Interview Interlude Playlist, Part 10: Dr. Jeff Hoffman

So they've got a new show coming out called One Strange Rock and it is produced by Darren Aronofsky of Mini Movie Fame and all about it's all about the science of planet Earth and the sort of intricate interconnected processes both geological and biological to keep the Earth stable as a sanctuary for life as we know it. And in that sense, it has a kind of uh, ecological Alexander von Humboldt kind of vibe that I really like.

I like it when you can see the large scale and small scale interconnectedness of all things to to make the world how it is. Yes, And speaking of Steve, this is a visual spectacle. Yeah, it's got a lot of really beautiful photography and it's hosted by Will Smith.

I don't know if he ever says Welcome to Earth, and it kind of hope so, uh, And it it tells stories through the experiences of a large cast of real life astronauts who are the only humans ever to venture beyond the shield that protects us from the universe at large. And so because of our partnership with National Geographic for this episode, we got an opportunity to talk to one of the astronauts on the show, Dr Jeff Hoffman, who flew five Space Shuttle missions, including a Hubble Space

telescope repair mission. And this is a great interview. We're just delighted to share it with everybody. Yeah. Dr Hoffman is very knowledgeable from multiple vantage points about the thing that we're gonna be focusing on today, which is the radiation risk from space and how Earth protects us. And he's knowledgeable in a couple of different domains because he's done high energy astrophysics and knows all about the radiation environment of our Solar system in the universe at large.

But he also has a direct experience of what it's like to be an astronaut out in space to sort of go beyond our protective barriers. And that kind of perspective is kind of hard to come by because I would say, one thing, it's really easy to lose sight of in your day to day life, when you're reading about politics or playing with your dog or making some dinner. Is that your body is made of molecules, and in order for molecules in your body to do what they do,

they have to remain what they are. And most of the time, the internal chemistry of our bodies is pretty stable, right, But we have to recognize that the chemical stability of our bodies is an enormous and unique privilege provided to us by virtue of the fact that we live on planet Earth. Yea. And this we get into a truth that we touch on quite a bit on the show, and that is that Earth is just the right planet

for life as we know it. Kind of unsurprising, of course, being creatures that evolved on planet Earth, that planet Earth is just the right planet for us. But despite realizing the kind of anthropic obviousness of that fact, it is still a kind of strange and comforting feeling. Well, wait a minute, is it comforting or is it discomforting? The fact that most of the universe is going to be so hostile to us, so unbelievably hostile, so incredibly violent,

that it's just impossible to even consider. And I'm not even talking about the vaporizing heat of stars or the cold,

airless void of deep space. I'm talking about the fact that the universe is an acid bath of killer radiation, including ionizing radiation, which often takes the form of these high energy charged particles that blast through animal bodies, damaging and changing the molecules within them as they go along, and even changing the DNA of ourselves, altering the blueprints for cell replication and bringing about tissue damage, sterility, and cancer.

And so that body integrity and chemical stability we so take for granted to keep living is only possible because of the planet, the inhabit which shields us from being blasted by the Sun nearby and by the galaxy at large. Yeah, it's it's interesting to think about this that we we are creatures of the shallows. So life as we know it essentially thrives in a tide pool, protected from the

full onslaught of wind and wave. You know, if you've ever been to a to a number of beach environments, you've seen those areas right where um, where that the waves are crashing but there, but but there's this pool, this uh, this area of calm water that is protected from all of that, and that's where a lot of life can thrive that otherwise would not be able to

bear the hostilities beyond the rocks. And it actually reminds me of this quote by John Steinbeck Uh and and uh, he's not directly talking about what we're talking about here, but the comparison is just beautiful. He he wrote, the knowledge that all things are one thing, and then one thing is all things plankton, a shimmering phosphorescence on the sea, and the spinning planets and an expanding universe, all bound

together by the elastic string of time. It is advisable to look from the tide pool to the stars and then back to the tide pool again. Yeah, our earth is protected not from wind and waves, but from the full blast of solar and cosmic radiation. Instead of rocky sea walls were protected by a robust atmosphere and most importantly,

the magnetosphere. Yeah. The interesting other side to the fact that we've got this kind of connected consciousness that we're aware of, Like there is no real division between the Earth and the heavens. They're just different places. The only real division is distance, And so all the universe really is connected and does have a common origin in the Big Bang. But at the same time that connectedness, we use the word connected in such a happy way. It's

like nice to be connected to things. But you can also think about that is extreme vulnerability, like you are right next door to everything in the universe that would Russian annihilate you. And what we've got standing in the way of those those crushing annihilating forces beyond our power to control, is essentially a big magnetic field and a thin layer of gas around the rocky surface of the planet. That's right. So basically what we have going on here

