Science Friday - Big Bang Debate History, Black Hole Sounds, Maggot Healthcare, Forest Lichens. July 8, 2022, Part 2

Episode Date: July 8, 2022

A Debate Over How The Universe Began Even though it’s commonly accepted today, the Big Bang theory was not always the universally accepted scientific explanation for how our universe began. In fact, the term ‘Big Bang’ was coined by a prominent physicist in 1949 to mock the idea. In the middle of the 20th century, researchers in the field of cosmology had two warring theories. The one we would come to call the Big Bang suggested the universe expanded rapidly from a primordial, hot, and ultra-dense cosmos. Conversely, the so-called ‘Steady State’ theory held that the universe, at any given point in time, looked roughly the same. The story of how the Big Bang became the accepted theory of physics is also a story of two men. One, Fred Hoyle, was a steady state supporter who thought the universe would last forever. Meanwhile, George Gamow, the major public advocate of the Big Bang, begged to differ. They debated in the pages of Scientific American and in competing popular books, as both dedicated scientists and earnest popularizers of their field. And while Gamow ended up winning the debate, for the most part, the two men managed to come together in one way: They accidentally explained the origins of every element of matter by being part right, and part wrong. The truth, it turned out, would lie in the middle. Ira talks to physicist and science historian Paul Halpern about this story, detailed in his book, Flashes of Creation: George Gamow, Fred Hoyle, and the Great Big Bang Debate.   The World According To Sound: Listening To Black Holes Collide In this piece, you can actually listen to gravitational waves, the ripples in spacetime made by the tremendous mass of colliding black holes. It is possible to hear them, because their wavelengths have been shifted all the way into the human range of hearing by MIT professor Scott Hughes. Drawn together by their immense gravity, nearby black holes will swirl faster and faster until they are finally absorbed completely into one another. When the pitch rises, it means the force of gravity is increasing as the black holes collide. Not all black holes come together at the same rate or release the same amount of gravitational waves, so each combining pair has its own particular sonic signature. Some black holes collide quickly. Others slowly merge. Some produce relatively high pitches, because of the intensity of the gravitational waves, while others have a low bass rumbling. Some even make the sound of a wobbling top as the two black holes swirl around each other, before eventually meeting and becoming totally absorbed into one another.   A Maggot Revolution In Modern Medicine In a bloody battle during World War I, two wounded soldiers were stranded on the battlefield in France, hidden and overlooked under some brush. Suffering femur fractures and flesh wounds around their scrotum and abdomen, they lay abandoned without water, food, or shelter for a whole week. At the time, outcomes for these kinds of wounds were poor: Patients with compound femur fractures had a 75 to 80% mortality rate. By the time the soldiers were rescued and brought to a hospital base, orthopedic surgeon William Baer expected their wounds to be festering, and their conditions fatal. But much to his surprise, neither showed any signs of fever, septicaemia, or blood poisoning.   Read more at sciencefriday.com.   Trying To Determine Forest Health? Look To The Lichens There aren’t very many old-growth forest left in North America. And while it would be wonderful to be able to preserve all of them, resources to protect those forest patches are also in limited supply. So if you’re forced to choose between two areas of old-growth forest, how do you prioritize which of these islands of biodiversity to focus on? One of the standard ways to identify significant patches of forest is to look at the size of the trees. But new work published this week in the journal Frontiers in Ecology and the Environment suggests that examining the lichens in a forest plot may give a better picture of the ecological health of an area. Because lichens feed from the air flowing over them, they’re quite sensitive to changes in moisture, nutrients, and pollution, and need long, continuous periods undisturbed. Troy McMullin, a research scientist in lichenology at the Canadian Museum of Nature in Ottawa, Ontario, joins Ira to talk about the stories lichens can tell about the forest ecosystem.   Transcripts are available on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Ira Flato. Believe it or not, even though it's commonly accepted today, the Big Bang theory was not always the universally accepted scientific explanation for how our universe began. In fact, the term Big Bang was coined by a prominent physicist to mock the idea. Here's some background. In the middle of the 20th century, researchers in the field of cosmology had two warring theories, two opposing theories. One we would come to call the Big Bang, where the universe expanded rapidly from a primordial hot, ultra-dense cosmos, versus the so-called steady-state theory, where the universe at any given point in time would look roughly the same. The story of how the Big Bang became the accepted theory is also a story of two men. One, Fred Hoyle,

as steady state supporter, who thought the universe would last forever. And he was a story. And, George Gamov, the major public advocate of the Big Bang, who begged to differ. They debated in the pages of Scientific American in competing popular books. In fact, Gamov's Mr. Tompkin series was my favorite book for understanding relativity as a child. And he turned out to be right for the most part, and Hoyle, despite his many other achievements, is remembered not for his stellar work as a dynamic scientist, but for giving the theory the derisive but popular name, Big Bang. As always, there is much more to the story. And here to take us back in time is Dr. Paul Halpern,

