Speaker 1: Brought to you by Toyota. Let's go places. Welcome to
Speaker 1: Forward Thinking. Hello, and welcome to Forward Thinking, the podcast
Speaker 1: that looks at the future and says, but it's the
Speaker 1: scatter of thrust that really drives you insane. I'm Joe
Speaker 1: McCormick and I'm Lauren bulk Obama, and our regular host
Speaker 1: Jonathan Strickland is not with us today because he is
Speaker 1: out in the field on assignment. Yes, doing things that
Speaker 1: we cannot tell you about yet. No. I would say
Speaker 1: that he's out discovering the amazing technology of tomorrow. But
Speaker 1: really what he's probably doing is posing for selfies with
Speaker 1: very muscular men. Yes, that is entirely likely. You can
Speaker 1: watch the House Stuff Works dot Com channel on YouTube
Speaker 1: to find out more about that in a few weeks. Yeah,
Speaker 1: so today we wanted to address a listener request episode.
Speaker 1: Our listener, Keith on Facebook, has asked us to talk
Speaker 1: about all kinds of topics and we can't do them
Speaker 1: all at once, so we decided to pick the coolest,
Speaker 1: weirdest one of the bunch, being Stellar Engines. Stellar Engines.
Speaker 1: Now I know what the gearheads and the audience are thinking.
Speaker 1: Cadillac V eight right, the classic Cadillac V eight Stellar
Speaker 1: out of this world? Right? Yeah? Oh man, they don't
Speaker 1: make them like that anymore, or I don't know, they
Speaker 1: might still make those spoiler alert, I don't know anything
Speaker 1: about cars, um, But no, the use of the word
Speaker 1: stellar here actually refers to the more classical sense, as
Speaker 1: in stars. Yes, stars turned into engines. Put to our
Speaker 1: own devious uses, what would a star based engine even be? Um?
Speaker 1: As it turns out, it's real complicated, y'all, And it's
Speaker 1: really weird and really really cool. This is one of
Speaker 1: the coolest ideas I think we've looked at in a while.
Speaker 1: And it's also kind of cool because it's not even
Speaker 1: close to reality. So this is going to be one
Speaker 1: of our more on the speculative end. So yeah, this
Speaker 1: is not one of those like twenty to forty year
Speaker 1: kind of things that we usually wind up talking about
Speaker 1: on the show. This is so far out there thousand
Speaker 1: years in the optimistic sense. So, okay, let us talk
Speaker 1: about interstellar travel. Sure, well, we all know that one
Speaker 1: day we may want or even need to travel to
Speaker 1: another solar system. And what's wrong with our solar system? Joe? Well,
Speaker 1: you know, it's just in our Solar system. You get
Speaker 1: board being in the same place for a long time.
Speaker 1: I know, after a while, just seeing the same planets
Speaker 1: going around and around over and over. Don't you ever
Speaker 1: get tired of Mars? Yeah? Yeah, you get that interstellar
Speaker 1: wonder lust. Well, it's not just boredom and uh and
Speaker 1: discontent that might make us want to look to another
Speaker 1: solar system in our galaxy solar on we over time,
Speaker 1: our son is going to get into some trouble. Have
Speaker 1: you heard about this? H Well, I mean it's pretty
Speaker 1: much a bad seed. Yeah. Well, okay, so today we
Speaker 1: have our our healthy yellow son, the one that makes
Speaker 1: Superman as powerful as he is. Not all sons are
Speaker 1: like this, and in fact, sons have a lifetime, just
Speaker 1: like living organisms do. They sort of increase and decrease
Speaker 1: in luminosity at different periods of their life, and eventually
Speaker 1: they use up all of their stellar stuff. Right, the
Speaker 1: fuel that they that they fuse, the hydrogen that they're
Speaker 1: fusing to be that healthy yellow star. You know, it's
Speaker 1: not infinite, so this can be bad for planets orbiting
Speaker 1: the star. In October, there was a NASA blog post
Speaker 1: that was explaining that a team of astronomers had recently
Speaker 1: discovered evidence through a ground based telescope that there was
Speaker 1: this red giant star called beat plus forty eight seven
Speaker 1: forty and it was swelling to completely engulf a planet
Speaker 1: formerly in its or it So how did they figure
Speaker 1: this out? I thought this was really interesting. They realized
Speaker 1: the star had quote the fumes of a scorched planet
Speaker 1: in its atmosphere unquote, So the star aida planet. And
Speaker 1: we figured it out by smelling the star's breath, uh
Speaker 1: telescopically nonetheless, right, So yeah, they smelled its breath with
Speaker 1: spectroscopic analysis, so that you know, looked at the colors, uh,
Speaker 1: the luminosity coming off of the Sun, and they can
Speaker 1: look at what materials are in that based on that data,
Speaker 1: and they found that the star contained lots of the
Speaker 1: element lithium. Oh yeah, that's not something that you usually
Speaker 1: find in a red giant, right that That would be
Speaker 1: a very weird thing to find a bunch of in
Speaker 1: a in a star like that, because typically lithium gets
Speaker 1: destroyed inside stars over a long period of time, and
Speaker 1: red giants tend to be old. But you might find
Speaker 1: lithium in a star if it's if it's being produced
Speaker 1: by the consumption of another big chunk of matter, and
Speaker 1: that's what they figured out happened. There had been another
Speaker 1: planet there that probably spiraled into this red giant as
Speaker 1: it heated and swoll on up, and it was like
Speaker 1: oh no, no, no no, and it ate the planet.
