The cosmological model that incorporates all of the available data from different measurement techniques, like the CMB, supernovae, baryon acoustic oscillations, etc. is called the _____________ model.
Concordance
someday out sun will explode in a supernova
false
four characteristics of electromagnetic waves are
amplitude, frequency, wavelength, speed
as you move closer to an object
iTS Angular size gets bigger
the reason a good place for telescope is above earth atmosphere is bc theyre closer to the stars
false
in order to get cutting edge scientific results, one of the best place for an optical telescope is
a very dark one
In a Universe with Ω > 1, without the presence of dark energy, the expansion of the Universe would
reverse and then collapse
Which of the following are possible explanations for the dimming of Type Ia supernovae?
the universe is expanding faster with time
true
TRUE
The _____________ ____________ was originally proposed in order keep the Universe static within the theory of general relativity.
cosmological constant
According to the current best measurements, the density of dark energy has been constant over the age of the Universe.
true
at early times in the history of the universe, the matter density dominate over that of radiation
T
The creation of ______________ particles in the vacuum of space is one possible candidate for dark energy.
virtual
F
a steeper slope on a hubble diagram means the expansion rate is lower
F
virtual particles are just like real particles except tht
their energy and lifetime are governed by the uncertainty princlpe and there can be many of them in seemingly empty space
the fact that type la supernovae are dimmer than predicted is strongest evidence for dark energy
T
one of the possible explanation for dark energy is called, proposed that the universe is filled with a dearying and casuing the explanion to speed up
quintessence
stars form when clouds of gas and dust contract due to the force of
gravity
the space shuttle travels at 28000 km/hr. after 4 hrs, how far has it traveled
112000km
if an object in blue shifted, it is moving away from you
false
what is not s unit of measurement for time?
light years
if a telecope is 10 times bigger in diameter it will gather
100 times more light than a smaller telescope
dark energy has been shown to result fromt he so called vacuum energy, the result of the quantrum fluctration of particles in the vacuu
F
if the fraction of dark energy is lwoer, supernovae will look
brighter
in an accelerating universe, the scale factor
grows at an ever increasing rate over time
A ________ is the general name for a particle made of two or three quarks.
hadron
dark energy is just another term for dark matter, but they are the same thing
F
Photons are one example of a:
field boson
The amount of hydrogen, helium, and lithium present in the Universe can be explained by nuclear fusion that took place everywhere in the Universe when it was a few minutes old.
TRUE
Baryon
general name for a particle made of three quarks
Protons are one example of a:
baryon
Inflation is an appealing theory because it explains (check all that apply):
why the Universe is homogeneous and isotropic on large scales
why the geometry of the Universe is flat
Protons were created during:
Quark confinement
Inflation is another word for the Hubble expansion.
FALSE
THE BIG BAND THEORY DESCRIBES HOW THE UNIVERSE CHANGES OVER TIME, BUT NOT WHAT STARTED IT
TRUE
WHICH OF THE FOLLOWING ISOTOPES HAVE A MEASURED PRIMORIDL ABUNDANCE
HELIUM-3, HYDROGEN,LITHIUM, DEUTERIUM, HELIUM-4
SPACE AND TIME WERE CREATED WHEN THE UNIVERSE BEGAN
TRUE
pARTICLE RESPONSIBLE FOR INFLATION IS KNOWN AS
INFLATION
space and time were created when the universe began
tru
by mass, approx. what percent of the atoms in the universe are those heavier than hydrogen
2%
by mass, aprox. what percent of the atoms in the universe are hydrogen?
75%
isotropy
there is no preferred direction in the universe
In the late 18th century, William and Caroline Herschel were the first to determine that Andromeda was a separate galaxy outside the Milky Way.
false
In a ________ structure formation scenario, small structures formed first and stuck together to form bigger structures.
bottom up
size or distance
Size of a galaxy filament:200 million light-years
Size of the local group:15 billion light-years
Size of the disk of our Galaxy:100,000 light-years
Distance to nearest star:4 light-years
Distance to Andromeda galaxy:2.5 million light-years
Galactic __________ are bubble-like areas of space millions of light-years across that do not contain many galaxies.
Galaxies with active regions of star formation tend to be bluer in color.
tru
The force that is primarily responsible for the growth of large-scale structure is:
gravity
What is the temperature of the gas between galaxies in a galaxy cluster?
30-100 million K
From recent galaxy surveys, we have learned that galaxies are distributed evenly around the Universe.
