Science Friday - Hurricane Lane, Disposable Contacts, Brief History of Time. Aug 24, 2018, Part 1

Episode Date: August 24, 2018

This year was both the 30th anniversary of Stephen Hawking’s science blockbuster A Brief History of Time, but also the year the famed physicist himself passed away. In memory of Hawking and celebration of his work, Science Friday Book Club listeners joined up to read A Brief History of Time, ask questions, and explore the far reaches of what we know about the universe—how it began, how it will end, and what it’s made of in the meantime. In the final chapter of this summer’s book club, Yale astronomer and physicist Priya Natarajan and physicist Clifford Johnson of the University of Southern California join Ira Flatow and SciFri producer Christie Taylor to talk about the man, the book, and the science—and where the field has gone since. Unlike their reusable counterparts that are changed out weekly or even monthly, daily single-use contact lenses don’t need to be cleaned and stored at the end of the day. While these contacts are better for the health of your eyes, it also means throwing out little pieces of plastics every day—and some of these contact lenses are infiltrating our waterways. Research from Arizona State University estimates that 20 to 23 metric tons of contact lenses end up in waterways each year. Charles Rolsky, a Ph.D. student in the Biodesign Center for Environmental Health Engineering at Arizona State University, joins Ira Flatow to discuss how contacts are polluting our water. Plus, a strong Pacific hurricane, fueled by unusually warm water, has Hawaii in its sights—and more short stories in science news.   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. In the U.S. hurricane season, you know, usually refers to tropical weather activity in the Atlantic, the Caribbean, Gulf of Mexico. This week, however, a combination of unusual weather conditions and bad luck have set up a powerful Pacific storm. You've heard it, and you've seen her hurricane lane bearing down on the Hawaiian islands, bringing strong winds and heavy rains. Although the storm has been downgraded to a category three hurricane, parts of the big island have already. seen over 30 inches of rain from the storm with more on the way. Joining me to talk about that and other selected short subjects in science is Rachel Feldman, Science Editor at Popular Science. Always welcome. Thank you for having me, Ira. You're welcome. Okay, give us what's the latest on the storm.

Yeah, so, you know, at least based on the last update I saw, Lane is actually now down to category two and is, you know, continuing to downgrade. I think the general thought is that by Friday night, Saturday morning, the worst of it will be over. But, you know, the Hawaiian islands are not set up to get hurricanes. They're just not. And, you know, as you said, it's kind of a combination of weather patterns and bad luck. You know, why don't we hear about Pacific hurricanes more? Well, it's a much bigger ocean with less coastal landmass than the Atlantic.

You know, we really have set ourselves up in North America to just constantly be hit by hurricanes in major metropolitan areas, not as true in the Pacific. And also, there's usually kind of an atmospheric pattern that keeps these storms that form around Mexico from making landfall in Hawaii. And that wasn't as strong this year. Those winds just weren't blowing the right way. There's also slightly warmer water than average in Hawaii, and that fuels hurricanes. So, you know, a combination of bad luck and weather conditions, you know, there's a lot of flooding on Big Island right now, and that rain will probably continue even after the storm, the majority of the storm passes, because it's moving very slowly. It's moving about five miles per hour.

You remember, we had a similar problem with Harvey in the U.S., where it was a storm that really just did not want to leave. So even once the worst of it is over, they're going to keep getting rain, and they're going to keep getting flooding and landslides. And actually on Maui, where the storm might not even hit directly, they're seeing such intense winds. that there's a brush fire on West Maui that is, you know, being fueled by these hurricane winds, and the rain hasn't started yet. So they would actually really like the rain to get started on West Maui. So, yeah, definitely everybody who lives on Hawaii or is on the islands this weekend

should really listen to emergency warnings and stay safe. Yeah, stay safe. Let's move on to news this week about changes to energy policy and the EPA. This is... Yeah, so the clean power plan got a lot less clean. It was originally set up in 2015 by the Obama administration, and the goal was to lower carbon emissions from energy, you know, from the energy sector. Of course, carbon contributes to climate change and also can cause health problems. So the idea was to drop those emissions in the energy sector by 32% by 2030.

Trump's EPA just released their version of the plan called the Affordable. Clean Energy Rule or ACE. And it's pretty dirty. It's only going to lower those emissions by 3% of the target seen by the CPP. Now, the CPP was supposed to lead to $20 billion in climate benefits, $14 to $34 billion in health care savings, and it was supposed to prevent 3,600 premature deaths, I think, annually. In contrast, the affordable clean energy rule really puts front and center that it's going to make energy cheaper, but the projections say it will only make energy cheaper by about half a percent.