Professor of Physics at the University of the Sciences and author of a new book, Flashes of Creation, George Gamov, Fred Hoyle, and the Great Big Bang Debate. He joins us from Philadelphia. Welcome to the program, Paul. Thank you so much for having me on Science Friday. Nice to have you. First, let's set the scene of what we knew about the universe at the time these two men was supporting opposing theories? Why was the origin of the universe in question at all at that time? Well, the origin of the universe scientifically was first examined by Albert Einstein when he developed his general theory of relativity back in 1915. And Einstein found that his theory produced a rather strange solution that would expand over time. And at first he thought the solution was a big

mistake. But then later after Edwin Hubble and others mapped out the behavior of galaxies in the universe and saw that all the galaxies except the nearby ones were actually moving away from us faster and faster, that meant that the universe was expanding. And Albert Einstein realized that the universe was growing after all. It was a dynamic cosmos. So then people such as George Lamatra, who was a Belgian priest and astronomer, speculated that the universe came from something called a primeval atom or something that included all the matter in the cosmos, and that it expanded many, many billions of years ago and formed the present-day universe. And then people start to think, well, are there alternatives to the idea of the universe expanding?

And one motivation for that was when they used Hubble's data to try to estimate the age of the universe, they came up with two billion years or three billion years, much less than the age of Earth or the age of stars. So there seemed to be a blatant contradiction between the data they found and the present-day knowledge of the universe, the fact that the universe must have had existed before stars were produced. And that's when Fred Hoyle came up with the idea of the steady-state universe. universe, which expands, but new matter fills in the gaps, so it lasts forever.

And why was Fred Hoyle so sure that he was right that the universe was in this steady state? Well, Fred Hoyle was a very instinctive scientist, and he actually came up with the idea of steady state, along with two other scientists, Herman Bondi and Tommy Gold. After seeing a movie, it was a horror movie called The Dead of Night. And that film has a plot in which the beginning of the film and the end of the film are pretty much the same. Somebody goes to a house and realizes that he experienced the house in his nightmares, later wakes up and the whole thing turns out to be a nightmare. But then he's invited to the same house again, and everything happens over and over again in the film.

And after seeing that film, they went to Herman Bondi's apartment, and Tommy Gold said, well, what if the universe is like that? So they put their minds together, and Fred Hoyle came up with the idea of continuous creation, that small amounts of matter would pop up in the universe very, very slowly over time, and that matter would eventually form stars and galaxies and repopulate the areas where older galaxies move away from. And Hoyle thought that was a much more satisfactory idea of explaining the universe than the Big Bang, because instead of having all the matter created at once, which he derided when he coined the term the Big Bang, he thought that it made more sense to think of matter coming in so slowly that it was undetectable,

and therefore science would not be defied. I have to take a sidetrack here and ask you, if you think it's unusual in your experience as a physicist and a scientist to find that inspiration comes from a science fiction horror movie. It is unusual, but it's a rather delightful story, and who knows they might have been thinking about that in other ways, but looking back, they attributed their discovery to the movie, but people get inspiration in so many ways. There's a story about Leo Zillard thinking about the chain reaction by reading a science fiction story by H.G. Wells and coming up with the idea. So people are sometimes inspired by science fiction. Wow, that's a great story. And Gamov, where did the idea for the

Big Bang come from? Well, Gamov took up the idea from others. He was a student of somebody named Alexander Friedman, who developed one of the first solutions to Einstein's equations. And like Einstein's original solution, Freeman saw that general relativity can lead to an expansion of the universe. And Freeman did not shy away from that hypothesis, even though there was no real evidence for it at that time. And Gamov was in Freeman's class at the University of Leningrad. And Gamov was inspired by Freeman. And later, when he developed ideas in nuclear physics, start to think about developing, a theory about how all the elements are created. So we decided to combine the idea of nuclear fusion

and the idea of the hot early universe and come up with a theory that all the elements in the universe are created at the fiery beginning, which later became known as the Big Bang. And Fred Hoyle coined the term on a BBC TV show, is that correct? It was a BBC radio show that Fred Hoyle was invited on to to talk about his own ideas. And at that time, he wasn't really so much aware of Gamov's theories, which were pretty new, but he was aware of Lamatra's ideas and other ideas of the expanding universe. So he said, well, there's steady state, and then there's an alternative, which he called the Big Bang. And he used that to kind of say, well, isn't it kind of silly to think about the idea of all the

matter being created in a colossal explosion? And explosions were pretty much on people's minds at the time because it was only a couple of years after the first atomic bomb blasts. And people really didn't like the idea of explosions. So it kind of derided the theory of people started associating it with explosions and bombs. You know, this idea that you just said, the idea that Fred Hoyle would go on the BBC radio and talk about it in public, this was not unusual for him or George Gamov, correct? They used the popular media to get their points across. They They didn't just argue in scientific papers but wrote popular science books and even science fiction. Did their ideas about the universe translate easily for the public?