is the Earth solid intercore and liquid outer core. They play a crucial role in protecting life as we know it from deadly deadly radiation. Differences in temperature and composition in the two core regions drive a powerful dynamo emitting Earth project protective electro magnetic field. And remember this is one of the key factors we have to consider improposed interplanetary space travel and establishing stations in other worlds. The only planets in our Solar System with some form of

magnetosphere in place our Mercury, Earth, Jupiter, Saturn, Uranus, and Neptune. Right, so then, of course you've also on the surface of the Earth got the atmosphere to count on, because that means that there's more stuff that radiation has to get through to it to you, and so the atmosphere will block some kinds of incoming radiation. But the other big protector is the magnetosphere that keeps these particles directed away

from the Earth. Some of course still get through, right, And also the magnetosphere serves to protect the atmosphere as well, Yes, because if you don't have a magnetosphere, your atmosphere over time can be stripped away, which is one of the things that they think probably happen to Mars long ago. Right. So it's our protective barrier against the elements. It's our battlements. And the only humans who have walked these battlements are

astronauts such as Dr Jeff Hoffman. Now, most astronauts never even go beyond the shield that protects us, right, we know that astronauts in space are exposed to extra levels of radiation, and that's one reason you want to limit your time and space. You're like, you can't go live in the I S S forever. They want to bring you back eventually because the more time you spend up there, the more you're exposed to this dangerous radiation that could

harm you in the long run. But even up in the I s s you're still you're still benefiting from a large part of the Earth's protective shield. Right. Yes, it gets a lot worse if you want to go to the Moon, right to Mars, or colonize another planet. Yeah, because then you're going beyond Earth's protection. So I guess we want to go now to our conversation with Dr Jeff Hoffman UH to talk about the radiation risks posed by the universe and what astronauts have done and can

do to protect themselves. But first I guess we should give you just a little bit of background on Dr Hoffman. Yeah, So his original research interest were in high energy astrophysics, specifically cosmic gamma radiation and X ray astronomy, and then his doctoral work at Harvard entailed balloon born low energy gamma ray telescopes and the design and then the testing of this technology. From nineteen seventy to nineteen seventy five.

During post doctoral work at Leicester University, he worked on several X ray astronomy rocket payloads, and then he worked in the Center for Space Research at the Massachusetts Institute of Technology from nineteen seventy five to nineteen seventy eight as projects scientist in charge of the orbiting h e A oh one A four hard X ray and gamma

ray experiment, which launched in August ninety seven. But then in seventy eight he was selected to become an astronaut and he went on a total of five different Shuttle flights. So in eighty five he went up on a Discovery, nineteen ninety on Columbia, two on Atlantis, ninety three on Endeavor, and then in nine on Columbia. All told, one thousand, two hundred and eleven hours in space twenty one point

five million miles. That's a lot of miles. Frequent flyer, Yeah, so he he is a not only a pedigreed scientist, of a pedigreed astronaut. Five Shuttle flights, that's impressive. That's five more than the vast majority of human beings. All right, we're gonna take a quick break and when we come back, we will be heading straight into our interview with Dr Jeff Hoffman. Thank hey, Dr Hoffman, welcome to the show. We're really glad to have you well, nice to be here,

looking forward to it. I was wondering if you'd would start off by telling us a little bit about your research from before you became an astronaut. What what made you interested in high energy astrophysics and um, what were your pursuits in that field. Well, I grew up with an interest in space. I lived in or near New York City. My dad used to take me to the planetarium to see the new show every month. UM. I

saw the birth of the space age. You know, I was alive whence but Nick was first launched when You're a Gagaran and John Glenn flew and so. I was also interested in human spaceflight, although it was apparent to me that all the early astronauts were military test pilots and that was not a career for me. But space in general I was fascinated with and went on to become an astronomer. I got a doctorate in an astrophysics at Harvard UM, and I was attracted by UH, what

we call high energy astrophysics. It was a totally new field at the time UM the discovery of X rays from celestial objects and gamma rays. UM. It was a new branch of astronomy opening up just like radio astronomy opened up back in the nineteen thirties. And UM that struck me as being UH an area where we were almost bound to make new discoveries because we had never looked at this type of radiation before. So my professional career as an astronomer consisted in designing X ray telescopes

and then putting them into space. First with I was using high altitude balloons when I did my pH d thesis, and then UM I spent three and a half years at Leicester University in England, UH and we had both sounding rocket experiments where we would put our telescopes up above the atmosphere. You have to go above the atmosphere because X rays and gamma rays are absorbed in the atmosphere, which is a good thing for us here on the ground, but it makes life difficult for astronomers because you have

to go above the atmosphere to see this radiation. And and that was kind of cool as well, because I was always interested in space and rockets and and so I was combining the technological interest with what I thought was a very exciting scientific field. And then I came back to M I t and we we had actually our own X ray satellite, and the most exciting research that I was doing we discovered these things called X

ray bursts. You look at an X ray object giving out relatively low level of radiation fairly constantly, you know, and then all of a sudden, you know, bam, it increases by hundreds and hundreds of times and then gradually fades away over the course of anywhere from a few

seconds to a few minutes. And we we discovered lots of these, and this was a completely new phenomena, and that was probably the most exciting thing that I did scientifically, was uh, finally figure out what was what was causing these.

