Astronomy 120 - Stars and Galaxies » Fall 2022 » Unit 13 Quiz

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Question #1
Hubble and Humason noticed that the galaxies that they studied are moving
A.   with space.
B.   not at all.
C.   outside of space.
D.   through space.
Question #2
How do astronomers detect the motion of distant galaxies?
A.   By tracking the disappearance of the most distant galaxies, one by one.
B.   By observing the steady dimming of the galaxy's light.
C.   By observing shifts in emission or absorption lines of the galaxies.
D.   By noting the sudden appearance of new galaxies where none was previous seen.
Question #3
Astronomers have found the cosmic microwave background (CMB) radiation. What is the nature of this radiation?
A.   It is a faint, almost uniform, radio signal.
B.   It is a weak background of cosmic neutrinos.
C.   It is a bright, almost uniform, x-ray glow.
D.   It is a weak and very patchy glow at visible wavelengths.
Question #4
How was the CMB created?
A.   The fusion of H into He by the first stars.
B.   The combined effect of billions of distant quasars.
C.   The formation of quarks in the big bang.
D.   The burst of radiation from the big bang as it cooled down.
Question #5
The "Hubble Age" is the calculated age of the universe, according to the Hubble constant. Astronomers have calculated the Hubble age to be
A.   6500 years.
B.   67.8 billion years.
C.   13 billion years.
D.   4.65 billion years.
Question #6
The fact that Hubble and Humason noticed that galaxies were moving away from us was measured by the galaxies'
A.   luminosity.
B.   galactic type.
C.   redshift.
D.   hydrogen content.
Question #7
A galaxies recessional velocity is dependent on its
A.   acceleration.
B.   luminosity.
C.   galactic type.
D.   distance from us.
Question #8
The cosmic microwave background radiation corresponds to the universe's present day temperature of
A.   ~3 ºC.
B.   ~3 K.
C.   millions of degrees, in any scale!
D.   ~3 ºF.
Question #9
What do astronomers infer from the motion of distant galaxies?
A.   The universe is expanding.
B.   The universe is contracting.
C.   The universe is spinning.
D.   The universe is imploding.
Question #10
The "Hubble constant" is a constant (a number) that defines the expansion rate of the universe. The Hubble constant has been measured from a graph of the Hubble Law to be
A.   ~70 km/s/Mpc
B.   13 billion years
C.   ~40,000 miles/s
D.   ~68 mph/km
Question #11
Which of the following is NOT a proposed form of dark energy?
A.   æther, quintessence
B.   æther, quarks
C.   Einstein's cosmological constant
D.   quintessence
Question #12
Our understanding of the expansion of the Universe has changed with time. It is only since the year ___ that astronomers have theorized the existence and effects of dark energy.
A.   1998
B.   1995
C.   1980
D.   1988
Question #13
Ω0 =
A.   13 billion
B.   1
C.   42
D.   73%
Question #14
Dark energy accounts for approximately what percent of the mass-energy density of the universe?
A.   27%
B.   73%
C.   5%
D.   100%
Question #15
The shape of the Universe is
A.   negative
B.   positive
C.   flat
D.   saddleback
Question #16
Astronomers believe that the expansion rate of the universe is
A.   increasing.
B.   decreasing.
C.   remaining the same.
D.   incalculable.
Question #17
According to astronomers, the final fate of our universe is to
A.   disappear in the blink of a deity's eye.
B.   implode instantaneously.
C.   shrink slowly and collapse in the "big crunch."
D.   expand forever.
Question #18
Due to the expansion of the Universe, space
A.   itself is expanding, faster and faster
B.   neither getting bigger, nor smaller
C.   and all its contents are shrinking, faster and faster
D.   is expanding while its contents remain motionless
Question #19
The change in the expansion rate of the universe is theorized to be caused by
A.   dark energy.
B.   dark matter.
C.   dark nebulae.
D.   dark chocolate.

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