User blog comment:Giganta/Character Flaws/@comment-4821105-20120703083646/@comment-1038387-20120703090219

Impulse has always come from the future.

Though usually, it's a 1000 years from now, not 50. That's because Iris was originally from 2950 or so, and Barry spent some time in that future too. Or something. 50 years makes much more sense.