reading a few
00:04:30 --> 00:04:33 years ago but but that yes that per that
00:04:33 --> 00:04:36 inflationary period as we call it would
00:04:36 --> 00:04:40 have created gravitational waves.
00:04:40 --> 00:04:44 >> Uhhuh. Uh or maybe a gravitational wave
00:04:44 --> 00:04:45 but
00:04:45 --> 00:04:46 >> I was about to say
00:04:46 --> 00:04:48 >> maybe just one big one
00:04:48 --> 00:04:48 >> that's right
00:04:48 --> 00:04:52 >> at that point. But the the issue is um
00:04:52 --> 00:04:56 that uh it is a gravitational wave of
00:04:56 --> 00:04:59 very very very low frequency.
00:04:59 --> 00:05:02 So um the gravitational waves that we
00:05:02 --> 00:05:04 get from colliding neutron stars for
00:05:04 --> 00:05:10 example uh they produce waves which are
00:05:10 --> 00:05:12 basically have a frequency which is in
00:05:12 --> 00:05:14 the audio range which is why we can you
00:05:14 --> 00:05:17 know turn those uh gravitational wave
00:05:17 --> 00:05:20 signals into an audio signal very easily
00:05:20 --> 00:05:22 after you've amplified it up a bit and
00:05:22 --> 00:05:24 after LIGO has done its magic on it and
00:05:24 --> 00:05:27 that's where we get this chirp signal as
00:05:27 --> 00:05:30 as two neutron stars or whatever merge
00:05:30 --> 00:05:33 together uh and and eventually that
00:05:33 --> 00:05:35 because they're spinning ever ever ever
00:05:35 --> 00:05:37 more rapidly uh and so the frequency
00:05:37 --> 00:05:38 goes up of the waves that are being
00:05:38 --> 00:05:41 emitted and and then stop uh at a high
00:05:41 --> 00:05:43 point because that's where they've co
00:05:43 --> 00:05:47 coalesed into a single object. Um now
00:05:47 --> 00:05:49 you can think of those
00:05:49 --> 00:05:54 uh audio frequencies. Uh you know we
00:05:54 --> 00:05:56 might talk about something like 500 htz
00:05:56 --> 00:05:59 as an audio frequency or you could take
00:05:59 --> 00:06:03 440 htz as u the frequency of of um the
00:06:03 --> 00:06:06 standard a note in the in the musical
00:06:06 --> 00:06:11 spectrum. Um so if let's stick with 500
00:06:11 --> 00:06:14 because that's an easy one. Uh so the
00:06:14 --> 00:06:16 the the period of time between one peak
00:06:16 --> 00:06:20 of the of the wave and the next uh is
00:06:20 --> 00:06:23 1/500th of a second. And so if you think
00:06:24 --> 00:06:27 that's the inter interval of time of a
00:06:27 --> 00:06:29 characteristic gravitational wave from
00:06:30 --> 00:06:33 uh two colliding objects. Now the issue
00:06:33 --> 00:06:37 as I understand it is that the interval
00:06:37 --> 00:06:41 between peaks in a gravitational wave uh
00:06:41 --> 00:06:44 produced by inflation
00:06:44 --> 00:06:46 is about the same as the age of the
00:06:46 --> 00:06:50 universe now. It's not uh 1/500th of a
00:06:50 --> 00:06:53 second. It's you know several several
00:06:53 --> 00:06:57 billion years u perhaps even tens of
00:06:57 --> 00:06:59 billions of years. It's quite a while
00:06:59 --> 00:07:02 since I read up on this. So, so normal
00:07:02 --> 00:07:04 gravitational wave technology is simply
00:07:04 --> 00:07:06 not equipped to detect these low
00:07:06 --> 00:07:08 frequency
00:07:08 --> 00:07:10 ultra ultra low frequency gravitational
00:07:10 --> 00:07:12 waves, but there might be other ways of
00:07:12 --> 00:07:15 seeing them. Uh, and one of the things
