3 ms·

I doubt it has to be a good insulator. The air is travelling up the tube at high speed and there isn't time for it to cool significantly before it emerges.

• chroem- 9y ago
  No, it would have to be a very, very good insulator. You're talking about three miles of tubing exposed to high speed winds and large convective heat losses. Anyone who's taken a course on thermal power systems would know that this is absolutely preposterous.
  • sp332 9y ago
    I'm not saying it's feasible or anything, but he's talking about moving air at over 100 miles per hour. It would only take a couple of minutes to get to the top.
    • roceasta 9y ago
      Right, plus it's a 30 metre diameter tube. The bulk of the air moving up the centre would be insulated by the outer layers of air near the inner skin of the tube.
      • chroem- 9y ago
        That's not how convection works. It won't be moving quickly in the first place if it cools off. This whole farce of a thread is really tempting me to sink time into calculations to prove that this is absolute bullshit.