The Podcast of the Lotus Eaters - PREVIEW： Brokenomics ｜ Living in Space with Grant Donahue： Part I

00:00:00.320 Hello and welcome to Brokernomics. Now by popular demand, planetary scientist Grant Donoghue is back and we're going to continue our thoughts on the whole big wide spacey stuff. So Grant, thank you for coming back.

00:00:13.780 Very pleased that I'm apparently in, let's see more expression, by unpopular demand I have returned.

00:00:20.400 Yes, well if our audience like it then very good. You know, we've got to look after the audience, haven't we? Because I mean they pay the bills and everything. They pay my bills anyway.

00:00:30.000 Well in fact they don't pay my bills, they mainly pay Carl's bills. But I'm sure you and I are getting something out of it somewhere, yes.

00:00:38.160 There is that. I've managed to do this one in the studio as well, which is nice.

00:00:44.960 We're moving up in the world.

00:00:45.920 I've got my Great British flag behind me and you've replicated that energy, which is good. That's exactly what we need.

00:00:52.460 So right, our last couple of chats, we started off didn't we, with industrialising space.

00:00:56.340 Yes. And we managed to go from low-arth orbit to the local cluster. So I think that was pretty much success.

00:01:02.860 So good afternoon's work.

00:01:04.300 Yes. And then in the second one, we thought, well, what are the aliens out there? And we had a long chat and I think the conclusion was no bloody idea.

00:01:10.900 Could be zero, could be many. I think if I had to bet on any number, I'd probably bet on zero.

00:01:16.620 Maybe a few microbes in the odd alien plants or something, but who the hell knows.

00:01:23.600 And in this one, we thought we might talk about living in space and a few other topics around that as well.

00:01:32.180 But I seem to remember we were going to start with sort of the limits of technology, because you made a sort of interesting point when we were communicating about doing this one,

00:01:41.980 that a lot of the technology just basically hasn't got a shuffle on.

00:01:48.140 You know, jet engines of the 1950s are not fundamentally that different than jet engines of today.

00:01:53.020 What's your thinking there?

00:01:54.860 Well, there's a popular conception of engineering as downstream from physics.

00:02:01.000 And in many cases, that's true. You know, it's you discover physical principles and then engineering is the way to exploit them.

00:02:07.000 But the problem is that engineering predates physics by a long way and that in practice, that's really not how it works.

00:02:13.020 You don't have physicists who are hired on who are explaining the universe to engineers.

00:02:18.080 What's more, you have rules of thumb, you know, series of rules of thumb.

00:02:21.260 So, and then you, and you, your physicists will let you develop and refine them and make them more precise.

00:02:26.740 But all of that is, I'm so sorry. I think I just struck the microphone.

00:02:30.740 All of that is, it is all dependent upon the ability for the universe to offer us things.

00:02:40.620 I don't like to say exploit. I feel like I'm always defaulting to video game logic, but physical principles, which we can, which we can chase down and we can, we can turn to use.

00:02:49.980 So, you know, for example, the fact that water is incredibly common, but it also expands many, many times when you heat it.

00:02:56.380 And so that allowed us to develop the steam engine.

00:03:01.280 But you gave the example of jet engines.

00:03:05.960 The way that technological progress usually works in this respect with regards to engineering is that you have revolutionary and evolutionary phases.

00:03:12.880 And you can use the example of firearms, right?

00:03:17.020 Where you have muskets that got, they became, they were introduced as handguns, you know, in Europe in the, in the 15th century, handguns or however you want to pronounce it.

00:03:26.540 And they progressed very rapidly.

00:03:27.700 But if you look at a musket from the 16th century, like a milket, you know, a Swiss milket or a brown bess from the 18th century, they're not actually that fundamentally different.

00:03:38.500 And the brown bess isn't that much fundamentally better. 1.00

00:03:41.700 It's, it's, there's, you have this revolutionary development and then marginal, marginal, marginal.

00:03:45.620 And jet engines are a really good example because they show how a jet engine was revolutionary over a piston engine in that there was a period where there was parity and then the jet engines just took off.

00:03:58.120 But then you ended up investing more and more and more for smaller and smaller returns because you're converging.

00:04:03.540 And this is why, you know, early aircraft looked so different to each other, but modern aircraft all look so, so similar because you're converging on one, you know, on not, not an ideal,

00:04:12.080 but on as ideal as possible, you can an exploitation of that physical principle.

00:04:16.620 And the question is, is the universe going to keep giving us those forever?

