Titans of Science: Jocelyn Bell Burnell

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0:54BBC Sounds, music, radio, podcasts. Hello, welcome to 5 Live Science. I'm Chris Smith from The Naked Scientist. Coming up, we ask leading experts in the fields of health, AI, space, marine science and archaeology for their standout moments that defined 2024. And a bit later on, Titans of Science returns with the woman that discovered pulsars and inspired some iconic album art along the way. It's astrophysicist Jocelyn Bell Burnell.

1:25The Naked Scientist on 5 Live. And we start this week with health and epidemiology. With 2024 drawing to a close, parliamentarians in the UK voted on a landmark bill that would allow some terminally ill adults to end their own lives. It was said by some to be one of the most significant and sensitive topics to have been voted on by British MPs in recent decades. But what will it mean? And what still needs to happen if this bill is going to pass into law? Well, I've been speaking to Linda Bald,

1:56who's Professor of Public Health at the University of Edinburgh. This is an important bill. It's the terminally ill adults end of life bill. And what it would do is make it legal for over 18s who are terminally ill to be given assistance to end their own life. The reason it's important is because many countries around the world have looked at their ageing populations, of course, and recognised that people who are nearer the end of life really should have more opportunities to think about how they die, particularly people who are terminally ill and are experiencing a lot of suffering.

2:28So the bill just generally will be obviously for adults. They have to live in England and Wales, so it's the England and Wales bill. They have to have the mental capacity to make the choice and to have that to be a settled and informed wish. And they actually have to make two separate declarations that are signed and witnessed. And then independent doctors have to be satisfied that the person is eligible. And the bit that's tricky and really hasn't been worked through and is different from other countries is a high court judge will be involved.

3:00They have to hear from at least one of the doctors and can also speak to the dying person or anyone else they consider appropriate. So it's really a physician-assisted suicide and it could be a very important piece of legislation if it's passed. What has actually happened in parliamentary terms though? Because there was a big vote and it passed through, but what does that actually mean in practical terms? They've had this first reading of it. Does anything actually change at this stage? No, it doesn't change at this stage. What happens now is it goes through the parliamentary process.

3:31I think what's interesting about this is MPs are given a free vote. So normally for a new piece of legislation at first reading, MPs would vote with their party and they'd be whipped to do so, which I always think is a tricky term, but that's the ancient term that we use. So a free vote. And then what happens is it will go to committee. So there's a series of committee stages and there'll be further readings of the bill in the House of Commons, but also in the House of Lords. So we can't assume that this bill will become an act. It may not pass because what happens is

4:02through those stages amendments can be introduced or people might change their mind. In other countries where they do have equivalent legislation, I'm thinking Canada as one example, how has it gone down and been received? And how does that compare with what is being proposed for the UK or rather England and Wales at this stage? One piece of evidence I read suggests that over 200 million people have accessed a similar legislation. The first country to do this was Switzerland in 1942.

4:32Canada is an important example and so are many of the US states. They are different though just in terms of how they operate their systems. So there's assisted dying and that means that the person who's terminally ill receives the drugs from a doctor and then they administer it themselves. So the person administers it. Assisted suicide is where you help somebody end their life. And euthanasia is the act of deliberately ending a person's life to relieve suffering. But assisted dying is what we're looking at here.

5:02And so other countries have this as well. Oregon actually is probably the most useful example, Chris, because it's part of the US, the first part of the US to do this, I think from around 1997. And it's kept their legislation really quite similar throughout that period. And what they do in Oregon is actually quite similar to what's going to be in place in the UK. In relation to other countries, there are differences. So the groups that can be included, I think Netherlands and Belgium have some of the most expansive legislation.

5:36So children even are included in that under very specific circumstances. Some countries include people who are not going to die in the next six months but are experiencing unbearable suffering. So there's different versions of it. But I think what we're seeing internationally is a movement to consider a dignity in death really, which is what this is all about. Would you regard 2024 then as a watershed moment for this? It is a watershed moment because it's the first time that the UK Parliament has voted in favour of it.

6:08I mean, in my area of research in public health, which often involves legislation on a range of issues, when you see a bill pass the first reading, even if it doesn't get through in that period, it means it will come back in future years. So I think it's a watershed moment. And in Scotland, where I'm based, we would have separate legislation. But we've also seen a similar pattern of two bites of the cherry, so two previous rounds of legislation not passed, but the one that's coming before the Scottish Parliament now and will be coming forward next year.

6:39We'll see whether our MSPs vote in favour, as has occurred in England. Linda Bald with her healthful look at 2024. Well, it's also been another bumper year for artificial intelligence. In fact, AI pioneers scooped Nobel Prizes this year. It's also only two years since the launch of ChatGPT, which was probably the first insight most members of the general public got into how far and how fast this field has progressed. So where are we now? Who are the major players when it comes to AI? And what have been the standout moments of this discipline in the last year?

