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Speaker 1: Welcome to Stuff to Blow Your Mind from how Stuff

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Speaker 1: Works dot Com. Hey, welcome to Stuff to Blow your Mind.

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Speaker 1: My name is Robert Lamb and I'm Joe McCormick. And

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Speaker 1: today we've got a very special episode for you all

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Speaker 1: out there. We are doing a partnership with National Geographic YEA.

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Speaker 1: So they've got a new show coming out called One

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Speaker 1: Strange Rock and it is produced by Darren Aronofsky of

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Speaker 1: Mini Movie Fame and all about it's all about the

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Speaker 1: science of planet Earth and the sort of intricate interconnected

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Speaker 1: processes both geological and biological to keep the Earth stable

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Speaker 1: as a sanctuary for life as we know it. And

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Speaker 1: in that sense, it has a kind of uh, ecological

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Speaker 1: Alexander von Humboldt kind of vibe that I really like.

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Speaker 1: I like it when you can see the large scale

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Speaker 1: and small scale interconnectedness of all things to to make

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Speaker 1: the world how it is. Yes, And speaking of Steve,

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Speaker 1: this is a visual spectacle. Yeah, it's got a lot

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Speaker 1: of really beautiful photography and it's hosted by Will Smith.

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Speaker 1: I don't know if he ever says Welcome to Earth,

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Speaker 1: and it kind of hope so, uh, And it it

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Speaker 1: tells stories through the experiences of a large cast of

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Speaker 1: real life astronauts who are the only humans ever to

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Speaker 1: venture beyond the shield that protects us from the universe

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Speaker 1: at large. And so because of our partnership with National

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Speaker 1: Geographic for this episode, we got an opportunity to talk

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Speaker 1: to one of the astronauts on the show, Dr Jeff Hoffman,

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Speaker 1: who flew five Space Shuttle missions, including a Hubble Space

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Speaker 1: telescope repair mission. And this is a great interview. We're

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Speaker 1: just delighted to share it with everybody. Yeah. Dr Hoffman

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Speaker 1: is very knowledgeable from multiple vantage points about the thing

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Speaker 1: that we're gonna be focusing on today, which is the

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Speaker 1: radiation risk from space and how Earth protects us. And

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Speaker 1: he's knowledgeable in a couple of different domains because he's

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Speaker 1: done high energy astrophysics and knows all about the radiation

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Speaker 1: environment of our Solar system in the universe at large.

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Speaker 1: But he also has a direct experience of what it's

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Speaker 1: like to be an astronaut out in space to sort

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Speaker 1: of go beyond our protective barriers. And that kind of

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Speaker 1: perspective is kind of hard to come by because I

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Speaker 1: would say, one thing, it's really easy to lose sight

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Speaker 1: of in your day to day life, when you're reading

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Speaker 1: about politics or playing with your dog or making some dinner.

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Speaker 1: Is that your body is made of molecules, and in

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Speaker 1: order for molecules in your body to do what they do,

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Speaker 1: they have to remain what they are. And most of

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Speaker 1: the time, the internal chemistry of our bodies is pretty stable, right,

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Speaker 1: But we have to recognize that the chemical stability of

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Speaker 1: our bodies is an enormous and unique privilege provided to

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Speaker 1: us by virtue of the fact that we live on

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Speaker 1: planet Earth. Yea. And this we get into a truth

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Speaker 1: that we touch on quite a bit on the show,

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Speaker 1: and that is that Earth is just the right planet

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Speaker 1: for life as we know it. Kind of unsurprising, of course,

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Speaker 1: being creatures that evolved on planet Earth, that planet Earth

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Speaker 1: is just the right planet for us. But despite realizing

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Speaker 1: the kind of anthropic obviousness of that fact, it is

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Speaker 1: still a kind of strange and comforting feeling. Well, wait

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Speaker 1: a minute, is it comforting or is it discomforting? The

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Speaker 1: fact that most of the universe is going to be

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Speaker 1: so hostile to us, so unbelievably hostile, so incredibly violent,

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Speaker 1: that it's just impossible to even consider. And I'm not

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Speaker 1: even talking about the vaporizing heat of stars or the cold,

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Speaker 1: airless void of deep space. I'm talking about the fact

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Speaker 1: that the universe is an acid bath of killer radiation,

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Speaker 1: including ionizing radiation, which often takes the form of these

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Speaker 1: high energy charged particles that blast through animal bodies, damaging

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Speaker 1: and changing the molecules within them as they go along,

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Speaker 1: and even changing the DNA of ourselves, altering the blueprints

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Speaker 1: for cell replication and bringing about tissue damage, sterility, and cancer.

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Speaker 1: And so that body integrity and chemical stability we so

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Speaker 1: take for granted to keep living is only possible because

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Speaker 1: of the planet, the inhabit which shields us from being

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Speaker 1: blasted by the Sun nearby and by the galaxy at large. Yeah,

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Speaker 1: it's it's interesting to think about this that we we

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Speaker 1: are creatures of the shallows. So life as we know

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Speaker 1: it essentially thrives in a tide pool, protected from the

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Speaker 1: full onslaught of wind and wave. You know, if you've

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Speaker 1: ever been to a to a number of beach environments,

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Speaker 1: you've seen those areas right where um, where that the

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Speaker 1: waves are crashing but there, but but there's this pool,

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Speaker 1: this uh, this area of calm water that is protected

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Speaker 1: from all of that, and that's where a lot of

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Speaker 1: life can thrive that otherwise would not be able to

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Speaker 1: bear the hostilities beyond the rocks. And it actually reminds

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Speaker 1: me of this quote by John Steinbeck Uh and and uh,

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Speaker 1: he's not directly talking about what we're talking about here,

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Speaker 1: but the comparison is just beautiful. He he wrote, the

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Speaker 1: knowledge that all things are one thing, and then one

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Speaker 1: thing is all things plankton, a shimmering phosphorescence on the sea,

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Speaker 1: and the spinning planets and an expanding universe, all bound

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Speaker 1: together by the elastic string of time. It is advisable

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Speaker 1: to look from the tide pool to the stars and

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Speaker 1: then back to the tide pool again. Yeah, our earth

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Speaker 1: is protected not from wind and waves, but from the

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Speaker 1: full blast of solar and cosmic radiation. Instead of rocky

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Speaker 1: sea walls were protected by a robust atmosphere and most importantly,

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Speaker 1: the magnetosphere. Yeah. The interesting other side to the fact

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Speaker 1: that we've got this kind of connected consciousness that we're

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Speaker 1: aware of, Like there is no real division between the

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Speaker 1: Earth and the heavens. They're just different places. The only

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Speaker 1: real division is distance, And so all the universe really

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Speaker 1: is connected and does have a common origin in the

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Speaker 1: Big Bang. But at the same time that connectedness, we

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Speaker 1: use the word connected in such a happy way. It's

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Speaker 1: like nice to be connected to things. But you can

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Speaker 1: also think about that is extreme vulnerability, like you are

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Speaker 1: right next door to everything in the universe that would

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Speaker 1: Russian annihilate you. And what we've got standing in the

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Speaker 1: way of those those crushing annihilating forces beyond our power

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Speaker 1: to control, is essentially a big magnetic field and a

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Speaker 1: thin layer of gas around the rocky surface of the planet.

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Speaker 1: That's right. So basically what we have going on here

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Speaker 1: is the Earth solid intercore and liquid outer core. They

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Speaker 1: play a crucial role in protecting life as we know

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Speaker 1: it from deadly deadly radiation. Differences in temperature and composition

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Speaker 1: in the two core regions drive a powerful dynamo emitting

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Speaker 1: Earth project protective electro magnetic field. And remember this is

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Speaker 1: one of the key factors we have to consider improposed

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Speaker 1: interplanetary space travel and establishing stations in other worlds. The

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Speaker 1: only planets in our Solar System with some form of

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Speaker 1: magnetosphere in place our Mercury, Earth, Jupiter, Saturn, Uranus, and Neptune. Right,

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Speaker 1: so then, of course you've also on the surface of

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Speaker 1: the Earth got the atmosphere to count on, because that

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Speaker 1: means that there's more stuff that radiation has to get

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Speaker 1: through to it to you, and so the atmosphere will

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Speaker 1: block some kinds of incoming radiation. But the other big

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Speaker 1: protector is the magnetosphere that keeps these particles directed away

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Speaker 1: from the Earth. Some of course still get through, right,

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Speaker 1: And also the magnetosphere serves to protect the atmosphere as well, Yes,

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Speaker 1: because if you don't have a magnetosphere, your atmosphere over

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Speaker 1: time can be stripped away, which is one of the

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Speaker 1: things that they think probably happen to Mars long ago. Right.

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Speaker 1: So it's our protective barrier against the elements. It's our battlements.

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Speaker 1: And the only humans who have walked these battlements are

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Speaker 1: astronauts such as Dr Jeff Hoffman. Now, most astronauts never

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Speaker 1: even go beyond the shield that protects us, right, we

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Speaker 1: know that astronauts in space are exposed to extra levels

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Speaker 1: of radiation, and that's one reason you want to limit

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Speaker 1: your time and space. You're like, you can't go live

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Speaker 1: in the I S S forever. They want to bring

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Speaker 1: you back eventually because the more time you spend up there,

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Speaker 1: the more you're exposed to this dangerous radiation that could

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Speaker 1: harm you in the long run. But even up in

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Speaker 1: the I s s you're still you're still benefiting from

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Speaker 1: a large part of the Earth's protective shield. Right. Yes,

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Speaker 1: it gets a lot worse if you want to go

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Speaker 1: to the Moon, right to Mars, or colonize another planet. Yeah,

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Speaker 1: because then you're going beyond Earth's protection. So I guess

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Speaker 1: we want to go now to our conversation with Dr

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Speaker 1: Jeff Hoffman UH to talk about the radiation risks posed

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Speaker 1: by the universe and what astronauts have done and can

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Speaker 1: do to protect themselves. But first I guess we should

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Speaker 1: give you just a little bit of background on Dr Hoffman. Yeah,

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Speaker 1: So his original research interest were in high energy astrophysics,

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Speaker 1: specifically cosmic gamma radiation and X ray astronomy, and then

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Speaker 1: his doctoral work at Harvard entailed balloon born low energy

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Speaker 1: gamma ray telescopes and the design and then the testing

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Speaker 1: of this technology. From nineteen seventy to nineteen seventy five.

