Science Extra: Echoes of a tsunami
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Science continued to spark wonder and reshape our understanding of the world last year. We discovered what it takes to make the planet shake and shudder for nine days straight. And why are physicists so obsessed with proving Albert Einstein wrong? Welcome to Science Extra on Radio National. I'm Belinda Smith, and today we'll tear into some of the plumpest, juiciest science stories from the past year.

I'm joined by two of the most curious cats I know, ABC science reporters Jacinta Bowler and Carl Smith. Welcome. Hey there, Belle. Hey. Straight up.

What were the biggest science announcements of 2024 for you, Carl? A few big ones that stood out to me is that we have three new moons in the solar system. What? So there's two more around Neptune and one around Uranus. So update your trivia knowledge bell. And the latest tally puts Neptune at 16 known moons and Uranus at 28. And one of these little Neptune moons has the longest known orbital journey yet for any moon. It takes 27 years to whip around that icy rock. Wow.

Wow. That is a slow moving space rock. Unreal. Another stuff that stood out to me, SpaceX caught a rocket. Great work. Probably handy. And we narrowly avoided stepping into the Anthropocene epoch. It would have come into effect in August of this year, but the proposal was rejected immediately.

after 15 years of deliberation by Earth scientists. And there's a fairly dramatic row reported by The Guardian on what happened in that space, if you wanted to go and look further. It's pretty intense. I mean, they could have, I think if a couple of people had voted, it probably would have been different. We could have had the Anthropocene, maybe. I think we still do, a little. Yeah.

What is the Anthropocene, by the way? Yeah, so this is the era or the epoch that is defined by humanity's impact on the world in the geological record. There's a lot of different definitions thrown around. There was a whole working committee to try and figure out, you know, how they would define it, what they would look for. But it was nixed in the end, so no Anthropocene. All right, Jacinta, what about your big stories of the year? We still have not found dark matter. Oh, man.

If we'd found it, that would definitely be the biggest story of the year. But alas, there's been lots of these scientific experiments trying to find, you know, dark matter. And, you know, even the most sensitive detectors, even the best ones out there, they still can't find it. The latest one was in August, a really impressive detector called Lux Zeppelin, just

couldn't spot it. And so we're still looking for what dark matter could be. What do they think dark matter is? And why are we so interested in finding it? Well, there's a couple of hypotheses. Hypothesi? Hypotheses. Hypotheses.

There are a couple of options for what dark matter could be. One of them, and this is the one that we thought for quite a while, is something called WIMPS. That's Weakly Interacting Massive Particles or WIMPS. And so that basically is the idea that it is a particle. It's out there. We can find it. If only we look hard enough and have sensitive enough detectors, which I'm sure is very helpful for the scientists that are trying to get more funding for this.

But as far as we look, I mean, they're really weakly interacting because we really, really, really can't see them. There's other options that might be out there, but they're all a bit more experimental. So, you know, we'll see what happens, but maybe 2025's the year. Like we know that there must be something out there because we can see the effects on gravity, the gravitational pull is...

that dark matter has on matter that we can literally see. Yeah, dark matter has to be there. They just can't work out what it is or where it is or any of the other details. It's a hell of a lot of missing mass. I think five times more than the mass of physical matter in the universe. So there's a lot of stuff out there that we've got to find. And what else did you think was worthy of a chat today? There was a lot of interesting research about AI. There has been a lot of things happening at the moment.

But in the last 12 months, there wasn't anything huge. You know, there wasn't a new boson or the first photo of a black hole, for instance. I think that last year has been really incremental and there's still lots of interesting discoveries, but probably not the one big thing. Something that did rock our world, figuratively and literally, is the fact that we're now

Scientists solved a real head-scratcher of a mystery last year. Back in September 2023, super sensitive devices all around the world, which pick up the teeniest, tiniest vibrations from the Earth, they all registered a huge burst of activity, like something really big had gone down. And that big signal didn't just fade away, it repeated every few hours for nine days. It was like something was thumping the planet like a drum.

Earth scientists were stumped until September, just gone, when they identified the culprits. Carl, what was it? So I actually visited one of these listening stations deep underground in Germany just after this had been identified in late 2023. This place I went to is in an old abandoned silver mine in the middle of the Black Forest surrounded by granite. And they detect these tiny, tiny little rumbles in the Earth.

Everywhere around the world, places like this spotted this unusual signal and it kept repeating. I talked to a scientist, a seismologist there named Dr. Rudolf Widmarschniedrich, who said that

Wow.

