Multiple Choice
About what was the temperature of the universe when a typical cosmic microwave background radiation photon was no longer able spontaneously to create an electron and positron pair?
A) 1000 K
B) 100,000 K
C) 1 million K
D) 1 billion K
Correct Answer:

Verified
Correct Answer:
Verified
Related Questions
Q8: Describe the four fundamental forces of nature
Q21: Assuming the Hubble constant is equal to
Q22: A grand unified theory unites which forces?<br>A)
Q23: The COBE and WMAP satellites detected fluctuations
Q24: In the early 1960s,physicists named Penzias and
Q26: Which of the following was NOT created
Q27: After the Big Bang,as the universe cooled
Q28: Was the Big Bang an explosion that
Q30: At what stage in the universe's history
Q61: How does the addition of a nonzero