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Jupiter's Giant Leap, Gravity's Infinite Debate & Cosmic Queries: #478 Q&A · Space Nuts: Astronomy Insights & Cosmic Discoveries

• 0:00
  Speaker 1: Hi, there, Space Nuts again Andrew Dunkley. Here, this is
• 0:03
  Speaker 1: a Q and A episode where we let the audience
• 0:06
  Speaker 1: set the agenda, and today we'll be answering questions about
• 0:10
  Speaker 1: the size of Jupiter. That's a why question, another maybe
• 0:16
  Speaker 1: what if question? Or why question? Is gravity finite? And
• 0:22
  Speaker 1: what would the night sky have been like if you're
• 0:26
  Speaker 1: standing on the surfaces of Earth in its very early era?
• 0:30
  Speaker 1: Plus the demise of comets, can we generate solar power
• 0:34
  Speaker 1: at night? And the acceleration of the universe. All our
• 0:37
  Speaker 1: questions will be answered on this episode of Space Nuts.
• 0:42
  Speaker 2: Fifteen second Channel ten nine ignition Space Nuts or three two.
• 0:54
  Speaker 1: One Space Nuts as the Night Report. It Bil's good
• 0:58
  Speaker 1: and you just can't get an enough of audience questions.
• 1:01
  Speaker 1: It is Professor Fred, what's an astronomer at large? Hello Fred?
• 1:05
  Speaker 3: Hello Andrew, Yes, sir, I do enjoy the audience questions
• 1:09
  Speaker 3: because it tells me we've got an audience which is some.
• 1:14
  Speaker 1: And we get a lot of questions in audio and
• 1:17
  Speaker 1: text format and we might as well go straight to
• 1:21
  Speaker 1: our first one. And this one comes from David Dave
• 1:27
  Speaker 1: in Verrel in northern New South Wales in Burrell, the
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  Speaker 1: gem capital of New South Wales. I would I would
• 1:35
  Speaker 1: suggest a lot of people go up there. FOSSi king
• 1:37
  Speaker 1: for gems and Dave, thanks for your kind words. Of course,
• 1:41
  Speaker 1: in a recent episode, I went public about my fight
• 1:44
  Speaker 1: with prostate cancer, and Dave has been dealing with his
• 1:48
  Speaker 1: own issues. But Dave, I appreciate your your thoughts. Thank
• 1:53
  Speaker 1: you so much. Dave asks Gray, Andrew and Fred. Just
• 1:58
  Speaker 1: a quick question for Fred, because I wouldn't know the answer.
• 2:01
  Speaker 1: Is that what you're saying, Dave? Why? I don't why
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  Speaker 1: did Jupiter grow to such a massive size compared to
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  Speaker 1: other planets. Was there simply just more gas and material
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  Speaker 1: available in that part of the solid disc where it formed. Jeez, Dave,
• 2:17
  Speaker 1: he might have answered it straight up, or is there
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  Speaker 1: something else in play here?
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  Speaker 3: For it's an interesting story, and I'm grateful today for
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  Speaker 3: sending me down the rabbit hole of Jupiter's formation to
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  Speaker 3: see what the story is. I mean, it's what Dave
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  Speaker 3: says is partly the case. There's a big reservoir of
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  Speaker 3: gas and dust. I mean, we think it was the
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  Speaker 3: dusty material that formed the core, and then the gas
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  Speaker 3: was collected once that was in place. But there's some
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  Speaker 3: subtleties here, and I'm going to point Dave in particular
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  Speaker 3: to a very nice article. It's six years old now
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  Speaker 3: twenty eighteen on the Scientific American website, really excellent website
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  Speaker 3: with you know, very high degree of accuracy. But it's
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  Speaker 3: called why was Jupiter's rapid growth delayed for millions of years?
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  Speaker 3: And it's basically saying that it wasn't just a continuous
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  Speaker 3: growing process that Jupiter underwent, but it actually was was delayed,
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  Speaker 3: and the mechanism for that delay is quite interesting. So
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  Speaker 3: this is basically research that came from from Swiss Switzerland.
