Stop & Jot 1. Why do we have day & night?
2.
Is it the same time (3pm) everywhere in the world? (Hint: If it is 3pm in Boston will it be 3pm
everywhere else in the world?)
3. Why is it summer in one part of the world and winter, in another part?

If you chip a tooth, most likely you will go to the dentist to have the missing material filled in. currently the material used to fill in teeth is a polymer that is flexible when put in, yet is hardened to the strength of a tooth after irradiation with blue light at a wavelength of 461 nm. what is the energy in joules for a photon of light at this wavelength?