It was actually neutron stars um orbiting around regular stars, and the gravitation of the neutron star was such that it would suck hydrogen off the regular star, and the hydrogen would accumulate in a layer on the surface of the neutron star, and then eventually the whole thing would detonate in a in a huge thermonuclear explosion. So what we were looking at were hydrogen bombs, you know, ten miles in diameter. Uh, you know, it's pretty spectacular stuff.

So that was really exciting, and I was all set for a uh you know, career as an astronomer. And but that was now in the mid to late seventies when NASA was getting ready to fly what was then the brand new Space Shuttle. And neat thing about the Stay Shuttle from my point of view, was that it had a crew of seven, but they only needed two pilots. The pilots were still going to be military test pilots, but it really opened things up for engineers, scientists, and

medical doctors. And when NASA put out a call for for astronauts for the Space Shuttle and and indicated that yes, they really did want scientists and engineers and doctors, um, I thought, well, I'll apply and I was lucky enough to get selected the first time around. So that basically was the end of my career and astronomy research. I had a I'd say it was quite successful, and had I not been selected, I I hope I would have had a good career as a research aster physicist. But

getting selected by Nazis and astroall certainly changed my life. Interesting, before we ask you about a little bit of your spaceflight experience, I just wonder does research into high energy astrophysics, Like, if you're looking at neutron stars and bursts of X rays and gamma rays and stuff in the universe, does that change the way you feel about the sky when you look up at it and most people look up and see twinkling stars and it feels kind of nice

and cool and calm. Do you do you envision the universe emotionally as one full of radiation and danger and high energy? Oh? Absolutely? I mean, you know, when you look up, just a simple look up at the stars, everything looks pretty constant and unvarying. And when you realize that there's things exploding and going off all over the place that trem in this areas of high gravitation, high magnetic fields, charge particles. Uh, yeah, the universe is a

pretty violent place. Um and uh, you don't see it with your naked eye, but modern astronomy has has opened this up to us. Dr Hoffman, can you tell us about some of your your space flight experience? So what was the Hubble service mission? Like, well, let me let me start a little bit further back with my first base flight, because that, of course, for any astronaut, is is an exciting moment when you get the call from management and they say, oh, you've been You've got an

assignment to your first space flight. Um. We were supposed to take up two satellites and put them into orbit and theres pop them out of the cargo bay of the shovel, which was what the shovel was doing in the early days, and then come home. It was going to be a short, relatively short mission four days or so. UM. And as it turned out, the second of the two satellites that we popped out of the Shuttle didn't turn on. UM.

You know, I had nothing to do with us. All we were supposed to do was was get it out of the Shuttle into orbit. But when when we reported that it did not seem to have activated, NASA went into a big study mode and they figured out the there was only one single point failure that we could possibly do something about. There's a little switch on the

outside of the satellite that maybe had gotten stuck. And so they scheduled, for the first time in NASA history, an unplanned spacewalk where my partner and I went out. See I had been trained to use space suits, but we weren't planning to do a space walk on my first flight, but they sent us out to fix it, and um, so that was a totally unexpected, uh, incredible experience, you know, getting to go out and do a spacewalk, which you know all astronauts would like to go out.

It's the most intimate experience that you can have of being in space, is actually putting on a space suit and going out of the airlock and and it's you know, kind of you face to face with the rest of the universe. It's it's an incredible experience. And we did a good job. And and so um I got identified as as somebody who was good at space walking, and I worked on a lot of advanced spacesuit development and

various things. And then when it came time to select a crew to go up and try to repair the Hubble telescope. And of course, nowadays, people who weren't alive at the time when Hubble was put in orbit don't don't really appreciate what a disaster it was for NASA. I mean, this billion and a half dollar telescope which had been launched with great expectations about how was going to revolutionize our view of the universe, and then to find out that it couldn't focus properly. I mean, how

could NASA make a huge mistake like that? Was what everybody was was asking and it was absolutely critical. I mean, as I say, people don't remember what a disaster it was. But NASA and Hubble were the joke of late night comedians. Pubble was denounced in the halls of the U. S.