00:07:15 --> 00:07:17 people have looked for, uh, and I'm not
00:07:17 --> 00:07:21 really very well up on this, but there
00:07:22 --> 00:07:24 is a potential
00:07:24 --> 00:07:26 signal in the cosmic microwave
00:07:26 --> 00:07:28 background radiation that the flash of
00:07:28 --> 00:07:30 the Big Bang that we see that that gives
00:07:30 --> 00:07:33 us what the universe looked like 380
00:07:33 --> 00:07:34 years after the Big Bang. That's that's
00:07:34 --> 00:07:38 what we're seeing there. that um that
00:07:38 --> 00:07:41 radiation uh contains information not
00:07:41 --> 00:07:43 just on its brightness but also on its
00:07:43 --> 00:07:45 polarization
00:07:45 --> 00:07:47 uh you know that radiation is polarized
00:07:48 --> 00:07:50 a bit like light can be polarized and
00:07:50 --> 00:07:53 I'm not really drawing the drawing the
00:07:54 --> 00:07:55 links very strongly here but I
00:07:55 --> 00:07:58 understand that there are links between
00:07:58 --> 00:08:00 very low frequency gravitational waves
00:08:00 --> 00:08:02 and that polarization signal so it's one
00:08:02 --> 00:08:04 of the things that people are looking
00:08:04 --> 00:08:05 for to try and detect this this
00:08:05 --> 00:08:08 polarization uh within the cosmic
00:08:08 --> 00:08:10 microwave background radiation. So it's
00:08:10 --> 00:08:13 not at all a dough question uh but it's
00:08:13 --> 00:08:15 quite a complex answer.
00:08:15 --> 00:08:18 >> Yeah. Yeah. But the the big bang itself
00:08:18 --> 00:08:22 could have initially been one you know
00:08:22 --> 00:08:24 created one gravitational wave.
00:08:24 --> 00:08:25 >> Yes. That's right. Yeah. That's more or
00:08:25 --> 00:08:26 less it.
00:08:26 --> 00:08:28 >> Yeah.
00:08:28 --> 00:08:30 >> There you go. Um you're right on the
00:08:30 --> 00:08:33 money. It's just a matter of finding a
00:08:33 --> 00:08:36 way of seeing them. Would they Is it
00:08:36 --> 00:08:38 possible these gravitational waves still
00:08:38 --> 00:08:39 bouncing around like the cosmic
00:08:39 --> 00:08:41 microwave background radiation?
00:08:41 --> 00:08:43 >> Well, yes. Yes. But um at such a low
00:08:43 --> 00:08:45 frequency that you don't actually know
00:08:45 --> 00:08:47 it's there. You've got to find other
00:08:47 --> 00:08:49 you've got to find other ways of
00:08:49 --> 00:08:50 detecting it because there's got not
00:08:50 --> 00:08:51 going to be any change in the
00:08:51 --> 00:08:53 gravitational wave signal over, you
00:08:53 --> 00:08:56 know, a human experimental lifetime. If
00:08:56 --> 00:08:59 you've got a frequency whose time
00:08:59 --> 00:09:00 interval is measured in billions of
00:09:00 --> 00:09:02 years, forget it.
00:09:02 --> 00:09:04 >> Yeah, that's a tough one.
00:09:04 --> 00:09:06 >> Forget it.
00:09:06 --> 00:09:08 >> Thanks, Boa. That's a great question and
00:09:08 --> 00:09:10 thanks for sending it in. Uh, we've got
00:09:10 --> 00:09:11 a question from one of our regulars,
00:09:11 --> 00:09:15 Renie, uh, who is from sunny West Hills,
00:09:15 --> 00:09:17 California. Uh, this is a what if
00:09:17 --> 00:09:18 question. And theoretically, if the sun
00:09:18 --> 00:09:21 were never to die, let's assume it's
00:09:21 --> 00:09:23 just never going to die, would the Earth
00:09:23 --> 00:09:26 eventually erode, decay,
00:09:26 --> 00:09:28 and die on its own?