So they started zeroing in on this one fjord up in Greenland. And in this massive international collaboration with people using satellites to monitor what was going on up in that part of the world, with the Navy from Denmark going in to take...

and videos of what had happened up there. Because that's what the Navy does, right? They just go in and take photos. A mystery seismic event? Well, fair enough. And so they started piecing together this puzzle and they realised that what had happened was there was a landslide in a glacier and this massive amount of rock and ice came down into a fjord

And this fjord was kind of a funky structure. And the water, as it was displaced, kind of washed backwards and forwards in part of this fjord. Like, imagine water sloshing back and forth in a bathtub. Yeah.

And that amount of water going bang, bang, bang up against either side of the fjord created this incredible bizarre signal that was detected right around the world. Right. So that repeated signal was these devices picking up the thumping of the water against the side of the fjord? Yeah, exactly. Wow. How big was this wave? Yeah, they were, I think it was almost 200 metres high. High? Last I checked, inside this fjord. And there was some damage to...

like a little research station out there where some dog sleds sometimes stop. Uh, there was, uh, no harm done in this. No people were injured. No dogs were injured. Uh,

But the scientists behind this did say that, you know, there are occasionally some cruise ships that come through these fjords. And if you had, you know, a giant cruise ship with a big amount of water like that sloshing back and forward or a glacier collapsing into a fjord, you'd have some trouble. This is Science Extra on Radio National. I'm Belinda Smith, joined by ABC science reporters Jacinta Bowler and Carl Smith.

Another story of discovery, but one a little closer to home, was a rare find on Jigara Lizard Island on the Great Barrier Reef. Archaeologists unearthed dozens of pottery fragments, some of which could be 3,000 years old. Jacinda, you covered this story. It seems like pottery is kind of everywhere where people are. We make things out of clay and fire them and then use them to do stuff.

Why was this a particularly interesting and exciting discovery? Yeah, so I want to start with the age here. I feel like it's worth noting that 3,000 years ago in Britain, it was the Bronze Age. This is a very, very, very long time ago. But what was happening in Australia in this kind of area near Papua New Guinea was there was this group called the Lapita that were sailing from Papua New Guinea down through the Solomon Islands, through Vanuatu, Fiji, Samoa and American Samoa. They're really pretty amazing people.

And when they went through these new places, you can tell because there are things like bananas, pigs and pottery that are then strewn in the areas that they left in the fossil record where they go. In this particular story, we're looking at Jiguru and this is a part of far north Queensland. What they found is pottery on this island that

But they don't think it was done by the Lapita. They think it was potentially a collaboration between the Aboriginal people. And that is one of the only and definitely the oldest Aboriginal pottery that we know about at all.

So why Aboriginal potters and not Lapita? Like, why couldn't it be, oh, the Lapita people showed up and they're like, oh, let's experiment with different styles. Yeah. So the researchers who found this are pretty sure it's Aboriginal pottery. There's a couple of reasons for this. One is that it's different to the Lapita pottery. It doesn't have the same kind of telltale signs of Lapita being in the area that some other areas do. So that's the pig and the other remains? Exactly. Yeah. You don't have the taro. You don't have things like that.

But the other reason why they think it might be the case is because traditional owners in the area believe that this is something that they once did and they've got stories about this happening. I will say that not everybody agrees. When we did the story last year, there was some talk with other researchers who weren't quite sure why Aboriginal people would be using pottery in the first place. They have lots of different ways that they can carry things.

For example, baler shells, they have their own little handle inside of them. Whether you would actually need pottery, go to all the effort of, you know, firing clay to make something to carry things in is something that maybe hasn't been fully ironed out yet. But I think what's really fascinating about this story is that 3,000 years ago, long before Europeans had done

anything near Australia, there are these groups, these multiple groups having these conversations, sharing culture. And I think that's really quite incredible. One thing that kind of strikes me is like, why does it have to be utilised as something like carrying something? Why can't it just be, oh, this is a cool thing, something nice to make or, you know, creativity? Because as we know, First Nations people, incredibly artistic, incredibly creative and

Why wouldn't that just translate into sculpting pottery? I'm glad you said that, actually, because where it is positioned, where it's found on this island, it wasn't actually somewhere where Aboriginal people would live long term. Oh, really? They would go and visit that island and do ceremonies there.

So the idea that it could be something that, you know, is a ceremonial pottery or some other thing like that, that's something that the researchers looked into. So it could be the physical component of something that's been passed down through oral traditions as well. Absolutely, yeah. Lovely. Well, thank you so much, Carl Smith and Jacinta Bowler. Lovely to speak to you. Always treasure my time with both of you. So thanks heaps. Thank you, Belle. You're so nice.

