Quasars are far more luminous than Type I supernovae; why not use them to calibrate Ho and the age of the universe?
What will be an ideal response?
Quasars vary over a period of weeks in brightness, and vary a great deal in luminosity from object to object. We need a uniform, consistent "standard candle", and the run-away detonation of a 1.4 solar mass white dwarf in a Type I supernova gives us just the desired combination of luminosity and consistency.
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What do astronomers generally believe about the origin of Mars's moons?
a. They formed with the planet out of the protoplanetary material. b. They formed elsewhere and were captured at a later time. c. They were ejected from Mars during its formation. d. They were once a single moon and a later catastrophic event broke them in two.
Binary black holes have much higher masses than their white dwarf and neutron star counterparts, which should lead to a much stronger emission of gravitational waves
What is the most reasonable explanation for why we have not yet observed gravitational waves from black-hole binaries? A) Black hole binaries are very rare, and wave detection is difficult. B) The waves disappear into the black hole. C) The waves must be coming from very far away and haven't reached us yet. D) Our current theories must be wrong.
Mass is a measure of how difficult it is to change the velocity of an object
Indicate whether the statement is true or false
In the early 1900s, a scientist named ______________ revived the idea of continental drift
Fill in the blank(s) with correct word