July 15, 2021

One Big Ancient Star Explosion

One Big Ancient Star Explosion

Astronomy, Science, Space, and Stuff.
Space Nuts Episode 261 with Professor Fred Watson & Andrew Dunkley
●News from Andrew for Space Nuts fans as the podcast’s universe expands
●An ancient star explosion that appears to be more powerful than any...

Astronomy, Science, Space, and Stuff.
Space Nuts Episode 261 with Professor Fred Watson & Andrew Dunkley
●News from Andrew for Space Nuts fans as the podcast’s universe expands
●An ancient star explosion that appears to be more powerful than any supernova we’ve ever seen Fred has details.
●Enceladus’s methane plumes…what they’re all about.
●Our listener questions focusing on the UK…from James and Duncan. Fred has the answers.
For more Space Nuts, supporter links, sponsor links, to visit the shop, buy a book, leave us your questions, and stream podcast episodes on-demand, visit our website at https://spacenutspodcast.com or the new www.bitesz.com site https://www.bitesz.com/show/space-nuts/ (mobile friendly).
Find all of our show links at https://linktr.ee/biteszHQ




Space Nuts 261 AI Transcript

[00:00:00] Promo Dude: [00:00:00] 15 seconds. Guidance is internal 10, nine ignition sequence

to nurse as the magic board. It feels good.

Andrew: [00:00:16] Hello, once again, and thank you for joining us. This is the space nuts podcast episode 261. I'm your host, Andrew Dunkley. And joining me as always is professor Fred. What's an astronomer at large. Hello.

Fred: [00:00:29] Hi, Andrew, how are you doing today? I am quite well, and I'm very excited.

I have news. I have really fabulous news. I have a space. Nuts is going to be syndicated on the community radio network, Australia wide, possibly as soon as August, but most likely September, we will be doing a, um, a, a shorter version of the program. But it will be, um, basically, uh, available to over 400 radio stations around [00:01:00] Australia.

So I'm really excited about that. You become more famous. I become more adequate and, uh, we, yeah, we, we, um, like I had to be available to a whole new audience, so it's, uh, it's really fabulous. And the, and the way this network system operates is we will be given a time slot and we'll be broadcast on that time slot every week.

And that will be available live to the various radio stations, or they can download, uh, the, the recorded version of the program and put it in wherever they like. So we're really thrilled and it's just one more giant leap for space nuts. So, wow. Yeah. That's fantastic. Fantastic news. Yeah, maybe we should,

maybe we should lift our game. Andrew. That's probably a bit of that thinking I'm thinking is a necessity. Yes. But, uh, nah, can't wait. Um, so I'll let you know when that's all, all [00:02:00] on board. On this week's episode, we're going to be talking about an ancient star explosion that is, um, seemingly more powerful than any supernova we've ever seen.

This is one cataclysm, cataclysmically massive explosion by the sound of things. And, uh, yes, it happened a long time ago. So don't. Uh, and, uh, the story I'm most excited about this week, Fred is methane plumes that have been detected from satins, moon and celibacy. And the headline on the story, which I thought of before I read the headline on the story was could this mean life?

Uh, well, it is one of the telltale signs, but, uh, could be other things as well, but we'll talk about that. And we're going to focus, uh, our questions on the UK because the UK, um, uh, England specifically, uh, not having a good time of it after the, uh, European cup. Whoops, shouldn't have. Uh, but, uh, James wants to know about some of the fundamental forces and whether or not dark energy should [00:03:00] be added to the list.

And Duncan is all talking about all sorts of bodies in space, but, um, you know, uh, focusing on the OT cloud and things like. So I will answer those questions a little later on, but first of all, Fred, let's talk about this, uh, this mega explosion that has made the news. And it sounds like it happened a long time ago, but it was one of the, um, probably, you know, bigger than a supernova.

That's that's a mighty big bang. And was it the big bang? No, no, no, it wasn't the big bang. What do you call it? A super supernova. I mean, a super-duper Nova that'd be a good, but um, the, the science exciting for astronomy. Well, they're calling it hyper Nova. Uh, which, um, I like that. Yeah, I like that too. I like that hyper Nova.

