Imagine a species that evolved on a planet where there was no metal (or not much) of any kind.

They, of course, discovered fire and were able to start building buildings and basic machinery from wood. Later their technology changed and became biology focused with a strong knowledge of DNA manipulation, so they were able to create bone-based kinetic weapons, and even computers based on nerve tissues.

However, space-faring requires strong materials for structure and combustion too.

So, is it possible for them to reach space, and if yes, how?

  • $\begingroup$ Calcium is a metal $\endgroup$ – user15036 Feb 27 '16 at 16:24

If I imagine really pie-in-the-sky style, I could replace most of the metals necessary in the actual launching of ships into space. There are carbon structures, silicates and plastics which could be used as pressure vessels and heat shields, etc. necessary to get a ship into space, especially if we assume the planet has a lower gravity and thus escape velocity than our Earth. Crystalline structures could be used for a sort of radar for navigation and radio for communication...

The problem I run across though is in the precision tools necessary for the discovery process and creation of all the systems necessary. Nothing melts, forms, keeps an edge, sharpens, measures, conducts, bends or holds its form like metal. Sure we have laser and water based cutting tools as well as diamond saws, etc., but it is hard to imagine a scenario where we discovered their usage without having metals.

Also energy storage and transmission becomes an issue. Electric eels and other animals that use true bio electrics rely on iron and copper to do so (in admittedly small amounts). To cut out all metals, you would have to use a sugar based energy storage system and bio-luminescence; nerves can only maintain a signal for short distances (less than 100 meters or so), so relays would be necessary every so often, and speed becomes a factor very quickly. No speed of light approximation here.

It becomes easier if you don't rule out all metals. Salts are fairly important to the development of life as we know it and by definition a salt is a combination of one metal and one non-metal. Also calcium, since you mention bone-based science, is a metal. If you only rule out iron, copper, zinc and nickel, you could imagine a civilization that was extremely different from ours. Perhaps these metals do exist, but in such small quantities that iron is considered more valuable than gold to us? Remember that just 200 years ago aluminum was the most precious metal due to its perceived scarcity. Your civilization could have gone totally bio-based for a long time before discovering a smelting process...

Anyway, I love Tyranids/Zerg, and would like to help you out more here, but if we base this entirely in science, this is really hard to do.


Issues that I can't get around

  • Life as we know it is heavily mineral based...bone doesn't exist without zinc and other minerals that can be used as metals.

  • How did they gain the knowledge of dna without the precision that metal brings? Can optics (microscopes) feasibly come to be without metal? Is the knowledge and manipulation of electricity really come to be without metals?

  • how did they develop computers based on nerve tissues without discovering the metal within those cells and how to refine it?

  • remember salt, the basis on how our muscles work, is a reaction that involves salt...sodium. Not exactly stable, but a metal nonetheless...

I guess the questions above come down to 'how scarce is metal'?

Can't call this life as we know it. Leaves me with a biological organism that has evolved the ability to travel in space without really knowing how they got to that stage (in the same manner a swimming dolphin is not aware of how it came to be able to swim).


Yes. One approach would be biochemical.

You can get pretty strong materials when you combine non-metallic advanced materials (composites, carbon nanotubes, advanced polymers, ceramics etc...)

You can also GROW things you need (for SciFi example, see Yoozhan Vong of Star Wars EU's New Jedi Order era series, or tree spaceships from Saga of the Seven Suns).

One open question would be whether the planet's "mostly lacks metals" imply lack of fissionable material (Uranium).

If not, you can have nuclear powered spaceflight, which by any and all estimates is vastly superior to chemical powered crap that our current civilization makes do with.

Electricity might be a difficult issue to get around; it was discussed in another answer.


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