00:04:20.060 So, so throw in a bit of economics here.

00:04:22.240 There is, there is a principle called Wright's law, which covers this.

00:04:26.180 And it basically says in any sort of industrial process, each cumulative doubling of production, you get a certain percentage increase in efficiency.

00:04:37.420 So, I mean, I looked at this in cars because it was part of my analysis when I was making my investment into Tesla.

00:04:44.440 Basically, if you want to get a 15% cost reduction in making cars or efficiency or, you know, 15% improvement, roughly, you need to, you need a cumulative doubling.

00:04:54.600 Now, at this point, that means producing something like 6 billion cars in order to get the next 15%.

00:05:00.360 And so the thinking with my investment in Tesla is, okay, is electric cars, are they going to be on the same Wright's curve as normal cars, or are they going to get their own?

00:05:11.280 Because if it's their own, doubling the number of electric cars is actually quite easy in the early days because there wasn't very many of them.

00:05:18.080 And it does appear to be the case.

00:05:19.920 You are getting that 15% reduction.

00:05:21.620 So, I can imagine that this applies, whether it's 15%, it just happens to be that in cars, this applies to most technologies, that each cumulative doubling gives a percentage increase.

00:05:31.620 But at some point, and probably only a few years into it for a mass-produced thing, you're having to churn through a hell of a lot of these things to get the next small increment.

00:05:41.840 Precisely.

00:05:42.540 No, exactly.

00:05:43.020 And which is more, with something like space travel, you have the problem that the cost of entry is already astronomical, right?

00:05:52.300 The cost is already very high for developing a rocket engine.

00:05:57.280 You know, you look at the Falcon.

00:05:59.420 Elon Musk spent a catastrophically large amount of money getting the Falcon and the Falcon Heavy as good as they are.

00:06:06.460 Well, you almost ruined it.

00:06:07.520 Yeah.

00:06:08.080 Exactly.

00:06:08.520 And now they are working, and they are very good, but they're actually, you know, he's still fundamentally using that same technology.

00:06:15.100 The starship is not, the starship is really evolutionary.

00:06:18.240 It's an attempt to take all of the principles that were developed in the Falcon and to bring them through.

00:06:23.080 I mean, there are revolutionary elements.

00:06:24.560 The use of steel instead of, for the body and that sort of thing, the greater focus on lifting capacity, the scaling.

00:06:32.340 But fundamentally, he's using steel in the body.

00:06:35.120 Yeah, so the body, it is, but it's also much, it's much less likely to fail, to fail.

00:06:43.980 So you can reuse it more easily.

00:06:46.780 You can use special alloys and special principles to squeeze out little bits of efficiency in almost any engineering principle.

00:06:57.220 I think it was Carl Goldsdorf who said, you can't save a ton on a locomotive, but you can save a kilogram in a thousand places.

00:07:06.740 You can squeeze the efficiency out of a design, but that means hiring engineers to look at every little bit and find out where can I shave a half a meter?

00:07:15.660 Where can I shave a pound?

00:07:16.700 The Starship, at least as I understand the design philosophy, and I'm not an expert on propulsion, but as I understand the design philosophy, it's an attempt to do the opposite.

00:07:27.240 You're relaxing those design constraints such that you can get something which is more tolerant of mismanufacturing or the stresses of being dropped in and out of the atmosphere of heating and cooling.

00:07:38.660 And so that improves reusability.

00:07:43.080 Okay.

00:07:43.960 So what does this tell us?

00:07:46.060 Because if our broader topic is living in space, what does that tell us?

00:07:50.980 I suppose what it tells us is the thing that we touched on in the first of our discussions, which is getting stuff up out of Earth is ridiculously expensive.

00:08:05.560 And yes, we can expect improvements, but ultimately, it's probably only going to go so far.

00:08:13.020 So if you are going to start living in space, well, basically, you're going to have to start making everything there as well.

00:08:18.220 Precisely.

00:08:18.580 Yeah.

00:08:18.840 Like it's it's we already know that even if you were to make things as cheap as physics allows you to make them.

00:08:27.480 Right.

00:08:27.580 Let's say that you had a stairwell that you could you could, you know, build the Tower of Babel and and carry things up a stairwell to space.

00:08:34.340 That's still actually quite a lot of energy compared to the cost of just making the things in orbit.

00:08:39.060 And we can't do anything like that.

00:08:41.580 And so so long as we are limited to doing something as expensive as rocket science to move something as simple as cargo from the surface of a body to the low orbit of a body,

00:08:50.900 there's always going to be massive economic incentive to find some alternative method.