Speaker 1: It it quote ingested the planet. Okay, so this is
Speaker 1: eventually going to happen to our son and our planet.
Speaker 1: And I'm not talking about like in the next twenty
Speaker 1: to forty years that this is. This is a few
Speaker 1: billion years down the line, yes, right. One of the
Speaker 1: researchers who found the evidence of this said that the
Speaker 1: same kind of fate could be in line for the
Speaker 1: inner planets of our Solar system within about five billion years.
Speaker 1: Now five billion years. It's it's hard to get two
Speaker 1: worked up about five billion years. Personally, I worry a lot,
Speaker 1: but yeah, I'm not. I can't actually be worried about that.
Speaker 1: But at least we we may worry for you know,
Speaker 1: our descendants or the or our you know, the robots
Speaker 1: built by our descendants that take over the planet, or
Speaker 1: the distant future progeny of zebras. I care about future zebras,
Speaker 1: Zebra babies of the future, right, right, well, unfortunately for
Speaker 1: the zebra babies, they won't be able to wait for
Speaker 1: the Sun to all out eat the Earth started. That
Speaker 1: bad stuff will happen way before that actual consumption, right. So, yeah,
Speaker 1: as the intensity of solar radiation bombarding the Earth slowly
Speaker 1: gets stronger, and it just will steadily over time, Earth
Speaker 1: will at some point become unable to sustain life. So
Speaker 1: in there was a three dimensional climate model devised by
Speaker 1: the and I apologize to French speakers out there, but
Speaker 1: I'm going to try to say it the Laboratoire day
Speaker 1: meteorology dynamic. Dynamic, Yeah, I don't. Yeah. So this climate
Speaker 1: model that they came up with predicted that the solar
Speaker 1: radiation will increase the Earth's surface temperature enough to boil
Speaker 1: the oceans and cause Earth to lose all its liquid
Speaker 1: water in about one billion years. That is a much
Speaker 1: tighter deadline of Sun eating us. Okay, so before then,
Speaker 1: I gotta find a plan. B We we can't just
Speaker 1: wait it out. So a pretty straightforward one would be
Speaker 1: to move to move to a nicer neighborhood, find a
Speaker 1: new planet in another solar system, and get all of
Speaker 1: the humans there or all of the zebra people of
Speaker 1: the future grandchildren. But moving all of these organisms to
Speaker 1: a new planet might not be so easy. So we've
Speaker 1: talked about the problems with interstellar travel unless you've got
Speaker 1: a spaceship that goes the speed of light or faster,
Speaker 1: and we all know the problems with that. You know,
Speaker 1: Einstein's special relativity says you can't go faster than the
Speaker 1: speed of light. We may someday come up with some
Speaker 1: crazy way to bind that rule, but we shouldn't bank
Speaker 1: on it right now. It seems kind of like a
Speaker 1: law of physics. So unless you can get pretty near
Speaker 1: the speed of light, the journey between stars becomes prohibitively long,
Speaker 1: like probably thousands of years. Uh. The nearest star to
Speaker 1: Earth is the tiny red dwarf star Proximus Centauri, which
Speaker 1: is in the Alpha Centauri system. It's about four point
Speaker 1: two light years or about thirty nine point nine trillion
Speaker 1: kilometers away. At the speed Voyager left the Solar System,
Speaker 1: which is around thirty seven thousand miles per hour, I
Speaker 1: see slight variations on that would be about you know,
Speaker 1: almost sixty thousand kilometers per hour, which is the quickest
Speaker 1: that anything that has survived its a journey thus far
Speaker 1: has ever moved, right, Yeah, and so at that rate
Speaker 1: it would take Yeah, it would take about eighty thousand
Speaker 1: years to reach Proximus Centauri. Uh, that's I mean, I
Speaker 1: guess if you're talking in the scheme of of a
Speaker 1: billion years, that's not so long. But tightening that up
Speaker 1: would be preferable, especially if that's just the journey to
Speaker 1: a kind of crappy star up, if we're being really honest, Yeah,
Speaker 1: it's this little red dwarf. I mean, you've got to
Speaker 1: you can't just go to any star with the spaceship.