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Speaker 1: During post doctoral work at Leicester University, he worked on

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Speaker 1: several X ray astronomy rocket payloads, and then he worked

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Speaker 1: in the Center for Space Research at the Massachusetts Institute

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Speaker 1: of Technology from nineteen seventy five to nineteen seventy eight

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Speaker 1: as projects scientist in charge of the orbiting h e

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Speaker 1: A oh one A four hard X ray and gamma

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Speaker 1: ray experiment, which launched in August ninety seven. But then

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Speaker 1: in seventy eight he was selected to become an astronaut

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Speaker 1: and he went on a total of five different Shuttle flights.

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Speaker 1: So in eighty five he went up on a Discovery,

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Speaker 1: nineteen ninety on Columbia, two on Atlantis, ninety three on Endeavor,

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Speaker 1: and then in nine on Columbia. All told, one thousand,

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Speaker 1: two hundred and eleven hours in space twenty one point

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Speaker 1: five million miles. That's a lot of miles. Frequent flyer, Yeah,

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Speaker 1: so he he is a not only a pedigreed scientist,

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Speaker 1: of a pedigreed astronaut. Five Shuttle flights, that's impressive. That's

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Speaker 1: five more than the vast majority of human beings. All right,

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Speaker 1: we're gonna take a quick break and when we come back,

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Speaker 1: we will be heading straight into our interview with Dr

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Speaker 1: Jeff Hoffman. Thank hey, Dr Hoffman, welcome to the show.

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Speaker 1: We're really glad to have you well, nice to be here,

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Speaker 1: looking forward to it. I was wondering if you'd would

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Speaker 1: start off by telling us a little bit about your

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Speaker 1: research from before you became an astronaut. What what made

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Speaker 1: you interested in high energy astrophysics and um, what were

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Speaker 1: your pursuits in that field. Well, I grew up with

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Speaker 1: an interest in space. I lived in or near New

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Speaker 1: York City. My dad used to take me to the

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Speaker 1: planetarium to see the new show every month. UM. I

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Speaker 1: saw the birth of the space age. You know, I

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Speaker 1: was alive whence but Nick was first launched when You're

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Speaker 1: a Gagaran and John Glenn flew and so. I was

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Speaker 1: also interested in human spaceflight, although it was apparent to

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Speaker 1: me that all the early astronauts were military test pilots

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Speaker 1: and that was not a career for me. But space

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Speaker 1: in general I was fascinated with and went on to

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Speaker 1: become an astronomer. I got a doctorate in an astrophysics

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Speaker 1: at Harvard UM, and I was attracted by UH, what

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Speaker 1: we call high energy astrophysics. It was a totally new

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Speaker 1: field at the time UM the discovery of X rays

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Speaker 1: from celestial objects and gamma rays. UM. It was a

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Speaker 1: new branch of astronomy opening up just like radio astronomy

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Speaker 1: opened up back in the nineteen thirties. And UM that

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Speaker 1: struck me as being UH an area where we were

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Speaker 1: almost bound to make new discoveries because we had never

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Speaker 1: looked at this type of radiation before. So my professional

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Speaker 1: career as an astronomer consisted in designing X ray telescopes

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Speaker 1: and then putting them into space. First with I was

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Speaker 1: using high altitude balloons when I did my pH d thesis,

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Speaker 1: and then UM I spent three and a half years

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Speaker 1: at Leicester University in England, UH and we had both

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Speaker 1: sounding rocket experiments where we would put our telescopes up

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Speaker 1: above the atmosphere. You have to go above the atmosphere

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Speaker 1: because X rays and gamma rays are absorbed in the atmosphere,

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Speaker 1: which is a good thing for us here on the ground,

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Speaker 1: but it makes life difficult for astronomers because you have

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Speaker 1: to go above the atmosphere to see this radiation. And

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Speaker 1: and that was kind of cool as well, because I

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Speaker 1: was always interested in space and rockets and and so

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Speaker 1: I was combining the technological interest with what I thought

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Speaker 1: was a very exciting scientific field. And then I came

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Speaker 1: back to M I t and we we had actually

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Speaker 1: our own X ray satellite, and the most exciting research

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Speaker 1: that I was doing we discovered these things called X

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Speaker 1: ray bursts. You look at an X ray object giving

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Speaker 1: out relatively low level of radiation fairly constantly, you know,

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Speaker 1: and then all of a sudden, you know, bam, it

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Speaker 1: increases by hundreds and hundreds of times and then gradually

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Speaker 1: fades away over the course of anywhere from a few

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Speaker 1: seconds to a few minutes. And we we discovered lots

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Speaker 1: of these, and this was a completely new phenomena, and

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Speaker 1: that was probably the most exciting thing that I did scientifically,

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Speaker 1: was uh, finally figure out what was what was causing these.

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Speaker 1: It was actually neutron stars um orbiting around regular stars,

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Speaker 1: and the gravitation of the neutron star was such that

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Speaker 1: it would suck hydrogen off the regular star, and the

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Speaker 1: hydrogen would accumulate in a layer on the surface of

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Speaker 1: the neutron star, and then eventually the whole thing would

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Speaker 1: detonate in a in a huge thermonuclear explosion. So what

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Speaker 1: we were looking at were hydrogen bombs, you know, ten

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Speaker 1: miles in diameter. Uh, you know, it's pretty spectacular stuff.

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Speaker 1: So that was really exciting, and I was all set

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Speaker 1: for a uh you know, career as an astronomer. And

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Speaker 1: but that was now in the mid to late seventies

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Speaker 1: when NASA was getting ready to fly what was then

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Speaker 1: the brand new Space Shuttle. And neat thing about the

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Speaker 1: Stay Shuttle from my point of view, was that it

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Speaker 1: had a crew of seven, but they only needed two pilots.

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Speaker 1: The pilots were still going to be military test pilots,

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Speaker 1: but it really opened things up for engineers, scientists, and

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Speaker 1: medical doctors. And when NASA put out a call for

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Speaker 1: for astronauts for the Space Shuttle and and indicated that yes,

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Speaker 1: they really did want scientists and engineers and doctors, um,

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Speaker 1: I thought, well, I'll apply and I was lucky enough

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Speaker 1: to get selected the first time around. So that basically

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Speaker 1: was the end of my career and astronomy research. I

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Speaker 1: had a I'd say it was quite successful, and had

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Speaker 1: I not been selected, I I hope I would have

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Speaker 1: had a good career as a research aster physicist. But

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Speaker 1: getting selected by Nazis and astroall certainly changed my life. Interesting,

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Speaker 1: before we ask you about a little bit of your

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Speaker 1: spaceflight experience, I just wonder does research into high energy astrophysics, Like,

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Speaker 1: if you're looking at neutron stars and bursts of X

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Speaker 1: rays and gamma rays and stuff in the universe, does

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Speaker 1: that change the way you feel about the sky when

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Speaker 1: you look up at it and most people look up

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Speaker 1: and see twinkling stars and it feels kind of nice

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Speaker 1: and cool and calm. Do you do you envision the

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Speaker 1: universe emotionally as one full of radiation and danger and

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Speaker 1: high energy? Oh? Absolutely? I mean, you know, when you

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Speaker 1: look up, just a simple look up at the stars,

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Speaker 1: everything looks pretty constant and unvarying. And when you realize

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Speaker 1: that there's things exploding and going off all over the

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Speaker 1: place that trem in this areas of high gravitation, high

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Speaker 1: magnetic fields, charge particles. Uh, yeah, the universe is a

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Speaker 1: pretty violent place. Um and uh, you don't see it

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Speaker 1: with your naked eye, but modern astronomy has has opened

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Speaker 1: this up to us. Dr Hoffman, can you tell us

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Speaker 1: about some of your your space flight experience? So what

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Speaker 1: was the Hubble service mission? Like, well, let me let

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Speaker 1: me start a little bit further back with my first

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Speaker 1: base flight, because that, of course, for any astronaut, is

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Speaker 1: is an exciting moment when you get the call from

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Speaker 1: management and they say, oh, you've been You've got an

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Speaker 1: assignment to your first space flight. Um. We were supposed

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Speaker 1: to take up two satellites and put them into orbit

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Speaker 1: and theres pop them out of the cargo bay of

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Speaker 1: the shovel, which was what the shovel was doing in

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Speaker 1: the early days, and then come home. It was going

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Speaker 1: to be a short, relatively short mission four days or so. UM.

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Speaker 1: And as it turned out, the second of the two

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Speaker 1: satellites that we popped out of the Shuttle didn't turn on. UM.

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Speaker 1: You know, I had nothing to do with us. All

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Speaker 1: we were supposed to do was was get it out

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Speaker 1: of the Shuttle into orbit. But when when we reported

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Speaker 1: that it did not seem to have activated, NASA went

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Speaker 1: into a big study mode and they figured out the

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Speaker 1: there was only one single point failure that we could

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Speaker 1: possibly do something about. There's a little switch on the

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Speaker 1: outside of the satellite that maybe had gotten stuck. And

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Speaker 1: so they scheduled, for the first time in NASA history,

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Speaker 1: an unplanned spacewalk where my partner and I went out.

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Speaker 1: See I had been trained to use space suits, but

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Speaker 1: we weren't planning to do a space walk on my

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Speaker 1: first flight, but they sent us out to fix it,

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Speaker 1: and um, so that was a totally unexpected, uh, incredible experience,

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Speaker 1: you know, getting to go out and do a spacewalk,

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Speaker 1: which you know all astronauts would like to go out.