Well, I think that's one remarkable thing about both Hoyle and Gamov. It's because both of them were not only excellent scientists and arguably each of them could have won the Nobel Prize, but each of them was also an award-winning popularizer. They both won prizes for their popularizations, and they both loved Hollywood. Gamov loved westerns, and Hoyle grew up watching movies because his mother played the piano in a cinema for silent movies. She was the accompanies for these movies. So Hoyle grew up watching movies, and they both have a cinematic sense of how to convey science in a very evocative way.

I was very interested in your statement in your book that says the epoch of scientists popularizing their own work for good or bad had commenced. No longer would theories be hidden in the pages of scholarly books and journals. This was a turning point, do you think? Yes. Well, the turning point came about because of new media. So first radio and then television, when people got early televisions in the 1950s, a lot of the reason they bought it is to see Milton Burrow, and comedy shows. But then, let's say they wanted an alternative. They might turn to a different channel,

and other stations would need material to fill the airwaves. So they would recruit scientists, such as George Gamov, to talk about their theories, and that became the first science popularization on television. Of course, there was also the advent of paperback books. You mentioned in Mr. Tompkins series. In the 1950s, people started buying, buying paperbacks, which are very inexpensive, and reading about scientific ideas and debating

about them. I still have my original copy of Mr. Tompkins from back then. You mentioned that for good or bad. What do you mean for good or bad as science popularizers? Well, sometimes valid scientific ideas would be overlooked in favor of something that was more marketable to the media. And a good example of that is that Albert Einstein in his later years developed all sorts of theories of everything, which were not experimentally proven. There was no way of verifying them. And theoretically, they were dubious. And yet, because Einstein was so famous, they would attract colossal media attention. The media would fight over the right to publicize Einstein's theories, even knowing that physicists were not really embracing them. In fact, physicists were running away from those theories in favor of things like

quantum electromagnics, and that got no media coverage at all. You also talk about apocalyptic theories, not on the Einstein level, but about the arrival of Halley's Comet being, well, very dangerous for us. Yeah, well, actually, when Gamow was a little boy, Halle's Comet arrived on its periodic journey. And there was a popular science writer, Camille. familial from a million who had speculated that Halley's comet had a atmosphere that would be poisonous. It turned out that it was, you know, a minimal amount of something that could potentially be poisonous in millions and millions of times, more concentrated amounts. So it was completely safe, but there was a mass panic because of that. So people were afraid of Halley's comet in 1910.

We have to take a break and when we come back more from Paul Halpern about George Gamov, Fred Hoyle, and the Great Big Bang Debate. You're listening to Science Friday. We're talking with physicist and author Paul Halpern about his latest book about the disagreements of two once-renowned science communicators and physicists in the middle of the last century. On one side, George Gamov, champion of the Big Bang theory, and on the other side, Fred Hoyle, who thought the universe exists. existed in a steady state rather than one sudden burst of matter and energy. I'd like to go back to the ways in which these scientists were different in so many ways from the classic stereotype. You write about Hoyle, quote, throughout his life, he argued strongly that scientists should be literate, proving his own thesis by writing or co-writing numerous well-regarded science fiction books that blended thought-provoking science ideas with intriguing

social issues. You point out that he wrote an opera about Copernicus. He speculated about alien life in his novels, The Black Cloud, and Afer Andromeda. Wouldn't you say he was a Renaissance man? Yes, both Hoyle and Gamov were Renaissance people. They really believe that culture was just as important as science. Hoyle, as he mentioned, wrote the Libretti for operas. He really believed in trying to explore all the facets of life. He was an avid mountain climber. and Gamov loved to travel and love to hike and go on motorcycle rides. So they really disproved CP Snow's conjecture about two cultures not communicating with each other, science and the arts.