00:09:28 --> 00:09:31 >> Um, yeah. Um, it's
00:09:31 --> 00:09:33 >> Well, my answer is no, because we'll
00:09:33 --> 00:09:35 destroy it first. It it could be very
00:09:35 --> 00:09:37 different. I mean what so if what Ren is
00:09:37 --> 00:09:40 saying is that yes the sun we know it's
00:09:40 --> 00:09:41 going to evolve over the next few
00:09:41 --> 00:09:43 billion years uh and it will change and
00:09:44 --> 00:09:45 that will eventually result in the earth
00:09:45 --> 00:09:47 being swamped by the outer atmosphere of
00:09:47 --> 00:09:49 the sun which might not be very nice for
00:09:49 --> 00:09:53 anybody left on earth. Uh but uh if that
00:09:53 --> 00:09:56 didn't happen, if the sun just um you
00:09:56 --> 00:09:58 know went on its merry way being a
00:09:58 --> 00:10:01 normal star,
00:10:01 --> 00:10:02 the there will be a few things that will
00:10:02 --> 00:10:05 happen over that time scale which
00:10:05 --> 00:10:06 wouldn't which wouldn't which we know
00:10:06 --> 00:10:09 won't happen because the sun's going the
00:10:09 --> 00:10:11 sun turning into a red giant's going to
00:10:11 --> 00:10:16 overtake it. One of them is uh the um
00:10:16 --> 00:10:19 tidal breaking of the earth's rotation
00:10:19 --> 00:10:21 so that it always uh faces the moon. So
00:10:21 --> 00:10:27 the earth's day will change from uh 24
00:10:27 --> 00:10:28 hours to something like if I remember
00:10:28 --> 00:10:31 rightly it's 42 days that it's it's
00:10:31 --> 00:10:33 about that length of time.
00:10:33 --> 00:10:35 >> Uh and that's it turning once and the
00:10:35 --> 00:10:39 moon will go around the sky around the
00:10:39 --> 00:10:41 earth in the same time. So the earth and
00:10:41 --> 00:10:43 the moon will constantly face one
00:10:43 --> 00:10:45 another with a a month and a day which
00:10:45 --> 00:10:46 are both equivalent to I think it's
00:10:46 --> 00:10:49 about 42 43 days something like that. Uh
00:10:50 --> 00:10:51 so that's that's going to change things
00:10:52 --> 00:10:54 quite a bit. Um so that would you know
00:10:54 --> 00:10:57 certainly alter the the um atmospheric
00:10:57 --> 00:10:59 dynamics of the earth if one side's
00:10:59 --> 00:11:01 getting warmed up for 40 of 20 days
00:11:01 --> 00:11:04 rather than just one day uh of day and
00:11:04 --> 00:11:08 night. So a lot of things change um and
00:11:08 --> 00:11:11 yeah the constant bombardment by the
00:11:11 --> 00:11:14 magnetic particles from the sun uh I
00:11:14 --> 00:11:16 don't know to what extent the earth's
00:11:16 --> 00:11:17 magnetic field might erode but there
00:11:17 --> 00:11:21 will certainly be be changes may even be
00:11:21 --> 00:11:24 >> what about go ahead go on sorry
00:11:24 --> 00:11:26 >> no I was just going to say if humans
00:11:26 --> 00:11:29 were still around in that period uh
00:11:29 --> 00:11:32 would we well okay no let me rephrase
00:11:32 --> 00:11:35 would we adapt as these things changed
00:11:35 --> 00:11:37 and reached that point, would we be able
00:11:37 --> 00:11:39 to adapt as a species and other life on
00:11:40 --> 00:11:42 Earth adapt to live in that kind of
00:11:42 --> 00:11:43 environment?
00:11:43 --> 00:11:45 >> Well, it certainly is these changes are
00:11:45 --> 00:11:47 ones that take place very slowly indeed.
00:11:47 --> 00:11:50 Uh and and over kind of longer periods
00:11:50 --> 00:11:53 than the characteristic evolution time
00:11:53 --> 00:11:55 to get from, you know, one mutation to
00:11:56 --> 00:11:57 another, whatever that might be for
00:11:57 --> 00:12:01 humans. Um, so yeah, they're they're
00:12:01 --> 00:12:04 slow and uh I'm sure humans could adapt
00:12:04 --> 00:12:06 to them. Uh, we're a pretty adaptive
00:12:06 --> 00:12:08 species. We might also by then be
00:12:08 --> 00:12:10 capable of building the mega structures
00:12:10 --> 00:12:12 that might protect us from some of the
00:12:12 --> 00:12:16 sun's funny things going on. Uh, it's
00:12:16 --> 00:12:18 hard to know really, isn't it? But but I
00:12:18 --> 00:12:19 I think generally speaking, I mean,
00:12:19 --> 00:12:21 Reny's question is a good one. Um, what
00:12:21 --> 00:12:24 happens if uh if nothing happens to the
00:12:24 --> 00:12:26 sun? Uh, does the earth just sort of
00:12:26 --> 00:12:29 survive? It probably survives. It will
00:12:29 --> 00:12:31 be changed. We might find we're all
00:12:31 --> 00:12:33 living in plastic domes or something by
00:12:33 --> 00:12:36 then rather than, you know, because the
00:12:36 --> 00:12:38 atmosphere has been so messed about
00:12:38 --> 00:12:41 with. But yes. Yes. I think I think I
00:12:41 --> 00:12:43 I'm I'm an optimist that humankind would
00:12:43 --> 00:12:44 survive.