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Speaker 1: It's the most intimate experience that you can have of

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Speaker 1: being in space, is actually putting on a space suit

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Speaker 1: and going out of the airlock and and it's you know,

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Speaker 1: kind of you face to face with the rest of

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Speaker 1: the universe. It's it's an incredible experience. And we did

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Speaker 1: a good job. And and so um I got identified

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Speaker 1: as as somebody who was good at space walking, and

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Speaker 1: I worked on a lot of advanced spacesuit development and

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Speaker 1: various things. And then when it came time to select

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Speaker 1: a crew to go up and try to repair the

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Speaker 1: Hubble telescope. And of course, nowadays, people who weren't alive

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Speaker 1: at the time when Hubble was put in orbit don't

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Speaker 1: don't really appreciate what a disaster it was for NASA.

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Speaker 1: I mean, this billion and a half dollar telescope which

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Speaker 1: had been launched with great expectations about how was going

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Speaker 1: to revolutionize our view of the universe, and then to

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Speaker 1: find out that it couldn't focus properly. I mean, how

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Speaker 1: could NASA make a huge mistake like that? Was what

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Speaker 1: everybody was was asking and it was absolutely critical. I mean,

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Speaker 1: as I say, people don't remember what a disaster it was.

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Speaker 1: But NASA and Hubble were the joke of late night comedians.

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Speaker 1: Pubble was denounced in the halls of the U. S.

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Speaker 1: Congress as a techno turkey. NASA was trying to get

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Speaker 1: Congress to approve funding for the International Space Station at

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Speaker 1: the time, and as you can imagine, NASA wasn't very

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Speaker 1: popular with Congress, so UM, basically they were told, you know,

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Speaker 1: go to something about Hubble and then come back and

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Speaker 1: talk to us about the space Station. In any case,

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Speaker 1: NASA wanted to do everything possible to reduce the risk

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Speaker 1: of failure in this rescue mission, and one of the

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Speaker 1: things that they decided was that only people who had

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Speaker 1: previously done spacewalks would be eligible to do the spacewalks

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Speaker 1: for the Hubble rescue. And and because of this unplanned

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Speaker 1: space walk that I did way back on my first flight, UM,

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Speaker 1: and I had had two subsequent flights since then, so

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Speaker 1: Hubble for me was my fourth flight, and I had

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Speaker 1: my spacewalkers Union cards. So I was fortunate enough to

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Speaker 1: be on the crew and that was suddenly, of all

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Speaker 1: the things I did as an astronaut, the one with

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Speaker 1: the most lasting impact was obviously rescuing Hubble and turning

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Speaker 1: it from basically nassas worst disaster um scientifically to its

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Speaker 1: most successful and productive scientific mission ever. So it was

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Speaker 1: a and and of course as a former astronomer, as

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Speaker 1: well as being an astronaut, being able to put my

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Speaker 1: two hands on the Hubble telescope up in orbit was

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Speaker 1: I mean, it was the thrill of a lifetime and

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Speaker 1: we fixed it and a great thing you did well.

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Speaker 1: I I know that many of my former astronomy colleagues

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Speaker 1: after the mission would come I can't tell you how

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Speaker 1: many people would come up to me and say, oh, Jeff,

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Speaker 1: thank you so much for thinking novel, because you know,

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Speaker 1: my my professional career was depending on this, And all

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Speaker 1: I could say was, well, it was a pleasure, you know,

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Speaker 1: thank you. It was pleasure, It really was. So you

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Speaker 1: mentioned that when you were out on spacewalks in in

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Speaker 1: the e v A, that you had this kind of

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Speaker 1: intimate experience with the universe. It was like putting you

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Speaker 1: face to face with the outer universe, and I wonder

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Speaker 1: about something. So there was a sci fi novel I

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Speaker 1: read a couple of years ago where a character is

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Speaker 1: born and lives her whole life in simulated environments inside

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Speaker 1: a generation starship, and she finally at one point comes

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Speaker 1: back to Earth late in life, and she's outside and

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Speaker 1: discussing the idea of getting sun burned. And she's so

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Speaker 1: unfamiliar with the concept of Earth and the Sun that

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Speaker 1: she calls this. She's horrified, and she calls this getting

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Speaker 1: burned by radiation from a star. I wonder, is there

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Speaker 1: a moment in space, you know, outside vehicle activity, where

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Speaker 1: you begin to think of the Sun not as the

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Speaker 1: sun but as a star and other kinds of alienation effects? Now, absolutely,

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Speaker 1: I mean this is something when I give public talks,

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Speaker 1: I I often show a picture of the sun in space,

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Speaker 1: and then I asked the audience, there's something very strange

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Speaker 1: about this picture. Can you figure out what it is?

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Speaker 1: And most people don't quite get it. But what you're

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Speaker 1: seeing is the sun in a black sky. And think

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Speaker 1: about it. You've never seen the sun in the black

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Speaker 1: sky because every time the weather is clear, you go

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Speaker 1: out and of course, our atmosphere scatters the blue light preferentially,

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Speaker 1: and so the sky is blue, and so every human

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Speaker 1: being throughout human history until the space age, has only

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Speaker 1: seen the Sun in the blue sky. We see the

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Speaker 1: stars in the black sky because there's not enough really

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Speaker 1: from the stars to be scattered and make the sky

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Speaker 1: look blue, but not the Sun. But in space, you

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Speaker 1: really see the Sun as a star in a black sky.

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Speaker 1: Of course, it's it's bigger and brighter than any of

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Speaker 1: the other stars because it's close to us. But yeah,

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Speaker 1: you really do appreciate the Sun as a star and

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Speaker 1: that that that was something I didn't have to go

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Speaker 1: out and it just looking out the window of the shuttle.

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Speaker 1: You you get that appreciation, but it's a totally different perspective,

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Speaker 1: as are so many other things that you see. I mean,

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Speaker 1: that's one of the things about being off the surface

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Speaker 1: of the Earth is that you look with a totally

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Speaker 1: new perspective. Just like most people don't remember the first

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Speaker 1: time they ever flew in an aeroplane, But if you

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Speaker 1: if you pay attention and look out the window, you

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Speaker 1: also get a totally new perspective on the on the Earth.

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Speaker 1: Although most people don't bother to look out the window

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Speaker 1: these days, but from space, we spent a lot of

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Speaker 1: time looking out the windows and I never got fired

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Speaker 1: of it. It was a completely um different perspective, not

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Speaker 1: only on the Earth, but on on the heavens. It

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Speaker 1: was great flying during the nighttime. You know, we'd start,

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Speaker 1: we'd enter darkness in the northern hemisphere and you could

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Speaker 1: look up and see all the familiar northern constellations, the Signus,

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Speaker 1: the Swan, which is the Northern Cross. And then fifteen

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Speaker 1: minutes later you'd be in the southern hemisphere and see

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Speaker 1: Alpha Centauri and the Southern Cross. And that's something else

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Speaker 1: that you never do when you're on the surface of

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Speaker 1: the Earth, is to see the northern and the southern

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Speaker 1: skies at the you know, within a half hour of

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Speaker 1: one another. Would you describe this as as being a

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Speaker 1: kin to the the overview effect? Well, the overview effect

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Speaker 1: um maybe some of the listeners don't aren't familiar with that,

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Speaker 1: but it was coined by Frank White. He's an author

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Speaker 1: who thought a lot about I guess he had this

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Speaker 1: kind of inspiration during an air airplane flight when he

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Speaker 1: was looking at the ground and and feeling a little

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00:25:04,800 --> 00:25:08,800
Speaker 1: bit removed from the Earth. But then he started thinking about,

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Speaker 1: you know, what what must it be like for the astronauts.

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Speaker 1: So he came down to Houston and I was one

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Speaker 1: of the first astronauts that he interviewed. And you know,

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Speaker 1: the idea is it It really does change your perception

432
00:25:20,800 --> 00:25:24,440
Speaker 1: of planet Earth to to look at it, uh and

433
00:25:24,440 --> 00:25:28,159
Speaker 1: and actually see the Earth as a planet um to

434
00:25:28,359 --> 00:25:31,119
Speaker 1: see from an airplane, you can look out the window

435
00:25:31,160 --> 00:25:33,920
Speaker 1: and see entire cities spread out below you. But from

436
00:25:33,920 --> 00:25:39,359
Speaker 1: an orbiting spacecraft you you can see entire countries or continents.

437
00:25:39,440 --> 00:25:44,440
Speaker 1: Really the Earth is very beautiful, and so you you

438
00:25:44,640 --> 00:25:49,120
Speaker 1: do get this relationship that develops between you and the planet.

439
00:25:49,160 --> 00:25:54,120
Speaker 1: At the same time, you can see examples of environmental

440
00:25:54,200 --> 00:25:58,280
Speaker 1: degradation caused by humanity, which is you know, now visible

441
00:25:58,320 --> 00:26:02,560
Speaker 1: from a cosmic perspective, and that's pretty scary, you know,

442
00:26:02,640 --> 00:26:08,280
Speaker 1: the deforestation of the Amazon, the silting up of harbors

443
00:26:08,359 --> 00:26:14,800
Speaker 1: and rivers and uh, just all sorts of things. And

444
00:26:15,160 --> 00:26:19,560
Speaker 1: you realize that you definitely get a feeling of the

445
00:26:20,040 --> 00:26:25,960
Speaker 1: finiteness of planet Earth and this sense of what it

446
00:26:26,080 --> 00:26:28,480
Speaker 1: is to be removed from the Earth and how that

447
00:26:28,600 --> 00:26:34,720
Speaker 1: changes your feelings for Planet Earth. Is what Frank called

448
00:26:34,760 --> 00:26:39,359
Speaker 1: the overview effect, and many astronauts have reported this. There's

449
00:26:39,400 --> 00:26:42,760
Speaker 1: now actually a movie that that you can find on

450
00:26:42,760 --> 00:26:47,880
Speaker 1: on YouTube or vimeo u the about the overview effect,

451
00:26:48,040 --> 00:26:53,919
Speaker 1: made by a cinematographer in in the UK interviews with

452
00:26:53,960 --> 00:26:58,040
Speaker 1: a lot of different astronauts, myself included. So yeah, it's

453
00:26:58,240 --> 00:27:03,040
Speaker 1: um it so totally different perspective you get when you're