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  Speaker 3: So we we believe that the planet is amals. These
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  Speaker 3: sort of kilometer sized asteroids are what basically was the
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  Speaker 3: raw material of the planets, and the planetimals in turn
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  Speaker 3: had grown from dust sticking together, part electrostatically in the beginning,
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  Speaker 3: but eventually by gravity and they formed their own you know,
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  Speaker 3: their own gravity pools in more stuff. So you've got
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  Speaker 3: these planetsimals, and the thinking is that during the first
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  Speaker 3: two million years of Jupiter's formation, it was in the
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  Speaker 3: right place for a lot of these things to smash
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  Speaker 3: into the proto Jupiter, and that made it hot. A
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  Speaker 3: lot of energy caused by collision, and what that does
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  Speaker 3: is stops the process of gas screting. In other words,
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  Speaker 3: you know the gas molecules that are out and about
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  Speaker 3: in space which are eventually going to form part of
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  Speaker 3: Jupiter's very thick atmosphere that make it the big world
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  Speaker 3: that it is. These authors are suggesting that the bombardment
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  Speaker 3: by planet simals gave so much heat energy that the
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  Speaker 3: gas did not want to collect it, it didn't accrete,
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  Speaker 3: and so the planet grew more slowly than it had been.
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  Speaker 3: And then it says, you know, the theory says that
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  Speaker 3: basically the first few million years, within the first few
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  Speaker 3: million years, it was twenty times the mass of Earth.
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  Speaker 3: But then the larger Planetisimals were bombarding it and they,
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  Speaker 3: as I've just said, crashed into to Jupiter, releasing energy,
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  Speaker 3: stopping the collection of gas, and so it's growth rate
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  Speaker 3: they now think had slowed down so that by three
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  Speaker 3: million years of age, it was only fifty times the
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  Speaker 3: mass of the Earth, which means that it took two
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  Speaker 3: million years to grow thirty times the mass of the Earth.
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  Speaker 3: But then sort of something happened, and it's a processed
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  Speaker 3: that the authors of this article is calling runaway gas
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  Speaker 3: secretion where the gas actually collects, and then that makes
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  Speaker 3: it more massive, and then more gas collects and it's
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  Speaker 3: more massive, and so it grew to its current roughly
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  Speaker 3: three hundred times the massive the Earth size that it
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  Speaker 3: is now.
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  Speaker 1: So this is like a like a like a snowball
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  Speaker 1: rolling down a hill.
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  Speaker 3: Yeah, that's a very nice and analog. Yeah, that's right.
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  Speaker 3: It's you know, you can't stop, it's going down the hill.
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  Speaker 3: It's gonna it's gonna collect more and more smooth hmm.
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  Speaker 1: Interesting.
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  Speaker 3: So the and they and you know, they think that
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  Speaker 3: once Jupiter started to become dominant, then it was a
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  Speaker 3: runaway effect because the bigger it is, the more stuff
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  Speaker 3: it pulls in, uh, and basically grows to its present size.
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  Speaker 3: It's an article that has got a lot of complexity
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  Speaker 3: in it, but is one that's worth reading, Dave, if
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  Speaker 3: you're interested in why Jupiter got to be the size
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  Speaker 3: it is. Actually, the original paper was produced was published
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  Speaker 3: in Nature Astronomy. But there's a nice scientific American article
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  Speaker 3: as I mentioned, why was Jupis's rapid growth spurt delayed
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  Speaker 3: for millions of years?
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  Speaker 1: There you are, Dave, there is a good reason for
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  Speaker 1: it right place at the right time, although it took
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  Speaker 1: a long time, it fits and starts all right. Thanks Dave.
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  Speaker 1: Great to hear from you.
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  Speaker 3: Okay, we take a.
