Evidence that the cosmic background radiation really is the remnant of a Big Bang comes from predicting characteristics of remnant radiation from the Big Bang and comparing these predictions with observations
Four of the five statements below are real. Which one is fictitious? A) The cosmic background radiation is expected to have a temperature just a few degrees above absolute zero, and its actual temperature turns out to be about 3 K (actually 2.7 K).
B) The cosmic background radiation is expected to have a perfect thermal spectrum, and observations from the COBE spacecraft verify this prediction.
C) The cosmic background radiation is expected to contain spectral lines of hydrogen and helium, and it does.
D) The cosmic background radiation is expected to look essentially the same in all directions, and it does.
E) The cosmic background radiation is expected to have tiny temperature fluctuations at the level of about 1 part in 100,000. Such fluctuations were found in the COBE data.
C
You might also like to view...
Recall that Hubble's law is written v = H0d, where v is the recession velocity of a galaxy located a distance d away from us, and H0 is Hubble's constant. Suppose H0 = 65 km/s/Mpc
How fast would a galaxy located 500 megaparsecs distant be receding from us? A) 65 km/s B) 65 Mpc/s C) 32,500 km/s D) 9 km/s E) 0.65 times the speed of light
Why is the Hubble Space Telescope equipped with more infrared and ultraviolet detectors than are optical telescopes on the ground?
What will be an ideal response?
Dana uses a rope to pull a box that weighs 600 N across a level surface with constant velocity. The rope makes an angle of 40° above the horizontal and the tension in the rope is 400 N. What is the coefficient of friction?
a. 0.89 b. 0.88 c. 2.00 d. 1.19 e. 0.84
The most active galactic nuclei are usually found at large distances from us; relatively few nearby galaxies have active galactic nuclei. What does this imply?
A) Supermassive black holes existed only when the universe was young and no longer exist today. B) Active galactic nuclei tend to become less active as they age. C) Active galactic nuclei can form only at large distances from the Milky Way. D) The jets seen in many active galactic nuclei must cause them to move far away from us.