Why do scientists believe that the earliest life forms most likely lived in the oceans? chemicals could not react to form complex molecules without water. early earth did not have an ozone layer. the land would have been too cold for life to form there first. all life relies on water.

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