• 7:29
  Speaker 1: Space nuts and next question comes from Dean in Redcliffe
• 7:34
  Speaker 1: and I wonder if Dean is a Dolphins fan. The
• 7:38
  Speaker 1: Dolphins football team based in Redcliffe in Queensland, and they've
• 7:42
  Speaker 1: just lost their coach to a team in Sydney, the
• 7:45
  Speaker 1: South Sydney rabbit Os. And guess what the National Rugby
• 7:49
  Speaker 1: League's done as the first game of next year the
• 7:52
  Speaker 1: Dolphins versus the Rabbits. So I'm wondering how Dean will
• 7:56
  Speaker 1: feel about that if he's a Dolphins fans. Here rahm
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  Speaker 1: Dean's question.
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  Speaker 4: Hi Fred and Andrew. This is Dean in Redcliffe in Queensland.
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  Speaker 4: I'm a retired architect and I've been a Space Nunts
• 8:08
  Speaker 4: listener for a long time. Finally I have got around
• 8:11
  Speaker 4: to send in in a question. I had always understood
• 8:14
  Speaker 4: that the effect of gravity was infinite, although negligible at
• 8:18
  Speaker 4: great distances. However, I recently heard that it may be finite.
• 8:23
  Speaker 4: This seems like a reasonable idea when I think about
• 8:25
  Speaker 4: ocean waves here on Earth. Ocean waves will dispact to
• 8:29
  Speaker 4: zero over enough distance if the wind stops pushing them.
• 8:33
  Speaker 4: Ripples from a pebble dropped in a still pond will
• 8:35
  Speaker 4: also dissipate to zero. This may be due to surface
• 8:39
  Speaker 4: tension and friction between water molecules, which is an inherent
• 8:42
  Speaker 4: quality of the medium conducting the waves. Now of my question,
• 8:47
  Speaker 4: space time is the medium that gravity distorts. Could it
• 8:51
  Speaker 4: beat at the stiffness of space? Time eventually overcomes the
• 8:54
  Speaker 4: diminishing gravity of a distant massive object so that its
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  Speaker 4: gravitational effect become zero rather than just negligible. T I'm
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  Speaker 4: on the right track with the particles and dark matter
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  Speaker 4: within space contribute to its stiffness and to the dissipation
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  Speaker 4: of gravity waves. Thanks for the podcast. Look forward to
• 9:14
  Speaker 4: hearing your answer.
• 9:15
  Speaker 1: M Thank you, Jan, great question, really good question.
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  Speaker 3: It is, And yeah, I guess the answer is maybe.
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  Speaker 3: I mean Dean's right. We've talked about the stiffness of space.
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  Speaker 3: Actually in one of the and we talked about taking
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  Speaker 3: one of the Fred's flippant facts, didn't we Yes, I
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  Speaker 3: said space is flexible, but not very It's Young's modulus,
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  Speaker 3: which is the measure of stiffness, which Dean would definitely
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  Speaker 3: be familiar with as an architect. The Young's modulus of
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  Speaker 3: space is one hundred billion billion times that of steel,
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  Speaker 3: so it's very stiff indeed, But I'm not sure that
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  Speaker 3: that stiffness would contribute to an attenuation of the gravitational force.
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  Speaker 3: We're kind of talking about two things. Gravity itself is
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  Speaker 3: the distortion of space. Gravitational waves, which we know travel
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  Speaker 3: at the speed of light, are basically vibrations in space,
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  Speaker 3: and you can imagine that gravitational waves would be attenuated
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  Speaker 3: to zero by the stiffness of space because of that
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  Speaker 3: Young's modulus. But gravity itself is an inverse square or
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  Speaker 3: which says that it's infinite. If you sort of have
• 10:49
  Speaker 3: a look online to see what people think about gravity
• 10:52
  Speaker 3: being whether it's infinite or not, there's some quite interesting.
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  Speaker 1: Aspects come out.
