Ever wondered what would happen if you dipped a ping pong ball into liquid nitrogen? We certainly did when we saw this story on CBS news! YouTube user makend0, explains the phenomenon of the liquid nitrogen ping pong ball and suggests the following:
“Tell the audience only that you’re immersing a ping pong ball in liquid nitrogen. Ask them to predict what will happen (a good guess would be that it will collapse in on itself). The unexpected result will give them a good opportunity to apply some bits of knowledge they possess (depending on their age: that liquid nitrogen is very cold, and at its boiling point; that a gas has a much greater volume than a liquid; how a jet works/conservation of momentum; that water droplets are visible but water vapor is not) and to analyze the problem (they should be able to figure out that the ball has a hole in it, and that the hole has particular characteristics). You can guide them to the solution by being as vague or explicit as you need to be based on how much time you have, but I recommend allowing them to closely inspect the ball only once they have deduced the existence of the hole. Temporize by repeating the demonstration.
A fun demonstration that has earned a triple-rainbow salute of wacky and wild science from us here at The Feed!”
For a step-by-step guide of how he achieved this, check out his Instructables post.