Maybe 10 times more powerful than a supernova. Remember supernova? Uh, there, there are several different types of [00:04:00] them, right? But they usually accompany the end of a star, uh, because what happens is, um, the star is blasted to pieces. The nucleus itself often collapses and depending on the mass, it can collapse into a neutron star or, or maybe a black hole.

Uh, however, um, there are. Chemical elements that we see in the universe that, uh, have been thought to have. Um, th th th their, their origin has not been certain. Let me put it that way. So remember the universe kicked off with just hydrogen and helium and actually tiny, uh, traces of a handful of other light elements as well that they were created in the big bang.

And then the hydrogen collected together formed stars. The stars. Uh, basically, uh, nuclear furnaces, uh, their high temperature interiors, uh, forged new elements inside, right? So you get [00:05:00] things like oxygen and carbon and stuff like that. And that actually a helium is also formed, even though there was helium in the original cloud of gas.

So, um, what, what we see is stars producing elements. Um, there are certain elements that can't actually be produced inside normal stars and include things like lead and gold they're heavier elements, and they have to have much higher temperatures and much more extreme processes to form them. Uh, and in particular, gold is it has been a bit of a puzzle and, um, in the recent years, When we've seen evidence of neutron stars colliding because we can see their gravitational wave signature.

Uh, that is one possibility for the formation of gold, but there is another one. Uh, and that is, uh, one of these hyper Navi, something that is even more powerful than a supernova, presumably because it comes about whether it's. Progenitor star the star [00:06:00] that is essentially turning into a high turnover is more massive than the early ones, maybe 25 times the mass of the sun, right.

Compared with, uh, a supernova, which would probably be smaller than that. So that's the backstory, Andrew. Um, so people have gone off looking for. Evidence of, uh, not just gold, but gold in, in unusual proportions with other elements. One of them is zinc. In fact, uh, so what they've found now is evidence of that having happened in the early universe.

So it's not a question here of astronomers seeing the explosion, the hyper Nova itself has not been seen. Okay. Bang a long, long time ago. Um, clearly it's light, it's taken a long, it might've taken a long time to get here. Um, but, but it hasn't been seen, but what has been seen is a nearby star it's well nearby, it's [00:07:00] seven and a half thousand.

If I remember, I only light years away, uh, which has unusual. Chemical properties. And it's because of those properties that astronomers have figured out that the only way it can get that particular mix of chemicals is by having been formed from the day Bree of a high turnover. So this star is not the one that, you know, is.

Done the deed, but it's, it's carrying a message if you like from ancient times that back in those days, and it might be 13 billion years ago, there was a nearby explosion that seeded the, uh, the gas cloud from which their staff formed, uh, with these heavier elements. So what, sorry, go on. Nope. Nope. What surprises me is how we can piece this together with such a scattered evidence.

Like we know this explosion happened, we didn't see it. [00:08:00] There's no record of it, except for the telltale evidence that exists in other forms. It's uh, yeah, it's quite extraordinary. It's it's almost like, um, you have to be a detective. Oh, yeah. Yeah. It's very forensic. Um, so, you know, astronomers are, that's the way they work.

It's just piecing together these little clues, um, and trying to find the body, uh, and in this case, the body is presumably the remnant of the hyper Nova. Um, so the story starts with a telescope, very close to where I used to work at siding spring observatory in Northwestern, new south Wales. It's, um, it's run by the ANU.

It is called sky mapper. Uh, and it does. What you, you know, what the, what the name tells you, it maps the sky. Uh, it it's a survey telescope, so forms images of the sky, but it does it with a lot of different color filters and those color filters especially chosen. So they'll show up unusual things. And one of the things they show [00:09:00] up is a deficiency of iron in the star and a deficiency of iron.

Is telltale a telltale signature of a really ancient star. So even though this star is nearby, so in our own galaxy, it's very, very old. Um, I mentioned 13 billion years old a minute ago. Um, and it is, that's about the figure that these scientists who are doing this work, who are predominantly Australian, I'm delighted to say, uh, that's the figure they put on it.

Uh, I've got to tell you the name of the star, Andrew. Because, yes, it's SMSs, S M S S J two, double zero three, double 2, 5 4 minus 1, 1 4 2 0 3 0.3. And I actually missed out a decimal point there before the 0.54. Um, th that, that name, it's a bit of a cheat really, because the name is. It's [00:10:00] not a name. It's actually, it's positioned in the sky.