And it's really just a continuation of this propping up of coal, even though coal is not economically viable. Yeah. Coal companies are out of business. Exactly. So however you feel about carbon emissions, coal is not a smart way to go, and yet we have this plan ACE that is going to. Is it going to increase deaths? Well, it's not going to decrease deaths the way the CPP would have. It essentially tells states that they can lower carbon emissions if they would like to.

All right, let's move on to more hopeful news. You have a story this week. It was really interesting about changing blood types. We can change blood types? Yeah, which I didn't realize this, but we've actually had the power to change blood types for decades. Really? Some researchers figured out how to change type A and B blood into type O blood. using an enzyme from coffee beans, you get your blood type based on the antigens on your blood

cells, which are either A or B, or you don't have them at all, which is type O. Those antigens serve as kind of red flags for the immune system. So if an unfamiliar antigen comes in, you're in trouble. Type O is universal for most people, at least, because it doesn't have any. So these enzymes are basically like digesting the blood to get rid of those antigens. What's cool in this new study is that they found... an enzyme that lives in like the human gut microbiome because there are similar proteins on the intestinal wall. So they found, you know, the spectral enzyme that is really good at digesting your blood just enough to turn it into type O.

There's a lot of work to do before this could, you know, turn all donor blood universal. For example, they have to prove they can get all the enzyme out so that it wouldn't continue to pull antigens from your blood once it was in your own. But it is a really cool finding. Let's move on to looking up. There's new evidence of water. I mean, actual clumping of water on the moon. Yes. So this is the best confirmation yet of ice on the moon.

This Indian satellite picked up a bunch of different molecular signatures of water ice at the poles. We're talking about, you know, sitting in the shadows of craters at minus 250 degrees Fahrenheit. So it's just these little clusters of water. Yeah, of course, it's exciting because lots of people would like to be able to make rocket fuel on the moon. The idea being that we can use up a bunch of fuel getting out of Earth's atmosphere, then refuel before heading to Mars. And water is a big part of that. Finally, a tale, this is really interesting, ancient matchup between a Neanderthal and a Denisovan. Yes, so these two ancient species of human that their last common ancestor was 390,000 years ago.

And yet, about 90,000 years ago, two of them. had a baby. We already knew that these species probably interbred the same way we know that Neanderthals and our species interbred based on our DNA. But this is the first time researchers found an individual that looks to have 50-50.

You know, they had a Neanderthal mom and Ed Denossum and dad, which is very cool. That is very cool. It's great news stories this week. A lot of them. Thank you. Thanks, sir. Rachel Feldman, the science editor at Popular Science here in New York. Now it's time to play Good Thing, Bad Thing.

Because every story has a flip side. We're going to talk about contact lenses. They've become more convenient, you know, because the single-use kind came on the market that made it very easy for people, made it, you know, very convenient to use. But when you open a new pair of contact lenses every morning, maybe you do that?

Do you throw out that little piece of plastic every night? And then, you know, you rush to flush the plastic lens, down the drain, maybe the toilet, maybe the sink. Well, it turns out of plastic. out that those plastic lenses are clogging our waterways. Here to tell us more about that is Charles Rolski, a Ph.D. student at Arizona State University. Welcome to Science Friday. Thank you so much for having me. I'm a huge fan of the show. Oh, that's great to have you on here. So tell us about it. So the good thing about this, of course, is that they are single use. They're better for your eyes,

right, because maybe keeps out some infections that we're using a contact lens might have. That's the good news? Sure, yeah, good news is maybe less time exposed to your contact lens holder or less time in your eye maybe you kind of reduce the chances of something bad happening. We can see that as a good thing. Okay, so then the bad thing is we've got so many of these being flushed down the toilet or the sink. Yeah, the bad news is people kind of, maybe they lose track of them. I don't wear them because it grosses me out to touch my eye, but I think you can accidentally or sometimes intentionally flush them down to sink or toilet and then from there they have a pretty incredible journey. That's interesting. I see the movie. How many, how many contact wearers and lenses are we

talking about? What's the bulk of this? So we're talking about roughly 45 million people in the United States wearing contact lenses every year, and an increasing proportion of them are switching to daily disposable just because they're easy. There's, you know, there's a lot of more, or health, a lot less health risks, and there's also incentives with buying in bulk. So we're definitely seeing a trend of those increasing. Do they know what percentage of people who wear the disposable are actually getting rid of them down the drain? So we did a survey here at ASU, and we found that around 20% of those wearing contact lenses

are actually flushing them down the sinker toilet. 15 to 20%, then, I guess, how many millions of people, that's a lot of contact lenses? Yeah, it ends up being thousands of kilograms ending up as waste every year, especially because they're going through and interacting with wastewater treatment plants, which was also part of our study.