And in fact, C.P. Snow was the one who invited George Gamov to write for a magazine called Discover Magazine that later led to him writing the Mr. Tompkins series. Yeah, you're right that his numerous popular books and articles contain clever sketches and wordplay and poked fun at his field in puns and parodies. I feel like I would have gotten along with him pretty well as a pun appreciator myself. Let's go back a bit to talk about the resolution of the Big Bang argument. As we know, it's the theory that won and is most widely accepted today. What was the evidence that eventually tipped the scales? Well, things were trickling in. in the late 50s and early 60s, such as, for example, the discovery of quasars,

which turned out to be very young, active galaxies, and formation, colossal sources of energy, but you only see them in the distant past. You don't see them in the present, which suggests that the universe evolves. But the real smoking gun was in 1964 and 1965 when two scientists, Arno Penzias and Bob Wilson, who had borrowed a communications satellite radio detector, had converted it to use to detect astronomical radio waves, looking at radio waves in the halo of the galaxy, trying to detect those.

And they got this unexpected hiss, and they thought maybe it was ambient radio noise or something from New York, which was nearby. they thought it might be the droppings of pigeons, and they call that a white dielectric material, which they scraped off the detector. After they had scraped it off and captured all the pigeons, and those pigeon cages are in the Smithsonian.

After doing all that, they still saw the hiss, or heard the hiss, I should say, in all directions. And they had a contact that knew that somebody named Bob Dickie at Princeton was working on a radio detector himself. And that's because Bob Dickie had this theory that the universe had previous eras in which radio waves could be left over from previous cycles of the cosmos.

And that theory predicted that there would be this cold radiation out there. And Dickie was about to build a detector to try to test for that. And when he heard about Arno Penzius, and Bob Wilson's discovery, they drove out there, they looked at the detector, they looked at the evidence, and they said, well, this is evidence of radiation from the early universe. And Dickie's associate Jim Peebles immediately did an analysis showing that the theory of the hot big bang

predicts radiation at exactly that temperature, or approximately that temperature, I should say, of 3 Kelvin, which is 3 degrees above absolute zero, Peebles later found out that Ralph Alfer, who was a student of George Gammov, had done a similar calculation back in the 1940s. So then after Peebles and Dickie announced the result, and it was all over the press, it was headlines in the New York Times,

then George Gammov and Ralph Alfer piped in and said, hey, wait a minute, we did stuff like that back in in the 1940s, perhaps we should get some credit for it. Did Hoyle ultimately accept this conclusion? He briefly went through a Big Bang phase. He thought, well, maybe there's some validity to the Big Bang and thought about that for a couple of years. But he was so proud of the steady-state theory and saw it as so elegant the idea that the

universe could last forever, that eventually he and several other physicists, developed an alternative called the quasi-steady state, and then the quasi-steady-stead theory, something else called iron needles, which permeates space. A little bit of a hokey idea, but they absorb radiation and rebroadcast it at just the right temperature

that the satellites and other instruments predict for the microwave background radiation temperature of the Big Bang. But also they said that the helium, produced in the Big Bang, which was another prediction, could be produced in galaxies instead. So they eventually had their own theory, a variation of steady state, and they held that that theory was valid into the end. And if somebody questioned Hoyle, he said, well, look, you always have to have alternatives. You don't want to be the geese following the herd. And in his last book, Hoyle had a photo of a mother goose leading a herd of geese to who knows where, and he thought that Big Bang

physicists were exactly like that. They were just following the leader blindly without thinking whether or not the Big Bang was right, but just doing it because it was fashionable. And Hoyo thought that at least you have to entertain alternatives. Great story. I know that these two scientists disagreed about the fundamental trajectory of the university. We've just been telling us about that. But collectively, right, they managed to explain the origin of about every element of matter. Gamov thought that Big Bang could explain everything from hydrogen up until gold and beyond. Hoyle thought all matter was created inside stars, and they were both wrong and they were both right. That's correct.

So Hoyle came up with a theory called stellar nucleus synthesis, which says that stars build up the elements during different processes. and one process happens when hydrogen is no longer being burned in the stars, and the stars start to contract, and helium is burned to produce carbon, and then as the stars continue to contract, they get hotter and hotter and produce the higher elements. Once they reach iron, stars undergo supernova explosions if they're massive enough, and the rest of the elements are produced in the supernova explosions. and the original elements that were produced are also released in the supernova explosions,

which is why the great Carl Sagan said, we are all made of star stuff, because everything in our bodies, except for the hydrogen and helium, everything around us, I should say, was produced in stars and released during supernova explosions. But the amount of helium in the universe can only be explained by postulating

that was produced in the Big Bang. But it turns out that the higher elements could not have been produced in the Big Bang because it cooled down very rapidly and was not hot enough to produce any elements beyond helium. So it turns out that Gamov developed the beginning of the story from hydrogen to helium, and Hoyle and his colleagues developed the end of the story, starting with the elements beyond helium. You know, it's interesting that neither of these men won a Nobel Prize for the physics work, even though what, they contributed to this breakthrough in our understanding of where matter came from.

