Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / #430: Dark Energy Theories & Voyager's Cosmic Rays: Your Queries Answered

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#430: Dark Energy Theories & Voyager's Cosmic Rays: Your Queries Answered · Space Nuts: Astronomy Insights & Cosmic Discoveries

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Hi there. This is Space Nuts where we talk astronomy and space science.
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My name is Andrew Dunkley, your host. Good to have your company.
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This is our Q and A edition where we take audience questions and we chop
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them up and throw them out because we don't know the answer to anything.
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But we are going to attempt to discuss atmospheric tubes. Now, this is
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a question that Jeff's come up with. It's a sort of a what if
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question, so we'll look at that. Paddy is asking questions about Voyager one,
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which has been in the news lately. And Oliver, one of our
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younger listeners, is talking radiation, dark matter and dark energy. All coming
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up on this episode of Space Nuts fifteen seconds. Guidance is in channel ten
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nine ignition sequence Space Nuts or three two more red ones Space Nuts. As
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can I report it. Bill's good and we say hello once again to Professor
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Fred. What's an astronomer at La TI? Fred? Hello, Andrew,
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fancy seeing you here? Yes, welcome back. It's been minutes. Not
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even sure it was minutes. I think it might just be saying continued.
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Do you think this joke is getting a bit old? Now? It's pretty
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awful in it. But space Nuts is nol for one thing. It's its
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bud jokes. Terrible jokes. Horrible jokes. Yes, we'll keep them coming
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too. Shall we get straight into it? No, let's let true.
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Well yeah, okay, fair enough. What I do love about space Nuts
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is we've got people listening all over the world, lots of questions coming from
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different parts of the planet. But we do have a young audience too,
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which I think is one of the great things about it, having young people
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having such an interest in astronomy and space science. One of those people is
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Oliver, and Oliver's got a well a pretty curly one, but he's got
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his own ideas on this as well. Let's see what he's on about.
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Yeah. Hello, I am Oliver from Queensland. I was just wondering a
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pretty interesting question. So you know that a black hole creates radiation, How
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can it doesn't get immediately softened? Does that mean the radiation has to go
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faster than the speed of light? But what if it's just going a bit
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faster? But what if black holes that could create dark energy that would actually
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solve a lot of things white it And if dark energy, what if that
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combines with matter particles and that creates dark matter. I think that would make
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a lot of scent. And with little things that can go fast, it
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goes over there and makes the border of the universe grow even faster and faster.
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And when it grows faster and faster, the reason it guru's faster and
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faster. I know, I'm saying faster and faster a lot back. What
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if it goes faster and faster because there's more space for the radiation to not
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collide with other minor particles, so it can go to the border of the
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universe quicker. So we can't tell because it's there because it's going so fast.
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Our telescopes, like the Hubble space telescope can't see it because it's going
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faster than the speed of light. It's just a quick question. Thanks,
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love the show, Goodbye. Please tell me a good answer. No,
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I don't really care as long as it gets solved there. I love that
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ending, Oliver. That's brilliant. Gosh, what a there's a lot in
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there that we've got to unpack. The first part was about radiation. How
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come radiation from a black hole doesn't get sucked straight back in? That's a
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good question. It's a great question and more, you know, thank you
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again, Oliver for getting in touch with us and for bringing a breath the
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fresh air to questions. It's great to have your I just I'm revved up
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by his excitement, you know too, I really am me too. So
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we think that hawking radiation, or the radiation that's emitted from black holes,
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doesn't come from the black hole itself. It actually comes at the event horizon.
