8 ways the world could suddenly end: stephen petranek at tedxmidwest Published 10 years ago • 4.1M plays • Length 22:52 Download video MP4 Download video MP3 Similar videos 29:55 stephen petranek: 10 ways the world could end 17:15 your kids might live on mars. here's how they'll survive | stephen petranek 18:36 is it okay to touch mars? 17:42 a theory you've never heard of | michael robinson | tedxuniversityofhartford 48:23 how nasa learned to land on the moon
