Would you take a dive in this? A handful of people did, in the 1930s. (Photo: By Mike Cole. Licensed under CC BY 2.0.)

Going down and going up have always been dangerous. Humanity has learned this only by doing it. Going into caves, or climbing mountains, or holding one’s breath and diving, or finding ways to ascend into the sky: these all have something to do with approaching death, which we tend to think of either as entering the earth or entering the heavens. No doubt that’s part of the ap...