Inspired by the short story "The Road Not Taken" by Harry Turtledove I've tried to picture the universe described. For those unfamiliar with its setting:

In the world of "The Road Not Taken" gravitational manipulation and FTL drive is fairly easy to discover and construct - humanity has just somehow not stumbled upon this technology yet. It is easy enough so that civilisations with technology equivalent to ours age of discovery era are capable of space travel, colonisation and most importantly - conquest. This technology can be effectively applied only to transportation.

Construction of a spaceship using technology available sometime between 15th and 19th century (the earlier, the better!) is quite a task. Luckly, drive is not a concern! Resembling rather a big box like object, with pilot attached to it, Handwavium Drive can move with arbitrary force in any direction and speed, including FTL outside of stars gravitational wells - we've got the technology! Addtionaly, thanks to drive's gravitional manipulation effect we can negate effects of high accelerations force overloads. It has rendered journeys between neighbouring stars in time and logistical effort comparable to our 17th century voyages from Europe to India.

As we all know space travel is always accompanied by multiple issues including, but not limiting to:

  • Cosmic radiation. We can lift easily any mass, hence radiation shield has nearly no limit to its mass - as long as ship will not collapse under its own mass when left idle on planet. What materials in industrial qunatities available in that period of time could be used for this purpouse? Can the shield be located only in ships prov, as most of the journey will be at FTL velocities?
  • Air leakage. If I recall correctly, even modern spaceships are not perfectly hermetic - air atoms are constantly leaking through the hull. Using state of art engineering of colonization era would it be possible to keep the crew from suffocating during months long journey?
  • Pilot visibility. Without modern radars how could the pilot see what is happening outside of his ship? Obvious guess is kind of a windshield, but I have hard time imaging that such windshield would be able to withstand pressure differences found between spacecraft and the void surrounding it.
  • Space pirates! Last but definitely not least, there can't be colonization era spaceships without proper pirates! Could space pirate ships with preindustrial weaponry and no automation pose any threat to other ships if both vessels could travel at relativistic velocities?

Proposed solutions should rely on the drive technology as little as possible, except for transportation and logistics.

  • $\begingroup$ Hello and welcome to Worldbuilding. There are two issues with your post. 1) What is the problem and the query? You need to be a bit more clear on what the problem you are facing is, the issue that got you stuck to the point you needed to ask for help. 2) If I interpret the post right, you are pretty much asking us to do your work for you. This is frowned upon. Ok, so you came across a High-Concept. That is all fine and well. But the mere existence of a High-Concept is not enough to make a post about it. You need to start building (this is Worldbuilding after all). :) (cont.) $\endgroup$ – MichaelK Sep 6 '17 at 10:30
  • $\begingroup$ Once you have started building on this concept, you may run into problems that makes you get stuck; issues that you need resolved before you can continue. And no matter how much you try to Google for it or browse other Worldbuilding questions, you cannot proceed. That is the moment you post here. Please feel free to visit the very splendid and worthwhile help pages to get excellent information about what makes good questions here. Again: welcome, and enjoy your stay. :) $\endgroup$ – MichaelK Sep 6 '17 at 10:33
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    $\begingroup$ Welcome to WorldBuilding Reillusion! To underline the point @MichaelK made you may want to read the Meta discussion How to deal with “I have a High Concept, please do my work for me” questions?. If you have a moment please take the tour and visit the help center to learn more about the site. It would be nice if you could edit your post to clarify how we may help you. Have fun! $\endgroup$ – Sec SE - clear Monica's name Sep 6 '17 at 10:42
  • $\begingroup$ MichaelK, Secespitus. Thank you for your insight! I will edit my post right-away. I did encounter specific issues, especially those listed in the post. I will elaborate on them to make the issue more specific. Nice to meet you, Wroldbuilding! $\endgroup$ – Reillusion Sep 6 '17 at 10:45
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    $\begingroup$ @MichaelK Those are really great ideas! Especially cosmic radiation effects eventually being misinterpreted as God's wrath. About point 3: In my opinion the real concern with air leakage regards hermetic airlocks - I could not find any sources indicating their construction prior to 20th century, but improvised solutions based on vacuum suction could probably be easily introduced. Yet again, thanks for those great insights! :) $\endgroup$ – Reillusion Sep 8 '17 at 10:11

None of the above. Radiation is a problem we face because we're so limited in the mass we can lift to orbit, because of the tyranny of the rocket equation. With an antigravity device mass is not that a problem and you can lift an equivalent of a napoleonic era ship-of-the-line. With up to three feet of wood between space and you, the amount of radiation received is less than you receive here on the Earth's surface - lighter materials such as wood are actually better than things such as lead, because they are seldom irradiated and thus doesn't emit second-hand radiation.