Every year it seems like we're bound to be bombarded with headlines telling us that Albert Einstein was proved right again. Last year was no different. In May, scientists reported how the hot disk of plasma circling a black hole gets pulled in. Instead of swirling around like water down a drain, the plasma plunged straight in like a waterfall. It was the first time that a black hole's so-called plunge zone had been observed. Yet Einstein's equations predicted it more than 100 years earlier.

Something even more exciting than proving Einstein right again and again is the prospect of proving him wrong. It's been done before, and physicists hope to do it again, and soon.

Shelby Trainor spoke with Professor Geraint Lewis about how physics could finally advance beyond Einstein, something we've been seeking for more than a century. I'm a professor of astrophysics and I'm a cosmologist at heart. And what that means is I study the evolution of the entire universe. And so what I want to do is, what is the universe made of? Where has it come from? Where is it going to?

And Einstein's name is written all over all of that because, of course, he gave us the general theory of relativity back in 1915. And the equations that we use to describe the universe are written in that mathematical framework.

So, you know, it's now everyday kind of thing is I have equations in front of me that come from the mathematics of Einstein and it's inescapable. Whenever you want to study the universe, because the universe is dominated by gravity on large scales, you can't get away from talking about Einstein and his theories of how gravity works. Where do you think Einstein has had his biggest impact?

Oh, that is a really difficult question. I was thinking about this this morning and I would put him on a pedestal for his work on gravity. I mean, that's inescapable. I said it, but that's the thing that dominates my kind of research.

But we have to go back and remember that Einstein had this miraculous year back in 1905 where he basically changed not just the path on which led him to his discovery of general relativity and gravity, but all of the other aspects. So he calculated how big molecules were, right? So that was an incredible kind of thing. And that on its own would have made him famous. But in the same year, he also published this thing about what's known as the photoelectric effect, which...

is one of the first real understandings of quantum mechanics. So his name is everywhere. So again, it's one of those kind of things where, yes, I could single him out for a particular success. But I think if you talk to other scientists, like those in the quantum world or other places, his name appears. He contributed quite a bit.

And I think one of the things that gets forgotten, of course, is that Einstein got a Nobel Prize in 1921. And that Nobel Prize was for his work on the photoelectric effect and other stuff and not around his theory of relativity, which is probably what he's most famous for. Because back then, of course, people weren't really sure. These cryptos,

crazy notions about the speed of light, etc. So, you know, he got rewarded for what for me is like not the important aspect that came later. But clearly he had an impact in his day. Yeah, but it took the world a while to catch up right to those theories and to realise how extraordinary they were. Yes. So we have to remember, of course, what he was asking us to take on board.

So in 1905, and for me, let's stick with relativity. The other stuff, of course, is wonderful, but relativity. So up until 1905, the universe was a simple place, right? Newton had defined the way the universe works. And he'd given us Newtonian mechanics, which is every student who learns physics, first thing you learn is what Newton said about the universe.

And to Newton, there's this stage in which everything takes place and that's space. And there's this clock that ticks away in the background. It's time, right? Time ticks away. And it just seems so obvious, right? It's like this is common sense, right?

But you get to 1905 and then Einstein says, now let's do away with that, right? So we'll stop with this notion that firstly, the time is absolute, right? That time ticks off at different rates dependent upon what observers are doing. And you sort of go, that's not very sensible, surely, because it doesn't count, you know, my experience. You know, if we set our watches together and we go off and do different things and we come back, our watches tend to be in sync, right? But

But of course, on our day-to-day perspectives, these effects are very, very small. But when things start to get up to these huge speeds, close to the speed of light, then these become big. And you realize that that's the way the universe works, that time is not this rigid, ticking universal clock. But it changes from place to place in the universe, which is kind of weird.

What do you think of the constant headlines Einstein was right, that we keep seeing popping up? You know, it seems once a year at least there's something. Yeah, well, they're good and they're bad. So it's good for a couple of reasons. Number one, of course, is that we got this mathematics written down by Einstein in 1915. And it's not like we get the theories from Einstein and then they're like an unalterable text, right? That's not the way science works. Science contradicts.

constantly stress tests what's in front of it. So we constantly test Einstein's theories. And yes, they always come back and they work. So, you know, at some level, it's a great sign of how science works is that we always test these things.

But scientists really want them to fail because we know at some level that our theories of the universe are not complete. We know that there is a big fracture in modern physics between the world of the cosmos and gravity on large scale and the world of the quantum, the world of the very small scale. They're written in completely different languages. And people have been trying, even Einstein was trying to do this on his deathbed basically, was trying to make these worlds fit together. And they just refuse to.