Those are its coordinates, uh, you know, on the celestial sphere that happens as we look at it. Uh, uh, and this has got, uh, well, the details of that is that it's, uh, I said it was deficient in iron. Um, the, basically the something there called the iron to hydrogen ratio is that. Hi on in it is about 3000 times less than the sun and that, you know, pushes its origins back to the very earliest history of the universe.

When iron was a very rare commodity, it hadn't been formed by many stars. So it's got this low level of iron, but it's got these other things as well, high, very high levels of the heavier elements like zinc, uranium europium and possibly gold. That's not. I think that's not been firmly detected yet. Uh, and this, this, these measurements come from follow up observations that have been made with the [00:11:00] telescopes of the European Southern observatory, the VLT, the very large telescope down there in Chile, which we in Australia have this strategic agreement with them.

Strategic partners. Until 2027. So Australian astronomers not only detected this, but followed it up with actually one of the telescopes at siding spring, the 2.3 meter telescope, uh, which is also not very far from where I used to work. My office was in the Anglo Australian telescope, which is about 300 meters away, probably from the 200, 2.3 meter.

Uh, and, uh, they also followed it up with a very large telescope, as I mentioned. So that's the story, what they've got. Is the first evidence that such a thing as a hyper Nova might actually have happened because they'd been predicted, they'd been thought about, but nobody's found that the firm evidence that they existed until now.

And so this looks like a big, you know, a big step forward in the, in the [00:12:00] research of the way stars form the way stars die as well. Hmm. So it stands to reason that this probably wasn't the only one in the history of the universe, but this is the first time we've found evidence of such a thing happening because of, you know, the basic fallout of it is.

Something that's going to remain in the past in terms of the universe, or could there be future hyper nervous? Uh, they're they're all in the past. Um, because we don't think stars have that mass form now, but of course, the fact that it's in the past, Doesn't hide it from astronomers, because excuse me, we've got this, um, facility to look back in time, uh, by looking at very distant objects.

So there's a really good chance that we might detect one of these things and it is thought that they are. The source of certain types of gamma Ray bursts, gamma Ray bursts have been measured [00:13:00] for 20, 30 years now. The flashes of gamma radiation, uh, um, one possible source of them is a hyper Nova. And it may well be that when people look at them, The, the details of these flashes in particular, you know, what shape they have when you spread them out in time?

Uh, like, is there a big bump at the beginning and something smaller at the end or something like that? That those are the details that people will they're looking at in future Gammer and sorry. Excuse me. Future observations of gamma Ray bursts that might betray the presence of a Hyperloop. Oh, the, the formation of the hyper Nova.

Yeah. Hmm. Hmm. Well, that will be rather exciting if we can pick up on that. So that's telling the loosen from another, another angle. Yeah. Yes, yes, indeed. Um, it's good thing that the, uh, the, the products of these hyper Novas aren't nearby ruined Erika. Oh,

yes. That's the reason these things remain valuable on earth [00:14:00] is because of their rarity. If we could get access to unlimited quantities of this stuff, we'd be in real strife. Plastic might become very, very valuable. Don't talk to me about plus news now. Uh, although I did read today in the news, Fred, that, uh, middle of next year, Australian government is going to outlaw soft plastics that includes styrofoam used in packing and all the soft plastic bags.

And all of that junk is going to be a gunner for the middle of next year, which is really good news. It makes a yeah, out of all the plastics, we can only recycle about a quarter of it. The rest goes into landfill, which is. Yes, a very unfortunate side effect of our ingenuity as human beings. I suppose you are listening to the space nuts podcast.

Andrew Dunkley here, Fred Watson

nuts. Thank you for joining us on the space and that's podcast. And thank you to our patrons, [00:15:00] who many in number. Who I put in a couple of bucks a week or a month actually to, to keep us afloat on the good ship space, nuts. It's made a board and it's got a lot of holes in it and patrons, yeah. Plug those holes for us.

So we greatly appreciate it. And if you would like to financially support space, It's purely voluntary. It's totally up to you. Uh, we are looking at a future benefits for patrons, so we'll keep you informed of that, but we're looking at better ways for you to, um, get a bit more bang for your buck, but if you would like to become a patron, certainly visit our website and click on the support space.