Speaker 1: You need to find a planet to sustain life, right,
Speaker 1: and not all planets are suitable for habitation. In fact,
Speaker 1: most probably aren't. It could be too hot, too cold,
Speaker 1: just in a constant bath of radiation. There might be
Speaker 1: a gas giant that's full of radiation itself, and of
Speaker 1: course you can't walk around on it. A good Earth
Speaker 1: is really hard to find. There's the other problem of
Speaker 1: once you're on the way, how do you keep yourself alive?
Speaker 1: How do you keep supplying yourself with food, energy, air,
Speaker 1: protection from radiation? In interstellar space, you could work on
Speaker 1: building sort of generation sustaining starships with ways of continuously
Speaker 1: creating new energy, maintaining an earthlike environment, etcetera. But then
Speaker 1: you're almost talking about having to build a second Earth
Speaker 1: to travel with you, and we're already on this perfectly
Speaker 1: good Earth. If the problem is the Sun, why not
Speaker 1: find a new son, Why not find a new Sun.
Speaker 1: So the idea here becomes that we could take everything
Speaker 1: we have with us when we travel to a new
Speaker 1: new solar system, literally every single thing we have, including
Speaker 1: the Earth, and for the journey at least including the Sun,
Speaker 1: because we are using it as an engine. An engine.
Speaker 1: You say, and engine, and I say, actually, I didn't
Speaker 1: say it at all. Well, no, this idea comes from
Speaker 1: others who have come before us. Who I mean, Yeah,
Speaker 1: I literally just said it out loud. But it wasn't
Speaker 1: my idea. Who were physicists who had incredibly strange and
Speaker 1: very cool ideas. So where does this idea of a
Speaker 1: stellar engine come from? Well, the original paper we want
Speaker 1: to look at is something from October of nine, and
Speaker 1: it was when the Russian physicist Leonage Skodov proposed a
Speaker 1: really interesting idea atty Congress of the International Astronomical Federation
Speaker 1: meeting in Brighton in the UK. And he said, what
Speaker 1: if you could turn an entire solar system into a
Speaker 1: vehicle or in his own words, quote a thruster for
Speaker 1: solar system motion control? How on Earth would that work?
Speaker 1: Or how on the galactic plane would that work? Yeah,
Speaker 1: we don't even have words for this context. It's really strange.
Speaker 1: So to clarify, the solar system is not motionless now,
Speaker 1: oh no, of course not. It's moving all over the place.
Speaker 1: We're not all over the place. I mean, there's there's
Speaker 1: a system of movement which it follows. Yeah. Well, just
Speaker 1: like the planets in our solar system or in orbit
Speaker 1: around the Sun. Our solar system is in orbit around
Speaker 1: the center of gravity of the Milky Way Galaxy, and
Speaker 1: of course the Milky Way Galaxy self is moving. But
Speaker 1: we're talking about controlling the trajectory of motion within the galaxy.
Speaker 1: So what did he have in mind. Here's the basic
Speaker 1: setup that Shadow envisioned. So you create a spherical arc mirror,
Speaker 1: basically a giant curved mirror that's a concave one facing
Speaker 1: our Sun on the inside. So imagine sort of a
Speaker 1: giant contact lens with the inside of it the curved
Speaker 1: inner side being a reflective mirror surface and that's pointed
Speaker 1: toward the star, in this case, our sun, like like
Speaker 1: like putting a like putting a big bowl of a
Speaker 1: few feet away from a grape. Yeah, yeah, sure. So
Speaker 1: this mirror would have a couple of forces acting on it.
Speaker 1: If you have gravity pulling it towards the sun, the
Speaker 1: Sun's gravity pulling it towards the Sun, right, and since
Speaker 1: it would be a very large structure, it would also
Speaker 1: have some gravitational force of its own. Uh. Then it
Speaker 1: would also have radiation pressure pushing it away like a
Speaker 1: solar sale. We've talked about solar sales before. Yeah. Yeah,
Speaker 1: because the radiation, the electromagnetic radiation from the Sun does
Speaker 1: have a pushing force. Yeah, we don't really feel it
Speaker 1: normally because it's a very relatively tiny force, but on
Speaker 1: a huge reflective surface in space, it makes a difference.
Speaker 1: The sunlight pushes, so the mirror would become settled in
Speaker 1: a place where these forces equalize, the solar radiation pushing
Speaker 1: the mirror out and the gravity pulling it in. But
Speaker 1: solar radiation would reflect off of the mirror instead of
Speaker 1: radiating out into space like it normally does, and it
Speaker 1: reflects back in the direction it came from towards the Sun.