And the only way that we are going to get a clue on how we can make this work is by finding the places where Einstein's theories fall over, where relativity doesn't work anymore. Because that'll be right. Oh, something else is now playing a part here.

But every test we do over and over again, it's like Einstein was right. And so it might just be that we haven't got to that precision yet where we find, you know, it might be very fine scale stuff that's given us the clue and we're just not there.

But we do this every day with our GPS systems. That's testing Einstein. We know the GPS gets us to the right place. And now we do things like looking at collisions between black holes and measuring their gravitational waves, etc., looking for where Einstein's theories don't work. And they always come back. Yep, completely works.

So the headline that you're waiting for is Einstein was wrong. Oh, absolutely. And again, that is what the physicists want. And the physicist that finds that knows that they'll be on their way to Sweden to pick up a Nobel Prize, right? I mean, it is one of those guaranteed things that if you crack this nut, that's the path that you're going down because you will change physics.

because we will get to a point where we will have something beyond what Einstein has given us. And every time you open a new door in science, new stuff starts to flow. And again, it's not obvious what it's going to be, but Einstein wasn't thinking about Google Maps on your phone when he was writing down the equations of relativity. But that's what it's turned into, right? So yeah, that's what we want to see. And that's why we continuously stress test our theories and

But, yeah, at the moment we haven't got there. Where do you think the next Einstein will come from? I know that it will look very different, but in terms of cracking that problem...

Do you think it will come just as out of the blue as his initial theories came? There's a bit of a misconception about Einstein at some level. And I just want to clear this up and I'm not going to put him down in any kind of way. But, you know, he... Go for it. Well, in 1905, he was a patent clerk, right? And everybody remembers this. He was a patent clerk and he revolutionized science.

But what people forget at some level is that he was a patent clerk with a physics education, physics and maths education. He wasn't an outsider. He was somebody who had been in, was out at the moment and was trying to get back in again. So, you know, he was doing the patent clerk job to get money, etc. And he was trying to get another university position. So he was educated in physics and the issues facing physics. So he wasn't an outsider. Right.

So the person who cracks this nut will not necessarily be a complete outsider. They will have to have had some exposure to the current theories about mathematics and relativity and all that kind of thing. So they will have some kind of scientific education there.

But where it will come from and who will it be, I wouldn't want to hazard a guess. You can have an idea that it'll probably come from a country with a good or, you know, a broad education system where people are educated.

And of course, back in the day, that was very focused on certain European countries and less so in other countries. But the world is really changing when it comes to education. The quote basically was along the lines of, you know, Einstein, of course, was outstanding. But what we don't know about were all the equal brains of

who basically slaved their lives in fields producing crops and never had the opportunity to make their contributions. We know those mines must have existed, right? They're not solely in the university-educated world.

people from Europe. We know that there are great minds all over the world and it's that education that will feed into that. I don't know where the next Einstein will come from, but there's a good chance they're not going to look like Einstein. And do you think that that way of working exists anymore either? You know, we've moved a lot. You mentioned before sharing of data across teams across the world and also massive teams working together. Even the Nobel Prizes struggles to

with this problem is it's never one person. And again, it wasn't Einstein on his own. He was working with other people's work and whatnot, and he was having discussions with other people. But he was more isolated, I assume, than many scientists are today. Oh, yes. I mean, of course, back then in 1905, everything was done by the speed of how long it takes a letter to get from A to B. So things, of course, are very, very different now.

But Einstein had his circle of friends. He knew the key mathematicians of the day. He knew Poincaré, he knew Minkowski, he knew Hilbert, all these kind of things. He knew those people. There was a circle that he moved in.

I think some of the biggest restrictions that he got, of course, in his life were that after he had done special relativity and was working on general relativity, there was World War I. And so, you know, then the correspondence between the scientists in Germany and the scientists in Britain had to basically stop and all this kind of thing. So...

It is a very, very different world in which science is being done today. And science is a mixture of individual enterprise because you're in it at some level for yourself, right? Because you're working on these problems because they interest you. But to tackle the big questions today...

Especially when it comes to experiments, it's very difficult to do that on your own. And of course, like the mega experiments that we have, like the Large Hadron Collider, like the gravitational wave detectors, etc. These are now billion dollar projects. That's the kind of funding that needs to go into this kind of thing if you want to make those breakthroughs.