7:12Well, this time last year, he was gearing up to give the Royal Institution Christmas lectures on this very topic. So who better to ask than the University of Oxford's Mike Waldridge? So I think the first thing we've seen is that the debate, I think, has calmed down a little bit. People have used these tools, they've experienced them, they've got to know a little bit about what they're good at and what they're not good at. And I think, you know, the initial, oh my goodness, we're on the edge of, you know, the end of AI, that kind of feeling has sort of died down a little bit.

7:44So that actually, I think, is a huge relief. We've still had AI on the front pages very, very regularly, but not quite in the same slightly hysterical tones. If I look back, what else do I see? Well, one remarkable thing throughout the year has been the rise of NVIDIA. So NVIDIA's core technology is graphics processing units, GPUs. Now, GPUs were invented so that teenagers could have realistic renditions of explosions in whatever computer game they were playing.

8:17That's what they're for. They're doing for processing graphics. But around about 2012, it was realized that exactly that technology was ideal for training neural networks, neural networks being the core technology underneath all of modern AI. And by using GPUs, you got 10 times more bang for your buck than you did using conventional CPUs. The CPUs, the central processing units that you have on a regular computer.

8:48Now, when that happened in 2012, we saw the progress in AI start to accelerate very quickly because we were getting 10 times more computer power available for the same amount of money. NVIDIA are definitely the winners here because they are selling those shovels in this gold rush. But everyone else appears to be just peppering the world with AI. What appears to be in a desperate hope that they'll hit the golden nugget of this is the killer function or the killer app or whatever.

9:18Is the bubble going to burst on this at some point? Because this is expensive, isn't it? The amount they must be investing in doing this. It must be bank balance breaking. To be blunt, I don't think anybody really knows what's going to take off. But the hope is if you put this everywhere, that you'll manage to land on the one that ends up winning. Another recent example is Apple Intelligence. And this is Apple's foray into generative AI. And it's exactly this model where they're embedding large language model technology in particular

9:49across all of their products into their email and sending text messages and their notes apps and all of that in the hope that it takes off. There is no guarantee that it will take off. If we go back to the 1990s, I don't know if you remember Clippy. And I don't know if you remember how you felt about Clippy. Clippy was Microsoft's attempt to embed AI in the 1990s. That annoying paper clip that kept popping up. The annoying paper clip. It looks like you're trying to compose a letter. Let me help. And then it would screw up all the settings.

10:20And it took half an hour to unpick all the damage it did. And then you wrote your letter and wished you'd never touched it. Yeah. Yeah, I remember Clippy. So Clippy was Microsoft's 1990s attempt to embed AI in their product suite. And it didn't just fail. It attracted ridicule. It rapidly became an embarrassment and was very, very quickly dropped. But actually, what we're seeing at the moment is not very different from Clippy. It's much more sophisticated technology. Unimaginably more sophisticated technology.

10:52But the mode of using it as a kind of an assistant that helps you do things is very, very similar. So it may well be that people just don't pick up this technology. But, yeah, what we're seeing is this just rush to put AI, generative AI everywhere in the hope that companies land on the killer app. And then how do they monetize it? How do they how do they get this recoup these incredible returns on investment? Whatever happens, please do not bring back that paper clip.

11:23That was Oxford University's AI guru, Mike Woodridge. 2024 has been a stellar year in the field of astronomy. The James Webb Space Telescope has discovered atmospheres on planets light years away. And the Euclid mission has begun to unravel some of the secrets of dark matter. But down here on Earth, much of the buzz around space has been about our planned return to the moon, which keeps, regrettably, being delayed. But space scientist and author David Whitehouse has been keeping a close eye on this aspect of the space race over the last year.

11:55Well, I think it's got to be Elon Musk and the latest test or one of the latest tests of his Starship and his super heavy booster. It's more powerful than anything's been been launched before. It's taller. It's relatively simple in terms of what it does. But it's done some spectacular things. One of the greatest, most watched space missions of recent years was when the Starship went into orbit and then flew around the world and came down in the Pacific, not far from Australia.

12:32But the super heavy booster that took it on the first few minutes of its flight and provided most of its thrust to get into orbit was actually returning to the launch pad and was captured by these two arms called chopsticks. And this was the very first attempt to do that. And I don't think anybody expected it to work, but it was absolutely spectacular. And it shows the difference in momentum and achievement between SpaceX and, say, NASA, in the sense that SpaceX flies more frequently.

13:06It is learning faster. It's prepared to fail. But when it fails, it learns from that and progresses. And that's why Elon Musk has become the centerpiece of going back to the moon. But also he has captured with his Falcon rockets the majority of the market to take satellites into space and has the only working capsule that can take astronauts to and from the space station. So this year, next year, and probably years to come, it's all about Elon Musk and what he does.

13:40You mentioned NASA. Of course, we should have seen NASA astronauts back heading to the moon in this year, shouldn't we? That's been put back. Any update on that? Well, yes. Alongside Elon Musk's success, he has a role in the return to the moon. And we should have seen in December this year, astronauts on Artemis 2 mission fly around the moon, testing out the Orion capsule and the space launch system.