00:12:44 --> 00:12:48 >> Yeah. Um now it's interesting because um
00:12:48 --> 00:12:50 I mean we we know what's going to
00:12:50 --> 00:12:51 happen. We kind of know when it's going
00:12:51 --> 00:12:54 to happen, but I if it didn't, it would
00:12:54 --> 00:12:56 create a whole array of new challenges
00:12:56 --> 00:12:59 for humanity because we would have to
00:12:59 --> 00:13:03 learn to live in a very
00:13:03 --> 00:13:05 somewhat hostile environment, I imagine,
00:13:05 --> 00:13:07 because um the the planet would not be
00:13:07 --> 00:13:09 the same. And I can't imagine what it
00:13:09 --> 00:13:12 would be like to have a 42 long
00:13:12 --> 00:13:14 >> 42 day long day.
00:13:14 --> 00:13:15 >> Um
00:13:15 --> 00:13:17 >> well, you know, birthdays would be few
00:13:17 --> 00:13:19 and far between, wouldn't they? uh they
00:13:19 --> 00:13:20 would, but you you know we're gonna
00:13:20 --> 00:13:22 we're going to know what that's like
00:13:22 --> 00:13:24 very soon because the the day on the
00:13:24 --> 00:13:27 moon is 20, you know, uh 29 days
00:13:27 --> 00:13:29 effectively from one
00:13:29 --> 00:13:31 >> full moon to another. So yeah, so we've
00:13:31 --> 00:13:33 we've we've already got something like
00:13:33 --> 00:13:36 that uh in store for people to
00:13:36 --> 00:13:37 experience. It'll be very interesting to
00:13:37 --> 00:13:40 see what even the Arteimus astronauts on
00:13:40 --> 00:13:43 the moon make of all that.
00:13:43 --> 00:13:45 >> Yeah. Yeah. Very interesting, Renie.
00:13:45 --> 00:13:46 That's a great question. Thanks for
00:13:46 --> 00:13:49 sending it in. Much appreciated. And
00:13:49 --> 00:13:53 next up, we've uh got Daniel. Uh this is
00:13:53 --> 00:13:55 um
00:13:55 --> 00:13:59 a sort of dark energy question. Sort of.
00:13:59 --> 00:14:01 Hey guys, Daniel from Adelaide here.
00:14:01 --> 00:14:02 There seems to be more and more
00:14:02 --> 00:14:04 discoveries lately in the very early
00:14:04 --> 00:14:05 universe that shouldn't be possible
00:14:05 --> 00:14:07 because not enough time has passed like
00:14:07 --> 00:14:10 size of galaxies or black holes. I've
00:14:10 --> 00:14:11 got a far out theory I'd love to share.
00:14:11 --> 00:14:14 What if time and dark energy were
00:14:14 --> 00:14:16 actually the same thing? So we know for
00:14:16 --> 00:14:17 about the second half of the universe
00:14:17 --> 00:14:19 that dark energy has been accelerating
00:14:19 --> 00:14:21 its expansion. Could this therefore mean
00:14:21 --> 00:14:23 that there was less dark energy in the
00:14:23 --> 00:14:25 first half? And if that's the case, what
00:14:25 --> 00:14:27 if time actually went slower in the
00:14:27 --> 00:14:29 early universe? So from our perspective,
00:14:29 --> 00:14:31 what took a really short amount of time
00:14:31 --> 00:14:33 actually happened in normal time with
00:14:33 --> 00:14:35 normal being in quotes. I'd previously
00:14:35 --> 00:14:36 asked a question on the show whether
00:14:36 --> 00:14:39 dark energy is related to black holes. I
00:14:39 --> 00:14:40 think there was a paper around the time
00:14:40 --> 00:14:42 that that kind of suggested that it was
00:14:42 --> 00:14:44 and we know that black holes do distort
00:14:44 --> 00:14:46 time. So, if time is part of the fabric
00:14:46 --> 00:14:48 of space,
00:14:48 --> 00:14:50 maybe dark energy is too, but it's
00:14:50 --> 00:14:52 actually one of the same thing. I'm
00:14:52 --> 00:14:55 expecting a very quick simple no, but I
00:14:55 --> 00:14:57 wanted to ask anyway.
