. >> these two are part of the university of otago chemistry outreach team.ey're going to do in their very first video is just kind of explode some ping-pongs in a barrel. you see dr. dave with a bottle of liquid nitrogen. they've already put something warm in there. when liquid nitrogen is heated to room temperature, it expands. here we get to see it explode at 1,000 franks per second. it's kind of almost beautiful when you see them rain down. >> it's a cool thing. scientists see people sharing these videos. >> people learn something today. you can do this in your backyard. >> those ping-pong balls will be everywhere. >> 1300 of them. >> some things are not what they appear to be. this looks to be an alpaca pillow. >> but see the real not any more. are you still waiting to change your bath tub? when i finally did it, it changed everything! only bath fitter can give you the new tub you've been waiting for, in as little as one day. with their unique tub over tub process. isn't that amazing! bath fitter will measure and make you a new custom bathtub that they i