At what point do the weak nuclear and electromagnetic forces split?
A) never, they are still united
B) at 1012 K, when pair production starts for neutrons and protons
C) at 10-43 seconds, when all four forces separate as the Planck Era ends
D) at about four seconds, when at millions of degrees hydrogen forms helium
E) after about 10-10 seconds, when the temperature drops below 10-15 K
Question 2What is meant by the wavelength of light? By its frequency? Explain how they are related to each other.
What will be an ideal response?
Question 3The radial velocity of a star's motion in space can also broaden its spectral lines.
Indicate whether the statement is true or false
Question 4How do astronomers define the superforce?
A) a force connecting electromagnetism with the strong and the weak nuclear forces
B) the GUT, with all five forces combined
C) the GUT, but with no dark energy added in
D) a force connecting gravity and the electroweak force
E) a force including only dark energy and gravity
Question 5The RR Lyrae stars all have periods of:
A) less than a second.
B) several minutes.
C) several hours.
D) several days.
E) several weeks.
Question 6The planet closest in size to Earth is
A) Mercury.
B) Venus.
C) the Moon.
D) Mars.
E) Pluto.
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