00:14:57 --> 00:15:00 >> All right. Thanks, Daniel. Uh, yeah. Is
00:15:00 --> 00:15:03 um time and dark energy, are they the
00:15:03 --> 00:15:04 same thing?
00:15:04 --> 00:15:06 >> You never get a quick and simple no from
00:15:06 --> 00:15:09 me, Daniel. It's always a long drawn out
00:15:09 --> 00:15:11 complex no.
00:15:12 --> 00:15:15 not always but I think in this case yeah
00:15:15 --> 00:15:17 your your thinking is interesting uh
00:15:17 --> 00:15:19 we've we've talked recently as well
00:15:19 --> 00:15:24 about the um the fact that um
00:15:24 --> 00:15:26 this new controversial theory from Joe
00:15:26 --> 00:15:29 Silk at all uh over in Baltimore
00:15:29 --> 00:15:31 suggesting that perhaps black holes
00:15:31 --> 00:15:33 super massive black holes came first
00:15:33 --> 00:15:35 they were formed in the early universe
00:15:35 --> 00:15:37 and that goes a long way to explaining
00:15:37 --> 00:15:39 uh the conundrum that you mentioned at
00:15:39 --> 00:15:40 the start of your question there that a
00:15:40 --> 00:15:42 lot seems to have happened in the first
00:15:42 --> 00:15:46 uh in the first uh few millions or
00:15:46 --> 00:15:48 hundreds of millions of years of the
00:15:48 --> 00:15:52 universe's existence. Um so we we kind
00:15:52 --> 00:15:55 of understand the grav the gravitational
00:15:55 --> 00:15:58 time dilation uh effects pretty well and
00:15:58 --> 00:16:01 they're actually quite small uh from our
00:16:01 --> 00:16:05 vantage point here 38 13.8 billion years
00:16:05 --> 00:16:09 later. Um, and we and but you're right
00:16:09 --> 00:16:12 to make the point that uh dark energy uh
00:16:12 --> 00:16:15 only seems to have appeared over the
00:16:15 --> 00:16:17 second half of the age of the universe,
00:16:17 --> 00:16:21 but that's more likely to be uh it's
00:16:21 --> 00:16:24 because it its measurable effect has
00:16:24 --> 00:16:26 only become apparent. We think that
00:16:26 --> 00:16:28 during the first half of the universe's
00:16:28 --> 00:16:32 age, um there was the galaxies within
00:16:32 --> 00:16:34 the universe were close enough to each
00:16:34 --> 00:16:36 other that gravitational attraction
00:16:36 --> 00:16:39 would have basically kept the expansion
00:16:39 --> 00:16:41 due to dark energy in check, the
00:16:41 --> 00:16:44 accelerated expansion uh due to dark
00:16:44 --> 00:16:47 energy. Uh and so it's only when you get
00:16:47 --> 00:16:49 past a kind of tipping point where
00:16:49 --> 00:16:52 suddenly the the mass of galaxies in the
00:16:52 --> 00:16:54 universe is not enough not strong enough
00:16:54 --> 00:16:57 gravitationally to break the
00:16:57 --> 00:16:59 acceleration of the expansion. By that I
00:16:59 --> 00:17:03 mean B R A K rather than B R E A K. Uh
00:17:03 --> 00:17:05 it's not enough to slow it down. And so
00:17:05 --> 00:17:09 the acceleration takes over. Uh and
00:17:09 --> 00:17:11 that's why it's a tricky thing just to
00:17:11 --> 00:17:14 try and tease out and we've talked about
00:17:14 --> 00:17:17 this recently as well whether the dark
00:17:17 --> 00:17:19 energy is a constant whether it's
00:17:19 --> 00:17:22 something that's uh a factor that hasn't
00:17:22 --> 00:17:25 changed in terms of its uh its release
00:17:25 --> 00:17:29 as space as space expands. Um it's
00:17:29 --> 00:17:31 because there is this added impact of
00:17:31 --> 00:17:34 the gravitational pull of the galaxies
00:17:34 --> 00:17:37 uh stopping us from basically seeing the
00:17:37 --> 00:17:39 effect of dark energy the accelerated
00:17:39 --> 00:17:41 expansion of the universe back in the
00:17:41 --> 00:17:42 early universe. So I think all those
00:17:42 --> 00:17:45 things are are well and truly understood
00:17:45 --> 00:17:48 and kept fairly separate by the by the
00:17:48 --> 00:17:49 scientists looking at them. And by that
00:17:50 --> 00:17:52 I mean time and and dark energy. So
00:17:52 --> 00:17:55 that's a long complicated no.