And I'm going to be very careful because people always go, oh, we shouldn't be funding science at billions of dollars, et cetera. I'm just going to point out that science is cheaper than an aircraft carrier, and I think it produces a lot more. But this is the scale, right? If you really want to...

answer big questions, you need to have that investment. As you mentioned, like particle physics, papers now have thousands of authors. And, you know, it goes all the way down. The people that build the little bits that go together, that fit into the Large Hadron Collider, everyone plays a part in all of this. Now, there still are some people who do smaller experiments where there's

sort of hope that there will be something fundamental that comes out of this or observations with telescopes, etc. But yeah, it's getting more and more difficult because most of the air quotes around easy stuff has been done. Most of the stuff that you could do in a laboratory has been done. Somebody has thought of these ideas before. It's now very technical and requires...

very specific sort of environments and usually lots of funding to get it to happen. If you could personally direct all the funding in physics, I know it doesn't work that way, but let's pretend.

where would you put most of that money? Which theory, which thought bubble at the moment would you throw the money behind? I would be very against putting all of our eggs in one basket because one of the most important aspects of science is that we're not politicians, right? And what I mean by that is that we have to be prepared to fail, okay? And we have to admit that we went down a path and it was the wrong path.

So I wouldn't want to say, oh, let's focus only on building, let's say, the next large Hadron Collider, which you already know will cost, you know, probably into the trillions, right? Because, well, because they, to build this kind of thing, right, they want a 100 kilometer tunnel underground with super cooled magnets and all this kind of stuff.

And I'm sure it will yield very interesting results, but that's not the only place where the interesting questions are. Now, if I was going to do it in Australia, I don't think Australia wants to build a large Hadron cloud, even though it's got the space for it, that would be good. But what is really needed in the world is a gravitational wave detector in the southern hemisphere.

And Australia is the ideal place for it. Stable continent, lots of space, and it would make a big difference because currently all these detectors, they are in the US, in Europe, and one going into Japan. We need one in the Southern Hemisphere because you need that different viewpoint to really see what's going on. So again, not all my eggs in one basket, but I'd put a good chunk into building an instrument like that in Australia. And before we get kicked out of the studio, one of the most important questions...

Have you had time to kind of think of

Or imagine a world without Einstein's theories and what that might look like, even for the everyday person or for you in your career? Well, I mean, I wouldn't have a career. If Einstein... I'm going to answer this in two parts. So firstly, if I was living in 1904 and I wanted to study the universe, I would simply not have the tools to do so.

Because back then, of course, we didn't know that we lived in an expanding universe. We didn't even know that we live in an individual galaxies where we have collections of stars living together. We didn't know that stars were powered by nuclear power. So people thought that they were basically just big hot balls of gas that were cooling down.

I wouldn't be able to, I mean, I would find stuff to do, of course, but I wouldn't be able to do anything remotely close to what I'm doing today. I would probably be tinkering in a laboratory and at the birth of quantum physics, hopefully doing something interesting, but I couldn't guarantee it kind of thing.

So it would be a different world. And of course, it's hard to imagine, as I said, if you removed Einstein, what the world would look like. But you can imagine what the world in 1905 looked like and how different it is today. And those differences today, much of it came from quantum mechanics and relativity. You only have to look at your smartphone. This is a result of not only material science, which has, of course, advanced hugely over the last 100 years,

But quantum mechanics in your electronics, relativity to talk to the GPS system, etc. The people back just more than 100 years ago, I doubt they could envisage that this kind of thing could exist, right?

Now, the other interesting question is if you built a time machine and went back and you assassinated Einstein, right? Yeah. Well, so this would be a tricky one. If I wanted to build a time machine, I would need to use relativity to make it work. And then if I killed Einstein, yeah, so there's another paradox straight away. But if I removed Einstein, right? So let's say he didn't contribute to any aspects of physics. Where would we be today? And that is a very difficult question to answer because

He definitely, definitely had moments of like complete insight where he changed things. So special relativity, it's like, you know, this is incredible. This is incredible. How did he come up with this? But at the time you realize that there were other physicists probing around and sort of going, oh, you know, Maxwell's electromagnetism doesn't quite work. And there's this idea that maybe there's this ether and there's this guy called Lorenz who sort of said, well, maybe things are shrinking when they're moving and that's, and so on.

there were these ideas stewing around and maybe it wouldn't have been 1905. Maybe it would have been a bit later. But I'd like to think that eventually somebody would have gone, oh, what if we do this? And then similarly with general relativity, it was Einstein's friend Minkowski that gave him the idea that space and time could be unified into a space-time. And it was other...

mathematicians and physicists that were feeding him ideas. And even when he published his relativity in 1915, it turns out that David Hilbert, a mathematician, had come up with the same mathematics at the same time.

