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CHAPTER27

Matias Gray avatar Matias Gray
24 July 2022
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question
rank the phases in the history of cosmic evolution from earliest to most recent.
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particulate galactic stellar planetary chemical biological cultural
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from the descriptions and the working definition of life, determine which things do and do not exhibit these characteristics.
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exhibits the four characteristics: -dogs -trees does not exhibit: -rocks -stars -viruses
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which part of the figure shows an example of matter/antimatter annihilation?
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only figure A
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which part of the figure shows an example of energy conservation?
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both A and B
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suppose that, rather than starting with an electron and a positron, the event shown in figure A started with two electrons. what would happen?
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move away from each other w/out meeting
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immediately after its birth, the universe:
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was dominated by photons
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listed following are events that occurred either before or after the first five minutes in the history of the universe. match these events to the appropriate time period.
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w/in the first 5 minutes: -antielectrons (positrons) as common as electrons -temperature fell to 10^15 K -strong force and electroweak force first became distinct -inflation occurred sometime after the first 5 minutes: -galaxies formed -stars formed -photons of cosmic microwave background releases -carbon nuclei formed by fusion
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present-day grand unified theories unite all of the fundamental forces except:
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the gravitational force
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about half a million years after the big bang, the universe had cooled to the point that:
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protons and electrons could combine to form atoms.
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classify the given types of matter as either baryonic (meaning ordinary matter that contains protons and neutrons) or as nonbaryonic (meaning "extraordinary" matter that consists of more exotic subatomic particles). drag the appropriate items to their respective bins.
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baryonic matter: -matter in our bodies -matter in stars -matter in brown dwarfs -dark matter consisting of jupiter-sized objects in galactic halos nonbaryonic matter: -dark matter consisting of weakly interacting subatomic particles -matter that probably makes up the majority of dark matter
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elements more massive than lithium were not formed in the early universe because the temperature was:
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too low.
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at what wavelength did the background radiation peak at the start of the epoch of multi nucleosynthesis?
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3 x 10^-9 mm
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in what part of the electromagnetic spectrum does this wavelength lie?
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gamma rays o hard x-rays
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during the history of the universe, what important event occurred about 0.001 seconds after the big bang?
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most matter was annihilated by antimatter.
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which of the following important events occurred earliest in the history of the universe?
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space-time rapidly expanded during a brief period of inflation.
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during the history of the universe, what important event occurred about 380,000 years after the big bang?
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light began to travel freely through the universe.
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essentially all the hydrogen nuclei that will ever exist in our universe were created _______________.
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by the time the universe was about 3 minutes old
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compared to when the cosmic microwave background was first released, the radiation of the cosmic microwave background today is ______________
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fainter and has most of its photons at longer wavelengths
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a __________________ predicts that the strong, weak, and electromagnetic forces should become indistinguishable at high temperatures.
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grand unified theory
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the ________________ is a single force that unifies the electromagnetic and weak forces.
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electroweak force
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_________________ was a dramatic expansion of the universe thought to have occurred when the universe was only a tiny fraction of a second old.
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inflation
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______________ forces us to think about why the sky is dark at night.
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olber's paradox
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observations of the ___________________ provide a way to test our theory of the big bang.
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cosmic microwave background
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when a particle of ordinary matter meets its precise opposite particle of antimatter, the result is ______________ with complete conversion of mass into energy.
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annihilation
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one of the problems with the standard big bang model is that:
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the temperature is almost exactly the same everywhere.
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the horizon problem in the standard big bang model is solved by having the universe:
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inflate rapidly early in its existence.
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the structure we observe in the universe is the result of:
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dark matter clumping long ago
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matter and energy clumping in the early universe result in:
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small but observable red shifts.
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according to our best estimates, the line that best describes the universe in figure 27.10 is:
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accelerating
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it is likely that the density of the universe is made up mostly of:
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dark energy
question
if those blobs represent clumps of matter around the time of decoupling (redshift = 1100), estimate the diameter of the clumps at the time of decoupling, assuming euclidean geometry.
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78 kpc