We had a special delivery of steaks from Mimi and Poppop (THANK YOU!) and it came with some dry ice in the bottom of the box. Of course, we had to call our Uncle Bill to see what fun things we should do with the ice! He had lots of ideas, some of them not really for children :) He suggested adding bubbles and some warm water in a "vase"....because he knew we didn't have graduated cylendars at our house ;) .....and tossing in a piece of dry ice. So, that's what we did! At first, it was smoky, but you can see some bubbles rising up in our container. Soon, they were all over the place! Very serious "thumbs up for science" from these two :) We started getting some really big bubbles towards the end - when I threw in a 'really big piece'.