454
00:27:03,240 --> 00:27:07,199
Speaker 1: hundreds of miles above the surface of the Earth. So uh,

455
00:27:07,359 --> 00:27:10,560
Speaker 1: going back to the idea of radiation risk beyond the

456
00:27:10,600 --> 00:27:13,320
Speaker 1: surface of the Earth. On the missions you flew in

457
00:27:13,400 --> 00:27:16,760
Speaker 1: the eighties and nineties, what did you and the other

458
00:27:16,800 --> 00:27:21,840
Speaker 1: crew members understand about radiation risk in space and what

459
00:27:21,840 --> 00:27:24,000
Speaker 1: what kind of measures were in place to protect you

460
00:27:24,040 --> 00:27:28,360
Speaker 1: other than just limiting the duration of missions. Shuttle flies

461
00:27:28,680 --> 00:27:31,240
Speaker 1: like the International Space Station and what we call low

462
00:27:31,280 --> 00:27:35,720
Speaker 1: Earth orbits. So we are basically below the Van Allen

463
00:27:36,080 --> 00:27:40,600
Speaker 1: radiation belts, were inside the Earth's magnetic fields, which shields

464
00:27:40,720 --> 00:27:46,920
Speaker 1: us from most h cosmic radiation. So um, it's it's

465
00:27:46,960 --> 00:27:52,240
Speaker 1: a much more benign environment than when you actually left

466
00:27:52,320 --> 00:27:54,560
Speaker 1: the Earth to head out to the Moon and you're

467
00:27:54,600 --> 00:27:58,679
Speaker 1: outside the Earth's magnetic shield and then you're exposed to

468
00:27:58,880 --> 00:28:05,159
Speaker 1: the direct um impact of galactic cosmic rays and U

469
00:28:05,840 --> 00:28:12,160
Speaker 1: and charge particles coming from the sun. UM you ultra

470
00:28:12,280 --> 00:28:16,840
Speaker 1: violet light, of course, is not deflected by the magnetic field,

471
00:28:17,080 --> 00:28:21,200
Speaker 1: and we have to have protection against ultra violet light

472
00:28:21,240 --> 00:28:24,800
Speaker 1: otherwise it would destroy our eyes, which is why the

473
00:28:24,880 --> 00:28:28,920
Speaker 1: space helmet spacesuit helmets have those those gold visors which

474
00:28:28,960 --> 00:28:32,840
Speaker 1: protect you. And there's ultra violet protection on all of

475
00:28:32,880 --> 00:28:35,879
Speaker 1: the windows of the Space Shuttle and the International Space

476
00:28:35,880 --> 00:28:44,760
Speaker 1: Station windows. So UM, you know, electromagnetic radiation, cosmic the

477
00:28:44,760 --> 00:28:48,160
Speaker 1: the ultra violet rays we have to protect ourselves against.

478
00:28:48,600 --> 00:28:51,400
Speaker 1: And then of course there's the infrared radiation from the sun.

479
00:28:51,480 --> 00:28:58,280
Speaker 1: The heat when you're in the direct sunlight, temperatures of

480
00:28:58,400 --> 00:29:01,120
Speaker 1: things exposed to direct sunlight and space can go up

481
00:29:01,160 --> 00:29:04,320
Speaker 1: above the boiling point of water. And so when you're

482
00:29:04,360 --> 00:29:08,720
Speaker 1: out in your space suit, you need good cooling and

483
00:29:08,920 --> 00:29:13,160
Speaker 1: we do that by sublimating ice and that cools off

484
00:29:13,240 --> 00:29:17,640
Speaker 1: the water, which we then circulate in in UH liquid

485
00:29:17,640 --> 00:29:21,400
Speaker 1: cooling garment with lots of tubes where you can run

486
00:29:21,440 --> 00:29:24,600
Speaker 1: the cold water right over your body and take away heat.

487
00:29:25,480 --> 00:29:27,520
Speaker 1: UH and you can adjust that because when you go

488
00:29:27,560 --> 00:29:30,840
Speaker 1: into the dark side, it gets very very cold, and

489
00:29:31,320 --> 00:29:36,280
Speaker 1: there you don't want this extra cooling so um. From

490
00:29:36,360 --> 00:29:39,440
Speaker 1: the electromagnetic point of view, we've got to protect ourselves

491
00:29:39,480 --> 00:29:42,800
Speaker 1: against ultra violet radiation, and we've got to have good

492
00:29:42,840 --> 00:29:48,280
Speaker 1: thermal control for heat for the charge particle radiation. As

493
00:29:48,320 --> 00:29:52,080
Speaker 1: I say, we're in a relatively benign place. When we

494
00:29:52,120 --> 00:29:56,120
Speaker 1: did our Hubble mission. Hubble was put as high up

495
00:29:56,160 --> 00:30:00,560
Speaker 1: as the Shuttle could go, about four hundred miles six uh,

496
00:30:00,560 --> 00:30:03,240
Speaker 1: and we were kind of scraping the bottom of the

497
00:30:03,760 --> 00:30:08,680
Speaker 1: van Ellen intervan Ellen radiation belts. So it was calculated

498
00:30:08,720 --> 00:30:10,800
Speaker 1: that we were going to get about ten times the

499
00:30:10,880 --> 00:30:14,640
Speaker 1: normal exposure for shuttle flight, which which still was nothing

500
00:30:14,680 --> 00:30:18,400
Speaker 1: to be concerned about from a cancer point of view.

501
00:30:18,480 --> 00:30:24,000
Speaker 1: But but they had us where radiation monitors the whole time,

502
00:30:24,080 --> 00:30:27,440
Speaker 1: and particularly when we went outside, and they tried to

503
00:30:27,440 --> 00:30:30,600
Speaker 1: schedule the spacewalks so that we would not be outside

504
00:30:30,640 --> 00:30:33,520
Speaker 1: when we went through what is known as the South

505
00:30:33,560 --> 00:30:37,000
Speaker 1: Atlantic anomaly, which was a part of the orbit where

506
00:30:37,040 --> 00:30:40,400
Speaker 1: the radiation is much higher than the rest of it.

507
00:30:41,000 --> 00:30:44,000
Speaker 1: That's about all you can do, obviously, if there were

508
00:30:44,040 --> 00:30:49,360
Speaker 1: ever a huge solar eruption. UH. We always had the

509
00:30:49,400 --> 00:30:53,000
Speaker 1: option of coming home and and uh, you know, getting

510
00:30:53,080 --> 00:30:56,200
Speaker 1: underneath the atmosphere for the extra protection, but we never

511
00:30:56,240 --> 00:30:59,640
Speaker 1: had to do that. What about extended future missions, how

512
00:30:59,680 --> 00:31:02,200
Speaker 1: did the change and what sort of solutions are being

513
00:31:02,240 --> 00:31:06,640
Speaker 1: developed to protect future astronauts. The radiation risk is recognized

514
00:31:06,640 --> 00:31:08,640
Speaker 1: as being one of the most serious if you're going

515
00:31:08,680 --> 00:31:11,720
Speaker 1: to be outside the Earth's magnetic field for a long time,

516
00:31:12,640 --> 00:31:15,200
Speaker 1: either on the surface of the Moon or on an

517
00:31:15,200 --> 00:31:18,320
Speaker 1: extended trip to Mars. On the surface of the Moon.

518
00:31:18,960 --> 00:31:21,400
Speaker 1: Actually getting to the Moon is is not such a

519
00:31:21,400 --> 00:31:23,320
Speaker 1: big deal because you can get there in three days

520
00:31:23,440 --> 00:31:26,160
Speaker 1: and so your exposure time is limited. But if you're

521
00:31:26,160 --> 00:31:28,920
Speaker 1: gonna spend any significant amount of time on the surface

522
00:31:28,960 --> 00:31:33,760
Speaker 1: of the Moon, obviously the Moon blocks about half of

523
00:31:33,800 --> 00:31:38,280
Speaker 1: the galactic cosmic rays, but but you're still exposed to

524
00:31:38,640 --> 00:31:41,760
Speaker 1: all the rest of them. And it may be that

525
00:31:42,600 --> 00:31:46,320
Speaker 1: you know, will they're they're talking about possibly having underground

526
00:31:46,400 --> 00:31:50,520
Speaker 1: habitats in waba tubes, which we know exists on the Moon.

527
00:31:51,280 --> 00:31:53,440
Speaker 1: You're gonna have to do something to shield yourself from

528
00:31:53,440 --> 00:31:56,520
Speaker 1: the radiation because being exposed to it for a long

529
00:31:56,600 --> 00:32:00,280
Speaker 1: time is going to be dangerous. That's something that very

530
00:32:00,280 --> 00:32:02,320
Speaker 1: difficult to do. If you're on a trip to Mars,

531
00:32:02,400 --> 00:32:05,800
Speaker 1: because you can't carry that much mass with you to

532
00:32:06,360 --> 00:32:13,200
Speaker 1: protect yourself and UM, so NASSE is interested in other ways.

533
00:32:13,240 --> 00:32:19,120
Speaker 1: There are some I think very interesting research going on

534
00:32:19,280 --> 00:32:26,720
Speaker 1: about UM pharmacological protection against radiation. If there were some

535
00:32:26,760 --> 00:32:31,200
Speaker 1: way that we could enhance the body's ability to repair

536
00:32:31,400 --> 00:32:37,440
Speaker 1: d NA UM, that would make the impact of radiation

537
00:32:37,600 --> 00:32:42,440
Speaker 1: much less serious. We know that there's bacterias which can

538
00:32:42,840 --> 00:32:46,040
Speaker 1: withstand hundreds of times the amount of radiation that a

539
00:32:46,120 --> 00:32:51,560
Speaker 1: human can. They've developed the ability to repair much more

540
00:32:51,640 --> 00:32:57,600
Speaker 1: significant damage to DNA than we're able to do. UM.