And that's a button, the support button, uh, spacing that podcast.com is where you'll find us space nuts, podcast.com. Okay, Fred, let's move on to our next story. This is the one that's got me super duper excited. Uh, there have been, uh, methane plumes detected on Enceladus. One of Saturn's moons. This is a, this is an ice giant.

Isn't it? An ice moon, [00:16:00] I should say, um, with, uh, what's believed to be, uh, uh, oceans underneath. Is, is that correct? It is correct. Yeah. And the evidence of that? Well, there's many pieces of evidence for the structure of a Rocky body. Global ocean over the top of it and an eye and an ice coating over the top of that.

Uh, there, there is good evidence from different sources, but in the case of Enceladus, um, it's really direct because of course the Cassini spacecraft, uh, very early on in the Cassini mission detected these plumes of ice crystal. Uh, spurting out of, uh, cracks in the ice near Enceladus. The south pole is really spectacular stuff, and I think it still sends tingles down our spines.

Just that the fact that we've got these guises of ice spurting out of a body at the other end of the solar system, quite remarkable. Did Cassini actually fly through one of those guys? I think yes, [00:17:00] several times there were several throughs because once they were discovered, which was quite early in the mission, the mission scientists, you know, made sure they had several orbits that took it.

I think within 50 kilometers of the surface of Enceladus, sometime it's a to, to go through the plumes. And so, uh, it was possible for them. Um, you know, the mass spectrometer equipment on board, the spacecraft to sample these things directly, not just to look at the spectrum of the light coming from these ice plumes, but actually fly through and collect bits of ice effectively, which is what they did.

Um, uh, of course, you've got to be careful when you do that. Um, I think they, they were only really getting to the th th the core of these ice plumes quite late in the mission, because you don't want to. Some of the big flying past the spacecraft or, you know, hitting it if there was a larger chunk. Uh, but no, it's, uh, it was from Cassini that we know [00:18:00] so much about these ice plumes now.

Um, I remember when. They release the w when the results were released of the, perhaps the first really careful analysis of what was in them. And it was, uh, as, uh, you've mentioned, uh, methane, uh, plus, uh, molecular hydrogen, sometimes called dihydrogen and carbon dioxide. Uh, and those. Particular molecules were identified and immediately the conclusion was drawn that they are possibly coming from Hyde hydrothermal vents in the bottom of Enceladus is ocean.

Um, now. Uh, it's not proof of find your thermal events, but it's very strongly indicative of that. And of course, partly because that's what you get from hydro hydrothermal vents on the bottom of verse oceans, uh, [00:19:00] and that, uh, really got people excited. What wasn't really commented on at the time was the high fraction of that.

Uh, you know, that set of different molecules that was actually me meeting, uh, or methane as it sometimes pronounced, um, that was higher than expected. And so the question that was asked by the researchers, uh, who've done this work and they come from the university of Arizona and, uh, uh, universal. Well Paris called the CRC university that you are science and arts, I guess science and literature, science and letters.

Uh, so the question asked by, um, actually one of the scientists in Arizona, we wanted to know could earth like microbes that eat the dihydrogen and produce methane a me thing. Explain the surprisingly large amounts of me thing detected by [00:20:00] Cassini. Hmm. Now the other comment that, uh, this person has made is searching for such microbes known as methanogens at Enceladus is sea floor would require extremely challenging, deep dive missions that are not in sight for several decades.

Well, I can understand that. I think that's a long way down the track. So what they did was they took the better, the better way forward. They built mathematical models. To, uh, look for different probabilities, uh, associated with the different processes, including biological processes that might, you know, that might fit the data is very, a very common ways.

They exactly this detective work that we were just talking about, you build a model that gives. That lets you test different hypotheses and gives each one a probability as to whether it could be the case. So, [00:21:00] um, the, the thing that they were checking is that on earth, um, the hydrothermal activity, which you remember is what happens because you've got cracks on the ocean floor and sea water sinks in, uh, Get circulated through the rocks underneath, which are heart and then kind of spews up again, cause it's close to a magma chamber or something like that under the surface.