00:08:55.980 Ah, right.

00:08:56.660 Yes.

00:08:58.600 Yes.

00:08:59.020 OK, this makes sense.

00:08:59.820 So if people are if people are going to live in space, they're going to need to.

00:09:03.820 So what we what we're going to need to do is.

00:09:08.780 You know, let's let's let's move on to, you know, some of the megastructures as to how people might do this in the future.

00:09:14.080 We're going to be heavily reliant on scaling up our industrial output, possibly starting at quite a basic level because you simply don't have the choice to do anything else.

00:09:29.120 So so if OK, let's OK, let's come on to that.

00:09:32.880 But we should probably skim by something like what are restricting principles for space living.

00:09:42.760 So I think we tend to approach this.

00:09:46.440 I think it's wise.

00:09:47.280 We can either go down the sci fi route, in which case we will be having a conversation about anything we can imagine.

00:09:52.320 Or we place the hard limits on.

00:09:56.120 Let's say no to anything that requires something which is ruled out by physics as we understand it.

00:10:04.040 So that rules out, for example, faster than light.

00:10:06.500 So we can't go faster than light.

00:10:08.760 And therefore, a future might look much more like an incredibly heavily populated solar system with possibly many times the population of something like the Federation in Star Trek or Star Wars or something like that.

00:10:25.400 But all clustered around a single system, but not what you typically see in star sci fi, which is a huge number of planets with moderate populations, at least in the short term.

00:10:36.140 Yeah.

00:10:37.380 Well, you know, you talk about slow exploration.

00:10:41.520 Well, what I'm saying is that, like, even let's say you can't achieve faster than light at all.

00:10:48.480 Let's say that the closest you can get is 10% the speed of light.

00:10:52.040 Give enough time and a sufficiently determined civilization will still settle the galaxy.

00:10:56.020 You still don't stay in one system.

00:10:57.400 But when I say short term, I mean in the scales of time that makes sense to history rather than thinking in geological or astronomical terms, in the sense that, you know, human beings will generate a concept and then we will propagate that concept outwards and lots of other human beings will interact with that concept.

00:11:14.480 It's like you drop a stone into a pond and that reflects off of the edges of the pond in the sense that, you know, you and I can take actions and have discussions and have conceptions on that time scale before everything is lost to the noise of our stones being dropped in the pond.

00:11:29.520 That is the sort of time frame where you would say, yeah, we're probably still going to be clustered around a star system or the star systems that we could reach in 20 or 30 years.

00:11:37.320 But if FDL is out, then colonizing even the local stars is, what, tens of thousands of years?

00:11:48.160 It depends how willing you are to play at the bounds of what is safe and sane.

00:11:54.780 An Orion drive.

00:11:56.440 An Orion drive, I'm sure you know the concept.

00:11:59.520 No.

00:12:00.260 Tell me.

00:12:00.880 Oh.

00:12:03.200 Something as, well.

00:12:04.460 So imagine a man comes to you and says, I can get you to a star in 50 years.

00:12:08.500 Downside, I'm going to need a lot of nuclear bombs.

00:12:11.100 Oh, that one. 0.72

00:12:11.960 Where they basically blow up a bomb behind it.

00:12:14.600 Exactly.

00:12:15.100 You have a pusher plate.

00:12:16.920 I might not buy a ticket for that one.

00:12:19.520 Right.

00:12:19.980 But nevertheless, the technology and the engineering has been there to do it for 30 years.

00:12:24.400 And in fact, the only reason we stopped exploring was nuclear non-proliferation treaties.

00:12:28.600 So in principle, you can get to, let's say, Proxima Centauri in less than a century.

00:12:36.080 Right.

00:12:36.220 That's not a comfortable journey.

00:12:38.220 That's not something you can do in one jump.

00:12:40.480 It's not something you can, and indeed, you can't send lots of fuel.

00:12:43.420 But it is right on the boundary.

00:12:44.920 You know, again, how long did it take to build the pyramids?

00:12:47.240 We worked on the pyramids for more than a century.

00:12:49.180 I mean, if you're going to go with the Orion drive and exploding the, you know, nuclear material behind you to push you along,

00:12:56.860 you definitely don't want Boeing building that craft.

00:12:59.460 And you definitely don't want a diversity higher flyer in it. 0.99

00:13:02.420 So, yes.

00:13:03.820 Okay.

00:13:04.280 Right.

00:13:04.440 I take your point.