Congress as a techno turkey. NASA was trying to get Congress to approve funding for the International Space Station at the time, and as you can imagine, NASA wasn't very popular with Congress, so UM, basically they were told, you know, go to something about Hubble and then come back and

talk to us about the space Station. In any case, NASA wanted to do everything possible to reduce the risk of failure in this rescue mission, and one of the things that they decided was that only people who had previously done spacewalks would be eligible to do the spacewalks for the Hubble rescue. And and because of this unplanned space walk that I did way back on my first flight, UM, and I had had two subsequent flights since then, so Hubble for me was my fourth flight, and I had

my spacewalkers Union cards. So I was fortunate enough to be on the crew and that was suddenly, of all the things I did as an astronaut, the one with the most lasting impact was obviously rescuing Hubble and turning it from basically nassas worst disaster um scientifically to its

most successful and productive scientific mission ever. So it was a and and of course as a former astronomer, as well as being an astronaut, being able to put my two hands on the Hubble telescope up in orbit was I mean, it was the thrill of a lifetime and we fixed it and a great thing you did well.

I I know that many of my former astronomy colleagues after the mission would come I can't tell you how many people would come up to me and say, oh, Jeff, thank you so much for thinking novel, because you know, my my professional career was depending on this, And all I could say was, well, it was a pleasure, you know, thank you. It was pleasure, It really was. So you mentioned that when you were out on spacewalks in in the e v A, that you had this kind of

intimate experience with the universe. It was like putting you face to face with the outer universe, and I wonder about something. So there was a sci fi novel I read a couple of years ago where a character is born and lives her whole life in simulated environments inside a generation starship, and she finally at one point comes back to Earth late in life, and she's outside and discussing the idea of getting sun burned. And she's so unfamiliar with the concept of Earth and the Sun that

she calls this. She's horrified, and she calls this getting burned by radiation from a star. I wonder, is there a moment in space, you know, outside vehicle activity, where you begin to think of the Sun not as the sun but as a star and other kinds of alienation effects? Now, absolutely, I mean this is something when I give public talks, I I often show a picture of the sun in space, and then I asked the audience, there's something very strange about this picture. Can you figure out what it is?

And most people don't quite get it. But what you're seeing is the sun in a black sky. And think about it. You've never seen the sun in the black sky because every time the weather is clear, you go out and of course, our atmosphere scatters the blue light preferentially, and so the sky is blue, and so every human being throughout human history until the space age, has only

seen the Sun in the blue sky. We see the stars in the black sky because there's not enough really from the stars to be scattered and make the sky look blue, but not the Sun. But in space, you really see the Sun as a star in a black sky. Of course, it's it's bigger and brighter than any of the other stars because it's close to us. But yeah, you really do appreciate the Sun as a star and that that that was something I didn't have to go out and it just looking out the window of the shuttle.

You you get that appreciation, but it's a totally different perspective, as are so many other things that you see. I mean, that's one of the things about being off the surface of the Earth is that you look with a totally new perspective. Just like most people don't remember the first time they ever flew in an aeroplane, But if you if you pay attention and look out the window, you also get a totally new perspective on the on the Earth.

Although most people don't bother to look out the window these days, but from space, we spent a lot of time looking out the windows and I never got fired of it. It was a completely um different perspective, not only on the Earth, but on on the heavens. It was great flying during the nighttime. You know, we'd start, we'd enter darkness in the northern hemisphere and you could look up and see all the familiar northern constellations, the Signus,

the Swan, which is the Northern Cross. And then fifteen minutes later you'd be in the southern hemisphere and see Alpha Centauri and the Southern Cross. And that's something else that you never do when you're on the surface of the Earth, is to see the northern and the southern skies at the you know, within a half hour of one another. Would you describe this as as being a kin to the the overview effect? Well, the overview effect um maybe some of the listeners don't aren't familiar with that,

but it was coined by Frank White. He's an author who thought a lot about I guess he had this kind of inspiration during an air airplane flight when he was looking at the ground and and feeling a little bit removed from the Earth. But then he started thinking about, you know, what what must it be like for the astronauts. So he came down to Houston and I was one

of the first astronauts that he interviewed. And you know, the idea is it It really does change your perception of planet Earth to to look at it, uh and and actually see the Earth as a planet um to see from an airplane, you can look out the window and see entire cities spread out below you. But from an orbiting spacecraft you you can see entire countries or continents. Really the Earth is very beautiful, and so you you do get this relationship that develops between you and the planet.

