How suddenly the world can change. Once, one mid-morning, I walked with a friend into a hospital to get important test results. We knew they might turn out good or bad but also we would have admitted that the odds were in our favour. Nevertheless, we were still on this side of the actual outcome. Hope was therefore still eternal. The familiar world we inhabited, not perfect but familiar and desirable, was still our home. When we walked out of the building an hour later it had changed. The traffic still flowed, people were still walking purposefully, the weather was the same. But we had landed on a new planet where the horizon of death had begun to rush remorselessly towards us.What might the passengers on the Germanwings flight that crashed into the quiet Alpine valley last week have been