Ask a question, make a hypothesis, and observe what happens in this Sesame Street interactive science experiment! Help renowned scientists, Cookie Monster and Emma, investigate what sinks in water and what floats in water! Experiment with a rubber band ball, a lime and lemon, Ernie's rubber duckie, and a coconut. Start the experiment here! Will Bert's underpants sink or float? Go to http://www.sesamestreet.org/sinkorfloat for the full interactive experiment and find out.