My travellers are capable of in-system flight and have access to a single ship that they're going to use to move supplies from a moonbase to a pristine pseudo-Earth (a bit like this).

They can ferry 21st(ish) century tech and the ship is going to keep flying as long as they have fuel and spare parts, which isn't indefinitely, but should be enough to transport about three hundred people and a few tons of supplies before it breaks for want of spares.

Obviously they're going to ascend the technology tree quite quickly, but are they going to jump over the steam engine entirely?

  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – Monty Wild
    Commented Sep 15, 2021 at 13:56

6 Answers 6


This is very much a game of requirements and the answer is that it could go either way, because in the 21st century we're still fundamentally using steam engines.

Sure, they're invisible to the average punter, but the device you're using to view this is highly likely powered by electricity generated using a steam engine. All coal, oil, gas, nuclear and some solar power is generated using steam turbines.

Your first task will be to generate electricity. From a standing start without the industrial base we use on Earth, wind turbines, water turbines and solar driven steam power are possibly the easiest power sources to build and run. All of them being passive once established and needing no fuel supply of their own.

Steam for static industrial purposes was an intermediary between wind/water and electricity. Given that they have the technology they'll almost certainly skip this step and jump straight into electricity for all these purposes once wind and water directly are no longer sufficient.

Transportation for a small colony can remain with beasts of burden and wooden carts. There's no reason to have trains at the early point, and by the time there's the population and industrial base to require them, going straight to electric or diesel would be most likely.

Once an industrial base and population level has built up they may start to use larger scale steam turbine driven power plants, but this will most likely be the only use of steam power. They will never use piston steam engines.

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    $\begingroup$ @GrumpyYoungMan don't take the things, take the tools to make the things. Waterwheels and windmills were made of wood long before any of the fancy composites came into use $\endgroup$
    – Separatrix
    Commented Sep 6, 2021 at 17:04
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    $\begingroup$ " They will never use piston steam engines." Is the steam catapult used on American aircraft carriers considered a steam piston? $\endgroup$ Commented Sep 7, 2021 at 0:33
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    $\begingroup$ @Separatrix My point was, define 'steam piston'. Steam is used in a variety of ways, for a variety of purposes. using a variety of methods. Steam is an extremely attractive option for a pre-metal-fabricating society that knows advanced ceramics.. $\endgroup$ Commented Sep 7, 2021 at 14:01
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    $\begingroup$ Regarding the 'beasts of burden', the OP is not clear about the local flora and fauna. Habitable does not mean highly evolved. I can not foresee there ever being cows or horses on a moon base. $\endgroup$ Commented Sep 7, 2021 at 14:03
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    $\begingroup$ @Separatrix "the moonbase is a redundant bit of colour" That assumes a fact not in evidence. One can assume this from the question, one can also assume the moon base is a self-sustaining colony of 100,000 or more that just does not have the ability to transfer objects to the ground and back. $\endgroup$ Commented Sep 7, 2021 at 23:23

The invention of the steam engine arose out of the need to pump water out of mines.

If there is any form of underground mining in your setting, it is very likely that they will need to solve the same problems of pumping water and poisonous gases out of these underground tunnels.

If you want electricity or if you want to repair electrical devices you will first need the right componenets. This includes copper for the wiring. Copper needs to be mined.

If you want fuel, like anything petroleum based, this will need to be pumped or mined and then pumped.

So to get at the copper and the fuel you will first need an intermediary step.

Water is plentiful, and heating it up is relatively easy. Steam engines are the logical next step.

Even if you bring down tech from the moonbase, sooner or later someone who doesn't have access to this tech will want to pump water and gases out of an underground mine.

Those who have access to the advanced tech might never need to use steam engines.

Anyone else will probably find the need for them just as we did.

  • $\begingroup$ To build a steam engine you're going to need to mine iron, copper is easier, hence why it was in use long before iron. Admittedly you'll need iron for magnets too, but motors fail in a far less spectacular way if done badly than steam engines $\endgroup$
    – Separatrix
    Commented Sep 6, 2021 at 17:06
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    $\begingroup$ @Separatrix One can make a steam engine entirely out of ceramics. A body of 300 scientists and engineers would certainly be able to manage it. The scenario is not to RECREATE human discovery, but to use in new and novel ways what has already been discovered over the centuries. "MacGyver the hell out of it" I believe the term is. $\endgroup$ Commented Sep 7, 2021 at 0:31
  • $\begingroup$ If they have a spaceship, they could potentially be mining a lot of their metals out of asteroids rather than out of the ground of planets. $\endgroup$
    – nick012000
    Commented Sep 7, 2021 at 4:19
  • $\begingroup$ @JustinThymetheSecond ceramics are even harder to handle than the steel required for a traditional engine and hence require an even larger industrial base. A basic motor and generator pair can be build by one man in a shed. $\endgroup$
    – Separatrix
    Commented Sep 7, 2021 at 7:28

The question is: in your world is there a universal tool. If yes, then they can survive. If no, then they can't.

