Based on Mr. Kaku's assertion that knowing what the stars are made of is as easy as running starlight through a prism, use the CER method to explain the use of light to determine composition of a star in detail. PLEASE i need help now its due tomorrow

Up until 1938, paleontologists accepted the idea that coelacanths (an ancient fish) went extinct at the time that they last appear in the fossil record, about 80 million years ago. but in 1938, a live coelacanth was discovered off the coast of south africa that was compared to the fossil record and found to be the same species what goal of science does this discovery represent