UNSAFE, NOT FOR KIDS! Main article: http://bit.ly/TNXQ7
http://amasci.com/amateur/liquid_n2.html
Can't get liquid nitrogen? Then make your own -80C/110F fake version by using Dry Ice. Note that this science demonstration involves several major safety hazards, and should only be performed by skilled educators. If used for science fair projects, close parent/teacher supervision is required.
But also go see http://bit.ly/EKqgi SFGATE: "The War On Curiosity" (stamping out hobbyist science in order to keep kids safe.)
For lots of suggested low-temp physics demonstrations click on the above liquid_N2 link. Or, search www for: liquid nitrogen demonstrations.
Note that dry ice comes from companies listed in your local yellow pages. Some welder-supply stores carry it. In Seattle, you can find it in the seafood section of QFC neighborhood grocery, and at some Fred Meyer stores. Ask for dry ice pellets rather than slabs if they have them, so you won't have to chop it up yourself.
And if you're going to use it in drinks or punchbowls, make certain you have FOOD GRADE DRY ICE, since the other stuff is full of grease from petroleum distillation.
.
Lots more stuff at SCIENCE HOBBYIST http://amasci.com/unew.html
.
Note: trolls/spammers blocked immediately, zero tolerance