Can a machine produce a copy of itself? Yes. All biologocal entites do, with little dregredation between generations. This meams it is theoretically possible to build self replicating technology. An implelemtation of such a machine could be called a "universal tool", able to contruct any device at least up it's own technological level.

If this device exists in your universe, then your settlers/colonists/whatever's first priority is to have the universal tool duplicate itself a few times, and to store some of them as backups in case of failure. Then they can build whatever they like. If they want a steam engine to solve a practical problem (eg power generation, pumps, whatever), then they can build one. If there are no problems that a steam engine solves best, then they won't build one.A steam engine is nice because you can throw anything combustable in the boiler: wood, oil, dung, coal, corpses. It's hard to make an internal combustion engine run on anything other than highly refined fuel.

So what would this machine look like?
A biologocal replicator consumes raw materials for two purposes: to provide energy and to provide useful molecules. With these it can stay alive, mantain itself, and when the conditions are right, replicate.

So let's assume the same for our mechanical replicator. It has to consume material for energy, or have some external source (eg plants have photosynthesis. This machine could be solar powered). It also has to consume at minimum it's constituent materials in order to mantain itself or replicate. Eg if your replicator contains uranium, you'll need to 'feed' it uranium for it to replicate.

What it has to be fed depends on the tech level of the replicator:

  1. Large/macro parts (current gen electro-mechanical replicators can assemble themselves from a stock of servos/motor/batteries)
  2. Refined materials (eg steel bars, silicon wafers)
  3. Correct chemical compunds (eg can feed it steel powder)
  4. Raw matching atoms (eg can produce steel from carbon+iron in dirt),
  5. Generic matter (can induce fission/fusion to transmute materials. Can build anything given hydrogen and time).

Only replicators of level 4 and 5 are useful on a non-industrial planet. Tech level 1 is possible today. Tech level 2 involves miniaturising most of human industry into a box. Feasible but very hard. CNC's + 3D printers are effectively work towards this. With current tech this is possible but hard. Someone's probably putting this machine together in a lab in the nex few decades. Level 4 requires micro/nanotech quite far in advance of what we have. Level 5 is far far future.

Back in the days of tall-masted-ships, the ships would carry a carpenter and a sailmaker so they could 'self-repair'. Probably by the time we're sneding ships drifting around the solar system we'll do the same: send miniature factories/crappy replocators on board. Maybe not enough to reconstruct everything, but enough to make significant contribution to restarting/maintaining a technological society.

  • $\begingroup$ What a good answer, it was a long time since I have seen one of such on wb, in categoryy of technologies. Well done. $\endgroup$
    – MolbOrg
    Commented Sep 7, 2021 at 14:35
  • $\begingroup$ @MolbOrg We do seem to me missing the input from the contingent that was able to supply well-thought-out evidence-based flexible and creative answers to 'reality-check' tags. "Here's how it CAN be done' rather than 'It CAN"T be done in any way I can think of', which basically just makes the answer opinion-based.. $\endgroup$ Commented Sep 7, 2021 at 23:32
  • $\begingroup$ This method, being used today, seems to be a cross between level 3 and 4. Currently limited in application and not a universal tool, but in 50 years from now? emerald.com/insight/content/doi/10.1108/RPJ-11-2015-0178/full/… $\endgroup$ Commented Sep 7, 2021 at 23:41
  • $\begingroup$ @JustinThymetheSecond idk, did read your other comments as well. Idk maybe the topic itself isn't easy. Few q I have here on wb, so as I did some posts in the past on FB - it seems like it not that easy for people to recognise potencial of navigating technology tree as a graph and combine things from past and present to fit a bill of materials and/or other requirements, restrictions which are a result of different environment. Which is prerequisite for bootstraping situations. Yep, wb currently is lacking on technology side, and usually there not that much q's which would attract those people. $\endgroup$
    – MolbOrg
    Commented Sep 8, 2021 at 21:00

They don't skip the steam engine because they don't reach the steam engine in the first place. The problem is many specialties are needed to build even a steam engine. Specialists have a minimum quantity of one and realistically at least two so the master can teach the apprentice. Most of your group has to be food producers.

Those books, if durable enough, greatly speed the development of the technologies described therein (and unless they're written for the purpose most books will not have anything like all the information needed!) as the population grows enough to support the specialties involved.