F
With few exceptions, the farthest galaxies from Earth have the largest redshifts.
tru
Reionization was caused by the first stars, not quasars.
tru
Which of the following could be the mass of a galaxy cluster?
10^14 solar masses
Irregular galaxies tend to be bluer than elliptical galaxies because
the blue stars outshine the red and yellow stars
Elliptical galaxies are known for their prominent regions of active star formation.
false
An ellipsoidal cloud of gas is collapsing due to gravity. Along which axis will the cloud of gas collapse first?
the shortest axis
Approximately how many galaxies does our local group contain?
40-50
What do we mean when we say the Universe is expanding?
Galaxies are carried away from each other by the stretching of space.
As the Universe expands, it becomes hotter and more dense.
false
The Universe began with a giant explosion, like a bomb.
false
When we say that the universe is isotropic and homogeneous on large scales, we mean that:
In the figure below, the galaxies obey the Hubble law. Rank the galaxies A, B, and C in terms of their speeds, from slowest to fastest, away from galaxy D.
If the Hubble constant is 70 km/s/Mpc, the age of the Universe will be older than if the Hubble constant is 80 km/s/Mpc.
true
In the figure below, the galaxies obey the Hubble law. Rank the galaxies E, F, and J in terms of their speeds away from galaxy N.
E>F>J
In the figure below, the galaxies obey the Hubble law due to cosmic expansion. What can we say about these galaxies? Select all that apply.
Their relative speeds are proportional to their distances from each other. The galaxies are moving away from each other.
the terms Universe and observable Universe basically mean the same thing.
false
The spectrum of galaxy A and galaxy B both contain the H-alpha emission line, which is normally seen at 653nm. However, in galaxy A the line has an observed wavelength of 710nm, whereas in galaxy B the wavelength is 685nm. Which galaxy is farther away?
galaxy A
Galaxy A has a redshift of 0.1. Since the time that light from Galaxy A was emitted, the Universe has stretched.
true
In general, the farther away a galaxy is from us, the faster it is moving.
true
As the scale factor increases, the physical distance between galaxies ________.
increases
The reason that the Hubble constant, H0, is a “constant” is that it is
Galaxies that emit tremendous amounts of energy are called
active
If the Earth were 5 times more massive, the Sun’s gravitational force on the Earth would be:
Star X is known to be 5 parsecs away from us and star Y is 10 parsecs away. Star __________ has a greater
parallax angle.
x
Using parallax from the ground to determine the distances to stars becomes impossible due to atmospheric
disturbances at a distance of about:
100 parsecs
Stars A and B are Cepheid variables with the same period. Star A is brighter than star B. The distance of star A
is ________ than that of B.
closer
If you wanted to calculate the total mass of a cluster of galaxies, you would want to measure:
The velocity dispersion of the galaxies in the cluster
How is the mass of the Milky Way measured?
By measuring the velocity of the Sun around center of the Galaxy, and using Newton’s law of Gravity to calculate the Milky Way’s mass
True or False? Galaxies are made up mostly of dark matter; the stars and gas that we observe only make up a small fraction of a galaxy’s mass.
true
If the mass of the Sun were evenly distributed out to the radius of Jupiter’s orbit, the Earth’s orbital velocity would be:
slower than it is with the Sun’s mass concentrated at the center of the Solar System
If the mass of the Sun were evenly distributed out to the radius of Jupiter’s orbit, then Neptune’s orbital velocity would be:
the same
We know that dark matter must exist in galaxies. If not, many of the stars in a galaxy would:
Fly away from the galaxy because the stars’ velocities are so large, and the galaxy would not have enough gravity to hold onto them
True or False? There is a lot of dark matter between the galaxies in a galaxy cluster, as well as within the galaxies in a galaxy cluster.
true
A rotation curve is a graph in which radius is plotted on the x axis, and ____________ is plotted on the y axis.
velocity
True or False? The planets in the outer Solar System have bigger (faster) velocities as they orbit the Sun than the planets in the inner Solar System.
false
Astronomers have now given the name ________ matter to the mass in galaxies and galaxy clusters that does not emit or absorb electromagnetic radiation.
dark
The term __________ refers to massive compact objects, such as faint white dwarfs, neutron stars, black holes, and brown dwarfs, that make up some of the dark matter in the Galaxy.
macho
Supernova A is farther away than supernova B. The brightness of supernova A will be ________ than that of
supernova B.
dimmer
1 parsec is approximately ________ light-years.
3.3
In astronomy, when measuring the apparent shift in position of nearby stars against the distant background
stars, the measurements are taken when the Earth is on opposite sides of the ________.
sun
Stars A and B both have the same spectral class. Star A is 7 times farther away than star B. The brightness of
star A will be ________ times dimmer than B.
