The discovery that the Universe is expanding faster today than in the past was possible because of observations of
A. Cepheid variable stars.
B. Type II (core collapse) supernovae.
C. galaxy rotation curves.
D. Type Ia (white dwarf) supernovae.
Answer: D
You might also like to view...
The best time for digging clams (when low tide is extra low) is during the time of the
A) new or full moon. B) half moon. C) quarter moon. D) none of these times.
Among the points and circles shown on this diagram, which one(s) have varying right ascension?
A) the celestial equator and the ecliptic B) Earth's equator and the celestial equator C) only the celestial equator D) the north and south celestial poles
List the six main regions of the Earth, in order, starting from the center
What will be an ideal response?
Why can't current theories describe what happened during the Planck era?
A) We do not yet have a theory that links quantum mechanics and general relativity. B) We do not know how hot or dense the universe was during that time. C) We do not understand the properties of antimatter. D) The Planck era was the time before the Big Bang, and we cannot describe what happened before that instant.