So again, it wasn't in isolation. There was lots of cross-pollination of ideas, etc. Again, I don't want to detract from Einstein's contributions. Physics would have evolved differently, but I would like to think that we would be in a very similar kind of place, that people would have cracked these questions with regards to how gravity works and how light works, etc. You can hear more of that chat with Professor Jarrett Lewis, along with a bunch of other great physicists and mathematicians on The Science Show.

jump into the ABC Listen app and search for how modern physicists are trying to make sense of gravity. Now we're turning the clock back 50 years with the new ABC podcast, The Weather That Changed Us. On Christmas Day in 1974, Cyclone Tracy decimated Darwin, destroying most of the city's buildings and leaving most of its nearly 50,000 residents without anywhere to live.

But that devastation also led to transformation. Building codes were overhauled, changing how we build houses across Australia today. And a warning, this episode contains the Standard Emergency Warning Signal, or SUSE Alert. Darwin in the 1970s sounds like the place to be.

It was a really delightful city, lots of trees. As you walked around the streets at night, you could hear people because every house was wide open. You could hear conversations and people lived the outdoor lifestyle with barbecues. It's often described as a cultural melting pot, made up of the communities that had migrated to Australia and lots of young people who were in the Top End looking for an adventure...

like engineering student Geoff Borton. There was a complete range of people, from people who were trying to escape to Darwin, create a new life. Young families, lots of young families up there because it was a posting that you did early in your career. Lots of government housing, so it was very much a government town.

And then, of course, the people that had been there their whole life, like Joy Cardona. It was just a fun place to be in because everybody knew one another, had a lot of relations, a lot of connections. On Christmas Eve 1974, Darwin was buzzing, people busily getting ready for Christmas Day and wrapping up the year with celebrations.

18-year-old Joy is on her way to a friend's 21st at a Chinese restaurant on the waterfront. Norm Hagen, his name is. He came up to play football in Darwin and he became very close friends with us and to this day he's still like a brother to me. There's an eeriness hanging in the sticky wet season air and there's been warnings a cyclone is on its way. But Joy isn't letting it ruin the holiday mood. After all, Darwin hasn't been hit by a cyclone in nearly 40 years.

And only three weeks ago they were being warned of another cyclone which never arrived. We weren't the worried ones. I think our parents were the worried ones. We weren't. We were too eager to go to a party, I think. Because we were having like the tailwind of sort of cyclones and we thought, oh well, that's just a bit of wind. But it was eerie because there's no birds. We noticed there was no birds around. They had gone already. When Joy arrives at the party, the weather is picking up. Thunder, lightning, thunder.

Rain pouring down, wind. But that's just like a normal day. It could go for two to three days if it used to rain for. So we all went to his party and I think we arrived there about seven and was having such a good time and we didn't have any clue what was happening outside. And we were all there celebrating and the lights kept flicking on and off. I thought, oh, here we go, we're going to lose power. I don't even believe that we had the cake by that time but we were also having a good time.

And then they said, no, we're closing. You all need to go home now. The cyclone's coming. I think we just laughed, really. You're right then. We have to go home now, you mob. As soon as Joy steps outside, she realises why. The wind was just like, oh my God, there is something happening out here. You can't describe the sky that night. It was orangey. It was pale. It was grey. It was like a monster movie. What the hell's going on here?

And, you know, the wind just picked me up because I was very light. Hang on, hang on. You got picked up by the wind? Yeah, because I was so light. Like, as it come, it lifted me up there and one bloke grabbed me and pulled me down. And that's when we realised that this is serious. This is not just a game. A cyclone is imminent. The Bureau of Meteorology has forecast that there is the likelihood of danger from wind-borne objects and that houses may be damaged.

This is the story about how Cyclone Tracy decimated Darwin and changed the way we build houses all across Australia. I'm Tyne Logan and this is The Weather That Changed Us. Engineering student Geoff Borton had been spending most of his summer break on Croker Island, 250 kilometres away. Because it's so remote, he'd been doing the weather reporting for the island via the radio.

including the cyclone warnings. So in those regular sessions, which were twice a day, I would be in touch with the Bureau and then they would feed out all of the coordinates so we could plot it on a map. The track was telling us that it was probably going to scoot by us. But as Tracey swung by, it was worse than Geoff could have imagined. Wind was roaring.