00:13:05.100 But I guess what I'm getting at is, you know, in our first episode, we looked out, you know,

00:13:12.060 potentially hundreds of thousands of millions of years.

00:13:14.320 But in this one, if we rein it back in, if we're looking at, you know, the next few tens of thousands of years,

00:13:22.100 I mean, perhaps even closer than that, you know, the next 500 years, it's probably going to be...

00:13:27.940 Nuclear, thermal, or chemical.

00:13:29.860 Well, it's going to be this system that I'm thinking we're developing.

00:13:32.560 Yeah.

00:13:32.920 Yes.

00:13:33.300 And we'd be restricted by those drives that you mentioned.

00:13:36.080 Maybe we might get a fusion drive.

00:13:37.600 But even then, you know, you're going to be talking about a handful at most of other systems.

00:13:43.240 So there's going to be huge population, possibly huge population density in this system that we kind of need to get our head around.

00:13:50.620 Okay.

00:13:50.920 So megastructures, when we come to megastructures, so actually define for the audience, what are we talking about when we say megastructures?

00:14:00.860 Megastructure is a term, like many speculative terms that refer to things we haven't, to classes of things we haven't built yet.

00:14:06.740 No one can really quite agree on it or agree how seriously we should take the concept or where the boundaries should be.

00:14:11.100 But broadly, megastructures refer to engineering projects, which represent an attempt to achieve some relatively simple objective, build a habitation sphere, or reduce something on the scale of geoengineering, which uses material in space that's orbitally significant.

00:14:31.680 Where you can start considering the body as having the political and economic significance of a body like Mars or Earth.

00:14:38.820 You know, it's a Dyson swarm.

00:14:41.340 It's a O'Neill cylinder.

00:14:43.480 It's super large space stations, which rotate with sufficient, can make force to generate gravity, permanent habitation, or something as simple as that blasted idea of putting a sunshade between the Earth and the sun at the Lagrange point to try and fight climate change.

00:14:59.480 It's the attempt to use engineering on a really quite grand scale.

00:15:02.620 It kind of reminds me of what the Soviet Union tried to do and ended up drawing up a small sea. 0.86

00:15:07.480 It's this wonderful dance between human ingenuity, human ambition, and human arrogance.

00:15:18.880 So there's lots to talk about there.

00:15:21.400 Of the megastructures, I've got to say my favourite is definitely the O'Neill cylinder, because I can just see in the next couple of centuries most people living in one.

00:15:29.560 So I would like to spend some time on that.

00:15:31.500 But maybe the editor can throw up on screen what I mean by that.

00:15:34.840 It's basically a large cylinder in which you can fit a large city or two, or possibly loads of farming space or leisure.

00:15:47.080 It gives you plenty of space for a couple of hundred thousand people if you want it, however you decide to spice it up.

00:15:52.940 But before we can get to that, coming back to our original thing that we talked about, you've got to build up your industrial capacity to get there, because you are most certainly not going to be launching a million tons of building material from Earth.

00:16:07.420 No.

00:16:07.900 It would be ruinously irredeemable.

00:16:11.560 So that kind of takes me to the point that surely we have to start with a lunar base.

00:16:18.720 Sure.

00:16:19.020 You can't conjure mass from nothing.

00:16:21.940 Yes.

00:16:22.100 And the reason the moon is the best candidate is just because it lets us get good at practicing things in space at relatively low stakes and relatively low costs.

00:16:33.540 Again, relatively.

00:16:34.640 Whereas low gravity and it's close.

00:16:37.340 Exactly.

00:16:37.780 But it's not so low gravity that it's irrelevant, right?

00:16:40.400 And it uses lots of physical principles.

00:16:41.940 And there's also lots of material.

00:16:44.740 And also it doesn't run into problems where, okay, let's say you built a base on Mars.

00:16:49.740 We'll enjoy 30 minutes lag time between any communications, you know, at the extrema of it because of the speed of light.

00:16:58.860 And three months getting there as opposed to whatever it is, like two weeks.

00:17:03.020 Yeah.

00:17:03.220 And which is more, if you have a catastrophic accident, I'm really glad your emergency help is three months away.

00:17:10.600 You know, I'm sure that's just wonderful.

00:17:13.600 Yes.

00:17:13.920 Very, very encouraging.

00:17:16.240 Okay.

00:17:16.560 So, because this is where I think that Musk is barking up the wrong tree because he just wants to go straight to Mars.

00:17:22.980 And it's like, well, I think you go straight to the moon, build a base there.