At the same time, you can see examples of environmental degradation caused by humanity, which is you know, now visible from a cosmic perspective, and that's pretty scary, you know, the deforestation of the Amazon, the silting up of harbors and rivers and uh, just all sorts of things. And you realize that you definitely get a feeling of the finiteness of planet Earth and this sense of what it is to be removed from the Earth and how that changes your feelings for Planet Earth. Is what Frank called

the overview effect, and many astronauts have reported this. There's now actually a movie that that you can find on on YouTube or vimeo u the about the overview effect, made by a cinematographer in in the UK interviews with a lot of different astronauts, myself included. So yeah, it's um it so totally different perspective you get when you're hundreds of miles above the surface of the Earth. So uh, going back to the idea of radiation risk beyond the

surface of the Earth. On the missions you flew in the eighties and nineties, what did you and the other crew members understand about radiation risk in space and what what kind of measures were in place to protect you other than just limiting the duration of missions. Shuttle flies like the International Space Station and what we call low Earth orbits. So we are basically below the Van Allen radiation belts, were inside the Earth's magnetic fields, which shields

us from most h cosmic radiation. So um, it's it's a much more benign environment than when you actually left the Earth to head out to the Moon and you're outside the Earth's magnetic shield and then you're exposed to the direct um impact of galactic cosmic rays and U

and charge particles coming from the sun. UM you ultra violet light, of course, is not deflected by the magnetic field, and we have to have protection against ultra violet light otherwise it would destroy our eyes, which is why the space helmet spacesuit helmets have those those gold visors which protect you. And there's ultra violet protection on all of the windows of the Space Shuttle and the International Space

Station windows. So UM, you know, electromagnetic radiation, cosmic the the ultra violet rays we have to protect ourselves against. And then of course there's the infrared radiation from the sun. The heat when you're in the direct sunlight, temperatures of things exposed to direct sunlight and space can go up

above the boiling point of water. And so when you're out in your space suit, you need good cooling and we do that by sublimating ice and that cools off the water, which we then circulate in in UH liquid cooling garment with lots of tubes where you can run the cold water right over your body and take away heat. UH and you can adjust that because when you go into the dark side, it gets very very cold, and

there you don't want this extra cooling so um. From the electromagnetic point of view, we've got to protect ourselves against ultra violet radiation, and we've got to have good thermal control for heat for the charge particle radiation. As I say, we're in a relatively benign place. When we did our Hubble mission. Hubble was put as high up as the Shuttle could go, about four hundred miles six uh, and we were kind of scraping the bottom of the

van Ellen intervan Ellen radiation belts. So it was calculated that we were going to get about ten times the normal exposure for shuttle flight, which which still was nothing to be concerned about from a cancer point of view.

But but they had us where radiation monitors the whole time, and particularly when we went outside, and they tried to schedule the spacewalks so that we would not be outside when we went through what is known as the South Atlantic anomaly, which was a part of the orbit where the radiation is much higher than the rest of it. That's about all you can do, obviously, if there were

ever a huge solar eruption. UH. We always had the option of coming home and and uh, you know, getting underneath the atmosphere for the extra protection, but we never had to do that. What about extended future missions, how did the change and what sort of solutions are being developed to protect future astronauts. The radiation risk is recognized as being one of the most serious if you're going to be outside the Earth's magnetic field for a long time, either on the surface of the Moon or on an

extended trip to Mars. On the surface of the Moon. Actually getting to the Moon is is not such a big deal because you can get there in three days and so your exposure time is limited. But if you're gonna spend any significant amount of time on the surface of the Moon, obviously the Moon blocks about half of the galactic cosmic rays, but but you're still exposed to

all the rest of them. And it may be that you know, will they're they're talking about possibly having underground habitats in waba tubes, which we know exists on the Moon. You're gonna have to do something to shield yourself from the radiation because being exposed to it for a long time is going to be dangerous. That's something that very difficult to do. If you're on a trip to Mars, because you can't carry that much mass with you to protect yourself and UM, so NASSE is interested in other ways.

There are some I think very interesting research going on about UM pharmacological protection against radiation. If there were some way that we could enhance the body's ability to repair d NA UM, that would make the impact of radiation much less serious. We know that there's bacterias which can withstand hundreds of times the amount of radiation that a human can. They've developed the ability to repair much more

significant damage to DNA than we're able to do. UM. There may be genetic clues about how to protect against radiation, so the point being that we've got to look for other ways besides just shielding, and of course developing better, more powerful propulsion systems so that we could get the Mars quicker would be a big help as well, not just from a radiation point of view, but logistically, you've

got to carry everything you need UH. You can't get resupplied once you're on your way to Mars, so all the food, the medical equipment, the UH spare parts and everything. They quicker you can get there, the better, So there's a lot of ways that that we're looking at that will make long duration spaceflight outside the Earth's magnetic field safer. But most of these things are still works in progress

