When did the photons in the cosmic microwave background first travel freely through the universe?
A) the moment of the Big Bang
B) about 10-10 second after the Big Bang
C) about 5 minutes after the Big Bang
D) about 380,000 years after the Big Bang
E) At the time, the first stars began to shine in the universe.
D) about 380,000 years after the Big Bang
You might also like to view...
Power: An ac series circuit has an impedance of 60 ? and a resistance of 30 ?. What is the power factor of this circuit?
A. 0.50 B. 0.71 C. 1.0 D. 1.4
An AC generator consists of 6 turns of wire. Each turn has an area of 0.040 m2. The loop rotates in a uniform field (B = 0.20 T) at a constant frequency of 50 Hz. What is the maximum induced emf?
A. 13 V B. 2.4 V C. 3.0 V D. 15 V E. 4.8 V
Discuss the discovery of galaxies, and the scientific debate that led astronomers to identify them as distant clouds of billions of stars
What will be an ideal response?
Which of the following is formed by direct freezing of water droplets?
a. Dew b. Snow c. Sleet d. Frost