Now the pebble bed reactor has the same basic safety features as a high temperature prismatic reactor in a sense that it has a meltdown free core.

You can sense temperature variations, proprioception (position of your muscles), and the force of gravity (you do this by knowing at what Angle your head is in while your eyes are shut).

The effect was especially strong after participants had spend five minutes outside and their bodies had had a chance to sense the change in temperature, Dr Gallup said.