541
00:32:57,640 --> 00:33:03,360
Speaker 1: There may be genetic clues about how to protect against radiation,

542
00:33:03,480 --> 00:33:05,960
Speaker 1: so the point being that we've got to look for

543
00:33:06,000 --> 00:33:11,600
Speaker 1: other ways besides just shielding, and of course developing better,

544
00:33:12,240 --> 00:33:15,120
Speaker 1: more powerful propulsion systems so that we could get the

545
00:33:15,200 --> 00:33:18,360
Speaker 1: Mars quicker would be a big help as well, not

546
00:33:18,480 --> 00:33:22,160
Speaker 1: just from a radiation point of view, but logistically, you've

547
00:33:22,240 --> 00:33:26,120
Speaker 1: got to carry everything you need UH. You can't get

548
00:33:26,160 --> 00:33:29,680
Speaker 1: resupplied once you're on your way to Mars, so all

549
00:33:29,720 --> 00:33:34,719
Speaker 1: the food, the medical equipment, the UH spare parts and everything.

550
00:33:34,800 --> 00:33:37,320
Speaker 1: They quicker you can get there, the better, So there's

551
00:33:37,360 --> 00:33:41,960
Speaker 1: a lot of ways that that we're looking at that

552
00:33:42,160 --> 00:33:48,560
Speaker 1: will make long duration spaceflight outside the Earth's magnetic field safer.

553
00:33:49,400 --> 00:33:52,880
Speaker 1: But most of these things are still works in progress

554
00:33:53,040 --> 00:33:56,920
Speaker 1: right now. We we don't have those solutions available now,

555
00:33:57,000 --> 00:33:59,720
Speaker 1: and and correct me if I'm wrong, But once you

556
00:34:00,080 --> 00:34:03,400
Speaker 1: get to Mars on a Mars mission on the surface,

557
00:34:03,440 --> 00:34:05,560
Speaker 1: you're not a whole lot better off than you are

558
00:34:05,600 --> 00:34:11,200
Speaker 1: in space right as far as radiation because first of all, Mars,

559
00:34:11,239 --> 00:34:12,919
Speaker 1: just like when you're on the surface of the Moon,

560
00:34:13,000 --> 00:34:17,720
Speaker 1: Mars is blocking half of the radiation just by its mass.

561
00:34:17,760 --> 00:34:20,359
Speaker 1: And then Mars does have a bit of an atmosphere

562
00:34:20,360 --> 00:34:23,000
Speaker 1: which gives you a little bit of protection. But you're right,

563
00:34:23,120 --> 00:34:26,279
Speaker 1: there's still the radiation environment on the surface of the

564
00:34:26,320 --> 00:34:31,840
Speaker 1: Mars of Mars is more severe than being in lower orbit,

565
00:34:32,160 --> 00:34:35,960
Speaker 1: and so radiation protection on the surface of Mars will

566
00:34:36,000 --> 00:34:38,000
Speaker 1: continue to be an issue, just like it will be

567
00:34:38,080 --> 00:34:42,240
Speaker 1: on the Moon. You'll have to have a certain amount

568
00:34:42,239 --> 00:34:46,040
Speaker 1: of protection in your habitats. But again, the other the

569
00:34:46,080 --> 00:34:50,080
Speaker 1: other thing, um, you know, there's two aspects of the

570
00:34:50,160 --> 00:34:54,000
Speaker 1: dangers of radiation. One of them is that in the

571
00:34:54,080 --> 00:34:56,840
Speaker 1: long term it will lead to an increased incident of

572
00:34:56,960 --> 00:35:01,480
Speaker 1: cancers like leukemia. Well, one of the things that we're

573
00:35:01,520 --> 00:35:05,200
Speaker 1: realizing is that our ability for early detection and treatment

574
00:35:05,239 --> 00:35:10,440
Speaker 1: in cancer is continually improving, and so maybe, you know,

575
00:35:10,520 --> 00:35:12,640
Speaker 1: twenty thirty years from now, that's just not going to

576
00:35:12,719 --> 00:35:17,400
Speaker 1: be as much of a problem. The other UH potential

577
00:35:17,440 --> 00:35:21,839
Speaker 1: problem from radiation are acute impacts. There. There have been

578
00:35:21,880 --> 00:35:27,359
Speaker 1: some experiments that have shown a potential loss of cognitive

579
00:35:27,840 --> 00:35:34,880
Speaker 1: capability for rats when they're exposed to radiation. Um, you

580
00:35:34,960 --> 00:35:37,480
Speaker 1: certainly would not like to get to Mars and find

581
00:35:37,480 --> 00:35:41,239
Speaker 1: out that your i Q is decreased by twenty points. UM.

582
00:35:41,560 --> 00:35:47,719
Speaker 1: There are potential effects of acute effects of radiation on

583
00:35:47,840 --> 00:35:52,239
Speaker 1: the circulatory system, on the nervous system, and that's an

584
00:35:52,280 --> 00:35:59,000
Speaker 1: area of very active research now it's relatively new. Traditionally,

585
00:35:59,040 --> 00:36:03,239
Speaker 1: we were just concerned with the long term impact of

586
00:36:03,360 --> 00:36:07,200
Speaker 1: radiation that is ultimately causing cancer, unless, of course, you

587
00:36:07,280 --> 00:36:09,879
Speaker 1: had a huge solar flare. You know, if you get

588
00:36:10,000 --> 00:36:13,799
Speaker 1: enough radiation all at one time, you're going to die

589
00:36:14,280 --> 00:36:20,560
Speaker 1: or have serious UH illnesses, and and um, you know,

590
00:36:20,640 --> 00:36:23,799
Speaker 1: we we would like not to be in space when

591
00:36:23,800 --> 00:36:28,200
Speaker 1: they have a huge solar flare. But you know, statistically

592
00:36:28,280 --> 00:36:31,120
Speaker 1: those don't happen very often and so far we've been lucky.

593
00:36:31,800 --> 00:36:35,560
Speaker 1: So we've discussed the ambient radiation risks in space. Obviously,

594
00:36:35,600 --> 00:36:38,520
Speaker 1: within our solar system, you you've got solar radiation to

595
00:36:38,520 --> 00:36:40,960
Speaker 1: worry about, and you've got charged particles from the from

596
00:36:40,960 --> 00:36:44,279
Speaker 1: the galaxy of the universe to worry about. But also UM,

597
00:36:44,320 --> 00:36:48,040
Speaker 1: apart from these ambient radiation risks, does it make sense

598
00:36:48,120 --> 00:36:52,280
Speaker 1: to also, uh, for space farers to worry about anomalous

599
00:36:52,400 --> 00:36:55,640
Speaker 1: radiation risks UM? I know, for example, like X ray

600
00:36:55,640 --> 00:36:58,480
Speaker 1: bursts and gam rey bursts are extremely rare in the universe.

601
00:36:58,520 --> 00:37:02,160
Speaker 1: Are they so rare that uh that we just don't

602
00:37:02,200 --> 00:37:04,960
Speaker 1: have to think about that? Or will the future of

603
00:37:05,000 --> 00:37:07,879
Speaker 1: space exploration needs don't really think about it? I mean

604
00:37:07,960 --> 00:37:13,200
Speaker 1: if if, uh, if there were a huge black hole

605
00:37:13,760 --> 00:37:18,080
Speaker 1: merger like I was observed with the gravitational radiation, you know,

606
00:37:18,200 --> 00:37:20,760
Speaker 1: billions of light years away, if something like that happened

607
00:37:21,239 --> 00:37:24,200
Speaker 1: right near us in the galaxy, it would be bad news.

608
00:37:24,239 --> 00:37:27,400
Speaker 1: But there's absolutely nothing we can do about it, and

609
00:37:27,520 --> 00:37:31,200
Speaker 1: so it's just not something that that we even bother

610
00:37:31,320 --> 00:37:34,120
Speaker 1: to think about. And what about solar anomalies, I know

611
00:37:34,200 --> 00:37:38,680
Speaker 1: you mentioned like a solar event solar I mean solar

612
00:37:38,719 --> 00:37:42,000
Speaker 1: flairs are recognized. I mean, there was a big solar

613
00:37:42,080 --> 00:37:46,440
Speaker 1: flare in nineteen seventy two in August, which just happened

614
00:37:46,440 --> 00:37:51,319
Speaker 1: to occur between Apollo sixteen and Apollo seventeen. Had it

615
00:37:51,360 --> 00:37:54,680
Speaker 1: occurred when astronauts were on the lunar surface, there's been

616
00:37:54,719 --> 00:37:57,719
Speaker 1: a lot of discussion of whether we've would have been

617
00:37:57,760 --> 00:38:00,440
Speaker 1: fatal or whether it would have just been very bad

618
00:38:00,480 --> 00:38:03,440
Speaker 1: for them. But it would have been a very serious effect.