Well, tell us what happens when they get there to the treatment plant. Well, so what happens is they encounter a couple different degradative atmospheres or environments. They have a nice little tango with a lot of microorganisms, which we've shown the microorganisms to break the contacts down a little bit. But ultimately, they persist, and the physicality of the treatment process can also turn the contact lenses into smaller pieces, which we lovingly refer to as microplastics. And from there, they end up in biosolids, which is the treated biological matter, and it can either be burned or. applied on land or sent to a landfill. So it ends up being a pretty fascinating journey for these little plastic pieces. So how did you know that the lenses weren't actually being filtered out of the

sewage waste system? To answer this in a non-discusting way, we checked the filters in multiple stages of the treatment process. And then we actually looked through the biosolids at the end of the biotreatment process or the water treatment process. And going through a lot of organic material was fun, but we ended up finding some contact lens fragments. And so this material was going to be chucked out to either be applied on land or sent to landfill or burned. I have to ask what the disgusting way of describing this would be. So we lovingly say, yeah, we say a biological material, but if you can imagine the majority of the stuff that comes out of your house is flushed, so I think your imagination can then ride with that one. So where do these bits of plastic

end up after they leave the sewage plant? So if it's land applied, you know, it can be sent to any type of agricultural area where they're looking to sort of enrich the soil. If it's sent to an incinerator, then it's going to be burned. And then it can also be sent to a landfill site. And the danger here is that microplastics are normed to absorb contaminants at pretty high concentrations. So they basically act as a vehicle for some of these nasty pollutants. So if you're burning it, it could end up in the atmosphere. If it's being land applied, you know, this is agriculture.

It's also got runoff. You know, it's basically acting as a vehicle to deliver some of these nasty things. So let's put a warning label on it and say, you know, maybe people will stop. Absolutely, yeah. We found that none of the contact lens boxes that we looked through had any type of disposal strategy suggested. So I think that if these manufacturers were to sort of put a small label on their saying to throw them with the solid waste, it would be good. Well, thank you, Charles, taking time to be with us today. Charles Rolski, Ph.D. student at Arizona State University.

We're going to take a break and come back and wrap up our book. Club, Stephen Hawking's a brief history of time. We want to know what you did. Did you read it? Give us a call. 844-8255. This is Science Friday. I'm Ira Flato. When famed physicist Stephen Hawking passed away this spring, the world took notes, certainly. He was interred at Westminster Abbey with Charles Darwin and Isaac Newton. Actor Benedict Cumberbach spoke at his funeral, while his frequent collaborator, Sir Roger Penrose wrote his obituary for The Guardian. And here at Science Friday, well, we said, what could we do to commemorate his life?

And we realized that a lot of people, a lot of our staff, hadn't read this most famous work. The general audience book about the big questions of the universe. Of course, you remember that. It's a brief history of time. So we read it, and we invited you to read it, and we're here one last time to talk about it. Did you finish the book?

What did you think? Is it different from the first time? Remember the edition we're reading is actually a different edition than the original edition. It might be have extra stuff in it that you didn't read the first time. We want to know what you thought. 844-724-8255. That's 844 Sci-Talk. You can also tweet us at SciFri.

With me is SciFri Book Maven, Christy Taylor, who's been shepherding this reading. Welcome. Hi, Ira. Good to have you back. Glad to be here. Okay. That's the thing we're here to talk about, right? It falls in the air.

People are starting to go back to school. You know, it's hard to believe we're at the other end of a sci-fi book club. It's come and gone. Yeah, but we really packed a lot into this brief piece of time. Sorry about that. We did a lot with this book club. We had artists create original hawking-inspired pieces of art. We had a cocktail party last week to sort of bring together physicists

and interested members of the public to do some, like, hands-on demos and stuff. We read a whole book and we answered as many questions as we possibly could for our listeners on Twitter in our newsletter and on the air. So we've really done a lot, I think, Ira. You know, I was like most listeners. I remember when the book came out. I opened it for a little bit. I read a little bit of it. Then I put it on my coffee table where everybody else had put their books.

So this really is the first time that I read the book straight through. How about you? It was my first time even trying. And I will say it was not brief. It took me some time. I had some chapters that stumped me that I had to reread. I will say quantum gravity is not an easy concept or just the unification of physics. So I'm glad that we're going to have some friends on here today to help us talk through some of the things here.

