Geoff Mulgan

On the other end of the spectrum, these women who do live long enough to collect Social Security face the challenge of being disproportionately dependent on the Social Security system for retirement income.

I wouldn't specifically say rock n' roll is dead, but I don't see a lot of charismatic performers in the way of new blood who are edgy and dangerous on stage, like Marilyn Manson, who you never quite know if he's going to make it through his own show.

Supplying fuel for a Mars expedition from the lunar surface is often suggested, but it's hard to make it pay off - Moon bases are expensive, and just buying more rockets to launch fuel from Earth is relatively cheap.