14:14But that has been put back at least a year because of problems with the heat shield with the Orion capsule. And it's somehow, when put against Elon's success, showing that the Artemis plan to go to the moon is now beginning to look complicated, very expensive, difficult to bring together and delayed. And so it seems to be going into the territory that scuppered all the previous attempts to put people back to the moon.

14:46And I think that one of Elon's goals, particularly since he's now so close to the incoming administration, will be to try and rationalize that and to try and, well, with his role in the Department of Government Efficiency, to save money. But I think it's part of saving a lot of money, he could actually bring SpaceX and NASA closer together. And we may see a big redesign of going back to the moon. It's quite a serious conflict of interest, though, isn't it?

15:16Because you've got this person who is very successful in that respect, commercially, and in forays into space, at the same time is going to command quite a lot of control and quite a lot of power. And command quite a lot of influence in Washington, in the administration, and therefore in what they decide to do. So is anyone kind of concerned about that or the fact that we have one person holding all the cards like this? Yes. Elon Musk seems to have moved himself through his political interest this year and his backing of President Trump into a center position for many things, including space.

16:00It was discussed on the grapevine that Elon Musk might even become the director, the administrator of NASA. But that presumably would have been too much of a conflict of interest. Having said that, it is traditional for the administrator of NASA to offer his resignation to a new administration in January for the president to decide who may want to replace him. So who knows? Space scientist and author David Whitehouse there. When I return to the marine realm and ask, with the effects of climate change ramping up around the world and an increasing number of species being added to the endangered list, which stories really are making waves?

16:39Will Tingle has been speaking with marine science communicator from the Out of Our Bubble podcast, Liberty Denman. Well, it's so hard to pick one thing in a space that moves so quickly and yet so slowly on a political front. So I'm actually not just going to pick one thing. I'm going to pick two, give you a bit of good news, a bit of bad news. I say that the bad isn't even that bad news. It's just interesting. The IUCN have actually released an updated report on the global status of Alaska Brank, so your sharks, rays, chimeras, which followed on from their last one in 2005. So it's been a nice 20 year waiting period of excitement to see what's changed.

17:13And then a bit of really good news is actually the Azores have declared the largest marine protected area in the North Atlantic. It will be Europe's most extensive MPA with their network covering 287,000 square kilometres, which has to be good news, I think. In terms of the sharks, IUCN thing, as you said, that seems an extraordinarily long time in order to get a report out. Why has it taken two and a half decades for us to get meaningful information? I think when you're covering off about 500 species of sharks, then you've got to consider all your rays as well.

17:46That's a lot of information to cover off a lot of species all around the world. It's a big task. So I feel that's always going to take a long period of time. And also when you're assessing change, when things politically take a long time to change. And also just to understand how populations are changing again, with long lived species, these things take a long time to occur. So I think when you're mapping that out, it takes a really long time for these things to be assessed properly. So that's probably why it's taken the 20 years or so. But it does have some good news, got some bad news.

18:18I tend to eat my veggies first. So what's the bad news? So unfortunately, this group of species, so the elasmobranchs, your sharks raising chimeras, are of the most threatened vertebrates on the planet. So about a third of elasmobranchs are in a threatened or worse status on the IUCN Red List of Endangered Species, primarily due to overfishing, which is really evident in the reported demand for shark meat that has actually increased almost twofold, as well as also seeing a diversification in products that we're seeing.

18:50So there's also gill plates, liver oil, skins on top of the sort of the standard meat and fins, if you will. And that can be quite an alarming thing, I think, to look at. Obviously, it's a multifaceted issue. It's also not just overfishing. You've got your climate change, your pollution, all of these other elements to it. But the report does also outline some huge strides where we are making improvements, especially since 2005. So what we are seeing is a huge increase in information and also a diversity of researchers that it's coming from.

19:22So to see that starting to shift is really, really exciting. And also some of the big improvements are that knowledge bases across places in Asia, Africa, Central America, the Caribbean, where there are these really, really exciting populations and such a huge, diverse range of species that we're seeing there. So to be able to see that increase in focus on collaboration and also collaboration with industry to overcome these issues, working with everything from small scale fishers up to that kind of large scale offshore work is really exciting to see.

19:52And those things are outlined in there. So it's not all bad. It's mixed reviews, I think. And the good news sounds like it continues with this MPA in the Azores. It absolutely does. Some of you may be aware of the 30 by 30 target that's trying to protect 30 percent of the ocean by 2030. The Azorean Sea actually covers about 55 percent of the Portuguese economic exclusive zone, and that makes up about 15 percent of the total EU waters. So the regional government moving to protect this is an incredible feat. And what I think we're really looking for now is that kind of total protection,

20:25really limiting extractive activities, whether that is mining, fishing, even the recreational side of things as well, anything that could impact the biodiversity there. So what will now be critical is the kind of how that is managed and ensuring that that community buy in from all of the different communities that are around the Azores. But it sounds like something that has been incredibly successful so far with the network that already has been existing historically. And to see that shifting is really positive to actually see some targets being hit, because I think it can be quite depressing sometimes to look at all of the things which we've spoken about,

21:00but not necessarily delivered on. So to see them actually delivering on this is really, really exciting. Liberty Denman there speaking to Will Tingle. Now, finally, it's been a big year for the study of where we all came from, paleoanthropology. And I went to see Cambridge University anthropologist Emma Pomeroy. Yeah, I mean, I was really spoilt for choice, really, with picking some studies. But this one was quite an important one, looking at cave art from Sulawesi and trying to redate it. I mean, cave art is notoriously difficult to date. And essentially you have to date the layers of calcium carbonate that form over the top of it.

