Skewered

What you need

  • One plastic bag, a ziplock or one that you can hold tightly shut
  • Wooden skewers, or sharp pencils
  • Water

What you do

  1. Fill the bag with water and seal or hold it shut. Leave some air at the top.
  2. Hold the bag by the top. Do this over a sink, outside, or over an unsuspecting friend
  3. Push a skewer into and through the bag, leaving them in place. You might need to practice, driving it in firmly and carefully and try not to wiggle the skewer too much.
  4. Keep adding as many skewers as you can.

What's going on

The plastic bag is made of polymers. Polymers are long chains of molecules, all linked together. When the skewer pierces the bag, these polymer chains move and stretch around the skewer. The result is that the plastic bag forms a light seal around the hole that the skewer has made. As long as the skewer stays in place the water is sealed in the bag.

Special safety advice

You are dealing with sharp sticks so be careful not to stab yourself. Stab only the bag.