How would you hope the field of cosmology remembers their contributions? Well, interestingly, I guess Gamov could have won the Nobel Prize, but he died fairly young. And at the time when he died, they weren't really giving too many prizes out for astronomy and cosmology. That became a relatively new thing later on, and then starting in the 1970s. And Hoyle really should have won the Nobel Prize for Stellar Nuclear Synthesis, but in his later years, he came up with certain fringe theories that were very unpopular. And I speculate in my book, Flashes of Creation, why Hoyle didn't get the prize. But another reason might have been that they thought the person who tested the theory came up with the theory himself. And that was

Willie Fowler who started testing the theory along with two other people, Jeff Burbage and Margaret Burbage, who her husband and wife. And that team, which are called B2FH for short, developed stellar nucleus synthesis as a whole. But they can only give the Nobel Prize for three people maximum. And they ended up giving it only to Fowler, which was a great. disappointment to those who knew Hoyle came up with the idea originally. Let's sum this up and talk about this book being about two creative mavericks with big personalities. And you write that there isn't necessarily room for such people in physics as it is studied today. And you say that physics like other sciences is collaborative

and team-driven and relies on big data. Is this a good thing overall for the progression of the feel? Well, when Gamov was working, and to some extent when Hoyle was working, it was possible to take some paper, for example, in quantum physics, and apply an equation to something else and work out the results overnight and publish it and have a ground-making discovery. But that era seems to be gone, and that's because in the 1920s and 1930s, there were so many discoveries. There were so many discoveries in fundamental physics. And that kind of slowed down from the 1940s until the 1960s. And it's sad that today there aren't so many discoveries in fundamental physics. There are discoveries in applied physics, such as biophysics, condensed matter, and so forth,

which are equally important. But in fundamental physics, there aren't enough experimental discoveries to justify continuing to come up with new theories. So that's why today, physics is done in big labs with giant experiments such as the LHC experiments in Switzerland. So the experiments require huge teams. And in terms of theories, it's unlikely that a single person will come up with a breakthrough based on all of the evidence out there and the difficulty in progressing beyond what we know. It just seems like it's a daunting task and requires many, many, many calculations and many, many people and many, many theories, not just a single person. And yet we still have these great mysteries about cosmology, about the universe.

I'm talking about dark energy and dark matter. which make up 96% of the universe, and yet we have no idea what they're made of. Is this not something fitting for a Maverick to come along and discover? Yeah, that is true. In cosmology, if somebody could come up with a valid explanation for dark energy or dark matter, that would be absolutely amazing, and that would be cause for celebration. and a possible avenue for somebody who's an extremely gifted maverick to make a breakthrough. So pay attention young people.

That's an area where maybe you can make a mark in cosmology, trying to explain dark matter and dark energy. This is Science Friday from WNYC Studios. In case you're just joining us, we're talking to science writer and physicist Paul Halpern, author of the book Flashes of Creation, George Gamov, Red Hoyle and the Great Big Bang debate. Any other thoughts that you have about these two giants of their fields or about where we're headed in physics now? Well, I think it's remarkable that they

were able to do so much and accomplish so much in so many different fields. And Gamov even made a contribution to the science of genetics. He came up with the idea that, you know, RNA can encode amino acids in triplets, you know, that was pretty amazing for him to speculate about that. He came up the basic idea of combinatorics. Other people developed the specifics, but it's remarkable that they could do so much in so many fields and also be some of the leading popularizers in their day. And I think today, unfortunately, people have to make a choice, either to be a groundbreaking scientist or a popularizer. It's hard for me to think of anyone who's been able to stay extremely active in science

to the extent that those physicists did and also be able to be as prolific in terms of science and science fiction today. But it could be possible, but it's become increasingly unlikely now that things are so specialized. Yeah. Paul, I want to thank you so much for your time today. My pleasure. It was great being on your show. Great book, Dr. Paul Halpern, author of Flashes of Creation, George Gamov, Fred Hoyle, and the Great Big Bang debate. And now for something a little different, but still appropriately cosmic. We're going to listen to a sonic treat from the world according to sound podcast. Turn up your headphones and enjoy. These are two black holes smashing