21:35And they've done this with some beautiful panels from two different sites and dated them to over 50,000 years, which is really quite remarkable. I mean, we probably think of a lot of cave art as being European, but this is showing some of the oldest that we have is actually from Southeast Asia. And we have representations of animals and kind of panels and scenes that perhaps suggest there's some kind of narrative behind the work. What does that tell us then about what we think was happening to anatomically modern humans

22:08in terms of how we were evolving, thought processes, society and so on? Because we can get a lot out of what people were doing and drawing, presumably, in terms of those deductions. Yes, especially with this kind of art where they are representing sort of figures and animals. There's a real suggestion of narrative and storytelling. And this is something that we think is probably really important in human evolution and in the evolution of Homo sapiens, our own species, and really recent human evolution

22:40as a way of sort of bonding groups together, but also passing on knowledge. And the fact that it comes from Southeast Asia is really exciting as well because a lot of people, so up till about 20 years ago, assumed these figurative arts panels were really something European and associated with what we call the European Upper Paleolithic, which is sort of the kind of stone tools that the earliest modern humans were making. So very exciting to have this from so far away from what many have considered to be the heartland of this kind of art.

23:16What does this do to our understanding of our out-of-Africa origins? Because certainly when I first started learning about paleoanthropology and so on, people were very fixed on the idea that about 50,000 years ago, that's when we began to leave Africa and go around the world. Well, if we've got this kind of level of detailed art already established so far from Africa, that must put the kibosh on that story a bit then. So we still have dates for around, say, 50,000 years for dispersals of modern humans into Europe,

23:48but actually the dates that come from Southeast Asia, parts of China, very famously Australia as well, tend to be in this earlier period of, you know, 60,000 or even earlier. The other thing that you've picked on is another paper, which this fascinated me as the sort of doctor and infectious diseases person that I am. You've got this paper on tooth enamel and using that to work out what a person's immune system was doing and therefore what sorts of things they might have been succumbing to or diseases they may have been fighting off.

24:21Yes, this was a really fascinating paper coming from a team led by Tammy Buonocera and colleagues from the University of California at Davis. And they focused on the remains of indigenous people from a site in California dating to the late 18th century. Basically, they looked at the tooth enamel. And sometimes we do this quite often today to try and tell the sex of the people. But they also looked for signs of immune proteins, such as immunoglobulin G and something called C-reactive protein.

24:57And these are signs of inflammation, so a stress response happening in the body. Why would those things be in the tooth enamel? Because they're in the serum, so circulating in the blood. And then while the tooth is forming, they are also captured in the enamel. And what's really interesting about tooth enamel, unlike the rest of the skeleton, which sort of gets replaced periodically over the years, tooth enamel doesn't. So it kind of captures a snapshot about the individual at the time they're forming those teeth,

25:27so during their childhood. This presumably gives us an insight into the kinds of things those people might have been succumbing to or the disease burden, really, at that point in their life. Absolutely. So they don't have quite the same simple pattern as tree rings do. But you're right. It's kind of incremental structures, so structures that are forming bit by bit. And so these results are showing us something about the lived experience of those people. And quite surprisingly, so interestingly, they were able to show by comparing the remains of

25:59indigenous people in the 18th century with those of European descendants from the same kind of area, and also more recent kind of donated teeth, that those from the indigenous communities were suffering much higher levels of physiological stress. So they were finding more of these immunoglobulins and more C-reactive proteins, which was suggesting that they've perhaps got a higher disease burden or higher levels of other stressors. And this is really exciting because it's suggesting that we can have another window

26:32onto understanding how people's lives were and the kind of experiences they had. Emma Pomeroy. Well, now it's time for the news and sports. But after that, our Titans of Science series returns and kicks off with the woman that discovered pulsars. That was the astrophysicist, Jocelyn Bell. Becky Hilliard turned Sella Jane from a blog into a multi-million dollar brand. And she did it by betting on herself before anyone else did. This conversation on Share the Lifestyle podcast is for anyone who knows they're capable of more.

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27:57Bunnell. Welcome back to 5 Live Science with me, Chris Smith. And today, our winter series of Titans of Science kicks off with Jocelyn Bell Bunnell, the astrophysicist who discovered radio pulsars during her time at Cambridge. Jocelyn Bell Bunnell, a dame Jocelyn Bell Bunnell, more accurately, isn't it, was born on the 15th of July 1943 in Lurgan County, Armagh. She attended Lurgan College and then Mount School, which was a Quaker girls' boarding school in York, and then went to read natural sciences at the University of Glasgow.