  • $\begingroup$ The minimum viable population that is able to sustain current levels of technology is probably on the order of 100,000 (and this is without the redundancy that you speak of). Of course, even at that level, I have some hesitation to say that it's possible to sustain all technologies... some medical specialties rely on being able to see multiple cases of 1-in-250,000 conditions, just to get enough practice in. Even for mundane things, abdominal surgeons are good at appendectomies because they do many per year. How many opportunities will you get with just 100k? $\endgroup$
    – John O
    Commented Sep 7, 2021 at 16:13
  • $\begingroup$ Maybe someone took this course. ceramics.org/professional-resources/career-development/… $\endgroup$ Commented Sep 7, 2021 at 23:37
  • $\begingroup$ @JohnO There are about 5.5 billion people in the developed world. Any profession of which there are less than 55,000 people will not be represented in a population of 100,000. I strongly suspect that applies to the entire space industry (many different professions are needed to design a bird and get it up there) and things like chip designers. I'm finding multiple medical specialties that wouldn't have even one practitioner, I doubt any subspecialty would exist but I'm not finding numbers. $\endgroup$ Commented Sep 8, 2021 at 2:25
  • $\begingroup$ @LorenPechtel Assuming these are proportional. A population of 100,000 will undoubtedly have 10 garbage men in the real world, but we can maybe use those 10 spots for oncologists and IC lithography experts. $\endgroup$
    – John O
    Commented Sep 8, 2021 at 2:27
  • $\begingroup$ @JohnO Only if you want to live in a pile of trash. You'll need a lot of people in the basic jobs. The initial group doesn't get nearly as many specialties as it's population. $\endgroup$ Commented Sep 8, 2021 at 2:42

Obviously they're going to ascend the technology tree quite quickly

Fundamentally incorrect. Knowledge is only one half of the equation, the other is industry.

Take the most primitive, rudimentary steam engine. The boiler needs to be constructed from relatively strong material in order to withstand the pressure inside it. You can start with lead and bronze, which are easy to mine and refine ("easy" being a relative term, given your lack of miners and high-tech refining processes) - but they're weak, which limits the pressure the boiler can sustain, which limits the amount of work the engine can do based on the amount of fuel it's provided with.

Since your human population is small, they don't have all day to spend collecting fuel, so they'd want to optimise the boiler for higher pressures by using iron and steel. Except that to make high-quality iron, which you absolutely need if you don't want your boiler exploding, you need a blast furnace which is nontrivial and requires a lot of fuel and babysitting. To produce even higher-pressure boilers you require high-quality steel, likely via the Bessemer process - which requires the construction and operation of a Bessemer converter. Again, nontrivial.

In other words, you can't get to high-level industry until or unless you have the population and supporting lower-level industries to enable that industry. And high-quality steel, which is effectively required to build steam boilers with enough capacity to make them useful, requires a LOT of industry. This is why iron- and steel-making were small-scale, specialised industries until two centuries ago: it wasn't that people didn't have the technology, it's that industry to enable the technology didn't exist, and therefore nobody bothered thinking about it.

Your colony has that technology, but it doesn't matter. They can't build it until they have the industry to support it, and to build that industry is simply not possible with 300 people; it's going to take generations. Especially when the colonists are going to be spending most of their time building and foraging and raising children and defending themselves from wildlife.

Assuming they don't all die, that is. We've eradicated smallpox on Earth, but your colony world probably isn't going to be so lucky. How are your colonists going to deal with a disease that has a 30% mortality rate? How are they going to deal with new diseases that human medicine has never encountered?

The whole Eden/"start afresh" scenario really can't work unless you have a LOT of people to start with, or you're willing to accept that your new society is going to slip down to 11th-century levels within a few generations. If you're lucky the knowledge they have might enable them to get to the 21st century in 500 years instead of 1,000, but it's not going to be quick no matter which way you look at it.

Oh, and I hope your computers containing all that knowledge are durable enough to still work after that amount of time with no maintenance...

  • $\begingroup$ Smallpox? On a completely alien planet that might not even be able to share Earth-like DNA? The only viruses and bacteria they will have are the ones they brought with them. $\endgroup$ Commented Sep 10, 2021 at 1:45
  • $\begingroup$ @JustinThymetheSecond If they're on a planet with non-Earth-like DNA they have even bigger problems... like not being able to grow any crops... or being unable to eat the native flora or fauna... or being completely unable to defend against any native bacteria or virus... $\endgroup$
    – Ian Kemp
    Commented Sep 10, 2021 at 6:35
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    $\begingroup$ Eating flora and fauna that does not share human DNA is not a problem to humans, unless it is toxic. The human body wants the nutrients, not the DNA. Not sharing human DNA just makes it inert matter, like eating cooked meat. Viruses act by injecting their DNA or RNA into a cell and having the cell reproduce it. If the viral material is non-human DNA, it cannot effect the cell. it is just inert material. Earth crops would grow just fine. $\endgroup$ Commented Sep 10, 2021 at 14:41

Yes and then again no.

Assuming they have access to suitable fuel, not guaranteed but highly probable on an Earthlike colony world with an active biosphere. They're not going to skip steam power altogether but they are going to skip the piston engine one generally thinks of when you say "steam engine" and move directly to the steam turbine. The main reasons these weren't used much earlier were matters of metallurgy and machining tolerances. Those are not obstacles to your pioneers so they'll use the mature and efficient form of thermal power instead of the clunky polluting prototypes of an earlier century. Unless something goes drastically wrong that is.


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