Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / #407: Unraveling the Universe's Expansion Enigma & Mars' Hidden Volcano

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#407: Unraveling the Universe's Expansion Enigma & Mars' Hidden Volcano · Space Nuts: Astronomy Insights & Cosmic Discoveries

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Hi there, Thanks for joining us so on yet another episode of Space Nuts.
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My name is Andrew Dunkley, your host, and it's good to have
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your company again. Thanks for joining us. Coming up, we'll be looking
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at an old chestnut, the expansion speed of the universe. The theory is
0:16
again under the spotlight due to for a change, non conflicting evidence, so
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we'll talk about that. And a giant volcano has been discovered and it was
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hiding in plain sight. Guess where. Yeah, you're right, we'll you're
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talking about that on this episode of Space Nuts. Fifteen second guidance in Channel
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ten nine ignition sequence Space Nuts four three two Space Nuts as when I report
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it, Bill's good and joining us to explore all of that is Professor Fratt
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Watson, Astronomer at Large. Hello, Andrew, Good to see your smiling
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face again. You look a bit healthier than you did last time I saw
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you. Yeah, yeah, improving. I generally don't suffer jet lag for
1:11
very long, but this time it's really hit me hard. And I think
1:15
it's got everything to do with the fact that I managed to sleep on the
1:19
flight home, which was bad because we got home at eight o'clock in the
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evening, so and I calculate I probably slept seven hours on the plane because
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it left in the evening and good, yeah, yeah, I know.
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And then when we got back, of course I didn't really feel that sleepy.
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So and it's taken me a long time to adjust, but I'm starting
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to get it all back, which is good. And yeah, getting over
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the illness that came with it. I do not recommend having a heavy cold
1:52
or COVID or whatever it is I had in conjunction with jet lag. They
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do not like each other and they fight with a nail. So yeah,
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not a fun combination, but I'm sure it's not uncommon in this day and
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age. But yeah, we're getting we're getting through. Its been a bit
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of a long haul. Boom boom, How are you how? Things fine?
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Thanks? Bit chaotic due to my upcoming trip as well, So we'll
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be we'll be fine. We'll be fine. Yeah, we can't wait to
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talk to you about that. In fact, when this episode is out,
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it's probably around the same time as you'll be at the event that you're attending,
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So that'll be good. Fred. Let's get stuck into it. We've
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got a couple of really amazing topics to talk about things we've talked about,
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well, one of which we've talked about many times before. The other we
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haven't because it's only just been discovered. We'll get to that shortly, but
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let's talk about this situation with the expansion speed of the universe. We get
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a lot of questions from the audience about it. It's in the news again
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because an old theory has sort of been confirmed by more evidence from a new
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source. And and that's I mean, that's great, but it's also got
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people saying, well, hang on a minute, this can't work. It
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doesn't doesn't add up. There's still a hole in the information and we can't
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figure it out. It's it's really quite an intriguing scenario and the real head
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scratcher. And there's a lot of scratch scratched heads in the astronomical community,
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exactly as you've suggested that, Andrew. So what what are we talking about.
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Let's, as they say on the radio, let's unpick the story a
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bit. We we have a number of different ways of measuring the expansion of
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the universe, and what we're talking about here, Andrew, is the expansion
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of the universe now. In other words, we're not talking about, you
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know, back in the day or back in the origins of the universe.
