On Jun/11/2020 at 20:26, David Spain wrote :
On 2020-06-11 8:01 PM, Alain Fournier wrote:
Yes but carbon nanotube aren't a material. Until someone figures out
how to make a useable material out of them, you can't make a cable
with them. Just aligning lots of nanotubes one next to the other
doesn't make a strong cable. You need to get the nanotubes to hold
together. And if/when someone does figure out how to make a useable
material out of nanotubes, it isn't sure that such a material will
still be highly conductive. It might be, in which case yes running
electricity in the cable might make sense.

Gee, weren't you just saying a few hours ago this was totally feasible
with today's technology? Or am I imagining things?

Did you not have carbon nanotubes in mind when you wrote that?

No I did not have carbon nanotubes in mind when I wrote that. I wrote
that using faulty memory. I thought that Edwards paper was about
building a space elevator with materials that actually existed when he
wrote his paper.

It is theoretically possible to build a space elevator using materials
that do exist today, but the taper ratio calls for an outrageously big
cable near geostationary altitude. The cost would be staggering.


Alain Fournier