together. Here are two more. We're hearing gravitational waves, the ripples and space time made by the tremendous mass of colliding black holes. We can hear them because their wavelengths have been shifted all the way into the human range of hearing by MIT professor Scott Hughes. When the pitch rises, it means the force of gravity is increasing as the two black holes collide. You can hear how these two black holes wobble like a top as they come together. Drawn together by their immense gravity, nearby black holes will swirl faster and faster until they are finally absorbed completely into one another. These sounds are part of a podcast and communal listening series. You can find out more at the world according to sound.org. After the break, we're going to change gears and dive into

the archives for a look at medicine using maggots. Yes, maggots. Stay with us. This is Science Friday. I'm Ira Flato. You've seen them on detective shows and horror movies, and they're not something you usually connect to medicine. What am I talking about? Maggots, of course. Last year, Sophie Bushwick led us on a trip through the unlikely medical history of maggots, and here's Sophie once more. When a baby fly hatches, it has one job, and that's job is to get as big as possible as fast as possible. This is why we often find those babies. All right, they're maggots. In organic matter, like dead animals or sometimes are trash, hey, a kid's got to eat. That voracious hunger and taste for dead flesh is one reason maggots have been

used to help heal wounds since antiquity. It turns out they work really, really well at getting infections out of the way so the wound can begin to close. But although maggots went out of fashion shortly after the invention of antibiotics, researchers want you to know that they're an old school remedy with increasingly appreciated benefits in the era of antibiotic resistance. Here with more is SciFri digital producer and archive dweller Lauren Young. She's the mind behind a piece up on the SciFRI website about the recent and ongoing advances in medical maggots. You can check that out on our website, ScienceFriiday.com slash maggots. Hi, Lauren.

Hey, Sophie. What got you looking into the story of medical maggots? All right, yeah. So it was a dark and stormy night. I was just kidding. I was pouring through the SciFri archives, digging around for stories for our series CyFri Rewind. And I stumbled upon this in a 1997.

conversation Ira had with author Michelle Brut Bernstein. When most people think about maggots, they probably think about something that people used before they knew better. But I was surprised to learn and interested to learn that doctors are actually still using maggots to do something, right? They are. Maggots have been warming their way back into clinical practice. So thanks to this intriguing tidbit, medical maggots sort of wriggled their way into my curiosity. So I really wanted to find out. find out more what researchers have discovered since this 1997 conversation. I had reached out to Dr. Yamni Nigam, a biomedical researcher and lecturer at Swansea University in the UK. She's been

studying these tiny fly larvae since the late 1990s and she's a big fan. Most people are like, oh, wow, oh, they feel really amazing and they're really, they're really cute, which is something that I've always said about. You know, I definitely never thought of them as cute. cute before, but, you know, when you watch them wiggle around long enough, they certainly grow on you, not literally, of course. And more importantly, maybe they can actually help us. So when maggots feed on dead flesh and decay, they have to eat alongside other decomposers like bacteria and fungi. So it's caused them to evolve some cool protective chemicals that also happen to benefit us. Yamni told me about the research of William Bear, a doctor who treated

soldiers during World War I. He observed that soldiers who had maggots in their wounds were remarkably free of infection, even if they had gone days without medical care. It was super, wow. Yeah, super fascinating observation. So the thing Yomni and other researchers are learning now, though, is why maggots are so good at healing wounds. And Yomni was so great to talk to once that we had to call her up again. I interviewed her earlier this week. We started out by talking about how maggots can make a difference in the wound healing process. Maggots are very speedy debriters. They are nature's debriters.

And by debridement, we mean getting rid of dead necrotic tissue. If a wound has dead necrotic tissue, debris of old skin and so on, it won't heal. It will never progress. If a wound is infected, it will never progress through the stages of healing. What maggots do very, very effectively is they remove the necrotic tissue and, And they absolutely get rid of the biological burden, the bacteria in the wound, and they kickstart the healing process. So they have plenty of roles to play within wound healing and wound debridement. Yamni, I mentioned earlier that we stopped using maggots when penicillin was invented,

but now they're hot again, aren't they? Indeed they are. I think the fact that we have so many resistant strains of bacteria that are not responding to our antibiotics anymore. They've evolved methods and ways of invading our antibiotics. And yet, if you put maggots in a wound that has a resistant infection, that infection will be cleared up. So people are beginning to look back to maggots because they know that they actually can treat resistant infections in wounds. And your work in particular is looking at why that is. So what have you learned about that? So we've been looking at a couple of things. Our main focus at Swansea has been looking at how exactly are maggots clearing a wound infection. We know that they can do it, but we didn't know how. And it's only recently that we've discovered that maggots actually secrete in their spit and sweat, if you like. It's excretion, secretion, really. They actually produce these antibacterial molecules. And there are vast numbers of these molecules. Lots of them are actually tailored to the wound infection. So if you put a maggot in a wound that has a particular species of bacteria in it, that magot will

up its gain to produce molecules that will specifically destroy that particular infection. That's called the inducible maggot activity. And many researchers across the world have shown this. But we, indeed, in Swansea, have identified a particular small molecule that we've trademarked that's called serratocin, that we know killed MRSA and kills lots of other different types of bacteria that are present within the wound. And has there been any movement to take some of those compounds that you know they secrete and just use that directly instead of just putting the maggots on the wound? I think you have to watch this space, really. Certainly that's a huge goal of scientists, clinicians. The public, I think, in general, would prefer to have a secretion-based ointment, let's say, rather than the real-life maggots.

