A few decades ago, there was great controversy among astronomers over the question of quasar distances, with some arguing that quasars are much nearer than application of Hubble's law would seem to imply.
Why do nearly all astronomers now agree that quasars really are quite far away? A) We now have images and spectra that show quasars to be embedded at the centers of distant galaxies and within distant galaxy clusters.
B) All quasars have large redshifts.
C) Now that we can explain bright quasar emission with power due to the presence of supermassive black holes, there is no reason to doubt that quasars are far away.
D) No one could think of a way to explain quasar speeds if they are nearby, so we concluded they must be far away.
Question 2
The presently accepted value of the Hubble constant gives an age of
A) 4.5 billion years.
B) 8-9 billion years.
C) 14 billion years.
D) 18 billion years.
E) 22 billion years.
A rocky shore at low tide, showing the great abundance that can be attained by populations of intert
Great thinkers
How to solve a linear system when the variable is in the denominator position (Question 2 of 2)
How to integrate using inverse trigonometric substitution (Question 5)
Hardy-Weinberg Question P1
Economics question