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Exam 4
Cosmology
25
Astronomy
Undergraduate 4
05/01/2012

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Term
From the 1970s to the present, the accepted value of H has almost doubled, so
Definition
The age of the universe is half what we believed.
Term
If Euclid is right, then ^o is
Definition
1.0
Term
On the basis of our current best estimate of the present mass density of the universe, astronomers think that
Definition
the universe is infinite in extent and will expand forever.
Term
The horizon problem in the standard BIG BANG model is solved by having the universe
Definition
inflate rapidly early in its existence.
Term
Why didn't elements heavier than helium form in the first minutes of creation?
Definition
Homogeneity
Term
Homogeneity and isotropy, taken as assumptions regarding the structure and evolution of the universe, are known as:
Definition
the Cosmological Principle
Term
the latest studies from ________ led to the discovery of "dark energy."
Definition
Type I supernovae at very large red shifts
Term
The redshift of the galaxies is correctly interpreted as
Definition
space itself is expanding with time, so the photons are stretched while they travel through space.
Term
The satellite that found the ripples in the cosmic background that led to galaxies is
Definition
COBE.
Term
According to (Radiation–Matter Dominance), when the universe was 10 years old, the density of radiation was
Definition
much greater than that of matter
Term
If ^o is less than one, then
Definition
the universe will expand forever.
Term
The age of the universe is estimated to be
Definition
greater than the age of the Milky Way Galaxy.
Term
What is the meaning of a "closed" universe?
Definition
The universe will someday stop expanding and begin collapsing inward.
Term
In which of the following models will the universe stop expanding?
Definition
Closed Universe
Term
The concept that the direction of observation does not matter overall is
Definition
Isotropy
Term
In the cosmological principle, we can easily test cosmic homogeneity with the red shift surveys, but isotropy cannot be so tested.
Definition
False
Term
The presently accepted value of the Hubble constant gives an age of
Definition
14 billion years
Term
The discovery of the cosmic microwave background was important because
Definition
it was was experimental verification of a prediction from the BIG BANG theory.
Term
Because almost all galaxies show redshifted spectra, we know that
Definition
the universe is expanding.
Term
What temperature has the BIG BANG cooled to by now?
Definition
Just over 2.7K
Term
The darkness of the night sky in an infinite universe is addressed in
Definition
OLBERS'S PARADOX
Term
The BIG BANG formed
Definition
hydrogen & helium, but nothing else.
Term
It appears that nearly 3 x’s as much dark energy exists in the universe than normal and dark matter combined.
Definition
True
Term
The background hiss that Bell Labs detected was the best observational evidence for the BIG BANG
Definition
True
Term
Deuterium abundance suggests that normal matter makes up only 3-4% of the critical density.
Definition
True
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