49
The apparent shift in position of an object relative to background objects is called:
Parallax
true
Supernova C is 10 times farther away than supernova D. The brightness of supernova C will be ________ times
dimmer than that of supernova D.
100
If a constant force is applied to an object, then it will:
Move with a constant acceleration
The Sun exerts a gravitational force on all the other stars in the Milky Way Galaxy.
true
If the Sun were 5 times farther away from Earth, its gravitational force on the Earth would be:
25 times smaller
The Sun exerts a larger gravitational force on the Earth than the Earth exerts on the Sun.
false
a spherically shaped, tightly gravitational bound, group of thousands of mostly older stars is called
a globular cluster
If a wave’s amplitude increases then its frequency will
not change
When an electron drops from a higher to a lower state, a/an ____________ spectrum is seen.
emission
The method by which light is spread into different colors is called:
Spectroscopy
From the lists below, choose the one that best ranks the following astronomical objects from smallest to largest:
Earth, Solar System, Galaxy, Universe
The four terrestrial planets are:
mercury, venus, earth, mars
Our best satellites orbit above the disk of the Milky Way
false
Approximately how far is it to the nearest galaxies?
millions of years
If no outside forces act on it, an electron that is in an excited energy state will
Move to a lower-energy state
A spectrograph is an instrument that is used to
Obtain a spectrum from a light source
The four fundamental forces are:
electromagnetic, strong nuclear, weak nuclear, and gravity
The eight major planets of our Solar System, in order of distance from the Sun (closest to
mercury, venus, earth, mars, junpiter, saturn, uranus, nepture
an atom’s mass number indiciates
the number protrons and neutron it has
the number of stars in milky way is
hundred of billion of stars
the farthest that human beings have themselves physically traveled is to the moon
true
Our Local Group is a collection of
galaxies
the milky way is what kind of galaxy
spiral
An atom that has lost electrons is called a/an
ion
The four gas giant planets are
Jupiter, Saturn, Uranus and Neptune
protons and neutrons are made up of
quark
The height of a wave’s crest is its
amplitude
The temperature of a red star is ___________ than the temperature of a blue star.
cooler
The dual nature of light means that it is both a wave and a/an _________.
particle
Radio stations broadcast using
light waves
True or false? Radio waves are a type of light.
true
The lowest possible energy state for an electron is called:
the ground state
True or false? The more energy a photon has, the faster it will travel.
false
Absorption lines in a spectrum generally indicate that
Light has been absorbed at specific wavelengths
what is photon
A particle of light
The molecular make-up of a gaseous nebula in space can be determined through spectroscopy.
true
If a wave’s wavelength increases then its frequency will
decrease
Between red, blue, yellow, and green light, which moves fastest in empty space?
They move at the same speed
If the frequency of a photon increases, then its energy will _________.
increase
astronomical objects smallest to largest
pluto, earth, jupiter, sun, solar system, globular cluster, milky way
what color flame is the hottest?
blue
the distance between two adjacent peaks (or troughs) of wave is known as its
wavelength
the wavelength of an infrared photon is _____ than the wavelength of a yellow photon
longer
emission lines in spectrum generally indicate that
the source is only emitting light at specific wavelengths
the smaller the impact parameter
the bigger the angle of deflection
if a gravitationally lensed image is far from the Einstein radius and the distortions are exceptionally small
weak lensing
the greater the distance to the source, the greater the size of the einstein radius
false
weak lensing
seeing lensing effect statistically with many galaxies
strong lensing
see pronounced distortion in images
microlensing
see magnification only of source
cmb data can be used to measure the overall curvature
f
What was the temperature of the universe at the red shift of 3
10.9K
If the overall curvature of the universe is hyperbolic, typical spot sizes in a map of the cmb will appear
Smaller than for a flat universe
Cmb is comi from all directions
T
The temp of the universe was
Hotter at a redshift of 3 compared to 2
If the overall curvature of the universe is spherical, the cmb power spectrum will peak at
Smaller values of I than for a flat
How many times hotter was the temp of the universe of the universe at a redshift of 20 than it is today
21
According to measurements of the cmb, the geometry test f the universe as a whole was
Flat
About how much difference in magnitude is the temp of a red spot compared toa blue spot on a map of the cmb as observed by wmap
1 part per ten thousand
At earlier times in the history of the Universe, the matter density dominated over that of dark energy.
false
The discovery of the dark energy was a surprise because astrophysicists generally assumed that the expansion would be slowing down.
true
Our solar system formed from an interstellar cloud of gas and dust.
