Comment Re:stupid comparison (Score 1) 501
So we don't build it out of concrete. The Yellowstone supervolcano will eventually blow and wipe out most of civilization sometime in the next few millennia, unless we do something about it. We can't simply drill a hole to the top of the magma, since that would set it off. What we have to do is tunnel down deep, to the lower part of the magma column, where the density is much higher and the pressure much lower. From there, we can allow the magma column to bleed off pressure gradually, providing us with a constant stream of incandescent magma that can be used for whatever we like. Then all we'd have to do is come up with a high-temperature insulated conveyor belt to transfer all the fresh magma to wherever the current end of the casting is. We could build 1000-foot walls, cast castles, create huge canals or reservoirs, whatever we like. So long as we keep coming up with good uses for a never-ending stream of white-hot magma, we're set.