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Gmn8piTmn t1_ixyq9rw wrote

Reply to comment by unocoder1 in Space Elevators Are Less Sci-Fi Than You Think by Sorin61

That’s the whole point it won’t be billions of tons. Through magic advanced material technology it will be light.

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unocoder1 t1_ixyrn6j wrote

Yeah, I just don't think that's realistic. If the cable is 100,000 km long and has a cross section of 1 square meter, it would weigh 122 million kg... if it were made of air. It would be almost a thousand times heavier if it was made of... water.

For 100,000 km cable to weigh "hundreds of tonnes", 1000 km should weigh tonnes and 1 km should weigh a few kilograms. I just cannot believe that will ever happen.

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Gmn8piTmn t1_ixzixjj wrote

Yes that’s why I had the “magic” crossed. Because it’s completely unfeasible. Even if we could make a one continuous strand of carbon nanotube cable that would have to be absolutely perfect in all its length. And when I say perfect I mean to the atomic level. A single misplaced atom cuts the tensile strength at less than half.

And that’s for a 35.000km single walled continuous carbon nanotube.

The longest we’ve made was 55cm.

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