T
An exploding star is known as a/an
supernova
Based on current observations, the age of the universe is about
14 billion years
After approximately 1 minute after the beginning of the Universe, the temperature of the Universe cooled enough so that which of the following could take place:
Nuclear Fusion
A star begins to die when the ________ pressure pushing inward overcomes the thermal pressure pushing outward.
gravitational
The current leading scientific theory for the evolution of the Universe is called the ________.
big bang theory
luminosity is measured in what type of units
watts
Stars that are less massive will live ________ lifetimes compared to our Sun.
longer
The more massive a star, the longer its lifetime.
F
As gas and dust collapse under gravitational forces, it is not until _______ occurs that a star is formed.
Nuclear fusion
The greater the luminosity of a star, the ________ its lifetime will be.
shorter
Stable atoms are most likely to become radioactive.
F
Relatively flat, round objects that occur when matter is being transferred onto an object, such as when stars are forming, are called ________.
accretion disk
The greater the luminosity of a star, the ________ its lifetime will be.
shorter
Before becoming a white dwarf, low mass stars will expel their outer layers of gas, creating a:
planetary nebula
A neutron star is created after a massive star undergoes:
a supernova
The heaviest element created by nuclear fusion inside a star is:
iron
Using the H-R Diagram, the majority of stars are:
main sequence stars
The Cosmic Microwave Background formed after about how many years after the beginning of the Universe?
380,000 years
The amount of time it takes the Earth to complete one rotation about its axis is ________.
24 hrs
Velocity is defined as:
Speed in a particular direction
When you look at galaxy that is 1 million light-years away it means that:
You are seeing the galaxy as it was 1 million years ago
If you travel at half of the speed of light to a star that is 4 light-years away, you will get there in 2 years.
F
When you look at distant astronomical objects you are also looking far back in ________.
time
The greater an object’s Doppler shift, the ________ it is moving.
faster
A light-year is a measurement of time.
F
Acceleration is a change in velocity.
t
If an object is red-shifted, it is moving ________ you.
away
If an object is blue-shifted, it is moving away from you.
F
If you measure the Doppler shift of an object, then you can calculate its velocity.
t
Our Galaxy is about 100,000 light-years across. If you could travel at the speed of light, how much time would it take you to go across our Galaxy? ________
100,000 years
Star X is known to be 5 parsecs away from us and star Y is 10 parsecs away. Star __________ has a greater parallax angle.
X
Using parallax from the ground to determine the distances to stars becomes impossible due to atmospheric disturbances at a distance of about:
100 parsecs
Supernova C is 10 times farther away than supernova D. The brightness of supernova C will be ________ times dimmer than that of supernova D. (Give a number.)
100
The earliest known culture to measure the size of the Earth and Moon, as well as the distance between them, by using geometry are the:
greeks
Stars A and B are Cepheid variables with the same period. Star A is brighter than star B. The distance of star A is ________ than that of B.
closer
In astronomy, when measuring the apparent shift in position of nearby stars against the distant background stars, the measurements are taken when the Earth is on opposite sides of the ________.
sun
Stars A and B both have the same spectral class. Star A is 7 times farther away than star B. The brightness of star A will be ________ times dimmer than B. (Give a number.)
49
Eratosthenes was the first to determine the size of the Earth by using geometry and the lengths of shadows.
T
An object’s absolute or intrinsic brightness is known as its:
luminosity
Supernova A is farther away than supernova B. The brightness of supernova A will be ________ than that of supernova B.
dimmer
The Tully-Fisher method is best used on what type of objects?
galaxies
Supernova C is 10 times farther away than supernova D. The brightness of supernova C will be ________ times dimmer than that of supernova D. (Give a number.)
100
The inverse square law can be used to find the distance to an object if the object’s flux and ________ are known.
luminosity
If a constant force is applied to an object, then it will:
True or False? The Sun exerts a gravitational force on all the other stars in the Milky Way Galaxy.
t
If the Sun were 5 times more massive, its gravitational force on the Earth would be:
True or False? The Sun exerts a larger gravitational force on the Earth than the Earth exerts on the Sun.
f
According to Newton’s Second Law of Motion, an object that is being pushed or pulled by a force has an acceleration that is ____________ proportional to its mass.
inversely
the most general definition of the word evolution is
change over time
if the mass of a black hole is 5 times bigger, its lifetime will be
125 times bigger
a black hole with a mass of millions or billions of solar masses is known as
supermassive
as the accretion rate of a black hole increases, its luminosity
increases
True or False? Every point on a solid, spinning wheel is moving with the same velocity because each point goes around a circle in the same amount of time.