00:17:55 --> 00:17:58 >> Yeah. Yeah. Um, okay. Daniel Winfred
00:17:58 --> 00:18:00 says, "I think these things have been
00:18:00 --> 00:18:02 long understood." That's that's his way
00:18:02 --> 00:18:05 of saying you're way off way way off the
00:18:05 --> 00:18:10 mark.
00:18:10 --> 00:18:12 >> But it's worth asking because otherwise,
00:18:12 --> 00:18:13 you know, obviously this is something
00:18:14 --> 00:18:15 people are thinking about. So, it's
00:18:15 --> 00:18:18 worth asking these um these
00:18:18 --> 00:18:21 >> different questions to um just, you
00:18:21 --> 00:18:24 know, see see if it's a possibility.
00:18:24 --> 00:18:26 >> Thanks, Daniel. Appreciate that.
00:18:26 --> 00:18:27 >> Great question.
00:18:27 --> 00:18:29 >> Uh, if you've got questions for us,
00:18:29 --> 00:18:30 please send them in because we could
00:18:30 --> 00:18:33 always use them. Uh, just, uh, go to our
00:18:33 --> 00:18:35 website, spacenutspodcast.com,
00:18:35 --> 00:18:36 spacenuts.io,
00:18:36 --> 00:18:38 and click on the various links. The AMA
00:18:38 --> 00:18:42 link will give you, uh, access to, uh,
00:18:42 --> 00:18:45 text and voice uh, audio. Or you can
00:18:45 --> 00:18:47 click on the little, it's not purple,
00:18:47 --> 00:18:48 it's green. When did they change the
00:18:48 --> 00:18:51 color of that? Uh, send us your Oh, no.
00:18:51 --> 00:18:52 It's It's purple when you hover on it.
00:18:52 --> 00:18:55 There you go. Uh send us your questions
00:18:55 --> 00:18:56 uh on the right hand side of our
00:18:56 --> 00:18:59 homepage and uh don't forget to tell us
00:18:59 --> 00:19:01 who you are and where you're from. Fred,
00:19:01 --> 00:19:02 we're done again. Thank you so much.
00:19:02 --> 00:19:05 >> Uh always a pleasure, Andrew. And I hope
00:19:05 --> 00:19:07 we'll stick it again very very soon.
00:19:07 --> 00:19:10 It's a distinct possibility. Could be
00:19:10 --> 00:19:13 with could be within 13.8 billion years
00:19:13 --> 00:19:14 in fact.
00:19:14 --> 00:19:16 >> Yes. Thanks uh Fred. See you soon. Fred
00:19:16 --> 00:19:19 Watson, astronomer at large. And uh
00:19:19 --> 00:19:20 thanks to Hugh in the studio for making
00:19:20 --> 00:19:22 our lives so much more difficult with
00:19:22 --> 00:19:25 these split episodes. But no, it's okay.
00:19:25 --> 00:19:27 Uh and from me, Andrew Dunley, thank you
00:19:27 --> 00:19:28 so much for joining us. Uh looking
00:19:28 --> 00:19:29 forward to your company on the next
00:19:29 --> 00:19:33 episode of Space Nuts. See you then.
00:19:33 --> 00:19:34 >> Space Nuts.
00:19:34 --> 00:19:36 >> You'll be listening to the Space Nuts
00:19:36 --> 00:19:38 podcast
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