Back, you may remember them from our kickoff. We have Priya Natarajan, our professor of astronomy and physics at Yale in New Haven, Connecticut. And then Clifford Johnson, a professor of astronomy and physics at the University of Southern California. He's joining us from NPR West in Culver City. So, hi, friends. Hi. Hi, good to be back. I want to start just with talking about the language in the book

because, again, one of the things that we remember hawking for is making or working to make physics more approachable. I had a lot of favorite passages. He talks about trying to visualize the shape of the universe if it curves in certain ways. He talks about this idea of traveling through such a universe. He talks about the expansion of space and time after the Big Bang.

Ira, do you have any favorite descriptions that Hawking gave us? Yeah, he had a description of how to visualize light. He created a little visual for a light that was, it was sort of like an egg timer shape. And you looked at it and I said, you know, I have seen this before in other physics books written since them. I didn't realize how far back it went all the way to Stephen Hawking's original book here. but it was hard to look at the visual

because it's not your typical X, Y diagram, and you have to actually study it. That image has stayed with me through the whole book. Yeah, I like that too. Priya, when you look at some of the descriptions that Hawking gave us in this book, do you have any that really stand out to you as a physicist? You mean as a physicist or for the kind of explanatory power,

sort of, I know, I liked a lot of the artistic impressions that he had because I think they were right on in terms of physics concepts and yet they conveyed sort of, so for example, there's in chapter six, he has this really nice kind of artist's impression of how a black hole would be feeding from a nearby star, this would be a stellar mass black hole, and what we would end up seeing. So to me, for example, that artistic impression, because it packs a lot of physics and correctly, is one of the ones that I really like a lot. And Clifford, what about you for explanatory power or physics concepts, either one? Well, I think the light cone example that Ira brought up is actually great because it shows that this is a tool that we actually use. as physicists, you know, if you sit in on a seminar on some technical aspect of quantum gravity

or something, you will see someone actually draw a light cone. And so it's actually great to see that some of the tools we use to visualize things can also be used and quite accessible with, you know, a good writer. And it also tells people that we rely on little cartoons to figure stuff out as well. It's a, it's not dumbed down. It's really the real thing. Yeah, and if you want to comment, our number is 8447248255. And you can also tweet us at SciFry. Yeah, those graphics were great.

Yeah. And I wanted to say, so, Priya, when you joined us for the kickoff of this book club back in July, we kind of hinted that we've learned a lot since Hawking wrote this book back in 1988. But also Hawking himself contributed a lot to our understanding of especially black holes. So looking back at this book that was written, back in 1988, what was the most groundbreaking thing that it introduced to us at that time? Yeah, so I actually did reread the book, although I had the old edition, so I was able to compare notes mentally to what we know now. So I think where we've made a lot of major leaps are

in the sort of real, the deeper understanding of astrophysical black holes that he kind of set up at the time, right? So the data was just starting to come in. But in this book, he, He already started to speculate how we might detect black holes, how they might grow, and now we know a lot more about how black holes actually form, how they actually grow, because we've had data in multiple wavelengths looking at black holes. Say the Chandra telescope has shown us how gas actually feeds into black holes, and the presence of supermassive black holes in nearby bright galaxies, has been, effects have been detected by Hubble Space Telescope data.

So, you know, he foregrounded. He kind of anticipated all these developments that were kind of along the pike at the time. And, of course, the most exciting thing that he was looking forward to, both in the book and later, was the detection of gravitational waves, the first detection from colliding black holes, which, you know, LIGO reported a couple of years ago. So I think he anticipated in this book a lot of the observational verification we would have for astrophysical black holes. And I keep making that distinction because, you know, Hawking works a lot on the sort of mathematical model of black holes, a mathematical solution.

But I think he could see that they were becoming quite real and in a major way in the sense that there would be an explosion of understanding and information about the properties of black holes. holds, the details of how they would feed and so on, so forth. And to say nothing of, you know, he also, this was before we got very detailed maps of the cosmic microwave background radiation. So the detection had already happened in the 60s, but the details, the detailed anisotrupes, the pock marks in this radiation map, relic map from the early universe, that the WMAP satellite and the Planck satellites have brought us, have really ratified the standard model of structure formation

that, you know, Stephen sort of laid out in this book and brought to the public. At the time, it was at the sort of frontier of our understanding. And now we have a really embellished picture, although, you know, there are still lots of things we don't know. We still don't know what dark matter is and what dark energy is. Yeah, well, and Clifford, so Hawking also tries to tell us about this crazy thing called string theory.