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  Speaker 3: One is that, well, gravitational waves aren't infinite because eventually
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  Speaker 3: they would reach the cosmic horizon, the microwave background radiation
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  Speaker 3: which is moving away at the speed of light, and
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  Speaker 3: these things would you know, they basically the gravitational waves
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  Speaker 3: themselves would interact with that and maybe cancel out. I'm
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  Speaker 3: not quite sure. I didn't really follow the logic of
• 11:26
  Speaker 3: that one. And someone else. I thought that because the
• 11:32
  Speaker 3: plank length is the length in matter below which the
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  Speaker 3: laws of physics don't apply, the plank length will be
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  Speaker 3: something that would stop gravitational waves being infinite. We're talking
• 11:52
  Speaker 3: about gravitational waves, no, not gravity, because eventually you get
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  Speaker 3: vibrations that were less than the plank length. That was
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  Speaker 3: the point of that. So a lot of stuff that
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  Speaker 3: seems to me to be going around in circles. But
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  Speaker 3: my my take on it is still that there's an
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  Speaker 3: inverse squall or gravity. Gravitation Uh, excuse me, excuse me.
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  Speaker 3: Reach is an infinite distance. It's effectively zero. It a
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  Speaker 3: symptotically approaches zero. That means it gets nearer and nearer
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  Speaker 3: to being zero. No fundation formally never reaches it, but
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  Speaker 3: it is. Yes, it's an infinite force. So I don't
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  Speaker 3: know that dark energy and dark matter thrown into that
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  Speaker 3: makes really add anything to it. It's a great question, lie,
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  Speaker 3: and it's maybe thick about these things. Sorry, Andrew, go ahead.
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  Speaker 1: So are we saying are we saying that they phase it,
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  Speaker 1: they just sort of fizzle.
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  Speaker 3: Well, maybe maybe gravitational waves do, and it might be
• 12:52
  Speaker 3: because of that stiffness. But gravity itself doesn't.
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  Speaker 1: That's okay until it runs into something else. And well
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  Speaker 1: it's also creating a gravity, yes, I meet. And yeah,
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  Speaker 1: and then did they just push against each other and
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  Speaker 1: create that?
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  Speaker 3: As you know, they can cancel out because exactly as
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  Speaker 3: you've said, that's how the brunch points work.
• 13:14
  Speaker 1: Yes, m M. It's really interesting and it adds more
• 13:19
  Speaker 1: to the empty vessel that is our knowledge of gravity.
• 13:24
  Speaker 1: It is should really don't understand gravity. Yeah, we just
• 13:29
  Speaker 1: know it's there. It's it's one of those I suppose
• 13:33
  Speaker 1: if someone ever figures it out, that's a Nobel prize
• 13:36
  Speaker 1: waiting the hell on, isn't it?
• 13:37
  Speaker 3: Definitely? Well, it will be quite when quantum gravity really
• 13:40
  Speaker 3: comes of age, when we really understand quantum gravity, which
• 13:43
  Speaker 3: we don't at the moment.
• 13:44
  Speaker 1: So yeah, that will meet right. Thank you, Dean and
• 13:49
  Speaker 1: all the best. Thanks for your question. This is Space
• 13:51
  Speaker 1: Nuts Andrew Dunkley here with Professor Fairy Watson. Space Nuts.
• 14:02
  Speaker 1: We've got another text question, Fred, and this one comes
• 14:06
  Speaker 1: from Daniel who is in Adelaide, and he said, I've
• 14:10
  Speaker 1: saved up a few quick fire questions I'm hoping you
• 14:13
  Speaker 1: could answer please. Yes, we'd be happy to do so.
• 14:17
  Speaker 1: So we'll knock them all off one at a time.
• 14:20
  Speaker 1: Quick fire means you don't have to spend too much
• 14:22
  Speaker 1: time on them. Fred, we know the universe's expansion has
• 14:26
  Speaker 1: been accelerating for about the last five billion years. Given
• 14:30
  Speaker 1: the night sky seems fairly full of stars to the
• 14:32
  Speaker 1: naked eye today, what would it have looked like if
• 14:36
  Speaker 1: you were standing on Earth when it formed? Would the
• 14:38
  Speaker 1: night sky have been as bright as day? For example?
