John Hockenberry, the panel’s moderator, asked Greene if he thought experimental evidence would come during his lifetime.
“I’d be surprised,” said Greene.
“And in your lifetime?” Hockenberry asked Kachru.
“…I’d be surprised,” conceded the young physicist reluctantly.
Chris Oakley, in the comments thread, immediately argued that the obvious follow-up question should have then been, "Why the f*** are you still working on it, then?". Funny, but not much more than that. Let me play the devil’s advocate for this once.
The question involved the time the two scientists think -or are willing to state they expect- to live, together with the time before they think a first evidence for string theory will concretize. So they had to give a statement on the ratio R=T_s/T_d between the time to an evidence for string theory and the time to their death, and they both said they would be suprised if this ratio R turns out to be smaller than 1.
If you consider it this way, claiming that sihce they believe that R>1 they should work on something else makes as much sense as saying that the Tevatron experiments should not have searched for the Higgs boson for all these years, given that the expected reach on the ratio R between the observable Higgs rate and the expected SM one is larger than unity…