Universe

What are the two major theories of the origin of the universe?

Fourth Dimension

What is meant by the fourth dimension?

What would an imaginary terrestrial observer see as the Sun runs out of hydrogen in the future? If life is confined to Earth when this happens, would life perish from heat or from cold?

What would an imaginary terrestrial observer see as the Sun runs out of hydrogen in the future? If life is confined to Earth when this happens, would life perish from heat or from cold? Explain. What kind of stars eventually become white dwarfs? What kind eventually become supernovae? What will be the ultimate fate of the Sun? Why?

Compare the solar system with the Milky Way Galaxy. (They are very different, but the terms are often confused.)

k. Compare the solar system with the Milky Way Galaxy. (They are very different, but the terms are often confused.) l. Describe the nature of the material between the stars, and how is it observed. m. Why are O and B stars the brightest in open clusters? Why are red giants the brightest stars in globular clusters?

What is Hubble's Law and its significance? How does it relate to the distance chain?

What is Hubble's Law and its significance? How does it relate to the distance chain? Consider the star-gas-star cycle in the Milky Way galaxy today. How is the star population is the halo different from the star population in the galactic disk?