28:29Jocelyn began her postgraduate studies in Cambridge in the late 1960s, where at the age of just 24, she discovered the phenomenon of pulsars. These are celestial entities that emit bursts of radio waves and other forms of electromagnetic radiation. And those findings led to a Nobel Prize, although not for her, and also inspired a famous Joy Division album cover. One of the best-known record covers, apart from Pink Floyd, possibly, with Dark Side of the Moon, ever. And since then, Jocelyn served as President of the Royal Astronomical Society, President of the Institute of Physics.

29:01She was the Chancellor of the University of Dundee. And in 2021, she was awarded the Royal Society's prestigious Copley Medal, which is given annually for sustained, outstanding achievements in any field of science. And I'm very delighted to say she is with me today in Cambridge. Hello, Jocelyn. Hello. Good to be with you. You're back here in Cambridge. This is where it really sort of started in a big way for you, isn't it? What was it like doing radio astronomy? Very masculine, shall we say. And considerable anxiety amongst the female dons, the female academics, that if we, the female students, didn't behave,

29:40there was a risk that the men would say, huh, trust a woman. No more women in Cambridge. What about the science, though? What was the situation with the topic you had chosen to study and why did you go into it? I became interested in astronomy as a teenager. I was good at science at school, especially physics. There was a glitch when it suddenly dawned on me, you do astronomy at night. And I like my bed. I like my sleep. And then I got to hear of astronomy at other wavelengths where the sun doesn't interfere in the same way.

30:14And in particular, radio astronomy, which you can do day and night. So from my mid-teens, I was saying I want to be a radio astronomer. Just tell us about that, because it's not obvious to many people that you can do astronomy with forms of light that are not the forms we can see, that normally you would observe as a colour. So tell us how that works. Our eyes are actually extremely limited. We see a very narrow range of wavelengths or frequencies. There's things like ultraviolet and infrared that we don't see.

30:46And if you go even further away from the bits we see, you find radio astronomy out the red end of the spectrum. And if you go out the blue end, violet end of the spectrum, you come to ultraviolet, X-ray, gamma ray. So there are many other kinds of radiations like light. Indeed, strictly speaking, light is a minority of all the possible radiations. But because it's what we're attuned to work with, we think it's a big thing. What does it unlock looking with those other wavelengths or colours of light we can't see that we can't see with visible light?

31:20Well, visible light can be blocked quite easily. Dust, for instance, will cut out visible light. You may have seen on foggy days how limited the sunlight is. So if we're able to study the universe in all these other wavelengths, then if that about 10% that is light is blocked for some reason, we've still got some chance of studying those objects. And how advanced was that field in the 1960s when you came here to do your studies, your postgraduate studies, your PhD? How far ahead were we?

31:52What was our kind of understanding of what the universe looked like in those realms at that time? Radio astronomy had started post-World War II. Indeed, there is a story that the Japanese were puzzled during the war, were puzzled by something that was blocking the radar. It was low in the east in the morning, high in the south in the middle of the day and low in the west in the evening. It was actually the sun. The sun, when it's got lots of sunspots, can give out radio waves, which could block the Japanese radar. But post-World War II, radio astronomy really took off.

32:25Studying the radio waves, not just from the sun, but from lots of other stars and galaxies and quasars and molecules in space and all sorts of things it's developed into. You joined the laboratory of Anthony Hewish. He was your supervisor, wasn't he? So what problem was he trying to solve and what challenge did he set you for your PhD? There had been a grad student called Margaret Clark, who had left just weeks before I arrived.

32:55Her particular project had been surveying the radio sky, looking at what objects were giving out radio waves. And she noticed that some of the objects that gave out radio waves, the signal wasn't steady. It fluctuated, it changed brightness. She noted that these were the objects that they thought were extremely compact objects. My thesis advisor, Tony Hewish, took over this idea and thought maybe if we look for fluctuating radio sources, they'll turn out to be the very compact ones, which at that stage were suspected all to be quasars.

33:31There weren't many known at that stage. It was a really hot topic. So finding more quasars was my particular project. And what is a quasar? We didn't know what it was at that stage. We now know it's got a massive black hole in its middle, maybe several hundred million times the mass of the sun. And some rather more normal material around the black hole, probably in the process of falling into the black hole. The net result is these objects are very strong radio sources, often quite bright in the optical as well.