Speaker 1: Shadow's idea was that you could use this system to
Speaker 1: control or at least help direct the motion of the
Speaker 1: Sun and with the Sun, the rest of the Solar system. Now,
Speaker 1: Lauren and I spent a lot of time staring at
Speaker 1: some math we toe really didn't understand ch time. We're
Speaker 1: not We're not astrophysicists, y'all. Yeah, let to see if
Speaker 1: we could say a little bit more about the way
Speaker 1: this thrust is generated. But if it is not abundantly clear,
Speaker 1: we are not astrophysicists. And suffice to say, the experts
Speaker 1: know what they're talking about. You could, in theory, use
Speaker 1: one of these things they say to perturb the motion
Speaker 1: of a star within the galaxy. Yes, and that is
Speaker 1: the official terminology that I've seen people use, perturb, which
Speaker 1: I think is just a really great verb to to
Speaker 1: apply to the Sun. Like you're annoying. I could perturb
Speaker 1: the Sun, turb the heck out of that Sun. Well,
Speaker 1: the Sun started it, I mean, we didn't tell it
Speaker 1: to swell into a red giant and eat the Earth,
Speaker 1: all right, So so so so we've got these this
Speaker 1: this dish and this this mirror and all of this
Speaker 1: is creating thrust in a direction to move the Sun,
Speaker 1: to move the Sun in the Solar system with it. Right,
Speaker 1: So we would call this a class a stellar engine
Speaker 1: or a scatterw thruster, and it would be sort of
Speaker 1: like a giant steering wheel for the Solar System, driving
Speaker 1: it where in the galaxy we wanted to go, and
Speaker 1: the movement would be really slow. We need to stipulate that, Yeah,
Speaker 1: very very slow. The obvious advantage though, would be that
Speaker 1: we wouldn't have to leave the Earth our home, or
Speaker 1: the Sun our energy source until we arrived at our
Speaker 1: destination in another Solar system. And then the final idea
Speaker 1: of this, the sort of ultimate conclusion, is that we
Speaker 1: could plan the movement of our Scotov thruster just so
Speaker 1: that Earth could be deposited into a circular orbit around
Speaker 1: another star. Yeah, once you get the Solar system close
Speaker 1: enough to a new solar system, you just kind of
Speaker 1: let it get nudged in, right, You line it up
Speaker 1: just so that the Earth gets captured by the gravity
Speaker 1: of the new star. And then we're back in business
Speaker 1: and we can keep making new Zebra children cities. Yeah,
Speaker 1: Zebra robot children cities. Indeed, now I know this sounds
Speaker 1: super sci fi, and to be honest, it really is.
Speaker 1: I mean, we don't have the capability of building anything
Speaker 1: like this right now, but it is an idea worth
Speaker 1: taking seriously, even just for the very long view of
Speaker 1: the survival of our species or maybe you know, our
Speaker 1: our our terrestrial organic form, whatever that might be. There
Speaker 1: is a great article that we were looking at in
Speaker 1: Popular Mechanics from July of last year that actually examines
Speaker 1: how you would build a scatter of thruster. That was
Speaker 1: really helpful. Yeah, yeah, because there's so much that you
Speaker 1: have to take into consideration here, um, like like where
Speaker 1: do we get the material for creating a mirror of
Speaker 1: this size and capacity? Right? Because exactly how big is
Speaker 1: the mirror we're talking about here? Um? Yeah, you know,
Speaker 1: just hundreds of millions of miles across. It would have
Speaker 1: to be in in diameter greater than the distance from
Speaker 1: the Earth to the Sun. Um, and it would which
Speaker 1: would probably mean that would have to weigh some sextillion
Speaker 1: or septillion, like even up to septillion pounds. And if
Speaker 1: you need a concept of what that's like, I'm crossing
Speaker 1: concepts a little bit here, but that's that's roughly the
Speaker 1: mass uh of like Pluto or the Moon, or Mercury
Speaker 1: or Mars. It's a little bit, it's a little bit.
Speaker 1: It weighs a little bit less than Earth itself. So
Speaker 1: so we we don't really have like a factory that
Speaker 1: could build this. We do not have a spare Earth
Speaker 1: to to to to create this mirror out of. But hey,
Speaker 1: we do have those other planets just mentioned. Oh no,
Speaker 1: are you talking about dismantling a planet and making a
Speaker 1: megastructure out of it? I'm not talking about that, but
Speaker 1: scientists certainly are. Yeah. Yeah, you'd you'd have to build
Speaker 1: it out of something um kind of light and and
Speaker 1: foil like relatively on the on the scale of metals,
Speaker 1: something like chematite would be really good for that. That's
Speaker 1: sort of like an iron ore. Yeah. Yeah, and you
Speaker 1: could mind something like that out of the planet Mercury.