• 14:42
  Speaker 1: That's his first question.
• 14:44
  Speaker 3: Yeah, the answers no, So our vantage point four point
• 14:49
  Speaker 3: six billion years ago when the Earth was forming, would
• 14:53
  Speaker 3: be similar to what it is today. Yes, galaxies are
• 14:56
  Speaker 3: closer together, and they might be, you know, a little
• 15:00
  Speaker 3: bit brighter than we see them now, but I think
• 15:04
  Speaker 3: it would still be a similar sky that we'd see.
• 15:08
  Speaker 3: You've got to go back a lot further in time
• 15:12
  Speaker 3: to be able to see a night sky as bright
• 15:15
  Speaker 3: as day. And what that is is still being able
• 15:17
  Speaker 3: to see the flash of the Big Bang, And at
• 15:19
  Speaker 3: the moment, that flash of the Big Bang has been
• 15:22
  Speaker 3: redshifted into microwaves, which is why we don't see a
• 15:24
  Speaker 3: brilliant sky. But we would if our eyes were sensitive
• 15:28
  Speaker 3: to microwaves, or if we were looking at the early universe,
• 15:33
  Speaker 3: you know, not long after it became transparent, then we'd
• 15:35
  Speaker 3: see a very bright sky.
• 15:38
  Speaker 1: That just a totally unrelated question, but that just prompted
• 15:41
  Speaker 1: in my mind a thought about animals and insects. Would
• 15:44
  Speaker 1: they see the night sky completely differently to us?
• 15:48
  Speaker 3: That's what some of Mani's work is about. She works
• 15:51
  Speaker 3: on that sort of thing from the point of view
• 15:53
  Speaker 3: of light pollution. Yes, they do. They're sensitive. Many of
• 15:57
  Speaker 3: them are sensitive to different wavebands than what we are,
• 16:01
  Speaker 3: and in fact, something in sex need the night sky.
• 16:04
  Speaker 3: Dung beetles work by aligning the direction of trouble with
• 16:08
  Speaker 3: the milky way, so you know, it's quite an extraordinary Yeah,
• 16:12
  Speaker 3: they do check it out.
• 16:17
  Speaker 1: Yep. Wow, so so many one liners I can't use now. Sprats. Oh,
• 16:26
  Speaker 1: that's fascinating. It's totally off the track in terms of
• 16:30
  Speaker 1: the question, but yeah, amazing. So that's your first answer, Daniel.
• 16:36
  Speaker 1: Your second question. When a comet passes a star, it
• 16:39
  Speaker 1: gets its dust and ice blown off. But will that
• 16:42
  Speaker 1: comet ever lose enough material to become nothing or does
• 16:46
  Speaker 1: it add material back in a tin back as it
• 16:51
  Speaker 1: traverses space. Well, some of them actually just end up
• 16:55
  Speaker 1: crashing into planets and the Sun itself, which means they're
• 17:00
  Speaker 1: adding to those things somewhat. But yeah, can they just
• 17:03
  Speaker 1: be sort of, as I've used this word before, fizzled
• 17:06
  Speaker 1: out over time.
• 17:09
  Speaker 3: Yeah, they can, And what you would be left with
• 17:12
  Speaker 3: is basically a trailer, you know, a trail of dust,
• 17:17
  Speaker 3: which is what we pass through when we see meteor streams.
• 17:22
  Speaker 3: So they probably are comets that have eventually dissipated. I'm
• 17:25
  Speaker 3: not sure that any that have been seen by humans
• 17:29
  Speaker 3: and recognized as comets. I'm not sure that any of
• 17:33
  Speaker 3: those have dissipated to being just trailers of dust. But
• 17:36
  Speaker 3: that's the end process, because you know, comets are made
• 17:40
  Speaker 3: of dust, which is sort of bonded together by ice,
• 17:42
  Speaker 3: and the ice sublimes. It goes straight into a gas
• 17:45
  Speaker 3: and gets blown away and some of the dust is released,
• 17:48
  Speaker 3: and eventually you're going to wind up just with a
• 17:51
  Speaker 3: little pile of dust that will spread itself along the
• 17:54
  Speaker 3: path of the comets forward.