And then it comes out into the water again through the highest hydrothermal vents. Now me things is actually produced by that itself, uh, on earth. Uh, the process itself produces me thing, but actually at a quite low rate and most of them may same. We see. It's from the microorganisms from the, from the, you know, the, the microbes themselves.

And so, uh, that's sort of thinking that went into this modeling of the scientists of the, of the, uh, of the [00:22:00] Cassini data, of the, of the, um, you know, the contents of the Alix plumes, uh, and what they found was. Uh, quite interesting because, um, if you, if you assume there's no biology there, you don't get enough methane in your models.

Uh, but if you throw in microbes into the models, then you do get enough meat there. I understand what you're saying. Yeah. So what they say, so there's a comment. Yeah. Yeah. A direct quote, which I'll read. Cause it's always nice to do that from one of the researchers. Obviously we are not concur, concluding that life exists in Enceladus is ocean.

Rather, we wanted to understand how likely it would be that Enceladus is hydrothermal. Could be habitable to earth like micro organisms. And the answer is very likely. The Cassini data tells us according to our models and biological Montana Genesis that's the formation of may thing [00:23:00] appears to be compatible with the data.

In other words, we can't discard the life hypothesis as highly, highly improbable to reject the life flight. To reject the life hypothesis. We need more data from future missions. So what it means, Andrew is that this is still an open question. They haven't ruled it out that maybe the methane is speaking of microbial life of the ocean in the oceans of Enceladus.

What an exciting result. That would be incredible. But as you and I have discussed many times, there is likely to be microbial life in the universe and we just have to find it. And the evidence is stacking up. This is starting to look more and more probable, uh, when you try it and it comes down to a mathematical, um, that the me Fein that's coming out of that.

Events is not sufficient to answer the question as to how it was formed. Something else [00:24:00] is contributing and life is one of those possibilities. Unless of course there's another way of producing methane that we haven't thought of that exists inside Enceladus, but. Hmm, that is right. That's exactly as it could be.

Yeah. It could also be seen as some sort of chemical, some sort of chemistry or they do gone. It's not right. So that's probably what they've gotten Enceladus. The, there might be some kind of chemistry that we just don't see happening or geochemistry, perhaps it is that we don't see happening on earth. So, yeah, so it's not proof, but it's really interest.

Well, the evidence is starting to really lend itself towards possibility if not probability, but yeah, we, until we are in a position to technologically, get there, get down, get in and get dirty with Enceladus. We, we only going to be able to [00:25:00] do what they did, which. Exciting in itself, but, uh, we're going to have to get down under there.

And that will be a technological challenge. I mean, this is a really big thick ice field and deep oceans and, uh, yeah, it sounds like an amazing place. It's not the only, um, ice moon in our solar system though, is that Europa's and other possibilities. Europe also has, um, ice plumes in fact, but the, that structure seems to be pretty commonplace.

All sorry. Three of the four, uh, big moons of Jupiter are thought to have that model. Titan has it, um, around Saturn, possibly, um, Triton, which is one of, uh, Neptune's moons and, uh, possibly even Pluto, Andrew, uh, that might have the same structure as well. Suggestion that might be an ocean. And that's amazing given our, you know, Pluto is so cold, honey surface minus 237 or [00:26:00] something like that.

Celsius. Yeah. Yeah. It may be one day. We discovered that there's life on all of these or in all of them. Wouldn't that be extraordinary, but, uh, yeah, let's just do it one at a time, I think, and sell it as first, the universe next we're simple minded folk. We can only do them one at a time. Yup. Yup. I can't walk into at the same time, so yeah.

So let's just stick to one task, but, uh, yeah, it is exciting news and let's hope that it is going to be found that that is evidence of some form of, yeah. Inside the ice moon and Solidus, this is the space and that's podcast with Andrew Dunkley and Fred Watson

nuts and hello to all our social media followers, to our YouTube, uh, viewers, thank you for following us on that platform. Uh, the space nuts podcast. Uh, on Facebook where you can all get together and talk to each other and [00:27:00] ask each other questions about whatever interests you in astronomy. There's a, there's a really strong group of, uh, of people who are always talking to each other about their telescopes.