Was that a weird idea at that time? It was a weird idea at that time, and it remains a weird idea, but weird and wonderful, because it really helped expand on and answer a number of questions that he was laying out in the book. He was one of the people responsible for doing some of the first major steps in our understanding of quantum gravity, which is what happens when you have this thing which comes from classical Einstein general relativity,

and by classical I mean there's no quantum stuff from Einstein's equations, this thing called the black hole. And then he thinks about what would happen if you sprinkle some quantum mechanics in there, as we have to because the universe is quantum mechanical. And he discovers the thing that bears his name, Hawking Radiation. And he, in the following years,

with a number of collaborators, he actually developed this wonderful framework of what's called semi-classical quantum gravity and he actually explains some of it in the book so all of that stuff to do with imaginary time and so on and so forth that's the toolbox

and he lays out some of it there but he's struggling because it's an incomplete theory of quantum gravity he's struggling to tell you what the end of the story is he explains that string theory is one of the approaches and tells you a little bit about string theory as it was understood at the time. What's happened since then is amazing. String

theory has a lot of shortcomings, but one of the things that's extremely good at we've become to realize is understanding quantum aspects of gravity in certain regimes. And it turns out that once we started understanding string theory well enough to study black holes, we were able to answer a lot of the questions that Hawking had asked about the quantum nature of black In fact, there was a big battle between him and the string theory field because he was actually resistant to some of our results for a long time. But some of the results turned out to be so beautiful and so compelling, he eventually changed his mind. We have a really interesting quote, a tweet here from Mark who actually teaches philosophy class. Political science, he says, I'll admit I didn't read along with the book club, but I assigned the intro and conclusion in my political science classes at NC State.

And here's the interesting reason, he says, because it does a masterful job of laying out the basic logic and process of science and the creation and accumulation of knowledge. I really like that. I was going to ask you, because you're someone who thinks about science, probably more than most people who aren't scientists. But you still have things that you get hung up on when we talk about these concepts, right? It's not just easy as pie, even though you keep reading and reading about this. I've read it 40 years trying to get some. The hardest thing I think for the public to think about is to come to turns with the concept of infinity. You know, when he talks about at the Big Bang, there was an infinite amount of heat.

How can you have an infinite amount of heat in zero time? You know, people, well, can't there be more heat? Can't there be more space? That kind of thing. And he does throughout the book tries his best to try to bring that to the public. It's a hard thing. It's a hard thing to understand. You agree, Clifford?

Yes, it is hard, and it's hard for us, too, as physicists. And I think it's important to realize that, that we have difficulties with some of these concepts as well. We don't have, you know, 10-dimensional brains that can think in 10 dimensions or what have you here we're talking about. We still use tools, such as certain kinds of mathematics, to help us limited creatures, understand some of those things.

The same thing is with infinity. No one has an understanding of infinity in an intuitive way. It really, it's either a process, you either arrive at it by a process, or it's a mathematical concept you can move around on the page because of the consistency of mathematics. I should say with the infinite stuff that's happening at the beginning of the universe,

those infinities are telling us that we have an incomplete understanding. The equations, Einstein's equations coupled with equations of the matter that are moving around telling us, us that there's, you know, lots of these things are going toward infinity when the equations get to that point. And it's telling us there's some new stuff there that will actually resolve those infinities. Infinities in the actual universe are placeholders for physics we don't yet understand.

Well, we understand our numbers 8447248255 talking about a brief history of time with Priya Netterjan and Clifford Johnson on Science Friday from W. NYC Studios? So actually, Priya, one of the things that happens, we talk about physics on the show a lot, as I told Ira, as you guys probably know, but we get a lot of questions from our listeners that any time that we talk about these kinds of topics, that they seem to cluster. So we get a lot of questions about the multiverse. So like what happens at the event horizon of a black hole, really?

You know, is travel backwards in time possible? people just seem really interested in these really extreme possibilities that seem to be presented when we talk about cosmos scale science. Why do you think people get hung up on these kinds of questions? Do you get hung up on these questions, Priya? Yeah, well, I think that, you know, one of connecting up to what Ira and Clifford were just talking about, I think this notion of the limits, the limits of equations suggest be the infinities, or singularities, right? They also point to limits of our understanding.

And black holes, because they encompass this sort of singularity, it's a place where our knowledge and understanding, the language of mathematics, everything breaks down, right? It's a very, they are tantalizing objects because they represent, if you will, sort of the boundary between what is known and what's not known. And that boundary has all these bizarre effects, right? So I think people are really attracted to the sort of the strange behavior, which is not something that you encounter, you know, in your day-to-day understanding of physics.

