Why do we need to postulate the existence of invisible matter and energy in the universe? What observational data
make it necessary?
What is the difference between dark matter and dark energy? What role does each one play in the Big Bang Theory?
Why do detectors build to look for dark matter in underground mines? Have any particles of dark matter been detected in these detectors?
How did Fritz Zwicky discover the dark mass watching the newly discovered galaxies in the 1930's?
How do you weigh things in space? How do you know how much mass there is in a galaxy?
What did Vera Rubin discover about the rotation of galaxies? How does this support the idea that there should be dark matter?
What things do you think that dark matter can be made of? Briefly describe (in a sentence for each) that they are the M.A.C.H.O.s, brown dwarfs, neutrinos, and W.I.M.P.s for theoretical physicists.
How to see explosions of Supernovas 1A allows us to conclude that the universe must expand rapidly, and that the speed of expansion increases as time passes instead of decreasing?
All the matter which is calculated by the scientists is not enough to produce the force of gravity that is pulling things... View the full answer