right now. We we don't have those solutions available now, and and correct me if I'm wrong, But once you get to Mars on a Mars mission on the surface, you're not a whole lot better off than you are in space right as far as radiation because first of all, Mars, just like when you're on the surface of the Moon, Mars is blocking half of the radiation just by its mass. And then Mars does have a bit of an atmosphere

which gives you a little bit of protection. But you're right, there's still the radiation environment on the surface of the Mars of Mars is more severe than being in lower orbit, and so radiation protection on the surface of Mars will continue to be an issue, just like it will be on the Moon. You'll have to have a certain amount of protection in your habitats. But again, the other the other thing, um, you know, there's two aspects of the

dangers of radiation. One of them is that in the long term it will lead to an increased incident of cancers like leukemia. Well, one of the things that we're realizing is that our ability for early detection and treatment in cancer is continually improving, and so maybe, you know, twenty thirty years from now, that's just not going to be as much of a problem. The other UH potential

problem from radiation are acute impacts. There. There have been some experiments that have shown a potential loss of cognitive capability for rats when they're exposed to radiation. Um, you certainly would not like to get to Mars and find out that your i Q is decreased by twenty points. UM. There are potential effects of acute effects of radiation on the circulatory system, on the nervous system, and that's an

area of very active research now it's relatively new. Traditionally, we were just concerned with the long term impact of radiation that is ultimately causing cancer, unless, of course, you had a huge solar flare. You know, if you get enough radiation all at one time, you're going to die or have serious UH illnesses, and and um, you know, we we would like not to be in space when they have a huge solar flare. But you know, statistically those don't happen very often and so far we've been lucky.

So we've discussed the ambient radiation risks in space. Obviously, within our solar system, you you've got solar radiation to worry about, and you've got charged particles from the from the galaxy of the universe to worry about. But also UM, apart from these ambient radiation risks, does it make sense to also, uh, for space farers to worry about anomalous radiation risks UM? I know, for example, like X ray bursts and gam rey bursts are extremely rare in the universe.

Are they so rare that uh that we just don't have to think about that? Or will the future of space exploration needs don't really think about it? I mean if if, uh, if there were a huge black hole merger like I was observed with the gravitational radiation, you know, billions of light years away, if something like that happened right near us in the galaxy, it would be bad news. But there's absolutely nothing we can do about it, and so it's just not something that that we even bother

to think about. And what about solar anomalies, I know you mentioned like a solar event solar I mean solar flairs are recognized. I mean, there was a big solar flare in nineteen seventy two in August, which just happened to occur between Apollo sixteen and Apollo seventeen. Had it occurred when astronauts were on the lunar surface, there's been a lot of discussion of whether we've would have been fatal or whether it would have just been very bad

for them. But it would have been a very serious effect. But that solar flare in nineteen seventy two was not nearly the strongest solar flare that's ever existed. I mean, there was the Carryington event back in the mid nineteenth century,

which was so powerful. Of course, that was we didn't have satellites, we didn't have electronics going, but they did have telegraph lines, and that solar flare collapsed the Earth's magnetic field to the extent that the moving magnetic field induced voltages in the telegraph lines, which caused fires in telegraph offices. I mean, if if a flare like that hit us today, it would cost Lloyds of London did an estimate of that. I mean, it would be like

a trillion dollars worth of damage. All of our satellites would be destroyed, Electronic systems all over the world, electrical power grids would go down, and there's nothing we can do about it except that statistically something like that happens maybe once every five hudred years or so. UM. So far we've been lucky. Not too much more you can say about it. Uh, we are. People are still doing research to try to be able to predict solar flares,

so far without many positive results. But I just read recently some new researches indicating that, you know, maybe they've made a breakthrough. UM. Being able to predict solar flares in advance would be a big help, so that at least you could get ready for it, and if you had astronauts on the Moon, at least they could try to get inside their shielding. But other than that, UM, it's statistics, and so far we've been lucky, all right, Dr Hoffman. In other interviews, you have stated that shimp

cocktail was your favorite food in space. Can you explain for our listeners why you selected? Sure? You know, when when when you take away gravity, there's an upward migration of it from your lower body to your upper body, and so you get a lot of extra fluid in your head. It's a little bit like having sinus congestion, and it it decreases your sense of smell, so that, um, you you, the food becomes very bland. They provide extra Tabasco sauce that we can sort of spice up our food.

