The case of Felix Baumgartner, who has successfully jumped from a balloon 128,000 feet up (38km) has made me think. I say successfully but there was no other way down, he couldn't decide after the ascent not to go through with it, no one was going to go up and help him; and of course once he had jumped he was going to reach the earth in one condition or another.
I used to have arguments with a friend, the late broadcaster and journalist Michael Vestey, about whether motor racing drivers were brave. My point was that they were risking their lives, perhaps, doing something they wanted to do: I didn't think Michael was brave for smoking cigarettes.
But Baumgartner's feat seems different. No one knew what might happen - in the event he started spinning out of control but got a grip on it; his visor demister didn't work so he couldn't see his instruments. If his suit had torn, his blood would have boiled. This was serious risk taking, to get that much higher, further, faster, to see what man was capable of.