• 17:57
  Speaker 1: Yeah, and the Earth passes through these dust else from
• 18:00
  Speaker 1: time to time when we see those meteorites that appear
• 18:05
  Speaker 1: in the night sky at certain times of the year, meteors,
• 18:08
  Speaker 1: they're only medials if you do their line meteorites when
• 18:11
  Speaker 1: they hit the ground.
• 18:12
  Speaker 3: Yeah, yeah, that's right. So we see, we see that.
• 18:14
  Speaker 3: It's all right, it's part of my job. They yeah,
• 18:19
  Speaker 3: they that's exactly right. We see the meteor showers which
• 18:22
  Speaker 3: are because we're passing through the dust trail from a comet.
• 18:26
  Speaker 1: And the last question from Daniel is could you develop
• 18:32
  Speaker 1: solar panels that work at night by collecting energy from
• 18:36
  Speaker 1: other stars and or the reflected light from the moon. Yeah.
• 18:41
  Speaker 3: The amount of light we get from stars in the
• 18:43
  Speaker 3: moon is very small compared with sunlight. And I mean,
• 18:47
  Speaker 3: we do know we can create electricity from all of
• 18:51
  Speaker 3: those objects, and we do it as soon as we
• 18:53
  Speaker 3: take a photograph of the stars of the moon with
• 18:56
  Speaker 3: a digital camera, because that's you know, the sun is
• 19:00
  Speaker 3: in your phone or your camera, generating electricity which you
• 19:06
  Speaker 3: can then measure and detect. But it's not really useful amounts.
• 19:11
  Speaker 3: And I think probably the physics of silicon, which is
• 19:16
  Speaker 3: one of the materials that does this, will probably limit
• 19:18
  Speaker 3: how much electricity you could collect. You probably have fairly
• 19:22
  Speaker 3: low efficiency, So I suspect the lunar panels are something
• 19:26
  Speaker 3: that we're not going to see much of in the
• 19:28
  Speaker 3: near future. They might be developed evictually.
• 19:32
  Speaker 1: Yes, I certainly know that my solar panels don't show
• 19:36
  Speaker 1: a sceric of electricity generation at night when we've got
• 19:41
  Speaker 1: a big, bright, full moon, because I've looked so technology. Yeah,
• 19:47
  Speaker 1: technology is beyond us at the moment, but I will
• 19:50
  Speaker 1: check again next time we've got a big moon, because yes,
• 19:54
  Speaker 1: I'm not in the same house now, I've got a
• 19:57
  Speaker 1: different array. So maybe it's in proved technology, but I
• 20:01
  Speaker 1: doubt it. I really doubt it would do anything. Thank you, Daniel.
• 20:06
  Speaker 1: I think that's all of your questions done, and our
• 20:08
  Speaker 1: final question today comes from Chris who is in Tasmania.
• 20:13
  Speaker 5: Hi, Fred Andrew, this is Chris here from the Human
• 20:15
  Speaker 5: Valley in Tasmania. My question is that we know that
• 20:19
  Speaker 5: the expansion of the universe accelerate, but I was wondering
• 20:22
  Speaker 5: if we're able to detect whether the rate of acceleration
• 20:24
  Speaker 5: is constant or ever so slightly variable, and whether that
• 20:28
  Speaker 5: might provide a clue as the structure of what the
• 20:31
  Speaker 5: universe is expanding in, as in the expansion hitting regions
• 20:34
  Speaker 5: of different density of who knows what causing the acceleration
• 20:38
  Speaker 5: to temporarily slow speeder.
