Later this week Jewish people around the world will be hosting Passover Seders. The Passover, or Pesach, seder is a meal wrought with ritual. Seder itself means order- and, indeed, there is an order to this meal, which is full of stories (mainly, the Exodus) and symbols. In an orthodox household the pre-dinner service may take hours with a meal lasting long into the night. Many modern, more reformed households look for fun seder ideas to make the holiday more engaging, especially to the children present.
Here’s a fun seder idea that also brings science to the table.
Have the kids gather round to watch for this simple, but impressive demonstration.
All you need is a bowl of water, ground pepper and a drop of dish soap. I also made a Moses figurine on a popsicle stick (great project for the kiddos!), but you can use a plain popsicle stick, your finger or just a drop of soap on its own.
Take a bowl and fill it with water and then sprinkle the surface with ground pepper, enough to cover the surface.
Put a drop of dish soap on the tip of your popiscle stick (or finger) and dip it into the bowl. As you’ll see in the video below, the pepper scatters very dramatically! Just like Moses sticking his staff into the Red Sea, so the Israelites could flee from bondage in Egypt.
The scattering pepper seems magical, or perhaps like an act of God, but it can be explained by science, of course. The pepper scatters because the soapy stick breaks the surface tension. Click here for a deeper explanation.
If you want to turn this from science fun into a science experiment, think of variables you can change. For example, will the effect change depending on the type or brand of soap you use? Is the effect more dramatic in a small bowl or large one? Does this work with other spices or anything else in your cupboard?