You could hear debris like bits of tree branches hitting the side of the building. The roof was starting to flap. All of his engineering knowledge suddenly very real. At that stage, I had no idea how strong the house was. Faced with that kind of noise, you don't feel confident and particularly feeling the house move and hearing bits of it banging.

made me think, yes, it could fly apart at any time. There was no way I was going outside. I had to be somewhere inside and I figured under the bed would be a good place to be so that if the walls came down, the bed would protect me.

My house was on the ground and there was quite a lot of water coming in. So it got to the stage where I thought, if I don't move out of here, I could drown under this bed. What Geoff was experiencing was terrifying, but it was just the edge of the cyclone. And Tracy was about to hit Darwin with its full force.

In Darwin, Joy hightails it from the party and drives straight home to shelter with her partner and daughter. Or as straight as you can, driving a Datsun 1200 in a cyclone. And as we were coming, the water was actually in the car. We were sloshing everywhere. The wind was blowing. Back at home, it feels like no time before Tracy rips into them. The tin roofs were the dangerous ones. They were flying in there like missiles. Everything was a missile.

It was a war zone. We were in a war zone on our own, fighting one person named Tracy. I heard this crackling and I thought, what's that? And I ran and grabbed my daughter out of the cot just in time when her whole bedroom window went flying into her cot. A glass was everywhere. We knew we were in danger then. And all I could do was put her on the bed, chuck all her Christmas presents on and distracted her until it opened her presents up.

In that moment, Joy was one of thousands of people across Darwin, cowering inside their home as Tracy tore the city apart. That night, everybody who had a spiritual belief or a being they prayed to, we all prayed as one group of people. Whoever you prayed to, whoever you adored up in the spirit world, we were praying. Everybody that night prayed as one group of people. By the next day, the Darwin she knew...

I used to watch the war movies and see a disaster in war movies. This was even worse. This was worse than the damage that was done. You know, houses next door was just flattened. There was nothing there. 40 people have been killed and hundreds injured in the... Like an atom bomb had gone off everywhere. This is Tiger Brennan, the mayor of what was once a prosperous city.

Cyclone Tracy had smashed Darwin with wind gusts over 217 kilometres an hour. 66 people died that night. Most were killed by flying debris...

or crushed under their home. What happened to your wife? My wife was killed. Kim, what was it like? I don't know. All I can remember is my dad saying, keep down, keep down. There's radio listeners in Melbourne wishing to establish radio contact with Cox Peninsula in Darwin. Because all communications were down, there was a brief moment when no-one else in the world knew what had happened to Darwin. But soon, the news spread. First, the main developments today.

Australia had had bad cyclones, of course. But not like this. Tracy hit Darwin bang on. Almost all of Darwin's 8,000 homes were flattened. 90% of them were uninhabitable. So everyone had to leave immediately.

Joy and her daughter were on their way to Perth. It was the most saddest, heartbreaking, devastating thing I've ever had to do. I lost everything and I have to go and do this new life, which I didn't know anything about, a new life. I didn't know anything else but Darwin. It was mostly men who stayed, people who could help out with the clean-up and rebuild.

Engineering student Geoff Borton was one of them. There was nothing left. No trees, no birds, no families. And it was eerily quiet. You'd drive along these quiet, empty, desolate streets and you'd smell something. And oftentimes, well, every time, it was either a fridge or a pet. But, yeah...

So it wasn't a hoot. It wasn't a fun place to be. At the same time as this mammoth clean-up effort was happening, the planning quickly moved to the new Darwin. Darwin was a territory, still is. So the bulk of the rebuild fell to the federal government under Prime Minister Gough Whitlam. I want to assure you that the Australian government will spare no effort to rebuild this city, to restore Darwin.

this city as a proper place for people to live and to work. It was clear to everyone something had gone terribly wrong. When Geoff was sheltering under his bed, he kept thinking one thing. During those few hours, I thought there has to be a better way of building houses than this. Gough Whitlam was thinking the same. It has been tragic that

Nearly all the housing which has been built in Darwin since the last great cyclone in 1937 has proved to be unsuitable for this district. The question was, how could they stop it from happening again?

So that's a rafter, and then across the rafters are battens that go immediately under the roof sheeting. This is Geoff Borton these days, showing me a model roof at his place. If you've got a nail like this, a nail will be very easily removed or quite easily removed by pulling out of the rafter itself. Instead, what we should be using is screws like this. He gets pretty excited about this stuff.

Jeff's now a senior cyclone engineer and Tracy led him to where he is today, showing me these screws. Something that has since become a critical part of the way we build houses. You see, in early 1975, when Jeff was walking around those quiet streets of Darwin in the weeks after the cyclone...

he noticed something. Essentially, the larger buildings had performed better than the housing stock. There were engineers from all over the world puzzling on this too. How had so many houses failed while the big buildings were still standing? Just three months after Tracy, they had some answers in a major report. Remember the tin roof missiles that Joy had described?