• 20:41
  Speaker 1: That's my question. Thanks. For the show. Really enjoy it,
• 20:44
  Speaker 1: Thanks Chris. The Huon Valley is a glorious part of
• 20:48
  Speaker 1: the world if you like cold weather. But I know
• 20:52
  Speaker 1: it's Tassy's wonderful. I've got some friends down there visiting
• 20:55
  Speaker 1: at the moment, and I'm checking out all their photos
• 20:58
  Speaker 1: on Facebook. Guard Judy and I actually honeymooned in Tasmania.
• 21:04
  Speaker 1: What's thirty thirty eight nearly thirty eight years ago? Oh
• 21:08
  Speaker 1: my gosh, No, it wouldn't be that long, you know.
• 21:13
  Speaker 1: How else's calm now? Thirty eight years ago? Thirty thirty
• 21:17
  Speaker 1: thirty seven years ago?
• 21:18
  Speaker 3: I don't know.
• 21:18
  Speaker 1: I can't end it up seven up Tilden, But thirty
• 21:21
  Speaker 1: five years ago, there you go. I find it. Judy,
• 21:24
  Speaker 1: what's he talking about? Yeah, she'd she just rolls her
• 21:28
  Speaker 1: eyes whenever I try to figure these things in. So, yeah,
• 21:33
  Speaker 1: acceleration of the universe, speeding up, slowing down, stopping, being interrupted.
• 21:39
  Speaker 1: What's the story? And we can't see that though, can we?
• 21:42
  Speaker 1: We can't see beyond a certain limit when we observe
• 21:45
  Speaker 1: the universe. We talk about the observable universe, and then
• 21:51
  Speaker 1: there's the universe beyond that because we just can't see it.
• 21:54
  Speaker 1: So we really don't know what's going on out there,
• 21:57
  Speaker 1: do we.
• 21:58
  Speaker 3: No, that's right, the bit that we can't see, we don't.
• 22:01
  Speaker 3: I guess it's more or less the same as it
• 22:03
  Speaker 3: is here. But look this question, and it's a great
• 22:07
  Speaker 3: one from Chris is right at the forefront of cosmology.
• 22:12
  Speaker 3: Has the accelerated expansion of the universe changed over time
• 22:19
  Speaker 3: or is it constant? And the theory that's been most
• 22:26
  Speaker 3: popular in the last twenty years has been that it
• 22:29
  Speaker 3: is constant. In fact, we've added what's called Einstein's cosmological
• 22:33
  Speaker 3: constant to the equations that describe that. So what it's
• 22:37
  Speaker 3: saying is the acceleration by constant, I mean, let me
• 22:43
  Speaker 3: change my wording slightly. It's proportional to the volume of space.
• 22:48
  Speaker 3: So the more space you have, the more acceleration you get,
• 22:51
  Speaker 3: the more dark energy you have, and hence the more acceleration. Now,
• 22:58
  Speaker 3: I think the current thinking is that there may be
• 23:01
  Speaker 3: a change. It may not be something that's got this
• 23:05
  Speaker 3: cosmological constant. It might have varied over the age of
• 23:09
  Speaker 3: the universe, and that would perhaps help to illuminate what
• 23:15
  Speaker 3: dark energy is, because that's the problem at the moment,
• 23:18
  Speaker 3: with no idea what it is. It's just something that
• 23:20
  Speaker 3: makes the universe expand more rapidly. It is a springiness
• 23:25
  Speaker 3: of space. That's a nice way to put it. Probably,
• 23:28
  Speaker 3: but it's not so any change in the acceleration wouldn't
• 23:35
  Speaker 3: necessarily In fact, probably not at all. As Christus conjectured,
• 23:40
  Speaker 3: it wouldn't speak of the universe plowing into an area
• 23:44
  Speaker 3: of higher density, because it's the universe itself that we're
• 23:47
  Speaker 3: talking about. It's not anything that it's in. It's just
• 23:50
  Speaker 3: the universe, the content based some time. Yeah, but yeah,
• 23:56
  Speaker 3: if it can be shown that it has varied, and
• 23:58
  Speaker 3: there are observations going on as we speak to try
• 24:00
  Speaker 3: and determine that. If it's can be shown that it's varied,
• 24:03
  Speaker 3: then yeah, that might illuminate what dark energy is and
• 24:08
  Speaker 3: give us some better idea because at the moment we
• 24:10
  Speaker 3: haven't a clue, and it's not just a clue nobody has.