34:03But they're known as quasars, which is an abbreviation for quasi-stellar radio source, hence quasar. There was still considerable uncertainty about what quasars actually were. We now know that they're the same kind of mass as a galaxy, 100,000 million stars, much more compact, and with a massive black hole at their centres, which drives lots of things. How were you trying to find them? It's a rather peculiar radio technique. Because they are extremely compact, and because we're viewing them through the gubbins that there is in space between the sun and the planets,

34:38it's called the solar wind, the solar wind means that the signal from these compact objects will fluctuate, twinkle. So basically, I'm looking for twinkling radio sources, which probably are quasars. And how do you actually find them? What's the antenna you have to erect in order to detect these signals? You do it at quite low radio frequencies. The wavelength was about 12 foot, which is quite a big wavelength. You're looking for a twinkling, so you can't take long exposures, which means you need a very, very big telescope to pick up lots of signal,

35:15because you can't average to improve the signal to noise. Right, OK. And what's making that radiation? Where are those signals coming from? We now know that quasars have massive black holes in their centres, and it's stuff around the black hole that generate the primary radio signal. Then as it travels through the space between the sun and the planets to reach us, the solar wind, the gas blowing out from the sun, affects it, alters its strength, so it fluctuates.

35:45So I'm looking for a fluctuating, randomly fluctuating radio signal, which means there's a very compact object out there, and it must be pretty strong if I can see it. You, therefore, start to get this data, having got the detection system working. When did it become apparent to you that there might be something interesting to see? I actually spent the first two years sledgehammering. I built the equipment, along with about half a dozen other people, and it took us two years. With a sledgehammer?

36:17Oh, yeah, yeah, yeah. I literally did a lot of sledgehammering. I could swing a sledgehammer. I was playing field hockey at the time, and I could hit the hockey ball from one end of the pitch to the other, which my teammates never learnt to, you know, start running.

36:33Did suddenly everyone on the hockey team want to be a radio astronomer, because clearly this is the path to greatness on the hockey pitch? It was useful on the hockey pitch, particularly if you're playing full back, because, you know, it shifts the ball to the far end of the pitch, and you and the other full back can stop and have a chat and watch the others doing things at the far end of the pitch. But what were you actually sledgehammering? We were building a radio telescope, and it had to be a very large area radio telescope, because we couldn't do these long exposures. So if you're operating with short exposures, you need large area.

37:07What was really good was the first time we switched it on, it worked, and it's probably the first radio telescope in history to work the first time you switch it on. Normally you switch it on and something's not working, so there's nothing coming in. What was the readout? What was the display then? How were you showing yourself what it was seeing, this telescope? We had pen chart recorders, you know, rolls of paper that rolled under a pen, and the pen did this continuous squiggle along this rolling sheet of paper.

37:39And I ended up with several miles of paper after six months of observing. And is that one of those pictures that Joy Division used as their album cover? Is that one of those charts? It's snippets from several charts taken and lined up. And so when did you then, you say it worked straight away, well, how did you know it was working, but when did you then say, ah, look, there are some interesting signals in here, I am seeing these twinkling phenomena I was going after? The purpose of the exercise was to find more of these quasi-stellar radio sources, and they became very clear as soon as I got the thing on and running.

38:13So that was my main thesis job, and in fact, we couldn't, Tony said, change the title of the thesis. So the majority of the thesis was on these quasars and how they twinkled. The twinkling is actually caused by plasma blowing out from the sun, solar wind it's called, and it's not smooth. It's a wind with clouds in it. And the clouds disrupt the radio signal from the distant quasar and make the quasar appear to change brightness. It's actually not itself changing in brightness.

38:46It's because of the mess made by this solar wind that you pick up a fluctuating signal. Whereas other kinds of radio objects in the sky are much more extended, and you see them through several different bits of the solar wind at the same time, and so the solar wind effect averages out. So it's a neat technique for picking up compact objects like quasars. It's a bit like when you've got the fog lights on on the car, the red, you can see through the fog. It doesn't scatter much, but the white light gets scattered all over the place.

39:17So he's an Irishman. Tyndall, John Tyndall discovered the Tyndall effect. That's exactly that, isn't it? Yeah, that's right. Yes, John Tyndall was Irish, yes. In the days when we didn't distinguish between North and South Ireland. But the thing that you're best known for is what you labelled on one of those charts you had miles of, that you wrote LGM, little green men, as a joke. I mean, it was a joke, wasn't it? But what was that, and why did that stand out to you, that signal? Once you've used the radio telescope for several weeks

39:48and seen all the kinds of phenomena it picks up, you get to say, yep, that's a quasar. Or that's radio interference, that's somebody with a badly suppressed car or a pirate radio station or something like that. There was on occasion another signal that didn't fit in either of those categories. It just looked different. You can explain it in terms of Fourier analysis, but we won't go there, I think, in this. It looked different. And the first few times I logged it with a question mark and carried on

40:20because I've got miles of this paper to plough through. And by the third or fourth time I saw it, my brain said, you've seen something like this before, haven't you? You've seen something like this before from this bit of sky, haven't you? And then it's easy because I'm storing the rolls of paper according to which latitude on the sky I'm observing in shoeboxes. So I find the shoebox that covers that latitude strip. Now, this is the one I've just seen. Wasn't there last time we looked at that bit of sky,

40:50but the two, maybe three times before it was there, and it's from the same bit of sky? What's going on? You probably know you see different constellations in the summer and the winter sky, but this phenomenon wasn't changing with the date. It was keeping its place amongst the constellations, apparently. And I showed this to my thesis advisor and he was quite convinced I'd done something wrong. So there was a famous occasion where he came out to the observatory at the time this thing was due to be passing overhead and watched me set up for the observations

41:24and saw the pulses coming in himself. And he began to take it more seriously then. What did they look like? What were those pulses? And why were they leaping out at you saying, this is not car interference, there's something a bit different here? The thing was going blip, blip, blip, blip, blip, blip. Now, quasars do a certain amount of blipping, but they go blippity-blip, blip, blip, blip, blip, blip, blip, blip, blip, blip, blip. That's the twinkling, isn't it? That's the variation you mentioned. That's right. That's right.

