Return to The Archive List Do you have a comment or response to this activity, submit it to the Do Science bulletin board. To get a Do Science logo product, click here. Send a t-shirt with an activity on the back (Condiment Diver activity is on back). More science activities can be found here: Great for Science Fair projects! While You're Waiting for the Food to Come by Eric Muller, Illustrated by Eldon Doty Hardcover version Paperback version To order or find out more about this book, click on the book cover above or on either cover version. Go to the Do Science Store

The world's simplest Cartesian diver. Ingredients: - Squeeze condiment packet (soy sauce, ketchup, etc.) - Clear plastic bottle with tight-fitting lid - A glass, bottle or cup of water The Recipe: 1) First, you have to figure out if your condiment packet is a good Cartesian diver candidate. Fill a glass with water and drop in your packet. The best packets are ones that just barely float. 2) After you have found the proper packet, fill an empty, clear plastic bottle to the top with water. Shove your unopened condiment packet into the bottle. 3) Replace the cap... and you're done! Squeeze the bottle to make the diver sink, and release to make it rise. Amazing!. Food for Thought: Many sauces are denser than water, but it is the air bubble at the top of the sauce that determines whether the packet will sink or swim. Squeezing the bottle causes the bubble to shrink. This smaller bubble is less buoyant and the packet sinks. Orginally published in The Physics Teacher, May 1996 By Eric Muller Photos by Amy Snyder Original copyright of While You're Waiting for the Food to Come 1995 Eric Muller