In this setting I imagine the planet has about 4.2 atmospheres of pressure at sea level and 1.17 G's, this is not necessarily fixed and if other values would allow earthlike life and human civilization, and produce more interesting effects then feel free to solve for other gravity values and atmosphere pressures, but both values are higher than on earth.

The planet in question is earthlike but larger with more gravity and a thicker atmosphere. Since a planet with a earthlike atmosphere, but higher atm's would have a higher partial pressure for oxygen and nitrogen, I think it could be reasonable for life to have evolved to deal with that so as to avoid toxicity from those elements. If the atmosphere just can't be plausibly similar to earths, but still allow earthlike life under these high pressures, assume it is different.

As for the aviation technology most things are the same, but there isn't any computing and engines can't generate any more thrust than a muscle of the same size limited by realistic earth biology, because magically grown muscles are the only power source. This severely limits how much power an aircraft can have. Certain materials are cheap and easy to to produce in this setting such as spider silk and limpet teeth like materials, and rare and heavy elements are far more common on this planet. Other than muscle power the only other form of propulsion is rockets, but the rockets have to use magically generated explosions, as thus the rockets are more like nuclear Orion rockets than traditional ones, though the explosions can be smaller down to that of a large cannon.

My question is, how would you expect aircraft and rockets to be different in this environment, with power limited to magically grown muscles (limited by biological realism, they're only grown and controlled via magic), and magical explosions, but more available rare materials, and different gravitational and atmospheric conditions?

  • $\begingroup$ Problem: high atmospheric pressure greatly decrease rocket efficiency while increase propeler's. It seems that your world has no magic or engine able to spin a fan, but human powered propeller would be very efficient. $\endgroup$
    – Madlozoz
    Feb 26, 2016 at 14:45

2 Answers 2


The increased atmospheric pressure will make flight easier, but the higher gravity will make it harder. Reduced thrust will make things like propellers less effective, and jet engines would be right out.

This leads us directly to a solution that is both pretty cool and viable - lighter than air transport.

This could either be done using helium or a similar gas created magically or it could be done by heating air. The heating again could be done magically or just by lighting a fire on the platform under the balloon.

The higher air pressure will make this more effective, as will the availability of silk for making the balloons.

Low but constant thrust created by the muscles will allow the airships to move slowly across the sky. Combine that with selecting appropriate trade winds and you would not be as fast as modern air travel but it would still get you there and do so very peacefully.

  • $\begingroup$ I'v thought about airships in the setting, one advantage they'd have is that certain technologies aren't possible, so they can't use radio to detect high flying airships, they can only use optical telescopes. I'v also considered super-light aircraft, and of course rockets exist as well but are exceedingly dangerous due to a lack of navigation computers. $\endgroup$ Aug 10, 2015 at 10:42
  • $\begingroup$ Unfortunatly, wind is a major problem in our world and would be even worth with 4 atmosphere. So, LTA would be VERY efficient but only carried by the wind $\endgroup$
    – Madlozoz
    Feb 26, 2016 at 14:49

Human powered ekranoplans

In 1979, with what we would call low tech material, Paul B. MacCready crossed the channel with a kind of flying bycicle.

Higher pressure improve efficiency of wings and propeller.
With 4 atmospheres, similar gravity and magically enhance muscle, any granny would ride similar "bike".

Also, a higher pressure would mean more erosion. You could expect this world to be rather flat. Combine with high pressure, it means that ekranoplans (ground effect vehicule) could be common.
Ekranoplans need less energy than planes. The only drawback is that they need flat ground and, obviously, you are less likely to hit a tree at 12000 feets. If your super earth have great plains and dedicated road, let's slide!!!

In case you don't know this technology, here is a video.
Note that this is NOT an hydrofoil. It doesn't need to touch the water and would work fine on a highway.

As Tim B suggest, lighter than air would also be efficient, but it would rather be the lorry of this world.

About the propulsion, it's up to you. Magic rocket, human powered propeller. You can also tow it like a kite.

Land sailing

With standard sail or with kite.

Higher pressure mean higher wind.

Feel free to mix this with the ekranoplane idea.


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