false
True or False? Galaxies are made up mostly of dark matter; the stars and gas that we observe only make up a small fraction of a galaxy’s mass.
true
If the mass of the Sun were evenly distributed out to the radius of Jupiter’s orbit, the Earth’s orbital velocity would be:
slower than it is with the Sun’s mass concentrated at the center of the Solar System
True or False? Dark matter is mostly made up of the remnants of dead stars, like black holes, neutron stars, and faint white dwarfs.
false
True or False? Every point on a solid, spinning wheel is moving with the same velocity because each point goes around a circle in the same amount of time.
false
Moving clocks tick ________ than clocks at rest.
slower
Energetic particles that move at extremely high speeds, close to the speed of light, and can be detected entering our atmosphere from space are called ________ ________.
cosmic rays
Observers in reference frames with constant velocity find that the laws of the physics are:
the same for all observers
Using E = mc2, one kilogram of feathers will produce less energy than one kilogram of bricks.
false
The speed of light is:
The same for all observers.
A particle moving at the speed of light makes what degree of an angle with the t and x axes in a spacetime diagram?
45 degree
The amount of energy contained in the mass of a particle observed to be at rest is known as its:
rest energy
________ are particles with half-lives of 2.2 microseconds. The fact that we see many more than expected reach the surface of the Earth means they are good evidence for special relativity.
muons
The length of time it takes for one tick on a moving clock is always greater than the length of time it takes for one tick on a clock at rest. This effect is called:
time dilation
If you observe two events that occur simultaneously then all other observers will see them occurring at the same time.
false
According to the definition of curvature in this chapter, a cylinder is curved.
false
If a white dwarf and a neutron star have the same mass, but the radius of a white dwarf is much larger than that of the neutron star, which will produce the greatest gravitational redshift?
neutron star
Clocks in a stronger gravitational field will tick ___________ than clocks in a weaker gravitational field.
slower
According to the definition of curvature in this chapter, a sphere is curved.
true
If you have a clock in a satellite orbiting the Earth, how does its rate compare to that of an identical clock on the Earth’s surface?
it runs faster
if a white dwarf and a neutron star have the same mass, but the radius of a white dwarf is 700 times larger than that of the neutron star, what is the approximate ratio between their gravitational redshifts? Hint: Compare GM/Rc2.
The gravitational redshift of the white dwarf is about 700 times smaller than that of the neutron star
If an object or frame is changing velocity, it is ______________.
accelerating
A gamma ray is emitted from a source at the top of a 20 m tall tower and travels to a detector on the ground. How does the energy of the gamma ray change?
It gains energy
A visible light photon is emitted from a source at the top of a 20 m tall tower and travels to a detector on the ground. How does the color of the photon change?
it gets bluer
Using the definition of curvature in this chapter, which of the following geometric objects are curved?
sphere
The Einstein equation says that spacetime curvature arises from the 4-dimensional distribution of ______________and _____________.
mass
energy
Black holes are shaped like funnels.
f
If the mass of a black hole is 5 times bigger, its thermal luminosity will be:
25 times smaller
black hole suck matter into themselves from far away, like cosmic vacuum cleaners
f
the fact that black holes are not perfectly spherical, but are oblate spheroids like earth and sun, is a result from which physical property
spin
As the mass of a black hole increases, the time for it to evaporate __________.
increases
a black hole with a larger mass will have a
smaller thermal luminosity
The more _____ a gravitational lens has, the stronger the lensing effect will be.
mass
The smaller the mass, the ________ the angle of deflection.
smaller
The smaller the distance to the source, the __________ the size of the Einstein radius.
bigger
The greater the impact parameter, the __________ the angle of deflection.
smaller
Match the type of gravitational lens with the type image it can create.
Spherical:Einstein ring
Elliptical:Einstein cross
Clumpy:Many arcs
Match the type of lensing with one of its applications.
Weak lensing:Determine mass distribution of a cluster of galaxies
Strong lensing:Determine large scale distribution of matter in the Universe
Microlensing:Determine amount of dark matter in the halo of our Galaxy
The more _____ a gravitational lens has, the stronger the lensing effect will be.
mass
If the mass of a point-source gravitational lens is 25 times bigger, the size of the Einstein ring will be:
5 times bigger
If the mass of a point-source gravitational lens is 25 times smaller, the size of the Einstein ring will be:
5 times smaller
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