Air leakage would be detected early when first pioneers died of suffocation, but this can be solved with several distinct methods, from caulking to build metal welded hulls. None would render the ship completely hermetic, but it all depends on how much time of travel they have to endure.

They absolutely need glass to look through, but they can improve its toughness by making the windows as little as possible. Probably using periscopes.

Pirates would not have any means to aboard a ship. Instead, they would break the hull with cannonballs, making it loose the air inside and killing everyone, then towing the vessel to its base.

HOWEVER this won't work. The road not taken is a short story and the implausability of its premise it's not put into question, but there's two insurmountable problem with this. No matter how simple the antigravity and FTL devices are, they need energy, as per thermodynamics laws. Since the age of discovery didn't have sun or nuclear powered sources of energy, this must be chemical (coal, or gas, or oil). Burning anyone of those inside the ship would quickly deplete the oxygen needed for the crew.

Second problem is the heat. No heat exchangers, so the temperature inside the ship would quickly roast everyone inside.

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    $\begingroup$ The laws of thermodynamics describe the situation as we know it for the moment. These laws do not dictate the situation forever. If mundane gravity manipulation was discovered, then the laws of thermodynamics would need to be amended, just as for instance the original atom model needed to be amended once people discovered that if you shoot neutrons at certain elements, then atoms can be divided. From being "atoms cannot be divided" the model became "atoms cannot be divided, unless you shoot neutrons at so called 'fissile* elements". $\endgroup$ – MichaelK Sep 6 '17 at 12:02
  • $\begingroup$ @MichaelK You can then call it "magic" and forget about it and the science-based tag. $\endgroup$ – Rekesoft Sep 6 '17 at 14:54
  • $\begingroup$ We are already in the realm of magic since the question postulates mundane gravity manipulation. There is nothing science-based about the concept that 15th century people can fool around with one of the four fundamental forces. $\endgroup$ – MichaelK Sep 6 '17 at 15:01
  • $\begingroup$ Heat would not be a big problem in short trip - human radiates a couple hundred of watt, this thermal power would heat 1 ton of water up 1 degree in 6 hours. So you don't even need ice - some metal/ceramic vessels with water would make the trip tolerable. $\endgroup$ – Vashu Sep 7 '17 at 2:45
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    $\begingroup$ Regarding it "not working", I am using a similar premise and got the same problem. But however you look at it, the FTL/Antigrav is magic already, so you can go pretty wild with how it works. In my current draft, it wrecks even the crudest electronics, and any long power lines (and no, shielding doesn't work). So any such civ would have never done much with electricity. As an energy source, it uses water and slowly turns it out into slightly warmer H2O2 (it somehow goes E=MC² on hydrogen atoms). Makes no sense? Indeed, another thing that makes it so hard to develop coherent scientific theories. $\endgroup$ – Eth Sep 7 '17 at 15:56

I think you are overlooking more important issues.

  1. Heat RADIATION A big wooden hull in space is still gonna have to be cooled, I'm not sure pre 19th century tech could make an effective radiator. I suppose you could just stick large metal poles through the hull to conduct heat out but these would be very inefficient, especially in a ship that probably has way more humans in it since very little would be automated.

Though, I suppose if travel time is very short, like days, you could load up on ice to act as a heat sink or build a very crude high-pressure to low pressure refrigeration system.

  1. Navigation. Even with anti-grav and a FTL you still have to calculate where to go, plot a direction and distance. They will have had calculus since the 1660's so for observable bodies they could probably calculate a course with telescopes, but remember that LONGITUDE determination took another 100 years, so all the precision instruments we take for granted simply did not exist for most of this range of time. Dead reckoning navigation at interplanetary or interstellar distances seems unlikely at best.

  2. Where would they go and what would they do when they get there? Even if they can get a wooden tub into space and get to another planet, how could they construct an atmospheric suit for exploration? The first fully armored atmospheric diving suit, which presumably could be reversed for a low pressure space walk, wasn't developed until the 1850's. They could possibly limit exploration to just earth standard atmospheres but who knows how many planets actually have that (and how many millions of ducats/florins/pounds and lives would be spent finding them).

  3. Probably the best use of this tech in early times would be for maximizing Earth exploitation by placing manned satellites for weather and navigation. Send an observation pod up into orbit and map out the new world, track big weather patterns, and set up some sort of reflective satellites sailors could use for terrestrial navigation (possibly only seen at dawn/dusk like the ISS). It's possible they could make a ram ship to push asteroids into different orbits so they could be exploited (crash precious metal asteroids into the desert for later recovery?).