619
00:38:04,040 --> 00:38:07,239
Speaker 1: But that solar flare in nineteen seventy two was not

620
00:38:07,440 --> 00:38:10,400
Speaker 1: nearly the strongest solar flare that's ever existed. I mean,

621
00:38:10,400 --> 00:38:14,080
Speaker 1: there was the Carryington event back in the mid nineteenth century,

622
00:38:14,120 --> 00:38:17,000
Speaker 1: which was so powerful. Of course, that was we didn't

623
00:38:17,040 --> 00:38:20,000
Speaker 1: have satellites, we didn't have electronics going, but they did

624
00:38:20,040 --> 00:38:24,680
Speaker 1: have telegraph lines, and that solar flare collapsed the Earth's

625
00:38:24,719 --> 00:38:28,480
Speaker 1: magnetic field to the extent that the moving magnetic field

626
00:38:28,600 --> 00:38:33,719
Speaker 1: induced voltages in the telegraph lines, which caused fires in

627
00:38:33,800 --> 00:38:36,839
Speaker 1: telegraph offices. I mean, if if a flare like that

628
00:38:36,960 --> 00:38:40,799
Speaker 1: hit us today, it would cost Lloyds of London did

629
00:38:40,840 --> 00:38:43,080
Speaker 1: an estimate of that. I mean, it would be like

630
00:38:43,120 --> 00:38:46,239
Speaker 1: a trillion dollars worth of damage. All of our satellites

631
00:38:46,280 --> 00:38:50,480
Speaker 1: would be destroyed, Electronic systems all over the world, electrical

632
00:38:50,520 --> 00:38:54,440
Speaker 1: power grids would go down, and there's nothing we can

633
00:38:54,480 --> 00:38:58,120
Speaker 1: do about it except that statistically something like that happens

634
00:38:58,160 --> 00:39:02,040
Speaker 1: maybe once every five hudred years or so. UM. So

635
00:39:02,160 --> 00:39:05,759
Speaker 1: far we've been lucky. Not too much more you can

636
00:39:05,800 --> 00:39:10,919
Speaker 1: say about it. Uh, we are. People are still doing

637
00:39:10,960 --> 00:39:13,800
Speaker 1: research to try to be able to predict solar flares,

638
00:39:14,400 --> 00:39:20,879
Speaker 1: so far without many positive results. But I just read

639
00:39:20,920 --> 00:39:24,680
Speaker 1: recently some new researches indicating that, you know, maybe they've

640
00:39:24,680 --> 00:39:29,120
Speaker 1: made a breakthrough. UM. Being able to predict solar flares

641
00:39:29,120 --> 00:39:31,440
Speaker 1: in advance would be a big help, so that at

642
00:39:31,520 --> 00:39:33,719
Speaker 1: least you could get ready for it, and if you

643
00:39:33,760 --> 00:39:35,960
Speaker 1: had astronauts on the Moon, at least they could try

644
00:39:35,960 --> 00:39:40,600
Speaker 1: to get inside their shielding. But other than that, UM,

645
00:39:40,719 --> 00:39:44,400
Speaker 1: it's statistics, and so far we've been lucky, all right,

646
00:39:44,480 --> 00:39:47,880
Speaker 1: Dr Hoffman. In other interviews, you have stated that shimp

647
00:39:47,880 --> 00:39:50,800
Speaker 1: cocktail was your favorite food in space. Can you explain

648
00:39:50,880 --> 00:39:54,880
Speaker 1: for our listeners why you selected? Sure? You know, when

649
00:39:54,960 --> 00:39:59,400
Speaker 1: when when you take away gravity, there's an upward migration

650
00:39:59,600 --> 00:40:02,320
Speaker 1: of it from your lower body to your upper body,

651
00:40:02,400 --> 00:40:04,719
Speaker 1: and so you get a lot of extra fluid in

652
00:40:04,800 --> 00:40:07,360
Speaker 1: your head. It's a little bit like having sinus congestion,

653
00:40:07,440 --> 00:40:13,040
Speaker 1: and it it decreases your sense of smell, so that, um,

654
00:40:13,600 --> 00:40:18,880
Speaker 1: you you, the food becomes very bland. They provide extra

655
00:40:18,920 --> 00:40:22,040
Speaker 1: Tabasco sauce that we can sort of spice up our food.

656
00:40:22,120 --> 00:40:25,560
Speaker 1: The nice thing about the shrimp cocktailers dehydrated, so the

657
00:40:25,640 --> 00:40:30,239
Speaker 1: shrimp themselves, uh, you know, there's nothing to write home

658
00:40:30,280 --> 00:40:32,120
Speaker 1: about you. You put a little bit of water on

659
00:40:32,200 --> 00:40:34,919
Speaker 1: them and they don't have that much taste, but they

660
00:40:34,960 --> 00:40:38,280
Speaker 1: pack it in a really really hot horse radish sauce.

661
00:40:38,400 --> 00:40:42,120
Speaker 1: So I found if I would eat a shrimp cocktail

662
00:40:42,960 --> 00:40:46,759
Speaker 1: before dinner every night, that horse radish would kind of

663
00:40:46,760 --> 00:40:50,560
Speaker 1: open up my nasal passages so that I could smell

664
00:40:50,600 --> 00:40:52,839
Speaker 1: and taste the rest of the food a little bit more. So.

665
00:40:52,920 --> 00:40:55,320
Speaker 1: That's why it was my favorite food, not because it

666
00:40:55,880 --> 00:40:58,920
Speaker 1: intrinsically taste good. I mean, as a shrimp cocktail, it

667
00:40:59,040 --> 00:41:02,160
Speaker 1: was you know, if they served it to you in

668
00:41:02,160 --> 00:41:05,320
Speaker 1: a restaurant, you'd send it back, But it really opened

669
00:41:05,360 --> 00:41:07,600
Speaker 1: up the nasal passages so that I can enjoy the

670
00:41:07,600 --> 00:41:10,560
Speaker 1: rest of my meal. Well, I guess it's those little

671
00:41:10,560 --> 00:41:14,200
Speaker 1: pleasures that make life forth living. There you go. Well,

672
00:41:14,480 --> 00:41:16,279
Speaker 1: thank you so much. It's been such a privilege to

673
00:41:16,280 --> 00:41:19,040
Speaker 1: talk to you, Dr Hoffman. We really appreciate your sharing

674
00:41:19,040 --> 00:41:21,600
Speaker 1: your time with us. Been a pleasure, and I hope

675
00:41:21,640 --> 00:41:25,000
Speaker 1: it's given maybe a new perspective to some of the

676
00:41:25,040 --> 00:41:29,560
Speaker 1: listeners who haven't heard some of this stuff. So um,

677
00:41:29,560 --> 00:41:34,479
Speaker 1: thanks for your interest and it's been fun. Yeah, thank

678
00:41:34,480 --> 00:41:36,200
Speaker 1: you so much. Thank you. You have a great day, sir.

679
00:41:36,760 --> 00:41:39,440
Speaker 1: All Right, well, thanks once more to Dr Jeff Hoffman

680
00:41:39,480 --> 00:41:43,200
Speaker 1: and to National Geographic for enabling us to have this

681
00:41:43,239 --> 00:41:45,759
Speaker 1: wonderful chat. We're gonna take a quick break and we

682
00:41:45,840 --> 00:41:48,319
Speaker 1: come back. Joe and I will discuss the interview a

683
00:41:48,320 --> 00:41:53,319
Speaker 1: little bit before we close out the episode. All right,

684
00:41:53,360 --> 00:41:56,600
Speaker 1: we're back, So Robert. Dr Hoffman mentioned a few things

685
00:41:56,680 --> 00:41:59,680
Speaker 1: in that interview that I thought were really interesting and

686
00:41:59,719 --> 00:42:01,560
Speaker 1: we might want to follow up and talk about a

687
00:42:01,560 --> 00:42:03,480
Speaker 1: little bit. One of the things you mentioned when we

688
00:42:03,480 --> 00:42:06,360
Speaker 1: were talking about solar anomalies was the idea of the

689
00:42:06,400 --> 00:42:09,880
Speaker 1: Carrington event or the solar storm of eighteen fifty nine,

690
00:42:10,320 --> 00:42:12,480
Speaker 1: And this just stuck in my mind because this is

691
00:42:12,520 --> 00:42:16,040
Speaker 1: one of the most fascinating and I think maybe lesser

692
00:42:16,120 --> 00:42:20,120
Speaker 1: known crazy astronomical events in history. Yeah, and indeed it

693
00:42:20,120 --> 00:42:22,799
Speaker 1: may have been the largest solar energetic particle event in

694
00:42:22,800 --> 00:42:25,799
Speaker 1: the past several hundred years. So why do we call

695
00:42:25,840 --> 00:42:28,440
Speaker 1: it the Carrington event? Well, it's a name for amateur

696
00:42:28,480 --> 00:42:33,080
Speaker 1: astronomer Richard Carrington, who observed quote two patches of intensely

697
00:42:33,160 --> 00:42:36,400
Speaker 1: bright and white light erupting from a cluster of dark

698
00:42:36,440 --> 00:42:40,000
Speaker 1: sun spots. They vanished within five minutes, but then within

699
00:42:40,040 --> 00:42:42,680
Speaker 1: a matter of hours, the effects of this event were

700
00:42:42,719 --> 00:42:45,320
Speaker 1: felt on Earth. So what do those effects look like? Well,

701
00:42:45,480 --> 00:42:50,080
Speaker 1: as a Dr Hoffman uh alluded to, telegraph communication around

702
00:42:50,080 --> 00:42:54,080
Speaker 1: the world began to fail. Sparks were flying from telegraph machine.

703
00:42:54,160 --> 00:42:57,759
Speaker 1: Telegraph operators were in some cases shocked, and then also

704
00:42:57,880 --> 00:43:01,840
Speaker 1: colorful auras in the sky were causing the birds to

705
00:43:01,920 --> 00:43:06,640
Speaker 1: chirp at night. Yeah. So the solar flaring question had

706
00:43:06,719 --> 00:43:10,399
Speaker 1: the power of an estimated ten billion atomic bombs, and

707
00:43:10,560 --> 00:43:13,960
Speaker 1: ice core samples reveal that the Carrington event was twice

708
00:43:14,000 --> 00:43:16,640
Speaker 1: as big as any other solar storm within the last

709
00:43:16,760 --> 00:43:19,279
Speaker 1: five hundred years. This is the kind of thing where

710
00:43:19,280 --> 00:43:22,200
Speaker 1: if it were to hit today, the estimates are just

711
00:43:22,480 --> 00:43:25,719
Speaker 1: in trillions of dollars worth of damage, it would just

712
00:43:25,719 --> 00:43:28,840
Speaker 1: be a massive blow. And Dr Hoffman alluded to this

713
00:43:28,880 --> 00:43:30,439
Speaker 1: as well, the idea that it would have. It would

714
00:43:30,440 --> 00:43:34,360
Speaker 1: impact our satellites, it would impact technology on a scale

715
00:43:34,400 --> 00:43:36,879
Speaker 1: that just simply did not exist in eighteen fifty nine.