Speaker 1: And so if you basically disassembled Mercury and and I
Speaker 1: can still not hear that word without just thinking, let
Speaker 1: no disassemble, Stephanie um. But but yeah, if you took
Speaker 1: apart Mercury and used the entire planet to build this,
Speaker 1: this sale this mirror, then you could make it work. Wow,
Speaker 1: I mean that is crazy, But then again, we are
Speaker 1: we are talking about sort of a a multi generational
Speaker 1: project that would have to be pretty far in the future. Yeah,
Speaker 1: and we would miss mercury. I'm sure it would mess
Speaker 1: up astrology a whole lot. I know, right, but wait
Speaker 1: a minute, no, no, no, no more mercury and retrograde.
Speaker 1: That's a bad thing, right, the thing people don't like.
Speaker 1: You know, it's terrible. It's like I lost my keys
Speaker 1: mercury did it something to that extent. Yeah, and and
Speaker 1: so so it sounds crazy, but um, it's actually a
Speaker 1: lot less crazy than trying to catch a lot of
Speaker 1: asteroids or something like that to do the same job.
Speaker 1: And and of course, by when I said that you
Speaker 1: would be disassembling mercury, I did not mean Joe, and
Speaker 1: I didn't mean that the Royal you. This would probably
Speaker 1: be a job for robots. Yeah. Yeah, I would have
Speaker 1: to be some kind of a massive fleet of robots
Speaker 1: doing this autonomously. I mean, it just really wouldn't make
Speaker 1: sense to go try to put people on mercury to
Speaker 1: mind its surface. Uh No, that would go poorly for people.
Speaker 1: So we're talking now essentially about mining mercury to create
Speaker 1: all this, or to turn into a thin sheet of
Speaker 1: reflective foil to put in space in a static position
Speaker 1: at the Sun to reflect all this radiation to generate
Speaker 1: thrust to move the Sun. Yeah, okay, okay, I'm with
Speaker 1: you so far. What are some things we might have
Speaker 1: to worry about when doing this, just to you know,
Speaker 1: concerns we should keep in mind while building a giant
Speaker 1: space mirror. Um. Well, I would want to make sure
Speaker 1: that we take pains to to not you know, either
Speaker 1: freeze or fry the Earth with this mirror thing, because
Speaker 1: the these that the mirror would probably be somewhere near
Speaker 1: the orbit of the Earth in order to make the
Speaker 1: materials stable. Um, we wouldn't want to melt the mirror either.
Speaker 1: That would be pretty bad. Um uh. And and having
Speaker 1: it relatively near by could potentially cause problems with um.
Speaker 1: The the amount of solar radiation that continues to hit
Speaker 1: the Earth, which we want, you know, we enjoy having
Speaker 1: sunlight here. It kind of drives the entire life cycle
Speaker 1: on this planet or can Conversely, we wouldn't want kind
Speaker 1: of extra radiation from the mirror to start hitting the
Speaker 1: Earth and fries completely. Yeah. I've seen some different considerations
Speaker 1: that different thinkers have had on what sort of the
Speaker 1: final heat situation would be with one of these in place,
Speaker 1: because there are different ideas about where you can put
Speaker 1: it relative to the Sun and the Another thing I
Speaker 1: think we should consider is how fast could this thing
Speaker 1: actually go and what are the conditions that would control
Speaker 1: its its speed capabilities? Yeah, we we mentioned this earlier,
Speaker 1: and and I wanted to put into into actual numbers
Speaker 1: exactly how slow this thing would be going UM because okay, okay,
Speaker 1: if the Sun is already moving at some five hundred
Speaker 1: thousand miles per hour UM, that's an incredibly rough estimate,
Speaker 1: you guys, Um, the first few million years of UM
Speaker 1: scoutof thrust could only change our trajectory a little bit. UM.
Speaker 1: One thermodynamicist by the name of Virile bad Askew or
Speaker 1: something to that extent. I'm sorry I didn't look this
Speaker 1: up before the podcast. Um. He's he's from the Polytechnic
Speaker 1: University of in Romania says it could take two hundred
Speaker 1: million years for us to change the trajectory of the
Speaker 1: Sun by as much as a hundred and thirty light years.
Speaker 1: And that's that's on the generous end. He He also
Speaker 1: said that it might be by as little as thirty
Speaker 1: light years. That's I mean, that's a big window. But
Speaker 1: then again, thirty light years is a long way. I
Speaker 1: saw that note you made, and then I was trying
Speaker 1: to figure out, well, what's within thirty light years? Uh?