But I myself have to say that I think the real thing is a factory of molecule production. It's producing whatever it needs in that wound. Not only is it producing enzymes that will digest the dead tissue, it's producing antibacterial molecules, but we also know maggots produce molecules that aid healing. So if you've put the whole package together, you've got a factory, a maggot factory on your wound for three to four days. That's as long as we leave them. and you've got very good beneficial effects from the whole thing.

And what would you tell someone who could benefit from maggot therapy but is maybe a little reluctant to try it? What would you tell them about what the process is like and what it feels like to have this therapy? The process is very simple in the sense that if the wound is suitable for maggot therapy and the clinician will assess that, they will then put tiny little baby, the cutest little baby maggots. they're a millimeter and they will go on the wound usually in the small polystyrene bags and that's

sealed so the maggots don't get out and these enzymes come out of the bag they go onto the wound the dead tissue they turn the dead tissue into a digestible soup almost for themselves and then they drink that up and that happens within two to three days very very quickly so that's a process the bag is then removed after three or four days and the maggots are then removed from the patient And the wound usually is absolutely sparkling clean at that point. So it is a very quick, efficient and very effective process. The feeling varies between patients. Some patients don't feel a thing.

And some patients say it tickles. And then some patients feel pain. And often we find that patients that feel pain might have some underlying pathophysiology or they might be very reluctant to have used maggots. And therefore, they have a negative association anyway. So we're finding all sorts of things. are investigating really how people react to maggots. And if stigma is part of what's holding back research and the use of maggots in medicine,

what do you think those who think that maggots are cute need to do to warm more people up to that point of view? We've launched what we call a lover maggot campaign. We've got websites of it. And I go out to the public. I go out to not just the general patients, but I go out to nurses and doctors too, because they often are also reluctant to use it. they're a little bit squeamish as well. And so I think it all depends on changing a mindset. It's increasing awareness that maggots can work really, really effectively, increasing acceptance,

changing the negative perception. And one of the ways that we've tackled this is by going into schools. So you know, if you put a little maggot on a three-year-old's hand, they'll be like, oh, that's so cute. But if you put a maggot on a nine-year-old's hand, they'll be like, oh, get that off me. So somewhere along the line comes an association with negativity. whether it's parents, whether it's the child themselves associating maggots with smell in the dustbin or dirt or whatever. And so we need to go into primary schools and really we need to show children how brilliant this particular medicinal maga is and how useful it can be. So that when the child grows up or when the child goes home and his grandparents have chronic wounds and leg ulcers and diabetic ulcers, he can actually say, but yes, I've learned that these maggots are brilliant and they're very beneficial.

So we are tackling all aspects, all sides, really, to try and get it more accepted by the public. Is part of this stigma connected with the name, Maggot? And do you think that maybe there's a different name that we could be using? We've had this chat repeatedly with a lot of people. One of my team said, why don't we call them high genies or something, a different name? And that's brilliant. But when you say, right, we're going to put high genies on you, and then the patient says, well, what's that? then you have to say, well, they're maggots.

So I don't think you can get around it. I think the stigma is, you're right, the name maggot does instill fear and repulsion in a lot of people. But I think they need to be aware that this species is a good species of maggot. This will really, really help wounds to debride, to disinfect, to heal. So I think it's all about explaining to patients, really, rather than just trying to disguise it, I think. And I'm afraid we have to leave it there.