00:17:27.580 You get your industrialization going.

00:17:30.500 And by the time you've got something sufficiently outputted from that, well, then you can skip planets and you can go straight to megastructures such as the O'Neill cylinders.

00:17:38.860 And once you have those, why do you need planets?

00:17:41.120 I mean, this is something I asked you in a previous episode.

00:17:44.040 It's like, why bother with planets at all?

00:17:47.200 Do you know if you've got an answer for that?

00:17:49.520 I think so.

00:17:50.800 Right.

00:17:51.060 The problem, I think, with social planners in general is that they believe that they can reduce societies and people into writs of requirements in the same way that alchemists and somewhat unpleasant atheists can reduce people to what's a human being?

00:18:09.660 Well, it's a certain amount of carbon, a certain amount of oxygen, and you can give a recipe.

00:18:14.540 And, you know, in some literal sense, that's true.

00:18:16.760 But I don't think you can reduce human beings to a life support requirement.

00:18:21.880 Not without removing that thing which makes life worth living.

00:18:27.440 How is this satisfied by Mars but not a cylinder?

00:18:31.880 Because fundamentally, one is something like the pyramids, right?

00:18:37.540 If you're building an O'Neill cylinder, that requires that there is a single person with a dream or an entity or all that idea.

00:18:43.800 And you're building essentially to a pre-planned thing because you can't just have everyone doing whatever the heck they like.

00:18:49.080 It is a coordinated engineering system.

00:18:51.140 It has to be a closed loop because you can't waste your water into space.

00:18:54.460 You aren't mining anymore.

00:18:55.500 You aren't producing anymore.

00:18:56.360 You don't have a local source of material.

00:18:58.260 I mean, now there are there's conceptions of a beehive where you would build an O'Neill cylinder into a non-rubble pile asteroid and then you would have some local production.

00:19:06.640 But nevertheless, you have to have something pretty close to a closed loop.

00:19:09.860 And the whole thing is dependent on keeping a pressurized atmosphere.

00:19:13.300 Well, you can live there, but you don't necessarily need to work there.

00:19:15.460 So you can set these things up circling the Moon, Mars and Venus.

00:19:19.200 So let's say, OK, we're going to we're going to go down the planet.

00:19:22.340 We're going to have a we're going to have a base on Mars.

00:19:24.220 OK, every time I go outside, I'm going to die of radiation or explosive decompression.

00:19:29.840 If I go to Venus, my cloud city, as we started off talking about, because I did that.

00:19:34.040 I think you got in touch after I did an episode with Bone, which he was arguing for Virgin Mars and I was arguing for Chad Venus.

00:19:40.100 Venus is lovely and you're going to have your beautiful floating cloud city and something close to Earth gravity.

00:19:47.960 But if you fall off, you know, it's it's not fun.

00:19:50.720 You go outside on a bad day and there's a cloud of sulfuric acid.

00:19:53.820 Yes. And your face just gets washed off.

00:19:55.600 You know, it's not fun.

00:19:57.760 But if I have an O'Neill cylinder, I can I can spin it to produce whatever gravity I like.

00:20:03.820 So I can, you know, when I'm in my 20s, I could be living on a on a one point two Earth gravity one and I'll get nice and muscly.

00:20:11.840 And then in my old age, I'll move to a point six one.

00:20:14.520 You can you can set your day cycle to whatever you want.

00:20:17.920 So I'll be I'll be going for something between 26 and 28 hours because that way I get a couple more hours in bed every day and I get more done.

00:20:23.900 There aren't enough hours in the day.

00:20:26.040 You can set that you could basically condition it to however you want, rather than having to struggle through what the planet offers you.

00:20:33.820 And it is a hell of a lot easier to make a perfect environment in the cylinder than it is to terraform.

00:20:40.800 You know, Mars is probably the easiest one to terraform.

00:20:43.600 Maybe Venus is. 0.64

00:20:44.760 But it's a colossal amount of work.

00:20:47.740 You could just build a bloody cylinder.

00:20:49.600 And the other thing is it is wildly more efficient.

00:20:52.720 So if you think about it, a sphere is a planet.

00:20:56.620 It is the least possible amount of surface area for a given quantity of mass.

00:21:00.780 Whereas a cylinder is kind of the inverse of that.

00:21:04.300 It's something close to the most possible amount of surface area for a given amount of mass, more or less.

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The Podcast of the Lotus Eaters - August 05, 2025

PREVIEW： Brokenomics ｜ Living in Space with Grant Donahue： Part I

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