Speaker 1: I found a website called soul Station. I'm not familiar
Speaker 1: with the source, so I don't know if it's entirely accurate,
Speaker 1: but at least based on what they say, there are
Speaker 1: a hundred and fifty celestial objects within a twenty light
Speaker 1: year radius of Earth. So a lot of these are
Speaker 1: brown dwarfs and stuff that really wouldn't be useful to us.
Speaker 1: But it listed at least to a sequence and seven
Speaker 1: G sequence stars, so I don't know. I mean, I
Speaker 1: could see even within thirty years, you could get to
Speaker 1: a reasonable number of objects out there. Thirty light years yeah, yeah,
Speaker 1: um over there. I mean, it's just just that number
Speaker 1: two hundred million years is a number that I have
Speaker 1: a hard time comprehending. Yeah, it's also worth thinking about
Speaker 1: it in the context of one billion years until the
Speaker 1: oceans boil. So sure, you know it's zebra children. Got
Speaker 1: to keep him in mind. We can't forget the zebra
Speaker 1: children of the future children Okay, alright, have such huge eyes.
Speaker 1: They will they'll be adorable. Um. Okay, so so, so
Speaker 1: all of these problems are kind of sad news for
Speaker 1: anyone who is hoping to build one of these mirrors
Speaker 1: like next week. Um. But they also do offer a
Speaker 1: really promising implication, and that is that any alien civilization
Speaker 1: that could have possibly created one of these could be
Speaker 1: pretty easy for us to spot. That's right. So there
Speaker 1: was a recent paper by Duncan h For again of
Speaker 1: the University of St. Andrew's, and he talked about the
Speaker 1: possibility of king for alien stellar engines as evidence of
Speaker 1: alien life. So we talked a little bit about looking
Speaker 1: for aliens in our episode on the Kardashev scale from January.
Speaker 1: But here's Forgan's idea. It goes pretty much like this.
Speaker 1: We already have astronomical projects that are looking for the
Speaker 1: transit of exoplanets across other stars in the galaxy. So
Speaker 1: you have a telescope stare at the light produced by
Speaker 1: a star, and then you try to observe changes in
Speaker 1: that light produced by the star to see if it
Speaker 1: would be consistent with a planet passing between us and
Speaker 1: the star and blocking part of its light. Of course,
Speaker 1: an alien civilization that built a megastructure like a Scattov
Speaker 1: thruster might also be detectable in the same kinds of data.
Speaker 1: So in a paper called on the possibility of detecting
Speaker 1: Class A Stellar Engines using Exoplanet transit curves, Forgan tries
Speaker 1: to model the kind of light curves we would see
Speaker 1: if we were observing exoplanet transit on a star that
Speaker 1: had a Scatoff thruster. So though the probability he rates
Speaker 1: of finding evidence for one of these things based on
Speaker 1: the methods and data we have available now is pretty low,
Speaker 1: we might have a more optimistic outlook once we compare
Speaker 1: this strategy with other directed tools for SETI. Yeah, anyway,
Speaker 1: I thought that was pretty cool. Even if we can't
Speaker 1: save our own planet with a scout Out thruster, we
Speaker 1: could at least maybe use it to know that there
Speaker 1: are other civilizations out there that are more proactive than
Speaker 1: we are. Yeah. Yeah, Although, speaking of saving our planet,
Speaker 1: I wanted to discuss a couple other reasons that we
Speaker 1: might have to do such a thing. Right, So, even
Speaker 1: maybe before our planet swells into a red giant or
Speaker 1: boils the oceans. In a billion years, we might really
Speaker 1: need to move our sun around. Yeah. Yeah, there are
Speaker 1: a couple relatively smaller reasons for this. Um. So, Joe,
Speaker 1: have you have you ever been worried about an asteroid
Speaker 1: or comet hitting the Earth? That is exactly the reason
Speaker 1: I've been hollowing out a cavern under my house to
Speaker 1: dwell in after the big one hits. We've got canned food,
Speaker 1: We've got lots of VHS tapes of sci fi movies
Speaker 1: from the eighties. I think we'll be good. A zebra. Yeah, Okay, Well,
Speaker 1: I've got a new source for your paranoia. Okay. Interstellar
Speaker 1: gas and dust clouds. Oh it sounds dusty. It sounds
Speaker 1: not terrifying at all. Actually, But what's important to keep
Speaker 1: in mind here is that, Okay, space is not all space,
Speaker 1: not all empty space. There's some stuff out there. There's
Speaker 1: lots of stuff. In addition to stars and planets and
Speaker 1: all of that, there are these giant clouds of gas
Speaker 1: and dust that are floating around in the interstellar medium
Speaker 1: between star systems. These things could count for as much
Speaker 1: as fifteent of the matter visible um visible across the
Speaker 1: electromagnetic spectrum. Not that like you can see with the
Speaker 1: naked eye, um, in our Milky Way galaxy. And according
Speaker 1: to one Michael Richmond of the Rochester Institute of Technology,
Speaker 1: that's some ten billion sons worth of stuff. Yikes, bunches
Speaker 1: of stuff. That stuff in question is mostly molecular hydrogen
Speaker 1: with just a tad bit of helium and dust for
Speaker 1: for for lack of a better word, just just little
Speaker 1: microparticles things. Um. And yeah, none of that is terrifying. Um.