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We're talking about the expansion speed now, and astronomers have got a slightly curious
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way of expressing that it is because the bottom line is, with an expanding
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universe, the further away you look, the faster something is receding from you,
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and that is just standard geometry. The further away you look, the
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faster it's moving. That was Hubble's discovery back in nineteen twenty nine. And
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the speed is that things are moving away from us are measured in units of
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kilometers per second. That's the speed. We can understand that, but it's
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kilometers per second per megaparsec. In other words, well, let me just
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tell you what a megaparsec is. It's a million parsex. One parsec is
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three point twenty six light years, so a megaparsic megaparsec is three point twenty
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six million light years. To use the numbers that we're more common more commonly
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familiar with, astronomers use parsex and megaparsex because that's the measurable quantity. You
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can't measure light year, but we can turn the measured quantity very easily into
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a light year, which actually is a nicer way of expressing things. It's
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one most people can get their heads around. The distance light travels in one
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year. So the value that the Hubble telescope arrived at. And remember when
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the Hubble telescope was launched back in nineteen ninety, one of its main aims,
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the main aim of the mission was to measure the expansion velocity of the
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universe, in other words, measure the Hubble constant. And that was because
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at that time, and I remember this very clearly, there was huge disparity
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in different camps on what this constant was, ranging from fifty kilometers per second
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to megaparsec per megaparseic to one hundred kilometers per second per megaparsic. In other
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words, they differed by a factor of two. Two groups of astronomers who
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were both convinced they were right, but their values were so far apart they
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could never be reconciled. And it turned out when the Hubble Telescope did its
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work and measured that expansion, the value was almost exactly the average of those
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two fifteen one hundred it's seventy three kilometers per second per megaparsec, and that
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is now the accepted value coming from the Hubble space telescope. However, the
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problem is that there are other ways of measuring the Hubble constant, and they
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involve looking back at the cosmic microwave background radiation, which is, as you
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know, we've talked about it many times before. It means we're looking so
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far in space that we're looking so far back in time that we're seeing back
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to a time when the universe was still luminous. We're seeing effectively the last
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vestiges of the flash of the Big Bang, and in fact we're looking back
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to within about three hundred and eighty thousand years of the d bank. Now,
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that cosmic microwave background radiation I call it the cosmic wallpaper because it's behind
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everything else that we see in the universe, but also because it's got patterns
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on it, like old fashioned wallpaper often did. And those patterns are caused
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by actually acoustic oscillations within the fireball of the universe, so slightly warmer and
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slightly cooler zones on that cosmic microwave background radiation, and by studying those you
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can arrive at a value of the Hubble constant. The problem is it doesn't
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agree with the Hobble. The method that the Hubble telescope used, which is
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to look at I didn't say, this is to look at a particular type
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of variable star SEFID variable stars which have a known brightness. They are what
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we call standard candles. So that gives you the Hubble telescope observations gives you
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seventy three kilometers per second permega passec, but looking at the cosmic microwave background
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radiation you get sixty seven kilometers per second per mega passec, which is it's
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sort of, you know, almost a ten percent difference, not quite but
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getting on that way. So that is what we call the Hubble tension.
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That is what whearies people that we are getting a different answer. And in
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a way, you know, back in nineteen ninety when the Hubble telescope was
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launched, people would have just ignored that difference because they would have said,
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well, you know, that's near enough for us to know what's going on.
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But today we're in an era which my PhD supervisor, Professor markham Longer
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was described as an era of precision cosmology. We are in an era of
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precision cosmology in other words, we can measure these parameters much more accurately than
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we ever could before. And so this difference from the cosmic microwave background radiation
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sixty seven kilometers per second megapassek to the Hubble telescopes seventy three kilometers per second
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per megaparsec. That is a problem and it's something that we would like to
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understand and we don't. So that's the backstory. Now, enter the James
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Waiting Space Telescope JWST, which I'm sure many people were hoping would absolutely solve
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this problem and say, Okay, this is exactly what's happening. And that
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didn't happen. No, it didn't. What the James Webs based telescope has
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done is confirm the Hubble telescope value. They've looked at the same sort of
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the same stars. They've looked with a much bigger telescope than the Hubble,
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penetrated much further into space because it's got a bigger mirror, and what they
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get is the same answer. And by the way, this is research led
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by Adam Reese of Johns Hopkins University. He was one of the three people
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who got the Nobel Prize for the discovery of the expansion, the accelerated expansion
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of the universe. So he's not somebody you know that you can ignore.
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Is research is top rank research done on a top ranked telescope, and it
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basically gives the same answer, in fact, not basically, it gives exactly
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the same answer seventy three kilometers per second omegaparsec as the Hubble telescope did.