Uh, and there are people who. Uh, throw questions in there, uh, at random for everybody to dis uh, discuss. And sometimes there are dozens and dozens of, uh, of, of opinions about this, that, or the other. It's a really good group. And if you love astronomy and you would like to join the space and that's podcast group, uh, go ahead and do so, because I think you'll enjoy yourself.

It's a lot of fun now. It's not the official. Facebook page for space. And that's, there's a different page for that, but this is, this is the one that's been created by space NATS listeners. So you can all talk to each other. So I think it's great that there's a little community there, uh, dedicated to space and that's listeners.

So check it out. It's the space. That's podcasts. On Facebook. Of course you can also follow the space nuts Facebook page while you're there. Uh, and we're on just [00:28:00] about every other social media platform that exists in the universe as well. So check it out now. We've got some questions. Fred questions from the audience.

This, uh, is James. Hello, friend Manju. This is, uh, James Davis originally. We're all in the Northwest of England and currently living in Aberdeen in Scotland. I have a question for you about the fundamental forces, uh, being gravity, electromagnetism, the strong and weak nuclear forces. Um, why do we not add a fifth force to that?

Um, I was thinking that dark energy. Should be possibly regarded as a, as a fifth force. Uh, you know, possibly you could add to that with, uh, with, uh, dark matter. Um, I also had that, uh, some people think that [00:29:00] gravity is not really a fundamental force, um, because it's an illusion created by the warping of space-time.

So perhaps you could, uh, clarify this. Um, thanks very much for listening to my question. I really love Isha. Thank you very much. Bye James. Thanks for the question. That's a, that's a deep thought question. That one, Fred, and to question whether or not gravity should be one of the fundamental forces, uh, very, very bold James.

Um, uh, maybe we could start by sort of reminding people what the fundamental forces are or 5,000 of them. We've got. We do. There's only four actually. Um, yeah, that's uh, yeah, it's a relief. Yeah. But, uh, it's a bit weird, so, okay. Uh, gravity is one of them. Uh, it's uh, sorry. I'm just watching a bird dismantle the windscreen wiper on my car, which is part of BSA.

Anyway, [00:30:00] thank you so much. Oh, no, no, it's a Butcherbird it's a, Butcherbird probably music liter it's gone now. Right? Sorry.

Um, yeah. Anyway, but my car was parked outside the window. Right? What was the question again? No, for fundamental, for. Which are generally assumed and have been for, I guess, a number of decades, gravity, uh, electromagnetism and the strong and weak nuclear forces. And they are pretty well understood, uh, in terms of the.

The, you know, the, the particulate nature of them there, that the forces, uh, uh, both, uh, forces and particles, these ones are anyway, they're carried by force carrying particles called Bose zones. Uh, and the one that doesn't have any kind of theoretical backing, [00:31:00] uh, today is gravity. Uh, so it's the, it's the one missing.

Um, there's, there's a slight quirk to them though, because we know a. We do know a for both zones that carry force, but it turns out that the weak force has to, uh, so the electromagnetic force is carried by the photon. Uh, the, uh, the strong force is carried by the glue on, and the weak force is carried by the w and Zed, both zones if I'm remembering this properly.

So, uh, so there are four. Particles, but only three fundamental forces that have particularly equivalents because, um, the thinking is that there must be something called a graviton that carries gravity, but we haven't yet either detected it or built a theoretical framework that allows it to, to exist. And James is right.

Um, we, we think in the world of relativity as, as gravity of being [00:32:00] a distortion of space, uh, and then. Begs the question. Does it need it on fundamental particle? Uh, people far clever than me seem to think it does. Uh, so I think there's still evidence for it. I think there's still a, you know, a strong, uh, Body of evidence that yes, gravity should still be regarded as one of the four fundamental forces.

But the idea of adding to it is one that is a hot topic in, uh, in, you know, fundamental physics, particle physics, and, and, uh, in fact astrophysics as well because, uh, for some time, and, and James mentioned dark energy when dark energy was first. Established as being real by the fact that the universe is expansion is accelerating.

That was that 1998 discovery made by the two groups, one here in Australia, one in, in the United States. [00:33:00] Um, so the AXA accelerated expansion of the university is what leads us to believe that there reason. Property of the universe called dark energy. Something that pushes space apart. And one of the first suggestions was, is this a fifth fundamental force?