716
00:43:36,960 --> 00:43:40,040
Speaker 1: But of course it would also greatly affect any exposed

717
00:43:40,080 --> 00:43:43,520
Speaker 1: astronauts or space farers that you know, we're colonists, or

718
00:43:43,560 --> 00:43:47,800
Speaker 1: wherever outside of the protection of our shield that didn't

719
00:43:47,800 --> 00:43:51,080
Speaker 1: didn't even fully protect us from this event. Yeah, yeah,

720
00:43:51,200 --> 00:43:54,480
Speaker 1: you know. I I actually interviewed a heliophysicist Dr c

721
00:43:54,680 --> 00:43:58,400
Speaker 1: Alex Young several years ago about solar storms, and he

722
00:43:58,440 --> 00:44:00,960
Speaker 1: pointed out that that our mom are an electrical grid

723
00:44:00,960 --> 00:44:03,680
Speaker 1: in particular, is just highly vulnerable to this sort of thing.

724
00:44:04,120 --> 00:44:06,239
Speaker 1: He told me, quote, the power grids that we have

725
00:44:06,320 --> 00:44:08,440
Speaker 1: in the US and actually all over the world are

726
00:44:08,480 --> 00:44:12,040
Speaker 1: interconnected in very fragile If the currents large enough, it

727
00:44:12,080 --> 00:44:14,680
Speaker 1: can short out the largest of the transformers, which can

728
00:44:14,760 --> 00:44:17,759
Speaker 1: knock out the power grid over the scale of a country,

729
00:44:17,800 --> 00:44:21,200
Speaker 1: of a continent, or even across the whole globe. Yeah,

730
00:44:21,640 --> 00:44:24,799
Speaker 1: and uh, for just a minor example of the sort

731
00:44:24,840 --> 00:44:28,560
Speaker 1: of thing, in Canada's hydro Quebec power grid experienced a

732
00:44:28,560 --> 00:44:32,640
Speaker 1: similar shock in nine from a particularly powerful sunstorm, and

733
00:44:32,680 --> 00:44:35,320
Speaker 1: this caused the grid to go down for over nine hours,

734
00:44:35,560 --> 00:44:39,400
Speaker 1: resulting in revenue losses estimated in the hundreds of millions

735
00:44:39,400 --> 00:44:42,120
Speaker 1: of dollars. And that was just the small potatoes compared

736
00:44:42,239 --> 00:44:46,080
Speaker 1: to something like the Carrington event. Yeah, with our earthbound minds,

737
00:44:46,160 --> 00:44:49,319
Speaker 1: it's impossible for us to grasp the real power and

738
00:44:49,400 --> 00:44:52,440
Speaker 1: magnitude of solar events. Like if you've never seen one

739
00:44:52,480 --> 00:44:55,840
Speaker 1: of those pictures of the Earth superimposed to scale against

740
00:44:55,920 --> 00:45:00,399
Speaker 1: a solar prominence, it's it's amazing solar prominence. Are these

741
00:45:00,400 --> 00:45:04,120
Speaker 1: events where this monstrous loop of plasma erupts out of

742
00:45:04,160 --> 00:45:06,680
Speaker 1: the photosphere, which is the apparent surface of the Sun,

743
00:45:06,960 --> 00:45:09,759
Speaker 1: and then it curves through the Sun's corona guided by

744
00:45:09,800 --> 00:45:12,759
Speaker 1: solar magnetic fields. And this is not even really the

745
00:45:12,800 --> 00:45:15,239
Speaker 1: core of the Sun itself, is just an event. It's

746
00:45:15,280 --> 00:45:18,200
Speaker 1: like weather, it's a it's an event on the surface

747
00:45:18,239 --> 00:45:21,239
Speaker 1: of the Sun. But this event itself is tens of

748
00:45:21,320 --> 00:45:24,799
Speaker 1: times bigger than the entire planet Earth. And you see

749
00:45:24,840 --> 00:45:28,160
Speaker 1: one of these pictures. When you look at the vulnerability

750
00:45:28,239 --> 00:45:33,279
Speaker 1: and tininess of human scale projects becomes absurdly apparent. The

751
00:45:33,280 --> 00:45:35,239
Speaker 1: comparison that comes to My mind is if you ever

752
00:45:35,320 --> 00:45:38,560
Speaker 1: been out in nature, as as I know you, you

753
00:45:38,640 --> 00:45:40,959
Speaker 1: like to venture out in the nature on hikes and

754
00:45:40,960 --> 00:45:44,200
Speaker 1: and so forth, you ever observe a bird's nest or

755
00:45:44,239 --> 00:45:48,359
Speaker 1: a wasp nest, some sort of animal structure or nest,

756
00:45:48,560 --> 00:45:50,479
Speaker 1: and you think about yourself, well, that's a horrible place

757
00:45:50,520 --> 00:45:54,120
Speaker 1: to put that, don't you know, tiny bird that eventually

758
00:45:54,160 --> 00:45:56,520
Speaker 1: the wind is gonna blow. Uh, don't you know that

759
00:45:56,560 --> 00:45:59,439
Speaker 1: when it rains, that's that's just not a very protected place.

760
00:45:59,480 --> 00:46:02,080
Speaker 1: Don't you know that's my front porch. And I'm probably

761
00:46:02,040 --> 00:46:04,960
Speaker 1: gonna knock you down eventually, just because you're inconvenient to me.

762
00:46:05,680 --> 00:46:08,680
Speaker 1: And then when you think about everything that that that

763
00:46:08,880 --> 00:46:11,800
Speaker 1: is life on earth, and then everything that humans have built,

764
00:46:12,000 --> 00:46:15,120
Speaker 1: and you think of the vulnerability that is intrinsic in

765
00:46:15,200 --> 00:46:18,719
Speaker 1: all of that. Uh, we're really no different from from

766
00:46:18,760 --> 00:46:22,040
Speaker 1: any wasp that decides to build its nest on the

767
00:46:22,080 --> 00:46:25,080
Speaker 1: bottom of a porch. Swing on a geologic or cosmic

768
00:46:25,160 --> 00:46:30,600
Speaker 1: time scale, our projects are so hilariously short sighted. But

769
00:46:30,680 --> 00:46:32,640
Speaker 1: then again that that's just how we're built, right. I Mean,

770
00:46:32,680 --> 00:46:36,799
Speaker 1: it's very difficult for us to seriously focus on a

771
00:46:36,840 --> 00:46:40,080
Speaker 1: project that we think will take place over say a

772
00:46:40,200 --> 00:46:43,520
Speaker 1: hundred thousand years or even a million years. Yeah, totally.

773
00:46:43,520 --> 00:46:46,000
Speaker 1: We're just we we are short sighted as a species.

774
00:46:46,040 --> 00:46:49,080
Speaker 1: That's what we've evolved to be. Now. On the subject

775
00:46:49,120 --> 00:46:53,640
Speaker 1: of long time scales and and the cosmic scale of events,

776
00:46:53,680 --> 00:46:57,600
Speaker 1: I asked Dr Hoffman about whether a space faring species

777
00:46:58,000 --> 00:47:01,120
Speaker 1: should really worry about things like murray bursts or X

778
00:47:01,200 --> 00:47:03,840
Speaker 1: ray bursts, which I think is kind of a weird

779
00:47:03,920 --> 00:47:09,120
Speaker 1: question because on one hand, it's something that would pose

780
00:47:09,200 --> 00:47:12,440
Speaker 1: a very serious threat, but these things are also incredibly

781
00:47:12,520 --> 00:47:15,800
Speaker 1: rare in the universe, and they're incredibly rare in the galaxy,

782
00:47:15,880 --> 00:47:20,600
Speaker 1: So it's hard to factor into one's idea about something

783
00:47:20,640 --> 00:47:24,520
Speaker 1: like space exploration how much you should worry about something

784
00:47:24,600 --> 00:47:27,719
Speaker 1: that is almost never going to happen anywhere near you,

785
00:47:28,320 --> 00:47:30,400
Speaker 1: but if it did, it would be catastrophic. Yeah, it's

786
00:47:30,440 --> 00:47:33,359
Speaker 1: coming to It kind of reminds one of of, of course,

787
00:47:33,400 --> 00:47:35,960
Speaker 1: the the seafaring explorers of old and to say, well,

788
00:47:36,000 --> 00:47:37,680
Speaker 1: if you go out in that boat, you you might

789
00:47:37,760 --> 00:47:41,160
Speaker 1: very well drown, you might run into a hurricane, etcetera.

790
00:47:41,760 --> 00:47:44,680
Speaker 1: And the hurricanes are pretty common. Yeah, those are pretty common,

791
00:47:44,719 --> 00:47:47,480
Speaker 1: and like if it was you would have to say, oh, yeah, well,

792
00:47:47,520 --> 00:47:50,439
Speaker 1: I we've we may very well drown, we may very

793
00:47:50,440 --> 00:47:53,680
Speaker 1: well die die on some distant island, but in the

794
00:47:53,760 --> 00:47:58,000
Speaker 1: chances here are are less. But it's ultimately the same scenario,

795
00:47:58,080 --> 00:48:00,480
Speaker 1: like it's it's of course it's safer to go out

796
00:48:00,520 --> 00:48:04,360
Speaker 1: and explore is certainly in the short term. But are

797
00:48:04,400 --> 00:48:06,279
Speaker 1: we the type of species that is going to do that?