I just can't sort of really fathom what it means like to have time slow down or what it means like to have a very strong gravitational field that the difference between sort of falling into a black hole between your hair and your toes is so strong that it means like to have a very strong gravitational field that it. can rip you apart. I mean, so these are very non-intuitive kind of phenomena that happen around the event horizons of black holes. And so I think they are really, really fascinating. I mean, I find it very fascinating to really think through, for example, right? So classically, when we try to understand what

happens when you start falling into a black hole, I mean, I've done these thought experiments, not just me falling in, right? because I'm a bit vain. I don't want to fall in quite yet. You don't have turned into spaghetti. Yeah, exactly. But if you throw a clock in, right?

So this whole idea, right, this conception of what does it mean to say that time really slows down? So you have a faraway observer who's watching you with a clock or just the clock falling in, they will see that the time on this clock is going to slow down and come to a complete stop at the horizon, right? And that is just super, super bizarre. Yeah, it's hard to get your mind around what that's like. But he tried to do as best as he could these great examples that you could relate to. And we'll talk about more of those examples with Priya Natarajan from Yale University and Clifford Johnson, USC in L.A.

Stay with us. Our number, if you want to get in on the conversation, 844-8255. You can also tweet us at SciFry. Maybe you read the book years ago. Maybe you want to read it again. It's worth a second read if you haven't. We'll be right back after this break. This is Science Friday.

I'm Ira Flato. Back with our SciFry Book Club to continue our discussion about the late Stephen Hawking's a brief history of time. And with me is SciFri Book Club producer Christy Taylor, physicist Priya Natarajan, and Clifford Johnson. And before we get back to the Science Friday discussion this afternoon, Cyfry had a party in Hawking's honor this last week.

We invited New Yorkers to join us for a time traveler cocktail party in honor of one Hawking himself through in 2009. We had hands on physics demos, displayed the winners of our art competition, and to cap it all off, physicist and author, John Eleven, remembered Hawking in verse, reading a work, by poet Marie Howe, originally composed for the university in verse event, held earlier this year at Pioneer Works in New York. Here is John Eleven commemorating Stephen Hawking Tuesday night. So it occurs to me maybe to mention that I knew Stephen. I was in Stephen's group in Cambridge

for many years, and in the hallways we used to joke about whose toes he ran over with his wheelchair when he was feeling impish. I think it was none of our toes, but we all pretended anyway. Just since we're talking about him tonight, I should say that knowing him, I don't think that his prodigious mind, his unbelievable accomplishments, can be strongly enough contrasted against those obstacles he faced. He really was just an unbelievable person. He was also incredibly arrogant and belligerent and difficult. Lenny Susskin said of his good friend Stephen Hawking, the man, was arrogant, impossible, but then again, so am I.

So this was my upbringing in theoretical physics. Just to say he is very much missed. And just to point out that he really did create a paradox, especially in the 70s, over black holes that no one has yet been able to resolve. Everyone tries to resolve. Even Hawking tries to concede occasionally, that there was this resolution.

and you brought it up earlier with the hawking radiation and the evaporation of the black hole. But there are two contrasting competing things that are going on in nature, and no one can figure it out. And the black hole is the terrain and the only terrain on which we're going to figure it out. And Hawking is the one who gave us this gift of revealing that to us, that that was the frontier.

That is the frontier. If we want to understand quantum gravity, the ultimate theory of everything, the final chapter is a brief history of time. We have to understand the black hole. And we don't, even since he first proposed this in the 70s, a couple of years after his diagnosis was supposed to be completely fatal. So on that note, he was a loved man.

He was a loved man. He was a difficult but loved man. So this is a poem by Marie Howe, and I'm honored that Maria Popova and Marie Howe asked me to read this poem, which was written for the universe and verse about Stephen Hawking, or at least inspired after Stephen Hawking. Do you sometimes want to wake up to the singularity. We once were. So compact, nobody needed a bed or food or money, nobody hiding in the school bathroom or home alone, pulling open the drawer where the pills are kept. For every atom belonging to me as good belongs to you, remember? There was no nature, no them, no tests to determine if the elephant grieves her calf, or if the coral reef feels pain. Trashed oceans don't speak English or Farsi or French. Would that we could wake up

to what we were when we were ocean. And before that to when sky was earth and animal was energy and rock was liquid and stars were space and space was not at all. Nothing. Before we came to believe humans were so important before this awful loneliness. Can molecules recall it what once was before anything happened? No I, no we, no one, no was, no verb, no noun. Only a tiny, tiny dot brimming with is, is, is, all everything home.