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So the event horizon is that sphere. It's an imaginary sphere around the
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black hole, but it's the point where there's the black hole's gravitational attraction stops
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any light emanating from the black hole. So outside the black hole, light
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can travel around inside the black hole, it can't because it just gets pulled
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back in. Sorry, outside the event horizon, light can travel around inside
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the event horizon, it just gets pulled back in. And we think hawking
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radiation, well, it seems to be the case that it's formed by what
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we call virtual party FLEs articles basically coming into being and disappearing again. And
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they come into being in pairs. And if one of the pair is inside
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the event horizon and the other one isn't, then the one that's outside the
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event horizon gets away and can travel because it's not within the region where the
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speed of light isn't enough to get away from the black hole. I hope
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that makes sense. But that's why the hawking radiation doesn't just get pulled back
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in. And it is electro excuse me, it is electromagnetic radiation. It
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is a mixture of the different wavelengths. It's probably pretty low energy, and
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we have never detected it, but the theoretical basis is sound enough that we
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are pretty sure that it exists. Okay, And what leads, by the
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way to the evaporation of black holes. It's an energy loss from black holes
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that over billions, many billions, perhaps tens of billions of years, the
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black hole will evaporate and disappear. Thankfully. Sorry, So that's one part
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of his question. Yes, he goes on to ask about a black hole
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being the reason the dark energies. Now, there are some theories and studies
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going on that suggests this. That's right, We've covered that, and I
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keep meaning to re look at that paper just to work out what the mechanism
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is. But there is certainly a view, if I remember rightly, was
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it Japanese scientists who postulated this. I can't remember. We should look back
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at it and perhaps do it in a bit more detail sometime. But yes,
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there was this view that perhaps phenomena taking place within black holes are what
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lead to the dark energy of the universe. The only issue with that that
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comes to my mind is that we we equate, we believe, and the
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evidence seems to be that the dark energy of the universe is totally uniform,
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that it's the same everywhere, And if it was something to do with black
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calls, you might think it will be a bit bomp it where, you
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know, the more black holes you've got in one part of space, the
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more dark energy you've got. But that doesn't seem to be the case.
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So I do need to look at that again. Andrew, Okay, yeah,
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but see that there in lies the problem with dark energy. We keep
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coming up with new theories, new ideas, new problems associated with those new
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theories and new ideas, and it just keeps going around and around and around.
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In our last episode was the question came up as to how the galaxies
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and galaxy clusters can possibly exist as they are if there isn't a dark matter
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halo big enough to cover it, so we've got our thinking wrong. Well,
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yeah, I don't know. And then Oliver goes on to ask if
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dark energy could, as it moves through the the universe, affect particles and
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become dark matter. Could they be a relationship between the two even though by
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name they're not actually very accurate or are well their names they're both called dark
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something, and that's probably where the similarity ends. Very different in their nature.
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And yes, it's a good point. We Oliver talked about, you
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know, there being more space in the universe as a dark energy makes it
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expand things can travel to the boundary of the universe more rapidly. We don't
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actually know if the universe has a boundary or not. We suspect it may
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not have. It may be infinite. The boundary that we can see as
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a horizon the cosmic microwave background radiation, which is what blocks our view beyond,
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so that we don't see that the you know, the more distant regions
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of the universe. The universe might be very big, indeed that we can
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see might be quite small in comparison, so and faster than light travel.
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I mean, Einstein's theory holds true. That in space itself, nothing can
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move faster than light. Space itself can and probably did during the period of
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inflation, and it may do again if dark energy keeps on accelerating the expansion
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of the universe, so that one day the universe is so big that some
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things that emit light it never gets here because that those that have been carried
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away faster than the speed of light by the space itself, but not the
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light moving through it. So interesting questions there. I do like your thinking,
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Oliver, and I hope as time goes on we might hear from you
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again. Oh that would be lovely, Oliver. Thanks very much for getting
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in touch with us, and don't lose that youthful enthusiasm ever, because it
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is such a ray of light, and I really appreciate hearing from you.
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This is space Nuts. Andrew Dunkley here with Professor Fred Watson. Space puts
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Now. Fred to a text question that came in from Patty. Hi,
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guys, thanks for answering my last question about the end of life. I
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remember that one. I remember that one. Yeah, thanks Patty. So
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here's a more boring one or four. After Voyager one's recent drama, what
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is a cosmic ray and how came it affects Voyager and not computers on Earth?