798
00:48:06,360 --> 00:48:09,120
Speaker 1: Of course, then again, if there were a nearby gamma

799
00:48:09,200 --> 00:48:11,680
Speaker 1: ray burst, as unlikely as that is, that would be

800
00:48:11,719 --> 00:48:14,759
Speaker 1: bad even if we were on Earth. Yeah, yeah, so

801
00:48:14,800 --> 00:48:17,680
Speaker 1: these in particular, like so the gamma ray bursts um

802
00:48:18,000 --> 00:48:21,719
Speaker 1: are omitted by powerful supernova that are dubbed hypernova and

803
00:48:21,760 --> 00:48:23,759
Speaker 1: you can think of these is it's just like the

804
00:48:23,880 --> 00:48:28,279
Speaker 1: energy shrapnel from a Titanic exploding star. And uh, you know,

805
00:48:28,520 --> 00:48:31,319
Speaker 1: even though they are rare, the radiation killing zone for

806
00:48:31,320 --> 00:48:34,400
Speaker 1: an exploding hyperstar has been estimated to be around six

807
00:48:34,480 --> 00:48:38,240
Speaker 1: thousand light years across compared to a normal star's thirty

808
00:48:38,400 --> 00:48:41,880
Speaker 1: light year kill zone, and even smaller gamma ray doses

809
00:48:42,360 --> 00:48:46,040
Speaker 1: can have a serious neurological impact on an individual. Oh yeah,

810
00:48:46,080 --> 00:48:48,320
Speaker 1: you don't want gamma rays no matter what. There was

811
00:48:48,480 --> 00:48:50,879
Speaker 1: a Cold Spring Harbor Laboratory study on mice that found

812
00:48:50,920 --> 00:48:54,600
Speaker 1: that gamma radiation targeted a particular type of stem cell

813
00:48:54,640 --> 00:48:57,560
Speaker 1: and the hippocampus, the an area of the brain you

814
00:48:57,600 --> 00:48:59,800
Speaker 1: know believe to be important for learning and mood control,

815
00:49:00,360 --> 00:49:03,680
Speaker 1: and normal doses of space radiation also pose a serious risk.

816
00:49:04,040 --> 00:49:07,960
Speaker 1: In a separate experiment, the NASA Space Radiation Laboratory dosed

817
00:49:08,040 --> 00:49:11,200
Speaker 1: mice with radiation equal to the amount and astronaut might

818
00:49:11,280 --> 00:49:14,719
Speaker 1: receive on a three year voyage to Mars, and scientists

819
00:49:14,719 --> 00:49:19,680
Speaker 1: discovered significant damage to hympocampus stem cells responsible for repopulating

820
00:49:19,680 --> 00:49:23,240
Speaker 1: the brain with new cells. So, without proper radiation shielding,

821
00:49:23,360 --> 00:49:26,480
Speaker 1: lengthy space exploration might be a recipe for the kind

822
00:49:26,520 --> 00:49:30,040
Speaker 1: of like cognitive and emotional breakdown that Dr Hoffman alluded to,

823
00:49:30,239 --> 00:49:32,560
Speaker 1: the idea that you would have your astronauts arrived at

824
00:49:32,560 --> 00:49:37,640
Speaker 1: their destination with reduced cognitive abilities, and that this is

825
00:49:37,680 --> 00:49:40,719
Speaker 1: exactly the time when presumably all the hard work is

826
00:49:40,840 --> 00:49:45,040
Speaker 1: right in front of them. They're gonna have to land

827
00:49:45,040 --> 00:49:48,040
Speaker 1: on the planet and the planetary explorers, but have to

828
00:49:48,080 --> 00:49:51,160
Speaker 1: do so with the reduced with reduced brain power, it's

829
00:49:51,160 --> 00:49:54,440
Speaker 1: a daunting problem. Now. Of course, in all of this discussion,

830
00:49:54,520 --> 00:49:57,480
Speaker 1: we don't want to give the impression of discouraging space

831
00:49:57,520 --> 00:50:00,440
Speaker 1: exploration or anything like. No, no, no, uh, just because

832
00:50:00,480 --> 00:50:03,279
Speaker 1: of all these risks. But in talking about them, it's

833
00:50:03,320 --> 00:50:05,800
Speaker 1: just that we have to recognize how hard this project

834
00:50:05,880 --> 00:50:09,600
Speaker 1: is and how dangerous it is, and how much investment

835
00:50:09,800 --> 00:50:13,200
Speaker 1: of research and technology it's going to take to make

836
00:50:13,280 --> 00:50:17,720
Speaker 1: this something that humans can safely and reasonably do. Yeah. Well,

837
00:50:17,800 --> 00:50:20,000
Speaker 1: we did an episode last year we talked about proposed

838
00:50:20,000 --> 00:50:24,960
Speaker 1: ways of genetically altering UH astronauts of the future so

839
00:50:25,000 --> 00:50:28,000
Speaker 1: that they might be less susceptible to the damages of radiation.

840
00:50:28,520 --> 00:50:32,560
Speaker 1: So there there are multiple fronts on which science, current

841
00:50:32,640 --> 00:50:36,560
Speaker 1: science and future science may be able to to tweak

842
00:50:36,600 --> 00:50:38,240
Speaker 1: all of this in our favor. But it is still,

843
00:50:38,280 --> 00:50:41,400
Speaker 1: as you said, it's a dangerous universe and UH and

844
00:50:41,480 --> 00:50:44,680
Speaker 1: we're ultimately a very fragile species. It is evolved to

845
00:50:44,800 --> 00:50:48,959
Speaker 1: thrive within a very slim portion of our own UH

846
00:50:49,120 --> 00:50:53,600
Speaker 1: atmosphere and within a slim portion of our own terrestrial environment.

847
00:50:53,960 --> 00:50:55,960
Speaker 1: Even a large portion of the Earth will kill you,

848
00:50:57,800 --> 00:50:59,840
Speaker 1: It's true. Yeah, if you were to teleport up to

849
00:50:59,840 --> 00:51:01,480
Speaker 1: the top of Mount Everest, you would not be able

850
00:51:01,520 --> 00:51:04,440
Speaker 1: to breathe, or if you were to suddenly appear at

851
00:51:04,480 --> 00:51:08,239
Speaker 1: the bottom of the ocean and find yourself of surrounded

852
00:51:08,239 --> 00:51:11,239
Speaker 1: by what three thousand atmosphere is worth of pressure, or

853
00:51:11,360 --> 00:51:13,520
Speaker 1: the north or South pole, or in the middle of

854
00:51:13,520 --> 00:51:16,319
Speaker 1: a desert. There's just a lot of bad places to be.

855
00:51:16,840 --> 00:51:18,719
Speaker 1: But I don't mean to trash the Earth, of course.

856
00:51:18,719 --> 00:51:20,319
Speaker 1: I mean this takes us back to the idea of

857
00:51:20,320 --> 00:51:22,400
Speaker 1: the overview effect that we mentioned a little bit with

858
00:51:22,520 --> 00:51:26,120
Speaker 1: Mr Hoffman, that having a cosmic perspective on the Earth,

859
00:51:26,200 --> 00:51:32,160
Speaker 1: realizing the ultimate kind of emptiness and violence and hostility

860
00:51:32,200 --> 00:51:36,279
Speaker 1: of the universe at large, and the the incredible uniqueness

861
00:51:36,280 --> 00:51:39,800
Speaker 1: and privilege of this one little rock floating in space,

862
00:51:40,560 --> 00:51:45,040
Speaker 1: it really should give us a perspective of thankfulness and transcendence. Uh,

863
00:51:45,200 --> 00:51:48,480
Speaker 1: something that makes the petty human squabbles kind of fade

864
00:51:48,520 --> 00:51:52,520
Speaker 1: away into non importance. All right, today you have it.

865
00:51:52,719 --> 00:51:54,880
Speaker 1: I hope everyone enjoyed our chat with Dr Hoffman. We

866
00:51:54,920 --> 00:51:58,000
Speaker 1: certainly enjoyed chatting with him. Absolutely. It was a pleasure

867
00:51:58,040 --> 00:51:59,239
Speaker 1: and I don't know, he gave me a lot of

868
00:51:59,280 --> 00:52:01,359
Speaker 1: stuff to think about. Yeah, this is the first time

869
00:52:01,400 --> 00:52:04,080
Speaker 1: we've had an actual space traveler on the show. Uh,

870
00:52:04,080 --> 00:52:06,759
Speaker 1: and it did it did not disappoint Maybe it won't

871
00:52:06,760 --> 00:52:09,399
Speaker 1: be the last time. Yeah, who knows. Now, if there's

872
00:52:09,440 --> 00:52:13,000
Speaker 1: anything in our discussion with Dr Hoffman that really leapt

873
00:52:13,040 --> 00:52:14,600
Speaker 1: out at you and you would like to hear a

874
00:52:14,640 --> 00:52:17,080
Speaker 1: whole episode of Stuff to Blow Your Mind on, let

875
00:52:17,120 --> 00:52:19,879
Speaker 1: us know about that, because because he covered a lot

876
00:52:19,880 --> 00:52:22,520
Speaker 1: of ground in the interview totally. Don't be shy to

877
00:52:22,560 --> 00:52:24,319
Speaker 1: get in touch with us and let us know what

878
00:52:24,440 --> 00:52:26,000
Speaker 1: you would like us to pick up on from that

879
00:52:26,080 --> 00:52:28,200
Speaker 1: conversation in the future, right, And you can do that

880
00:52:28,239 --> 00:52:32,879
Speaker 1: at our various social media accounts. We're on Facebook, Twitter, Instagram. Oh,

881
00:52:32,920 --> 00:52:34,640
Speaker 1: and check out Stuff to Blow Your Mind dot com.

882
00:52:34,640 --> 00:52:36,880
Speaker 1: That's the mothership. That's where you'll find links out to

883
00:52:36,880 --> 00:52:39,279
Speaker 1: our social media accounts. That is where you'll find links

884
00:52:39,280 --> 00:52:42,000
Speaker 1: out to our social media accounts, as well as all

885
00:52:42,000 --> 00:52:45,640
Speaker 1: the podcast episodes, some blog posts, etcetera. And hey, check

886
00:52:45,640 --> 00:52:48,320
Speaker 1: out One Strange Rock. It's a really beautiful show. It

887
00:52:48,520 --> 00:52:52,720
Speaker 1: definitely like HD home viewing experience. Big thanks as always

888
00:52:52,719 --> 00:52:56,120
Speaker 1: to our excellent audio producers Alex Williams and Tarry Harrison.

889
00:52:56,200 --> 00:52:57,480
Speaker 1: And if you want to get in touch with us

890
00:52:57,520 --> 00:53:00,200
Speaker 1: directly by email, you can do so as always at

891
00:53:00,320 --> 00:53:13,600
Speaker 1: Blow the Mind at how Stuff Works dot com. For

892
00:53:13,719 --> 00:53:16,040
Speaker 1: more on this and thousands of other topics. Is It

893
00:53:16,120 --> 00:53:40,040
Speaker 1: How stuff Works dot com