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And what they're doing is they're using a a combination of these sephid variable stars
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and another distance indicator, which we call type one a supernova. These are
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exploding stars that always wind up with the same maximum brightness. So you you
11:13
could describe these types of stars as standard candles because they are luminous and they
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have a standard brightness. And you can describe the work done on the cosmic
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microwave background radiation as being the standard rulers, because you're measuring the separation of
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hot and cold spots on the cosmic microwave background radiation glow itself and standard So
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we describe those as standard rulers because they are telling we kind of know what
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those separations ought to be, and we can measure how they look. Somebody
11:52
has suggested the possibility of a technique called standard signs, and I haven't come
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across that term before, but I like it very much. Where you can
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use gravitational waves, so using gravitational waves, and I guess the standard sirens
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is because they effectively the same frequency ranges as audio waves. Standard sirens from
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gravitational waves might one day help to resolve this problem. But at the moment,
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we simply don't have accurate enough values. The error bars are too big,
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so we don't have accurate enough values to use the standard siren method to
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resolve the issue. But that might be the way it goes. At the
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moment, Hubble tension remains with us, and we don't know what the expansion
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rate of the universe is. Well, you know, we know two numbers.
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We know two numbers, but we don't know which one's right. Yeah,
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So James Webb confirming the data from Hubble does not absolutely guarantee that that
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number is right. The other number is sixty seven kilometers per mega PARSEK,
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which was based on the barrier acoustic oscillation theory or evidence. The difference is
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six, which is a big number in an era, as you said,
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where accuracy is becoming the norm you, I can throw you on the spot
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here, Fred, do you have any theories about what the difference might be
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why exists? I mean, it's the big It's probably a dumb question to
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ask because no one knows the answer. No, But what I mean,
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one possible answer is really intriguing that you know, there are phenomena play that
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we don't yet understand or know about new physics. The universe might not be
13:52
as we think it is. We've got this very neat and tidy view of
13:54
the universe, and that's a fairly ambitious thing when you think that about a
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whole universe. We might have neglected something that we have not yet discovered.
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You know, certainly our basic theories are all correct. Relativity works perfectly,
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quantum theory works perfectly, and themselves are not reconcileable. So that's another tension
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as well. But the hubble tension may come down to something that we just
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have not discovered yet, and when we do, it might change our view
14:31
of the universe markedly. New physics, if I can put it that way,
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Physics that we don't yet understand could open the door to all kinds of
14:39
different things, extra dimensions, all sorts of things of that sort. So
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it's very exciting in its own way, this hubble tension. People are going
14:48
to keep chipping away at it until we get an answer, and somebody will
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come along with a theory that says, ah, what if there was a
14:54
fifth dimension and it did this to the other four? Ye, that could
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be the answer, but we don't know yet. Look, let me throw
15:03
a curveball at you, just because it is a curveball. But if we
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do find some new piece of information that answers the question, could that then
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put a dint in Einstein's theory of relativity because he's always thought he was wrong.
15:26
He always wanted to be proven. Yeah. So, and yet as
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yet all tests have proven him right. Yes, with a very high degree
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of precision. So what it might show is that Einstein's relativity is only part
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of the story. In a similar way to Einstein's theory of relativity, the
15:48
general theory, which is all about gravity, that showed that Newton's theory was
15:52
only part of the story. Newton's theory works really really well until you get
15:58
into high gravitational fields and it doesn't work at all. But you didn't know
16:03
about how gravitational feels and it works really well, but and it's well enough
16:07
that it is telling us part of the story, but not the complete story.
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Maybe the same is true with general relativity, with Einstein's theory, that
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part of the story, but not a complete thing. One more point with
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hubble tension. Somebody is going to ask the question as to whether or not
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the influence could be dark energy or dark matter or both. Is that a
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possibility. Well, they're all taken into account in these calculations, you know,
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we we do know about them, but they're all taken into account.
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Sorry, that's somebody with the answer. Hope it is. Where my phone's
16:42
gone? All right, just stop ringing anyway, So fair enough? All
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right, Well, it's it's one of those questions that will remain mysterious until
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somebody somewhere who will probably win a Nobel prize comes up with that light bulb
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moment, possibly a standard candle moment, Boombo. We'll have to wait and
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see. With the cosmic microwave background radiation diminishing, I assume it's diminishing.