Thank you. physicist and author, Janelle Levin, remembering Stephen Hawking, reading a poem by Marie Howell, commemorating our event that we're having, which is reading his famous book. Christy, we also commissioned art for this book club. How did that go? That went amazingly well, Ira. So we threw out an invitation to artists on this platform called LO for portfolios. And we got hundreds of submissions, people who wanted to create art that was inspired by some of the, quote, that we picked out of the book, and we narrowed it down to six from four different countries,

including the UK and Colombia. And it's this beautiful diversity of, and you can see this on our website at sciencefriiday.com slash art, but it's this beautiful variety of we have abstract sort of geometrical renderings that try to make you think about the poly exclusion principle and quantum electron spin. But then you also have illustrations of time dilation at the event horizon of a black hole and this sense of existential horror of that idea. So you have a lot of really beautiful things that came out of this, and we're really excited to show those to you. That's terrific. That's terrific. A lot of people calling in with comments now. Let's go to Huntsville, Alabama. Pat, hi, welcome to Science Friday.

This time I read it was kind of, you know, like the first time when you realize that doctors do. I think we'll lose it. And I think the line is awful. So I think what he was saying, that moment when you realize doctors don't know everything. And I know there are several moments where Hawking admits to being wrong about things in this book. He talks at one point about if the universe contracts, are we going to experience time backwards, for example? And he says, I thought so. But actually, I changed my mind.

Clifford, does this happen a lot? Is this a rare thing for someone to admit in public in science? It would be nice if it happened more often. It really depends upon the scientist, and there are some who are, I think, very open to discussion and back and forth and changing their minds, and I think that's becoming increasingly so with new generations of scientists. But there are indeed famous examples of people

who take positions and dig in at all costs. And I think Hawking was very, very gracious at a number of points when he changed his minds. There are a number of famous bets that you can read about, some of which he lost, concerning big issues in physics. And he's been very good about that, especially in later years. A tweet from Jay Saviller, who says, would you discuss the concept of matter and energy being consumed by a black hole, but not the information?

and how that relates to the theory that the universe is holographic, another idea put forth by hawking. Oh, Priya, I think this one's for you. Right. Well, let me just quickly add to the changing your mind, because it's related to this question, which is, you know, he famously changed his mind about the information paradox.

So when he postulated this idea of hawking radiation, there was this huge riddle, right, because it's believed that no information about the interior of a black hole or its formation could ever be extracted. It's an essential property of the black hole. But if particles were being radiated away at the periphery, as Hawking radiation suggests, then would they not be carriers of information, right? So originally Hawking thought that they would carry no information at all,

and the evaporation of a black hole would lead to total information laws. But the nice thing about him, as you've all talked about, is not only did he change his mind on this big question, and as Clifford mentioned, he had a bet, but he also did so publicly. So he acknowledged that he was wrong and that information could actually escape from black holes after all. And so I think that was what was sort of very gracious about him, right, that he did so publicly. Coming to the question of what really happens as a black hole sucks in matter. So matter that falls into a black hole, right, a small portion of the rest mass energy of that matter,

is converted into radiation. So one can think of it classically as the blob of gas, for example, is getting sped up as it's being pulled into the intense gravitational well of the black hole, and it starts to radiate because it gets heated up, and it starts to glow in the x-ray. So a very small portion of the mass

is actually left out as sort of a siren, as a signal as it's falling in. And this is how we actually see black holes at all. And the rest of the matter we believe just falls right in through to the event horizon. And what it does, it increases the mass of the black hole. So as the mass of a black hole grows, since the size of the event horizon is proportional to the mass, as a black hole accretes, is the technical word, gobbles more mass, the event horizon becomes slightly larger. So this is our current understanding of how we think black holes actually grow, other than

and the actual sort of collision between two black holes when they just go thwack. And they go thwack, they release gravitational waves, they jiggle the space time around them, and we've kind of detected the first sort of instance of two tiny black holes, not the supermassive ones in the center of galaxies like our own. We are yet to detect that collision,

but this kind of matter falling into a black hole pulled in from either a star that has strayed nearby or in the case of supermassive black holes, when gas is sort of swirling around and held in a feeding disk around the black hole from which it gets slowly siphoned in. That's sort of really where our current understanding is. And in terms of the information, classically, we really do believe that once this matter causes the event horizon, we don't actually know after the black hole has grown, and I'm putting inverted commas in the air here, its size is grown,

we just know that the mass has increased of the black hole. We don't actually, so we see the black hole, we can't tell how it grew to be the mass that it has. So for example, right, if all our mismatched socks got sucked into a black hole, we wouldn't know when we saw the black hole what actually went in. Yeah, yeah. We're not going to go there to find out either. That's right.