41:54Whereas this thing had a steady beat and it really looked man-made. It looked artificial. And we put a lot of effort into trying to explain it as something artificial. But it moved round the sky with the stars. And this thing, whatever it was, was keeping its place amongst the stars and getting four minutes earlier each day. Did you think for a second, do you think, I found aliens? It was unlikely to be aliens. And that idea disappeared as soon as I found a second

42:25and then a third and a fourth, all in different parts of the sky. Ah, so that would argue that whatever it was that was doing it where you first saw it, that phenomenon was obviously being repeated across the sky in other patches of the universe. And it was then a question of, so what's causing it? Yeah. And the interesting thing was the subsequent ones that I found were similar, but beat, pulsed at a different rate. Each one had its own rate. One of them had a pulse rate of a quarter second.

42:55It was really zinging along. And it was quite hard to catch it. It was going so fast. The other three were all one point something second period. So it was going blip, blip, blip at a reasonable rate. You knew then, once you started seeing these things coming from elsewhere in the sky and also tracking with the stars in the way you are, you knew you had to be onto something. So how did you pursue that then? Because you're in your PhD. There's only a limited amount of time and resource in a PhD. So what did you decide to do?

43:26Well, most of the effort went into establishing that this was real because they were so extraordinary. We couldn't publish and then discover, oh, we forgot to check such and such. And that's what's causing it. So we had to make sure we didn't fall into that trap. So the first job was to ask a colleague and his graduate student. They also had a separate radio telescope, separate receiver on the same site, but separate kit to ask them very quietly,

43:57could you take a look at this particular spot of the sky, please, and tell us what you see? And I vividly remember that particular test. We were working with a grad student called Robin Collins. My telescope saw the thing shortly before Robin's telescope was due to see it, and mine showed it was pulsing nicely. And then we went and stood by Robin's chart recorder and nothing happened. So then what? Well, the two academics started walking down this very long laboratory discussing,

44:28now, what could it be that shows in our radio telescope, not yours? Could it be, no, it can't be that because you're right. What about, no, it can't be that. It's quite a long laboratory. And I was padding along behind them. Robin stayed by his pen recorder. And we've got down the end of this long laboratory and suddenly there's a shriek from Robin. Here it is! And we were charging back up. Robin had miscalculated by five minutes when his telescope would see it. I mean, thank goodness it wasn't 25 minutes or we'd all have gone home.

44:59But that was fantastic. It's not some fiction of my equipment. It's being seen by a separate radio telescope with a separate amplifier and a separate pen recorder. A totally separate system. It's something way beyond the observatory, whatever it is. What did we have in our kind of repertoire of understanding of physics and astrophysics at that time that could account for that? Or was it a complete blank sheet? It had to be something physically very small because it's pulsing quite fast, responding quite fast.

45:32But it's also quite strong, whatever it is. It's got a sizable radio signal. So it's small and it's big. It doesn't quite make sense. We were really very puzzled as to what it was. If you've got something small but it's powerful, that sort of star regime, would that put it into the neutron star kind of regime then? Because you're talking about something incredibly dense, incredibly massive, lots of material in there but very compact. Yes, although we didn't see at that stage how a neutron star could produce blasts of radio waves

46:07or beams of radio waves. It has to be a highly magnetised neutron star spinning quite fast with its magnetic axis offset from the spin axis. So you get a beam coming out of the magnetic poles which then swings around as the star spins. Well, what's wrong with that? Why can't that be the case? Well, nobody'd ever seen anything like that before. They'd never seen LGM either. Well, some people probably thought they had seen LGM but never mind that.

46:37I know what you mean but no one had seen what you saw. And so what was wrong with saying, well, this is what we think it is then? I guess we were still trying to make sure we believed this. An important stage was when I found a second and then a third and a fourth. And the fourth one pulsed much faster. But astronomical objects are big things. How can they go bung, bung, bung, bung, bung, bung, bung at that rate? It doesn't make sense. Yes, but we had to publish.