17:18
Will there come a time where we can't rely on that anymore? It's diminishing
17:22
in the sense that that that radiation that we see that sort of wall of
17:30
radiation, which is what it is that is actually moving away from us at
17:34
the speed of light. But and and over time, those patterns what we
17:44
call the baryonic acoustic ostellations, which you refer to the patterns in the in
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the wallpaper, they will change. But we're talking about millions, if not
17:52
billions of years, so we've got a bit of time to this. We've
17:59
got time to work on it. Andrew, all right, sounds good.
18:03
We need it, Yes, sometimes we do. If you would like to
18:07
read up on that story, it is a really fascinating read. It's Science
18:11
alert dot com. This is Space Nuts. Andrew Dunkley here with Professor Fred
18:15
Watson buds Now. Fred to a discovery that has been confirmed and there will
18:27
be no doubt, and that is a major announcement at the fifty fifth Lunar
18:32
and Planetary Science Conference in Texas the other day that they have discovered a new
18:40
volcano beyond Earth and not surprisingly, it's on Mars. It's a monster and
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it's been in our face all this time. We just haven't really noticed it,
18:51
probably due to weathering or erosion or whatever you want to call it.
18:53
But yes, a new well it's not new, but it's new to us.
18:57
New volcano on Mars. Yeah, I mean we know of several volcanoes
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of Mars, and including the highest mountain in the Solar System, Olympus Mons,
19:10
twenty three kilometers high above the plains of Mars, a huge, huge
19:15
volcano. And this new discovery, which I might just mention at the beginning
19:23
of our chat about it is is by Dr Pascal Lee, who's a planetary
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scientist with the Seti Institute and also the Mars Institute based at NASA Ames and
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he is the lead author of the study. So what Pascal and his colleagues
19:45
have done is looked at many what you might call aerial photos of Mars,
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the you know, the the images imagery taken from orbiting spacecraft of which there
20:00
have been many since Mariner nine in nineteen seventy one, and combined it with
20:08
the radar measurements, the basically measurements of the height of the features on Mars's
20:15
surface, which have come from other spacecraft Mars Expresses one that's got radar on
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board. That's the European so sorry, the European Space Agencies spacecraft Mars Express
20:27
and others too. So they've built up a topographic map of Mars, and
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what they've looked at is a region which is called Noctis Labyrinthus or Labyrinthus,
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and that name gives it away. It's a labyrinth of features, basically features
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of the night, I guess because notice is what that means. So it's
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essentially what you might call a tangled area of geology, the Labyrinth of the
21:03
Night, named back in the early days of Mars exploration. But so it's
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easy to see why people have missed this. But when this group of scientists
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have looked in detail at actually the sort of eastern end of Notice Labyrinthus,
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they find basically all the symptom symptomatic structure of a volcano, an arc of
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mesas of raised hills which slope downhill away from the high area, the summit
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area, and this extends out more than two hundred kilometers away from what they
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actually speculate was the Cold era, the volcanic vent probably once containing a lava
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lake. We see lava lakes actually on Jupiter Moon EO. We can see
22:03
their effects. They're real. So we think that the scientists think that this
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caldra on this new volcano or newly discovered volcano also contained a lava lake.
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It is being called the Noctis volcano. That's the name that is being given
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to it because it is so close to the Noctis Lebrinthus region. Fantastic discovery.
22:33
Really extraordinary, isn't it? Yeah? It is, And it's a
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big one. It's over nine thousand meters in height and a diameter of four
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hundred and fifty kilometers or two hundred and eighty miles and the speak American twenty
22:47
nine six hundred feet from sea level I suppose to the summit. Do we
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call it sea level on Mars. No, it's got some weird name like
22:59
the standard day or something like that, but it's it's it's just a you
23:06
know, standard measurement. And it's funny though because curiously, you know,
23:15
the northern hemisphere of Mars is generally speaking below that, uh, and we
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think that the northern hemisphere of Mars once had an ocean in it, and
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so that datum is probably not far off what would have been sea level then,
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even though the sea's gone. But the but the you know, the
23:33
standard is the same. So yes, that that's the bottom line we're measuring
23:37
it. And in fact. I think in this case it's probably at the
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local topography or this volcano, the newly discovered one, and the major of
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other volcanoes that are on Mars, including Olympus Mons which is on the edge
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of this area, but this three other ones, Pavonia and two more.