Speaker 1: But if we happened to go through one, it would
Speaker 1: be bad. Through one cloud of a cloud of the stuff,
Speaker 1: it would be bad. Yes. And if you are shaky
Speaker 1: on the whole good bad thing, um, let me explain
Speaker 1: bad with a shout out to Jeffrey Winter's who wrote
Speaker 1: a really good piece for Discover magazine back in two
Speaker 1: thousand eight called how a cloud of space dust could
Speaker 1: wipe out life on Earth. Yay, okay, let's hear it
Speaker 1: all right. So the Solar system is surrounded by the heliosphere, right, Um,
Speaker 1: that's that thing that the Voyager satellites passed through well
Speaker 1: a while ago, but we found out about it recently. Um.
Speaker 1: And and it's a protective wall of solar wind which
Speaker 1: is plasma that's radiated out by the Sun. Um. It's
Speaker 1: magnetic at the edges, and it helps keep the planets
Speaker 1: in our system safe from from interstellar particles and radiation.
Speaker 1: And and the thing is, astronomers think that we've been
Speaker 1: in a really clear section of interstellar space for the
Speaker 1: past five million years or so. Um. If we were
Speaker 1: to hit one of these clouds of gas and dust,
Speaker 1: it would bombard our heliosphere, pushing it from from way
Speaker 1: outside of Pluto's orbit down into the orbit of of
Speaker 1: like Saturn or Uranus. Yeah. Um, And we're not super
Speaker 1: sure what effects this would have on Earth. UM that
Speaker 1: the heliosphere would probably still protect us from a bunch
Speaker 1: of this cloud, but some of it would probably reach
Speaker 1: the Earth and the hydrogen that that composes most of
Speaker 1: the cloud could start seeping into our atmosphere and reacting
Speaker 1: with our oxygen, which would change our air supply for
Speaker 1: the worse for us certainly. UM. And furthermore and more
Speaker 1: cosmic rays would be hitting the planet, which would endanger um,
Speaker 1: you know, our stuff and our people in orbit, and
Speaker 1: also greatly increase our radiation exposure here on the ground.
Speaker 1: So bad times. We do not want this to happen. Um. Unfortunately,
Speaker 1: these clouds are really hard for us to spot. We
Speaker 1: do know that there is one less than a trillion
Speaker 1: miles away, which is approximately two d and fifty times
Speaker 1: the distance from Earth to Pluto. If that helps. It
Speaker 1: doesn't really help me, to be honest, but it's a
Speaker 1: good number, um uh, which which which means that we
Speaker 1: could collide with the sucker in only two thousand, five
Speaker 1: hundred years. Oh, that's pretty soon. That's that's way sooner.
Speaker 1: Probably can't build a shut up thruster. Hey, don't don't
Speaker 1: underestimate future human zebra. Okay, maybe maybe sure, get that
Speaker 1: fleet out there, tear down Mercury. Nobody cares about Mercury.