47:08You couldn't sit on the result any longer. What was the reaction like? So you put this out there and you say, we've got this. We've found more examples of it. Did you speculate in that paper as to what it might be or did you just leave it as a blank canvas? I can't honestly remember without going back. We published the first one first and said we've got some more. So this is not alone. And then the other three followed in another paper a few weeks later. People were quite cross that we wouldn't give them the details of numbers 2, 3 and 4 right away

47:41because they wanted to follow up the observations. But the reaction to the first paper was phenomenal. There are umpteen stories of senior radio astronomers saying to somebody, I know you're scheduled on the telescope tonight. You're not. We're having the telescope to go and observe this fantastic new thing. So a lot of people were jumping on the bandwagon very quickly, very interested. What did it unlock? And how were you able to then pursue that observation to then solve the problem?

48:15I had another three of these that I had discovered. I found the first four and we published numbers 2, 3 and 4 in a subsequent paper. And the fourth one was a good deal faster. So that's obviously going to constrain what kind of object it was. There were various ideas floating around about what they might be. My supervisor, Tony Hewish, had one. When he gave the colloquium announcing the discovery in Cambridge, Fred Hoyle was in the audience. Tony thought it was a type of star called a white dwarf,

48:48which was probably oscillating, breathing in and out and launching shockwaves into the atmosphere with each breath. When he'd finished his colloquium, Fred Hoyle was the first person to speak. And in his best Yorkshire accent, I don't think it's an oscillating white dwarf. I think it's a neutron star. Neutron stars being a good deal smaller and at that stage, talked about by some mad theoreticians, but nobody really believed in them. No one believed neutron stars were real at that time.

49:20They were really rather extreme, but this was the proof that they existed. Well, that argues, well, they exist, but how did you explain the phenomenon that put you onto them in the first place, which was this pulsation? How did you then reconcile the fact we've got this giant ball of neutrons, very compact, very small, very energetic, but it's pulsing? How does that hang together? The pulsing is an observational effect. It's a bit like a lighthouse. The lighthouse beam is steady, but it swings around the sky and you only see it when it's shining in your face.

49:53So you see pulse, pulse, pulse, pulse. And it's the same with these neutron stars or pulsars, as they're now called. There's beams coming out of the north and south poles. And as this swings around, the beam may shine on your radio telescope or it may miss Earth totally. But if it shines on your radio telescope, you see pulse, pulse, pulse, pulse, each revolution. You were lucky it shone on your telescope. What was the reason that the pulse swings around though?

50:23Is that magnetic? The pulse is shaped by the star's magnetic field and the star is spinning. So you can think of a beam coming out of the north and south magnetic poles of this star, a bit like a lighthouse beam. And if the magnetic axis is offset from the spin axis, like it is on Earth, magnetic north is not at true north. Similarly for these stars, the beam is coming out of magnetic north, the star is spinning around true north,

50:54and so the beam cones around the sky. And if Earth happens to lie on that cone, you get a pulse. How on earth did you go forward from this? Because there's sort of one way to start a career is to build up gently. Another is to put a huge rocket under it and explode from the beginning. Was it not difficult then, having done this and seeing this dramatic beginning to your career, to then carry it on at that sort of pace? It was made very difficult by my getting married. I got engaged to be married between discovering Pulsars 2 and 3, I think it was.

51:28And we got married between my submitting my PhD thesis and having the viva. So the examiners didn't know what surname to use. And I married somebody who worked in local government. And the way we operated it was, he'd have a job and I'd get a job at a nearby astronomy place. And then, say after a bit, it's time I moved. And I could see my world falling apart. And he'd start looking at job adverts. And you'd say, if I go to Timbuktu or somewhere,

51:59is there anything astronomical anywhere near that where you might get a job? And that's the way we operated it. He'd go for the job. If he got the job, I'd then write a begging letter to the nearest astronomy place. And so I left radio astronomy and went to work in gamma ray astronomy, which is the other end of the spectrum. Not many gamma rays around. And then we moved again and I migrated to x-ray astronomy. And then we moved again and I migrated to millimetre and infrared astronomy.

52:30Absolutely crazy career. I don't think it even deserves the word career. And next time, Titans continues with the man that harnessed Google DeepMind's AI capabilities to understand how proteins form, why they have the shape they do, and even how we can design new ones that nature hasn't even thought of yet. That's the Nobel Prize winning biochemist, David Baker. And if you'd like to join in the conversation in the meantime, do please get in touch and drop us a line to 5lifescience at bbc.co.uk.

53:01In the meantime, from me, Chris Smith, and from all of us here at the Naked Scientist team, thanks for listening and goodbye. Every morning, Rick and I wake up with you on 5 Live Breakfast. 5 Live Breakfast with us two? I am doing a lot of chucking out. I'm even considering getting a skip. I've had the amount of fucking out. Anyway. You can't sort of mobile skip, just use that. That is true. 5 Live Breakfast. With Rachel Burden and Rick Edwards. Things to be proud of in the UK. Alan in Cookham says, queuing, we are excellent at this. Disciplined, orderly, unquestioning. We will sit in traffic jams for ages,

53:32without even tooting. Wow. Then he also says, maybe that's because we're not moving on a road. We're being physically assaulted by potholes. 5 Live Breakfast. It's weekdays from 6 on BBC Sounds. 6 Live Breakfast.