Thank you so much for joining us. You're very welcome. A pleasure. Thank you very much indeed. Dr. Yamni Nigam, a lecturer in biomedical science and self-described professor of maggots at Swansea University in the UK. You can learn more about her research and the status of maggots in medicine by checking out our producer Lauren Young's excellent piece on our website, ScienceFriiday.com slash maggots. Thanks for that story, Lauren. This is all so cool. You're welcome, Sophie. I'm never going to look at a maggot the same way. ever again. For the rest of the hour, let's head out to the woods. There aren't that many stands of old growth forest left in North America, and unfortunately, the resources to protect

and preserve those forests are limited. So how do you prioritize which of those islands of biodiversity to preserve? Until now, a standard way to identify the best patches of forest was to look at the size of the trees, right? Certainly makes sense. But New work proposes a new way. Tilt your head down and look at the lichens. Troy McMullen is a research scientist in lichenology at the Canadian Museum of Nature in Ottawa, Ontario. Welcome to the program. Hi, Ira. Thanks for having me on. Just tell us quickly what a lichen is. A lichen is actually a fungus that has learned a farm. It's a standard fungus that's transformed somewhat to form a greenhouse where it's growing algae. And the algae is photosynthesizing and producing carbohydrates and sugars to feed the fungus.

And what can the lichen tell us when you look at it about the health or diversity of the forest? Well, lichens have a large gradient of sensitivities to disturbance. So there's ones that will actually prefer to live in a city, and there's a whole gradient to those that will only really live in old growth forests that have been undisturbed for a long period of time. So the ones that we're proposing to use here are the ones that grow in these really old forests. And so you look down at the lichen and, And what do you actually look for? What do you see that tells you? Well, you're looking for the species that would be indicators of these old stands.

Or do you mean what do you see when you see a lichen? Yeah, when you see a little. Yeah. Yeah, so lichens come in all shapes and sizes. They are a lot like a coral reef in that there are many different colors. There are a lot of really spectacular shapes and sizes. And once you get an eye for them, you know, they tend to get overlooked because a lot of them are smaller, not always. but old man's beer, the big stringy, bright green stuff you see in the West Coast

and the reindeer lichens are growing on the ground, the big spiky things that those are the ones that grow in high abundance that people do notice. I'm Ira Flater. This is Science Friday from WNYC Studios. In case you just joined us, talking with Troy McMullen. So if you see lichens, does that tell you that the place is then healthy if you see the lichens going there? Well, healthy is a subjective term. A forest when it's young, just has the species that live in young forests. But what we can use lichens forest to tell us that some stands have not been

disturbed for a long period of time, and that's not reflected in the age of the trees. It's reflected in how long that site has been forested. So the trees might only be a few hundred years old. and by every definition that we have for old growth forest, that would fit them. But the diversity that's in those stands, that might have accumulated over hundreds or thousands of years. And that wouldn't be, you know, looking at the trees only as only a proxy for the species that would be there. Some stands have considerably more of this unique biodiversity than other states. This sounds harder than just looking at a patch of forest and saying, hey, the trees here look pretty big, pretty healthy. Yeah, exactly.

A good analogy is looking at a car. You can have two Ford F-150s sitting beside each other that look the exact same, but until you open the hood and climb inside, you don't really know which one would have the better features. So we're proposing you get in there and have a look at what species are in there that are really important. This is to give them a conservation value. And so we can identify the forests that we should be targeting more for preservation. If I want to go out lichen hunting or just to do lichen touring, if I can put it bad. How do I tell a lichen from a moss, from a fungus? What do I look for?

That's a good question. So lichens are generally brighter in color. But if you really want to get into the fine details, you add water. When lichens are dry, they're hard. And when you add water, they become soft. But if you add water to a moss or even a fungus, there are fungi that are wet. There's fungi that are dry. But when you add water, they stay the same.

same. So lichens really have an extreme change, and that's one easy way of knowing you've got a lichen. You're lichen, you're lichen. Sorry, bad jokes all the time. I always appreciate them, though. Good. I found it soulmate. So you see a lichen on a big slab of rock. Is it an old? I mean, what do you think is the oldest lichen in the world? Oh, they've been aged at thousands of years. Really? Lichens are really slow growing. So there are some that will grow right into the substrate. They'll they almost become part of the tree or the rock. And those ones grow extremely slowly, like on average, less than a millimeter a year.

So you're looking at some patches that are sometimes a foot in diameter. You know, that's been there a really long time. Wow. Are city slickers, we New Yorkers, we out of look and looking for lichen? Well, there's a few species that actually will like that kind of condition in New York City. So there are species in New York City. but not many of them, and they're generally very small. And that's one of the reasons that lichens are an overlooked and understudied group

because you tend to have to get out of the city and into more undisturbed areas to really see the spectacular ones. Tremnickmullen Research Scientist in Lichenology, where Likinol, yeah, do it yourself, at the Canadian Museum of Nature in Ottawa, Ontario. And that's about all the time we have for this hour. If you missed any part of the program, or you would like to hear it again, subscribe to our podcasts, or ask your smart speaker to play Science Friday. Of course, we're always happy to get email from you, our address, SciFry at Science Friday.com.

Have a great weekend. I'm Ira Flato.