Speaker 1: Get it done right, right, Okay, So we could at least,
Speaker 1: say maybe maybe possible, assuming all this works is as planned,
Speaker 1: that would be a very good reason to have one
Speaker 1: of these things active. Oh but then again, you know,
Speaker 1: it does take a while to get it started moving
Speaker 1: in the in the direction, So I don't know, but
Speaker 1: at least maybe we we can have one in time
Speaker 1: to dodge the next one. Yeah, And furthermore, there's other
Speaker 1: stuff out there that we that we do need to
Speaker 1: be tangentially concerned about such as close passage to another
Speaker 1: star system. Oh yeah, yeah, so so astronomers, uh, whose
Speaker 1: job it is to this kind of thing, have been
Speaker 1: projecting nearby stars paths out into the past and future,
Speaker 1: some ten million years each because why not, of course, Yeah,
Speaker 1: you want to know where stars are going to be,
Speaker 1: and they found that in the past ten million years,
Speaker 1: it's pretty likely that no stars have passed closer than
Speaker 1: three light years away from us. Okay, but in only
Speaker 1: thousand years, Uh, Proximus Centauri and Alpha Centauri could both
Speaker 1: be inside that range. Yeah. Um, so what happens when
Speaker 1: a star gets close to us, Well, we're not sure,
Speaker 1: but it could be close enough to disturb another feature
Speaker 1: of interstellar space, which is the conjectured or cloud, which
Speaker 1: is the uh supposedly is the icy band loosely connected
Speaker 1: to the Solar System and is where comets come from. Right,
Speaker 1: It's what goes way way out there into the darkness,
Speaker 1: and we can't see the stuff in it always. Yeah. Yeah,
Speaker 1: it's it's maybe about halfway between us and Proximus Centauri
Speaker 1: right now, so it's it's pretty far out there. But
Speaker 1: but comets and can come down into into the range
Speaker 1: of the Solar System, and the disturbance of this cloud
Speaker 1: could send a lot more comets down into the Solar System,
Speaker 1: sort of like just kicking sand into our face. Yeah, basically,
Speaker 1: except it could be deadly sand. Deadly comets, sand Man, Yeah, giant, giant,
Speaker 1: specially deadly because it sounds like comic sands. I'm sorry
Speaker 1: I said that, but let's let's keep it and move on.
Speaker 1: I agree there. There are also other than that, um uh,
Speaker 1: brown dwarf stars to worry about, which are also pretty
Speaker 1: difficult to detect, and at least hundreds of them are
Speaker 1: within a hundred light years of us UM. In the
Speaker 1: nine eighties, there was even a theory that Earth's periodic
Speaker 1: mass extinctions are caused by a star in loose companionship
Speaker 1: with the Sun that swings by every like thirty two
Speaker 1: million years or so. I don't think that's correct, actually,
Speaker 1: I but most scientists agree these days that that that
Speaker 1: that was wrong. Um. They were calling the star Nemesis.
Speaker 1: Oh yeah, Nemesis. Yeah, I've heard, Wait to Nemesis. I
Speaker 1: thought Nemesis was also a planet or is that planet
Speaker 1: x Nibiru? I am not sure. I do know that
Speaker 1: star trek Nemesis was a thing that happened. We need
Speaker 1: to get Ben and Madden here to talk about all
Speaker 1: of the secret planets they don't want us to know about. Well,
Speaker 1: not that Ben and Matt don't want us to know about,
Speaker 1: but they they don't want us to know. Yeah. So
Speaker 1: so there are many many reasons why, you know, you know,
Speaker 1: and all all of these potential dangers will probably come
Speaker 1: into clearer focus as our detection equipment improves and and
Speaker 1: and as we crunch some of those numbers that we
Speaker 1: have already received from some of our telescopes and etcetera.
Speaker 1: But uh, yeah, I think I think it's safe to
Speaker 1: say that we have totally solid reason for wanting to
Speaker 1: be able to move our solar system. And if out
Speaker 1: of Thruster is the way to do it, I say,
Speaker 1: let's start building today. You know, how do we get
Speaker 1: those robots to Mercury's Let's let's get a team of
Speaker 1: people on it. Somebody's got to build the robots first. Well,
Speaker 1: one thing I do want to be clear about is
Speaker 1: that the kind of stellar engine we've been talking about
Speaker 1: is not the only kind of stellar engine. In fact,
Speaker 1: as you probably heard of saying it's a Class A
Speaker 1: stellar engine. There are whole other types of megastructures that
Speaker 1: have been proposed for harnessing a huge amount of the
Speaker 1: energy of a star, and hopefully we can in other
Speaker 1: episodes talk about some of those, Like you may have
Speaker 1: heard of Dyson spheres, which have a great name. They
Speaker 1: have nothing to do with vacuum cleaners. They have everything
Speaker 1: to do with cosmic power, real cosmic power. Yes, uh
Speaker 1: and yeah, yeah, those those are Class B, and there's
Speaker 1: also a Class C. And we have already talked for
Speaker 1: quite a while today, so I think that we're going
Speaker 1: to leave that for another day. Uh. But in the meanwhile,
Speaker 1: if you would like to hear anything specific from us
Speaker 1: other than about more stellar engines, let us know. You
Speaker 1: can write us an email at f W Thinking at
Speaker 1: how Stuff Works dot com, or you can find us
Speaker 1: on Facebook, Twitter, or Google Plus. Our screen names there
Speaker 1: are submitteration of f W Thinking. You can check out
Speaker 1: f W thinking dot com for lots more video and
Speaker 1: podcast and written content. Uh. You can also chastise me
Speaker 1: for using the words content out loud. And we hope
Speaker 1: to hear from you, and you will hear from us
Speaker 1: again very soon for more on this topic. In the
Speaker 1: future of technology, visit forward thinking dot Com, brought to
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