Extremely large main sequence stars consume their fuel quickly and burn hot and bright. As they consume all their hydrogen, they become supergiants. Describe the changes that take place, in terms of luminosity and temperature, to
these large main sequence stars as they exhaust their hydrogen supplies.

Imagine you are standing in the antarctic during the southern hemisphere summer. the sky is clear and blue. there are no clouds in the sky. your shadow is cast on the icy ground. what is the color of the shadow?

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.

Which of the following statement is false