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Did NASA have to get people out of retire out of retirement to reprogram
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the seventies computer? And he's made a reference to the movie The Martian where
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they had to do that for the path find a mission that they had to
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reinvent during that show. Three, how can NASA hear such a week week
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signal? I've seen the DSN website and the signal looks weaker than a mouse
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part the moon. He's got a great turn of phrase, Isn't he's a
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technical term? Yeah? I know. We can shout really loud to Voyager,
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but the return signal is so weak. For will new horizons ever overtake
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Voyager given it smaller and launched on a bigger rocket. I think that's more
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than four, but that's a full episode covered. Thanks again, guys.
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Paddy from rainy Northern Ireland, home of the Amar Observatory, where, at
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the age of eight his interest in space began. Now, granddad, so
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it wasn't yesterday? Yeah, great questions, budd It at Alma's a wonderful
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place we visited a few years ago. I know the director there very well,
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he's a colleague of mine from Edinburgh days and also here in Australia.
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He worked for many years in Australia, Michael Burton. So let's go to
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the beginning that you've got a list of four here. What's a cosmic ray,
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Well, it's high energy particle. I think they're primarily muons if I
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remember rightly, and we think they come from distant galaxies, that there are
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products of energetic, energetic events in very different galaxies, and yet they're raining
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down on Earth all the time. How come it affects Voyager and not computers
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on Earth because computers on Earth are shielded by the Earth's magnetic field and its
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atmosphere, and so we are not irradiated to the same extent. We do
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get them though. Cosmic ray events are things that we used to deal with
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in some of the detectors that are used. In fact, I think we
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spoke about this a little while ago. Maybe we didn't, can't remember,
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but the recent araori which we saw on Earth May the tenth, we're also
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visible on Mars because the subatomic particles from the Sun affected the detectors on some
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of the cameras. We had the same thing actually with cosmic rays, which
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are much more energetic than the rays that come from the sun. Back in
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the day when I used to build instruments, one of the problems that we
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had was these cosmic rays essentially creating little bright spots in the images, which
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you had to be careful you didn't mix up with something that you were trying
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to try to measure. In fact, one of them we discovered that the
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window of the on the front of the detector was slightly radioactive, so we
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were getting our own cosmic rays from that. Anyway, the bottom line is
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protection by the atmosphere. Didn't have to get people out of retirement to reprogram
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the seventies computer, or probably it happens to us a lot. Certainly the
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Australian Astronomical Observatory, where we used to be astronomery in charge. That's a
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long lived observatory, celebrates its fiftieth anniversary this year, and so the original
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some of the original pro programmers still around. They're retired, but they are
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occasionally called in when there are problems. So it almost certainly happened with NASA
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too. How can NASA here such a weak signal? Well, big dishes,
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big that's right. The darks. The Deep Space Network website will tell
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you that the Tidbinbiller and the Goldstone and the Madrid stations all have very big
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detectors, very big radio telescopes that can pick up that really weak signal.
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Number four of Paddy's questions, will New Horizons ever overtake Voyager giving it smaller
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and launched on a big rocket, And the answer is no. You can
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very easily find the numbers on the Events Above website. They've got a page
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on spacecraft leaving the Solar System and the first thing you see is that the
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one that's going fastest is Voyager one, at sixteen point nine to three to
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three kilometers per second relative to the Sun at present. New Horizons, on
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the other hand, thirteen point six seventy five kilometers per second, so slower
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and not as far away. So Voyager one is always going to be the
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most distant object, the most distant human made object. It will it will
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always have that status unless it hits something, and New Horizons don't. Well,
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the odds of yeah, you never know, it might hit something.
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My guess is it will go on forever because space is so big. Yeah,
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maybe it might get captured by you know, it's further down the street
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to the chemist, but it's that's right. Space is big. That's right.