• 24:16
  Speaker 1: That's the sixty four thousand dollars question, isn't it really?
• 24:19
  Speaker 1: Indeed it is? Yes, Yeah, that's another Nobel Prize winner
• 24:23
  Speaker 1: probably if that's that one. Yeah, Yeah, so Chris, you're
• 24:27
  Speaker 1: you're asking Nobel Prize winning questions.
• 24:30
  Speaker 3: Exactly a lot of our listeners do, which is great.
• 24:34
  Speaker 3: That shows we should be a Nobel Prize winning podcast.
• 24:38
  Speaker 4: Really should we.
• 24:41
  Speaker 1: Well, they had the Australian Podcast Awards the other day.
• 24:46
  Speaker 1: We didn't get nominated because we didn't even know it existed.
• 24:52
  Speaker 3: Sounds like SMA.
• 24:55
  Speaker 1: Yeah, yeah, we just carry on, you know, we just
• 24:57
  Speaker 1: do our job. You guys can have all the prizes.
• 25:00
  Speaker 1: We'll just do our thing.
• 25:02
  Speaker 3: Yeah, listeners with us, Yeah, exactly right, exactly right, Thank you, Chris.
• 25:10
  Speaker 1: A great question, but yeah, a pretty tricky one at
• 25:13
  Speaker 1: this point in time. Maybe you down the track when
• 25:15
  Speaker 1: somebody's waving their prize in front of us in the
• 25:18
  Speaker 1: form of a Nobel prize, will know the ender of
• 25:21
  Speaker 1: that one. And if you've got a question for us,
• 25:24
  Speaker 1: go to our website and click on that little link
• 25:26
  Speaker 1: at the top that's got ama and send us your
• 25:29
  Speaker 1: text audio question and that way we will do our
• 25:33
  Speaker 1: level best to answer them for you. And that's about it,
• 25:37
  Speaker 1: and have a bit of a browse around the website.
• 25:40
  Speaker 1: Don't forget to join our social media followers on the
• 25:43
  Speaker 1: Space Nuts facebook page, Space Nuts on Instagram, or of
• 25:48
  Speaker 1: the supporters page the Space Nuts podcast group Facebook page.
• 25:52
  Speaker 1: That's where listeners get together and chat and compare their
• 25:55
  Speaker 1: astronomical pictures and they even tell a few terrible dad jokes.
• 25:59
  Speaker 1: I don't know where they got that idea from, but yeah,
• 26:02
  Speaker 1: it's it's a great little community if you want to join.
• 26:06
  Speaker 1: There's a few thousand people involved in that now, which
• 26:09
  Speaker 1: is quite incredible. And that's about it. Thank you, Fred,
• 26:15
  Speaker 1: We will catch you again real soon. Sounds good. Thank
• 26:18
  Speaker 1: you Andre all right, Professor Fred Watson, Astronomer at Large,
• 26:23
  Speaker 1: and Hugh in the studio. Yeah, it couldn't be with
• 26:26
  Speaker 1: us today due to cosmological inconsistencies. And from me Andrew Dunkley,
• 26:32
  Speaker 1: thanks for your company. We'll see you on the next
• 26:34
  Speaker 1: episode of Space Nuts. By For now, you'll be listening
• 26:38
  Speaker 1: to the Space Nuts podcast available at Apple Podcasts, Spotify,
• 26:45
  Speaker 1: iHeart Radio, all your favorite podcast player. You can also
• 26:49
  Speaker 1: stream on demand at bides dot com. This has been
• 26:52
  Speaker 1: another quality podcast production from nights dot com.