The nice thing about the shrimp cocktailers dehydrated, so the shrimp themselves, uh, you know, there's nothing to write home about you. You put a little bit of water on them and they don't have that much taste, but they pack it in a really really hot horse radish sauce. So I found if I would eat a shrimp cocktail before dinner every night, that horse radish would kind of open up my nasal passages so that I could smell

and taste the rest of the food a little bit more. So. That's why it was my favorite food, not because it intrinsically taste good. I mean, as a shrimp cocktail, it was you know, if they served it to you in a restaurant, you'd send it back, But it really opened up the nasal passages so that I can enjoy the rest of my meal. Well, I guess it's those little pleasures that make life forth living. There you go. Well, thank you so much. It's been such a privilege to

talk to you, Dr Hoffman. We really appreciate your sharing your time with us. Been a pleasure, and I hope it's given maybe a new perspective to some of the listeners who haven't heard some of this stuff. So um, thanks for your interest and it's been fun. Yeah, thank you so much. Thank you. You have a great day, sir. All Right, well, thanks once more to Dr Jeff Hoffman and to National Geographic for enabling us to have this wonderful chat. We're gonna take a quick break and we

come back. Joe and I will discuss the interview a little bit before we close out the episode. All right, we're back, So Robert. Dr Hoffman mentioned a few things in that interview that I thought were really interesting and we might want to follow up and talk about a

little bit. One of the things you mentioned when we were talking about solar anomalies was the idea of the Carrington event or the solar storm of eighteen fifty nine, And this just stuck in my mind because this is one of the most fascinating and I think maybe lesser known crazy astronomical events in history. Yeah, and indeed it may have been the largest solar energetic particle event in the past several hundred years. So why do we call

it the Carrington event? Well, it's a name for amateur astronomer Richard Carrington, who observed quote two patches of intensely bright and white light erupting from a cluster of dark sun spots. They vanished within five minutes, but then within a matter of hours, the effects of this event were felt on Earth. So what do those effects look like? Well, as a Dr Hoffman uh alluded to, telegraph communication around the world began to fail. Sparks were flying from telegraph machine.

Telegraph operators were in some cases shocked, and then also colorful auras in the sky were causing the birds to chirp at night. Yeah. So the solar flaring question had the power of an estimated ten billion atomic bombs, and ice core samples reveal that the Carrington event was twice as big as any other solar storm within the last five hundred years. This is the kind of thing where if it were to hit today, the estimates are just in trillions of dollars worth of damage, it would just

be a massive blow. And Dr Hoffman alluded to this as well, the idea that it would have. It would impact our satellites, it would impact technology on a scale that just simply did not exist in eighteen fifty nine. But of course it would also greatly affect any exposed astronauts or space farers that you know, we're colonists, or wherever outside of the protection of our shield that didn't didn't even fully protect us from this event. Yeah, yeah,

you know. I I actually interviewed a heliophysicist Dr c Alex Young several years ago about solar storms, and he pointed out that that our mom are an electrical grid in particular, is just highly vulnerable to this sort of thing. He told me, quote, the power grids that we have in the US and actually all over the world are interconnected in very fragile If the currents large enough, it can short out the largest of the transformers, which can knock out the power grid over the scale of a country,

of a continent, or even across the whole globe. Yeah, and uh, for just a minor example of the sort of thing, in Canada's hydro Quebec power grid experienced a similar shock in nine from a particularly powerful sunstorm, and this caused the grid to go down for over nine hours, resulting in revenue losses estimated in the hundreds of millions of dollars. And that was just the small potatoes compared

to something like the Carrington event. Yeah, with our earthbound minds, it's impossible for us to grasp the real power and magnitude of solar events. Like if you've never seen one of those pictures of the Earth superimposed to scale against a solar prominence, it's it's amazing solar prominence. Are these events where this monstrous loop of plasma erupts out of the photosphere, which is the apparent surface of the Sun, and then it curves through the Sun's corona guided by

solar magnetic fields. And this is not even really the core of the Sun itself, is just an event. It's like weather, it's a it's an event on the surface of the Sun. But this event itself is tens of times bigger than the entire planet Earth. And you see one of these pictures. When you look at the vulnerability

and tininess of human scale projects becomes absurdly apparent. The comparison that comes to My mind is if you ever been out in nature, as as I know you, you like to venture out in the nature on hikes and and so forth, you ever observe a bird's nest or a wasp nest, some sort of animal structure or nest, and you think about yourself, well, that's a horrible place to put that, don't you know, tiny bird that eventually

the wind is gonna blow. Uh, don't you know that when it rains, that's that's just not a very protected place. Don't you know that's my front porch. And I'm probably gonna knock you down eventually, just because you're inconvenient to me. And then when you think about everything that that that is life on earth, and then everything that humans have built, and you think of the vulnerability that is intrinsic in

all of that. Uh, we're really no different from from any wasp that decides to build its nest on the bottom of a porch. Swing on a geologic or cosmic time scale, our projects are so hilariously short sighted. But then again that that's just how we're built, right. I Mean, it's very difficult for us to seriously focus on a project that we think will take place over say a hundred thousand years or even a million years. Yeah, totally. We're just we we are short sighted as a species.