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What was there? Was there another one of she's at it, Thank
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you buddy. Fantastic questions, but yeah, well worth asking because Voyager has
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been in the news because the've had some technical issues but they've they've sorted them
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out, so that might be where they drag back the old retired nineteen seventies
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computer programmers with their tape cartridges and things like that. Yeah, those are
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the days. Like yeah, technology is taking the fun out of everything.
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Back in the day of tape and vinyl. Gosh, working in radio was
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such a joy. These days you push a button and go to sleep for
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a couple of minutes. It wasn't like that back in the day. I'll
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tell you now when I was a lad. I'm say from my perspective,
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things are far far better now than they It's certainly a lot easier until something
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breaks. Thank you, Patty space Nuts. Now to our final question Fred,
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and this one comes from Jeff. It's I'm down on the UK coast.
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I love the podcast, by the way, boys. My question is
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if you have a magic pipe for arguments say the meter wide diameter this pipe
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is totally in this story sport, but it doesn't weigh anything. So if
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you extend it out, say six hundred miles out into space, would it
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suck the atmosphere out? I don't think it would, but be interesting nominal
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years anyway. Cheers, chaps, keep it up, you know, I
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love what if questions? Jeffs And that's a real rip up. So it's
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an indestructible pipe, so space junk doesn't become a factor, and it's in
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the atmosphere. It's on Earth, and you shove it up out through the
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atmosphere into space where the atmosphere is almost nil, it's obviously hollow. Does
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it suck out our atmosphere and kill us all? Uh? No, which
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is great relief to all of us. Rather so, the reason why is
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that the atmosphere in the tube just feels the same gravitational pull as the atmosphere
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everywhere else. So the pressure at the bottom of the tube is always going
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to be the same effectively as the atmospheric pressure. It might vary slightly if
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the tube is sealed so that you can't get leakage of varian at the bottom
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then it won't be subject to the same quite the same atmosphere pressure changes that
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the outer atmosphere does. But it basically is still the atmosphere and it's still
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bound by the gravity of the Earth. So yep, it won't. It
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won't leak away. So why having the effect at all? You can't even
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wrong, japp is down. So if you're thinking about, you know,
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checking that out building a tube from the Isle of White up to six hundred
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kilometers, don't worry. It's not going to away. It'd be a big
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chimney. Yeah, that would be well, yeah, but the smoke it
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eventually back up, wouldn't It wouldn't get out in the space. If it
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was a chimney, that's correct, it would do what it does on Earth.
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It would just continue to it would continue to rise as long as it
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was warm, and that it would just contribute to the general less of the
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atmosphere in the tube. Indeed, all right, so you were right,
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Jeff. You didn't even need to ask the question because you knew the answer.
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But that's okay. I love these types of questions, the what if
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questions. By the way, if you do have a question for us,
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don't forget to visit our website, where you can click on the amail link
19:41
and send us a text or audio question, or click on the send us
19:44
your Questions button on the right hand side of our homepage where you can leave
19:49
an audio question. Don't forget to tell us who you are and where you're
19:52
from. We really do love to know where you're at. And while you're
19:57
listening to us on your preferred podcast platform, please leave a review. That'll
20:02
be doing us a wonderful favor. Apparently reviews make a huge difference to the
20:07
state of dark matter in the universe, or the dark matter on the Internet
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for that matter. Football Yeah, we love your reviews. We really appreciate
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them. And Fred and thanks to Jeff, Patty and Oliver for contributing today.
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Keep the questions coming, Fred, we're done for another day. Thank
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you so much. Sounds great, Andrew, and we'll touch up again soon,
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I hope, I hope so too. Yes, maybe today, maybe
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tomorrow, days, maybe next week. See then. Fred Watson astronomer at
20:38
large and Hugh in the studio doing what Hugh does best, and we don't
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know what that is. And for me, Andrew Dunkley, thanks for your
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company. Catch you next time on another episode of Space Nuts. Bye Bye
20:51
You'll Be The Space Nuts podcast available at Apple Podcasts, Spotify, I Heart
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