Yeah, it was them. So houses lost their roofs quite early in the cyclone. A huge number of houses lost their roof during Tracy, particularly when something like a window broke and suddenly there was a force pushing up on the roof from the inside.

And that set off this chain reaction. They lose their roofs, they crash into the next row, they lose their roofs, they crash into... You get this snowball of debris. Geoff says it was something they hadn't really considered in the 70s. The housing industry at that stage was viewed as a craft industry. This is the way we build houses.

This is what we have to do to stop the roof from falling in. And not too many builders have paid attention to what do we have to do to stop the roof from blowing away. But the bigger buildings...

They had factored it in. Houses weren't engineered per se, but commercial and government buildings were, and they performed much better. The report made a whole lot of recommendations about how the new Darwin should be rebuilt to avoid another Tracy. For instance, from then on, all buildings in Darwin, including houses, needed to be structurally engineered so that their roof stays on.

even if a window or door is broken. That was a very significant change in the way we build buildings. And there was also changes to the materials used, because a lot of them cracked and broke under the constant strain of the winds. This all might sound like really technical stuff, but actually some of it was really simple, like using screws in your roof. So in the past, everything had been nailed together, and nails you can pull out with a hammer.

and so that they could be pulled out by the wind, whereas screws lock themselves into the timber and are much, much harder to pull out. That kind of detail, a tiny little thing, was really important in holding buildings together. These small changes transformed the new homes in the rebuilt Darwin, but they didn't stop there.

Soon, Queensland took it on. People in Queensland said, yep, we know it happens here too. We've got to start looking at ways of implementing it. And today, 50 years on, every house, even outside of cyclone-prone areas, is built with the lessons of Tracy, thanks to the introduction of the Building Code of Australia in the late 90s. The Building Codes incorporated the lessons of Tracy through something known as wind ratings.

Because it's not just cyclone-prone areas that face strong winds. Things like living on the coast or on a hill or how sheltered your place is, they can all influence the wind speeds your house needs to handle. That wind rating will enable you to pull out windows that are going to be appropriate. All of the details that tie your roof down to be appropriate. The system of roofing that you're going to use that's appropriate for that wind classification. So if I walked down the street in...

South Coast, Western Australia, where I'm from, or in Melbourne, how much of the housing today has the fingerprints of Tracy on it? 100%. Yeah. Every single house that is built benefits from what we have learned in Cyclone Tracy and a whole bunch of other cyclones since. We know these changes have made a huge difference because of what's happened in other cyclones, like Yassi.

Yasi was a massive cyclone in Queensland, even more powerful than Tracy. But Geoff says it didn't cause as much damage. When we look at the data, in terms of houses totally destroyed, instead of it being around 70% as it was in Darwin, it was around 1% or 2%.

In terms of houses that were severely damaged, instead of being 90%, it's now around 7%. In 50 years, we've learned a lot. We're still learning as time goes by. But we have made an improvement. When it comes to a weather event that's changed Australia, there are a few people that I've spoken to who don't mention Tracy as number one. The changes to Australia's housing were a big part of that. And, of course...

The monumental change it made to the people who faced it. For Geoff... Cyclone Tracy did upset me a lot. It was quite some time before I could hear a Christmas carol without tearing up. But it also gave me a fire in my belly to improve things for buildings. And for Joy, it motivated her to start afresh. She went on to work across the public service and in Indigenous organisations...

She also got really into footy umpiring and was the first woman to umpire an Australian Rules football game. Tracy will never be forgotten for the people that lived here that night. It will never leave us. It will never leave us, Cyclone Tracy. She was a B-I-T-C-H, a big one. She played a big part, Tracy, in making me look what my life would be because we had nothing. It was like a little baby. We were just born again. What are you going to do with your life now?

Your life is in your own hands. Want more of the weather that changed us? You can listen to all the episodes right now on the ABC Listen app. And that's all from Science Extra. I'm Belinda Smith and thanks for joining me as we recap the year in science. Have a fabulous day.

Hollywood, it's all glitz and glamour and crazy headlines. But when it comes to the natural world, how accurate are the movies? Are father-son connections universal, like in The Lion King? Should groundhogs really be predicting anything? I mean, they sleep for eight months of the year. I'm Anne Jones and I'm going to break down Hollywood myths and tell you what they got right and what they lied about in my new series, Hollywood Lied To Us. On Radio National...

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