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They are in a region that's called the Tarsis. The tharstest rise that Tarsis
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depending on how you whether you're correctly pronouncing it or not, it's it's a
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high, high level region and that the thinking is that this was a sort
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of bulge caused by magnetic pressure underneath that gave rise to the Tarsis rise,
24:23
and the volcanoes have popped out through that. Olympus Mond is on the edge,
24:27
but not you not, this volcano is also on that high high ground
24:34
region. So it's fairly you know, it's a fairly good place to look
24:42
if you're going to try and find a new volcano. This region where there's
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a bulge probably caused by a magnetic pressure, is a good place to look.
24:51
And the other curious thing about it is that it's at one end of
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the valley's Marinaris. Yes, so I noticed that, correct, you know,
25:00
I was going to bring there that. But it's quite a fascinating part
25:04
of the planet around this is around the equatorial regions, I believe, and
25:07
you've got Vallas Marinaras, you've got the new volcano, you've got a string
25:11
of three to the west, and then Olympus Mons on the edge of that
25:15
region. It's a really amazing area, it is. That's right, So
25:19
Valles Marinaris, the Marina Valley's biggest canyons in the Solar System as far as
25:26
we know. But exactly as you've said there at one end of it.
25:29
It makes it look very much as though, you know, back in the
25:34
times when Mars was warm and wet, It's water flowed one way or the
25:38
other and probably away from the notis volcano down towards the low regions in the
25:45
northern hemisphere of Mars. So yeah, we're kind of building up a picture
25:48
of the of the early geography of Mars. It would have been quite spectacular
25:52
with the volcanoes and gigantic canyons. One a time to be off Mars with
26:00
a camera and yeah, absolutely. The other interesting thing that's come up in
26:06
this story is that of glacial ice. And they're already talking about this new
26:11
discovery being a potential location for a landing zone because of some of the potential
26:18
resources and what other information might be able to be gained from the kinds of
26:22
things that you might discovery. Yes, they've already identified a possible landing site
26:26
there. But you're right, and this glacier ice is thought to lie underneath
26:33
some of the volcanic deposits, so you know, it's probably pre dates the
26:40
volcanic activity. That means it's going back almost to the dawn of the Solar
26:44
system three point eight, three point nine, maybe four billion years ago.
26:48
Really extraordinary, extraordinary discovery, is there. Fantastic work by this team of
26:53
scientists' they've identified all kinds of volcanic features, you know, the sort of
27:00
stuff that you get, things called rootless cones, which are basically mounds that
27:07
surround a volcano, the various lava flows, pyroclastic deposits, that's all the
27:17
you know, the the rock and dust that comes out of a volcano.
27:22
We hear about pyroclastic flows on on our own planet, which are very very
27:29
dangerous because they've got carbon dioxide as well in the atmosphere. You can't breathe
27:33
in them, but there's ash, cinders, pomis, all sorts of stuff
27:37
coming down and it's all there in this region around the Octis volcano. So
27:42
superpose of work, I think, indeed, yes, and worth a read.
27:48
You can catch that story at the fizz dot org website. That's the
27:53
end of this particular program. And don't forget if you would like to follow
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out, I don't really understand it, but all comes down to statistics in
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the end. And Fred, that brings us to the end. Thank you
28:30
so much. It's a pleasure. Andrew, you haven't done the pointing down
28:34
to the button trick there, but that's where you press. Yes. That's
28:38
one. Yeah, very good. I'll see you next time. Maybe it's
28:44
a Q and a session sometime. Okay, it's very possible for it.
28:49
Thank you Professor Fred What's an astronomer a large part of the team here at
28:56
space Nuts and hoping you can join us on our Q and a episode coming
29:00
up very very soon. And thanks to Hugh in the studio for what I
29:03
do not know, but thanks anyway, and we'll catch you on the next
29:07
episode of Space Nuts. Until then, Bye bye, thank Spacenuts. You'll
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