I want to do that. Let me just remind everybody that this is Science Friday from WNYC Studios, talking about Blackhulls and Stephen Hawking. And, you know, one question I had that I thought I would try to get answered by you, Priya, and I thought maybe Stephen Hawking could answer it in his books, but the graphics weren't there for it. You mentioned the event horizon, and you mentioned the disc, an accretion disk around a black hole? Yeah. How is it like the rings of Saturn?

I mean, I'm trying to think, look at a black hole. I see a disc. Why is a disc forming in one spot as a ring and not going polar ring or instead of east or west? When I see a black hole, is it, is everything equal around the whole hole, or is there some more preferable area for these things to happen? Right. So I think there's sort of a preferred geometry and sort of the way to think about it. I agree.

It's really counterintuitive and it's hard to visualize. this sort of usual problem with having to plot on two-dimensional paper, right? Things that are essentially three and four-dimensional. So the way to think about it, because the black hole is so compact, right, think about flinging like a little baseball onto the black hole. The black hole is such a tiny spot in terms of the target, right, if you're shooting the target, such a tiny spot that you are almost always going to miss it. So you go, you'll miss it, but then the grip of gravity is so strong that you're,

that you get pulled back out, you come back in, and you're kind of held by the gravity, and then you go back again, right? So if you think about the sort of continual sort of things falling into a black hole with the size of the target is so tiny that you never hit bull's eye that you can imagine things being kind of captured around it. And that's the structure that we call,

we refer to as the accretion disc. And in the couple minutes we have left, I wanted, I apologize, Clifford, I wanted to make sure we were talking about how we talk about these things. Because just as science has advanced in the last 30 years, we've seen so many books about physics and the way the universe works and the way particles, physics work. We've had scientific advances, but we've also had maybe advances in science communication, Clifford. I know you've put out a book on this very topic. Yes, well, I think one of the great things, that's happened and I think people like Hawking and Carl Sagan and others have really helped

encourage this is feeding that thirst that people have to learn what's going on in fundamental research and and so there are many many different kinds of scientists writing about many different kinds of topics and so even if you didn't like a brief history of time there are other books on the same subject matter and there's other books about exciting areas of other physics as well and so I think that's been a really wonderful thing. I think Hawking helped with that by showing that it was possible to get people to buy lots of copies of a book about abstract ideas.

And so there are wonderful books, many of which you can find with an easy search. And we put some examples up. We suggested some, and I think you have them on your website. Yeah, that's at ScienceFriiday.com slash book club. There are some examples. Are we ever going to completely explain everything? Like, is there ever going to ever going to be one book that really just covers it all? Clifford, Priya? I would say no, and I think

that's good because I think there are many different ways of thinking about a topic. Not everyone thinks the same way, so it's good to have many different kinds of books written by different kinds of scientists that bring different aspects of it alive. So I wouldn't want there to be one book. Right, and I think this is the nature of science, right? There's no final answer. We always open up more and more questions. So I don't think we'll ever reach the position of having, being able to have the final word on everything, right? So things will always be evolving.

Our understanding is constantly evolving. And I think that whenever there are lots of exciting new discoveries, I think people, physicists feel very excited to share and write books. So I think we'll keep having lots of books written by lots of different people who think and imagine very differently, and visualize very differently.

And I think here technology is also going to be really important. I think augmented reality, virtual reality, are going to give us another very interesting canvas to start exploring these abstract ideas. Well, I want to thank you both for taking time to be with us. Christy Taylor, thank you for shepherding our book club. You're welcome. As always.

It's a pleasure. It was fun. Thank you. You're welcome, and you two keep writing books. Clifford Johnson, Professor of Physics, University of Southern California. The dialogue's a great graphic history. There. It's wonderfully drawn, and your book's too, Priya Natarajan, Professor of Physics and Astronomy at Yale. Thank you for both taking time to be with us today. One last thing before we go. SciFri is headed to Salt Lake City. Join us next month at Saturday, September 15th at the Eccles Theater,

where we'll talk about exploring new frontiers from the unusual life hiding in forest canopies to the other reaches of space. We've got a great evening of science planned for you, and we've got live music. You don't want to miss it. Tickets are going fast. There is more. info at Science Friday.com slash Salt Lake City. That's September, Saturday night, September 15th at the Echoes Theater, Science Friday.com slash Salt Lake City. Charles Berkwist is our director, senior producer, Christopher Talia Talyata. Interns are our Alexa, producer, our producers are Alexa Lim, Christy Taylor, Katie Haller. Our intern is Lucy Wong, and with technical help from Mitch Kim and Sarah Fishman, I'm Ira Flato in New York. Hi, Ira here, saying thank you for subscribing and

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