First, Kai does an experiment in which they fill 2 cups with cold liquid at the same temperature: 1 cup with the old lid and 1 cup with the new lid. They find that the liquid in one cup warmed up more than the liquid in the other cup after 10 minutes. Which cup do you think warmed up more? Why?

Ascientist notices that an oil slick floating on water when viewed from above has many different colors reflecting off the surface, making it look rainbow-like (an effect known as iridescence). she aims a spectrometer at a particular spot and measures the wavelength to be 750 nm (in air). the index of refraction of water is 1.3