  • $\begingroup$ They can navigate with unaided eye just fine - for example "just go right between this and that star, wait till you start to see red star in front, then steer straight to it". $\endgroup$ – Vashu Sep 7 '17 at 2:47
  • $\begingroup$ @Vashu I think that is a VERY simplistic navigation scheme that will be very difficult to do even within our solar system, much less between stars. It would be almost impossible for folks using simple 17th century telescopes to even see all of our planets, much less adequately distinguish between celestial bodies enough to know how far things even are. They might be able to head out to a star, but is it 20 LY away, 500, or 1000? And once they get there, how can they get back to Earth? Which star was it again? The type of star chart you propose would be almost impossible to create. $\endgroup$ – Jason K Sep 7 '17 at 14:43
  • $\begingroup$ To detect planets in a system, they should stop once inside the system, observe the sky, then move around and see if any "star" is at a different place. Some empirical observations based on star types will tell them where inhabitable planets tend to be. As for interstellar navigation, it depends on the details of the FTL. For example, if it is a "star network" type, they can simply wander along each nearby branch and map it, they don't even really need to map the network to the physical location of he stars in the sky. $\endgroup$ – Eth Sep 7 '17 at 16:15
  • $\begingroup$ @jason-k Ancient navigators knew all constellations and names of hundreds of brightest stars. With short travel(~20ly) sky would remain recognizable(traveling farther away - draw maps). Inside the system - you estimate distance to sun by it's angular size and by watching for bright planets(~Jupiter) get the plane of eucliptic. The H-drive moves fast enough to go btw stars in days, so it would be easy to spot planets - they move quickly and change brightness. Go round the star in the plane of eucliptic at the distance where it warms you just like Sun around the Earth and look out for planets. $\endgroup$ – Vashu Sep 7 '17 at 23:34
  • $\begingroup$ @jason-k You may be interested to know that I have tried flying in Celestia program and navigating by myself. Looking for Earth is surprisingly easy(like Venus it is very bright), going back to Sun is easy too if you know which constellation to go to(I drew schemes). The only hard part would be looking for nearby stars - most of those brown dwarfs are very weak but possible to detect from several ly. $\endgroup$ – Vashu Oct 13 '17 at 11:37

Cosmic radiation is actually the biggest problem you face, with an artificial gravity field that strong you can keep an atmosphere contained and use open windows the while no windscreen required, you use one though, at relativistic speeds dust particles are no joke. Basic radiation shielding can use that same atmosphere or a water blanket built into the hull but cosmic rays are extremely penetrating, even through gold baffles etc... minimising exposure is the only real solution. Space pirates are only going to be a threat in the same situations that normal pirates were: when they could overhaul a slower target in which case relative speed was generally low and range short. From ambush in which case they did have some degree of automation, firing on an area not a specific target. Lastly when actively engaged by a picket force. Otherwise most victims could, and did, run away reasonably successfully.


You could solve the cosmic radiation problem with shielding consisting of water or human waste.

Air leakage could be counteracted with constant production of oxygen from plants or something. Or from electrolysis, though I wouldn't think that they would've known about that in the Age of Discovery.

Pilot visibility seems to be an issue.

Space pirates (in space, of course) would only be an issue if they knew where other ships would be and rammed them at extremely fast speeds. I can't see pirates boarding or swordfighting in space.

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    $\begingroup$ This does not provide an answer to the question. Once you have sufficient reputation you will be able to comment on any post; instead, provide answers that don't require clarification from the asker. - From Review $\endgroup$ – L.Dutch - Reinstate Monica Sep 6 '17 at 11:21
  • $\begingroup$ @L.Dutch it does, actually, I think. Not to the whole question, but partial answers are valid. It is a little short and could benefit from some explanations, but in my opinion, it does count as an answer. $\endgroup$ – DonQuiKong Sep 6 '17 at 11:43
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    $\begingroup$ @DonQuiKong I don't remember seeing a Meta discussion about the community being kind to partial answers. There's a reason we put on hold questions that are asking about multiple things. If each of five answers addressed a different part of a single question, there's no way to judge which is the best to answer the question. $\endgroup$ – Frostfyre Sep 6 '17 at 12:08
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    $\begingroup$ @Frostfyre meta.stackexchange.com/q/144452/346854 And the best answer would be a complete one - but that doesn't mean incomplete answers can't be good. I'm not saying this one is long enough, but it is an answer. $\endgroup$ – DonQuiKong Sep 6 '17 at 12:46
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    $\begingroup$ Not a very good answer Imho, but at least it tried to answer some parts of it. Voting to delete is inapropriate. The answer is not wrong, so no downvoting from me. No upvoting either since the solutions are not that great. $\endgroup$ – Vincent Sep 6 '17 at 14:34

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