And in fact, it was given a name which was quintessence, uh, Quinn quintessence is a word that comes from, I think, ancient Greek ideas actually as, as being something fundamental, but it fits this perfectly because the. Quintessence is the fifth thing. Um, and so quintessence was highlighted as a possibility and in enough work was done on quintessence to recognize that it would be, it should be something that would evolve with the universe, that it would change as the universe, uh, evolve.

And it appears that dark energy doesn't, uh, which puts it more into a different box, not quintessence, but something we call the cosmological constant, which [00:34:00] was an idea that Einstein proposed, uh, actually. Back in the twenties. Uh, and that is that there is a property of the universe that is proportional to space itself.

In other words, there's something in the universe, a force that gets bigger, a space gets bigger because it's a property of space itself and that's something different from quintessence. It, it becomes. Um, not something that needs a, uh, a particle to carry it. I'm not explaining this very well. And it's probably because I don't really know the details.

I'm not familiar with the details of all this from the point of view of a, of a particle physicist, which I'm not. So, uh, but, but that is the state of play at the moment. Um, Um, dark energy is thought to be something different from the fundamental forces. If I can put it that way. Okay. Dark matter was something that James mentioned as well, that [00:35:00] matter is, has properties that tell you is some kind of it's made of the fundamental.

Particles that we see already. It's not a force. It's a, it's a, um, a laptop. It's something that is, is, you know, a party, um, uh, matter particle rather than a force particle. It's a thing. It's a thing. Yes, that's right. Rather than a force. Um, and we will presumably find it eventually, but we haven't done yet.

Sorry. That was a long answer to a short question, but a really good question. Thank you very much, James. It wasn't actually a short question, but anyway, shortest question. Yeah. So the bottom line for James is no, we're still only got the four fundamental forces. So far at this stage. Yes. Very good. Thank you, James.

Good to talk to you or good to hear from you. And, uh, thanks for sending in the question. Uh, the next question comes from Duncan. Hello Duncan from Weymouth in the UK here, again with another question [00:36:00] about your cloud, just looking at the distance between stars. On average, I read that it's about four light years and that New York cloud is forced to extend for two light years or at least ask.

Influence over it. I was just wondering if that's the case. Would it be that there is more of a general galactic morass of small bodies, rocks and small planetoids NINGs that we move through some of which get attracted in by the sun or indeed other stars, some get perturbed and frozen out, but. They could be just generally a galactic body rather than specifically related to the sun.

And we just move through it and pull some in, leave some behind, kicks them out into other stars and have a stars do likewise. And therefore, whilst there is a group of bodies out there, then. Or by any way, [00:37:00] specifically related to the sun and that they're just something that we travel through leaving a, almost like a week behind us of small disturbed rocks, like a boat plowing through the water just to fall.

I don't know what you think on that. Anyway, they are keep up the good work by then.

Okay, thanks Duncan. Uh, G where, where do you want to start Fred? Well, yeah, so it's, it's a great question. Um, uh, the cloud is postulated specifically to explain comments, uh, which are, you know, they're solid bodies, they're icy bodies, but they're, as we've discussed before, they're more like a snowdrift than an iceberg.

They're, they're fairly loosely bound and they they're very, very dull. Um, and the reason why Yana Watts back in the 1950s proposed the idea of this cloud sort of reservoir cloud was because of what we [00:38:00] observe in the distribution of long period comments, long period comments are ones that come directly from the cloud.

They come from way out exactly as, as Duncan consensus. A couple of light years away that, or cloud something like that. Maybe not quite that far, but of that order. Um, it's uh, so the, the observation is that these things come from all directions. They don't just come from one particular direction, which is what you would expect if it was the sun's gravity, sweeping up stuff, as it progressed through a galaxy, which is littered with them.

These bits and pieces. Um, as far as we know, the galaxy isn't particularly littered with them. We, we see, um, evidence of interstellar asteroids. We've seen both, uh, Omar mover or your favorite asteroid, uh, and the interstellar comment board itself, which both of which are known to have come from outside the solar system, but the art class.

Uh, [00:39:00] it, it it's partly because stuff comes from it in all directions. So w w they'd have a preferential direction if it was D due to this motion through the galaxy. Uh, but the, the other point is that, um, Stuff that is being swept up by the earth has a higher velocity than these comments do. Um, and that's what distinguishes comment borrower self from an audit cloud comment from a long period of standard long period comments, uh, it's big difference is that it's got a hyperbolic velocity is coming from outside the solar system.