That's what we've evolved to be. Now. On the subject of long time scales and and the cosmic scale of events, I asked Dr Hoffman about whether a space faring species should really worry about things like murray bursts or X ray bursts, which I think is kind of a weird question because on one hand, it's something that would pose a very serious threat, but these things are also incredibly rare in the universe, and they're incredibly rare in the galaxy,

So it's hard to factor into one's idea about something like space exploration how much you should worry about something that is almost never going to happen anywhere near you, but if it did, it would be catastrophic. Yeah, it's coming to It kind of reminds one of of, of course, the the seafaring explorers of old and to say, well, if you go out in that boat, you you might very well drown, you might run into a hurricane, etcetera.

And the hurricanes are pretty common. Yeah, those are pretty common, and like if it was you would have to say, oh, yeah, well, I we've we may very well drown, we may very well die die on some distant island, but in the chances here are are less. But it's ultimately the same scenario, like it's it's of course it's safer to go out and explore is certainly in the short term. But are we the type of species that is going to do that?

Of course, then again, if there were a nearby gamma ray burst, as unlikely as that is, that would be bad even if we were on Earth. Yeah, yeah, so these in particular, like so the gamma ray bursts um are omitted by powerful supernova that are dubbed hypernova and you can think of these is it's just like the

energy shrapnel from a Titanic exploding star. And uh, you know, even though they are rare, the radiation killing zone for an exploding hyperstar has been estimated to be around six thousand light years across compared to a normal star's thirty light year kill zone, and even smaller gamma ray doses can have a serious neurological impact on an individual. Oh yeah,

you don't want gamma rays no matter what. There was a Cold Spring Harbor Laboratory study on mice that found that gamma radiation targeted a particular type of stem cell and the hippocampus, the an area of the brain you know believe to be important for learning and mood control, and normal doses of space radiation also pose a serious risk.

In a separate experiment, the NASA Space Radiation Laboratory dosed mice with radiation equal to the amount and astronaut might receive on a three year voyage to Mars, and scientists discovered significant damage to hympocampus stem cells responsible for repopulating

the brain with new cells. So, without proper radiation shielding, lengthy space exploration might be a recipe for the kind of like cognitive and emotional breakdown that Dr Hoffman alluded to, the idea that you would have your astronauts arrived at their destination with reduced cognitive abilities, and that this is exactly the time when presumably all the hard work is

right in front of them. They're gonna have to land on the planet and the planetary explorers, but have to do so with the reduced with reduced brain power, it's a daunting problem. Now. Of course, in all of this discussion, we don't want to give the impression of discouraging space exploration or anything like. No, no, no, uh, just because

of all these risks. But in talking about them, it's just that we have to recognize how hard this project is and how dangerous it is, and how much investment of research and technology it's going to take to make this something that humans can safely and reasonably do. Yeah. Well, we did an episode last year we talked about proposed ways of genetically altering UH astronauts of the future so that they might be less susceptible to the damages of radiation.

So there there are multiple fronts on which science, current science and future science may be able to to tweak all of this in our favor. But it is still, as you said, it's a dangerous universe and UH and we're ultimately a very fragile species. It is evolved to thrive within a very slim portion of our own UH atmosphere and within a slim portion of our own terrestrial environment. Even a large portion of the Earth will kill you,

It's true. Yeah, if you were to teleport up to the top of Mount Everest, you would not be able to breathe, or if you were to suddenly appear at the bottom of the ocean and find yourself of surrounded by what three thousand atmosphere is worth of pressure, or the north or South pole, or in the middle of a desert. There's just a lot of bad places to be. But I don't mean to trash the Earth, of course.

I mean this takes us back to the idea of the overview effect that we mentioned a little bit with Mr Hoffman, that having a cosmic perspective on the Earth, realizing the ultimate kind of emptiness and violence and hostility of the universe at large, and the the incredible uniqueness and privilege of this one little rock floating in space, it really should give us a perspective of thankfulness and transcendence. Uh, something that makes the petty human squabbles kind of fade

away into non importance. All right, today you have it. I hope everyone enjoyed our chat with Dr Hoffman. We certainly enjoyed chatting with him. Absolutely. It was a pleasure and I don't know, he gave me a lot of stuff to think about. Yeah, this is the first time we've had an actual space traveler on the show. Uh, and it did it did not disappoint Maybe it won't

be the last time. Yeah, who knows. Now, if there's anything in our discussion with Dr Hoffman that really leapt out at you and you would like to hear a whole episode of Stuff to Blow Your Mind on, let us know about that, because because he covered a lot of ground in the interview totally. Don't be shy to get in touch with us and let us know what you would like us to pick up on from that conversation in the future, right, And you can do that

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