Tag Archives: high school science fair projects

Exploding Watermelons

7607-watermelon.jpgI love Halloween. One of my favorite activities is to “carve” pumpkins using a simple reation inside the fruit. First, you carve the face then carefully replace pieces. After creating a reaction by generating a gas inside and igniting it (ask your local chemistry teacher for the details) the face pieces are blown off with a small explosion.

Halloween is more than 100 days away and I just couldn’t wait. So I initiated the new weather anchor at the local Denver television station by introducing her to carving watermelons. The problem was, we didn’t really carve the watermelon, it exploded. Watch the Video to see how we skipped right over the carving and went straight to exploding.

Water Flowing Uphill?

Not exactly… but this stuff is really cool. It’s probably best described as a self-siphoning gel. The chemical is called polyethylene oxide or Polyox and it has an incredibly large molecular weight – about 4 million. When the powder is mixed with water (that’s the tricky part), the liquid becomes very thick and will literally siphon itself from one container to another. As a kid I order a product called Moon Blob – “The Gravity Defying Gel” – which promised to do the same thing. It did… but now I’m doing it as an adult! It’s tough to explain it… just watch the Polyox video.