So, uh, that's basically why we think the cloud is right. Uh, and, uh, uh, there's pretty good evidence. There's um, it will, there will come a time. I'm sure when we can direct when we can detect the Oort cloud directly, because. Even though these swarms of ICER, [00:40:00] I see comment nuclear are very cold. They still have an infrared signature.

Uh, they don't shine by much reflected light because there's, they're small, they're tiny objects and they're halfway to the nearest star. So, uh, what you're looking for is an infrared signature, which maybe we will see on day from bodies in New York plan. So just sort of, um, help my. Brian get through this.

Where do we think the cloud is? Uh, so if you think of the solar system, uh, Neptune's the furthest planet. Neptune is 30 astronomical units away. I think I'm writing saying that the cloud is probably more like 30,000 industrial chemical units away. It's it's, uh, it's a long, it's much, much further either than the planets or the copper belt of, you know, these icy asteroids.

Uh they're [00:41:00] there. There are one or two really distant. What it called extreme TNOs TNO is a trans Neptunian object, but one or two of these extreme TNO is that have all bits that make you think they might have, they might be directly coming from the Oort cloud because the far end of their orbit actually matches the distance to the cloud.

But they're quite rare because they're so faint and so distant. And they're small, you know, we're talking about tiny things here. So th the, the reason I ask is, um, because of the voice. Probes. Are they not that far out yet? No, they're not that far out yet. Ah, okay. Yep. Yep. Wow. It's big. Yeah. It's a long way off then.

Uh, you know, people talk about them crossing the edge of the solar system, but that's, it's the edge in magnetic terms rather than the edge in planetary terms. They haven't got to the cloud yet. Okay. Well, they probably will, but we may never know about it. We might not know that's right. Hmm. Okay. Uh, thank you, Duncan for your question.

Greatly appreciated, of [00:42:00] course, a, a reminder, if you do have questions for us and we've received a whole batch, which is fantastic. So we'll be working our way through those. Uh, I think we got about a hundred text questions. I don't think I'm exaggerating now we got quite a few, so we've got a bit to work with, but if you do have questions for us, go to our website and click on the AMA tab where you can send us a text question via the email interface, or you can record it.

If you've got a device with a recorder, like a mobile phone or a tablet or a computer bit with one of these, uh, Plugged into it, that big hulking microphone of mine. Uh, you can record your question just by clicking on the record button. Don't forget to tell us who you are. I've got a couple from, uh, people who haven't told us their name or where they're from, but that's okay.

We'll still use them. We'll just say, Joel. Uh, or Joanne blogs perhaps, but, uh, yeah. So send us your questions via website. And while you're there, don't forget to visit the space in that shop because it's worth visiting. There's lots of, um, [00:43:00] little doodads there for you to peruse and maybe buy for yourself or a friend or a relative, uh, that you hate that you'd love, uh, you know, anything like that.

Uh, and, and the other thing you can do on our website, Is listened to our back catalog all 260 past episodes are there. So if you'd like to go back and listen to some past episodes, maybe run through the headlines and pick one that tickles your fancy, you might go, oh, I want to learn about Mars. We only talk about Mars occasionally, like with what 261 episodes we've talked about Mars 258 cars.

So yeah, you won't have any trouble finding that, but, uh, yes. Uh, space nuts, podcast.com uh, Fred that wraps it up for another week. Thank you so much. It's good to catch up. Always good, Andrew. And I look forward to the next time. See you soon, which could be in about a week or so maybe so. Hmm. All right.

Thanks Fred. Fred. What's an astronomer at large part of the team here at space. And that's thanks again to Hugh back in the [00:44:00] studio who keeps it all together with super glue and plastic wrap. He's going to have to find something. Yeah. By the middle of next year. And for me, Andrew Dunkley. Thanks for your company.

Catch you again on the next episode. Bye bye Steve to this space, next podcast available at apple podcasts, Google podcasts, Spotify I heart radio, and oh, your favorite podcast player, you can also stream on demand at GuideStar. This has been another quality podcast production from bitesz.com.