Cosmic Times 1929

Who solved the mystery of spiral nebulae and determined that they are distant galaxies outside of our Milky Way Galaxy?

• Henrietta Swan Leavitt

• Edwin Hubble

• Harlow Shapley

• Milton Humason

What did Dr. Hubble use to figure out the distances to nebulae?

• Comets

• Cepheid variable stars

• Black holes

• Asteroids

What did Miss Henrietta Swan Leavitt discover about Cepheid variable stars?

• They are only found in the Milky Way Galaxy

• Their brightness is related to their period

• They are the most common type of star

• They are the smallest stars in the universe

What did Dr. Vesto M. Slipher first record about the electromagnetic spectra of spiral nebulae?

• They were all blue-shifted

• They were all green-shifted

• They had no shift in their spectra

• They were all red-shifted

What did Dr. Hubble discover about the speed of spiral nebulae?

• They are moving towards us

• They are not moving at all

• They are moving in random directions

• They are moving away from us

What did Dr. Hubble use to measure the redshifts of distant nebulae?

• X-rays

• Infrared light

• Electromagnetic spectra

• Ultraviolet light

What did Soviet scientist Alexander Friedman suggest about the universe?

• It is not expanding or contracting

• It is only expanding

• It is only contracting

• It is either expanding or contracting

What did Dr. Hubble's recent observations support?

• The views of Alexander Friedman

• The views of Vesto M. Slipher

• The views of Harlow Shapley

• The views of Heber Curtis

What did the 'Great Debate' in 1920 focus on?

• The size of the Milky Way Galaxy

• The formation of the solar system

• The existence of parallel universes

• The discovery of black holes

What did Harlow Shapley describe the Milky Way as?

• A galaxy with no stars

• A small galaxy with the Earth at its center

• An enormous galaxy of stars

• A galaxy with only one star