Test

Silent Steve · 11-02-2006, 05:03 PM

which of the following is not a piece of evidence in favor of the big bang theory

A the discovery of heavier elements in the oldest stars

B the background radiation

C the abundance of helium in the universe

D the expansion of the galaxies

according to the big bang theory, the first eddies to separate out eventually formed

A individual stars

B clusters of stars

C individual galaxies

D clusters of galaxies

which observed property of the 3 k background radiation implies most strongly that it has a cosmic origin?

A the shape of its spectrum (thermal).

B its present temperature (3 k).

C uniform intensity from all directions (isotropic).

D peak intensity in the millimeter part of the spectrum.

the background radiation comes from

A the combined radiation of all the distant galaxies

B clouds of hot material in clusters of galaxies

C the time when radiation and gas decoupled in the early universe

D the time when the universe was only a few seconds old

when we observe distant galaxies we are observing

A very young objects

B very old objects

C objects having the approximate age of the milky way

D distant galaxies; no statement may be made about age

the reason for the expansion of the universe is explained by

A the big bang theory

B the steady state theory

C theory of relativity

D Hubble's law

the existence of the cosmic background radiation implies that

A the big bang model is wrong.

B the universe began in a hot, dense state.

C the universe did not have a moment of creation.

D the universe began in a cold, low-density state.

after decoupling, the universe was:

A transparent to radiation.

B opaque to radiation.

C finally at densities such that stars could form.

D conducive to the production of elements heavier than iron.

according to the big bang theory, the observable universe began about

A 4047 B.C.

B 10 million years ago

C 18 billion years ago

D an infinite length of time ago.

the decelerating agent in the closed universe theory is

A gravity

B collisions

C time

D space itself

if the big-bang cosmology is correct

A the most distant galaxies we observe are now seen as they will be in the future

B nearby galaxies are seen at a more advanced stage of evolution than distant galaxies

C matter is being continually created

D the universe is not really expanding

the size of the observed universe is

A definitely finite

B infinite

C may be either finite or infinite

D is not defined

at the instant of the big bang there should also have been produced, in addition to an expanding universe,

A a flash of light

B galaxies

C life

D new forms of matter and energy

according to the big bang theory, the most distant galaxies, as seen by us, are

A closer together than nearby ones

B farther apart than nearby ones

C hotter than nearby ones

D smaller

according to the big bang theory, galaxies formed

A during the original explosion

B before the explosion

C after the explosion in the expanding cloud of gas

D only very recently after the expansion slowed down

the density of observable matter in the universe indicates that the universe is

A open

B closed

C flat

D static

the oscillating big bang theory would be favored, compared to the single big bang theory, if

A the explosion was found to be relatively weak

B another fundamental force was discovered

C the mass of the universe was sufficiently great

D Einstein's theory of relativity was found to be correct

just after the big bang the observable universe was

A condensed into a single, small object

B composed of sub-atomic particles

C under immense forces of pressure and gravity

D all of the above

the expansion of the universe is

A a steady process with no identifiable events

B a jumpy process that is completely unpredictable

C no longer occurring today

D a steady process occasionally punctuated by abrupt transitions

the expansion of the universe, away from the Earth, is

A predicted by the big bang theory

B observed

C consistent with our view of the Earth's position in the universe

D all of these

a big bang universe with less mass than required for an eventual contraction of the universe would

A be totally different than the observable universe in both content and extent

B be far smaller than the observed universe

C eventually die in the sense that all objects would be far removed from all other objects

D undergo a sequence of many big bang explosions

which of the following is true of the relative abundances of hydrogen and helium observed in the universe now?

A the hydrogen was formed in the first few minutes and the helium was formed in stars after they formed.

B all of the hydrogen and helium were formed in the first few minutes after the big bang.

C the hydrogen was formed after decoupling occurred, but helium was formed much later in stars.

D most of the hydrogen and a small amount of the helium were formed long after decoupling.

a universe with a positive curvature is

A closed

B open

C static

D flat

which of the following describes a "flat" universe?

A a universe that will expand to an infinite size and stop.

B a universe that will continue to expand forever.

C a universe for which the expansion will stop and reverse.

D a universe that can be described with Euclidian geometry.

if the average density of the universe is less than the critical density, the universe

A will expand forever.

B will eventually collapse.

C was produced in a big bang.

D is a steady state universe.

E violates the laws of energy conservation.

after the time when radiation became decoupled from matter(about a million years after the start of the explosion), what could take place that could not happen before this time?

A light elements could be produced.

B heavy elements could be produced in abundance.

C elementary particles could be produced in abundance.

D gravity could gather matter into clumps with masses about that of galaxies.

E stars and planets could form in great number.

if the universe were ever a uniform cloud

A stars would probably never be very common

B the cloud would remain in uniform motion forever

C local condensations would form easily within the cloud

D stars, by definition, would already exist

if the big bang theory is correct, our observable universe is

A infinite and unbounded

B infinite and bounded

C finite and unbounded

D finite and bounded

a better knowledge of which of the following would most aid us in determining whether the universe is open or closed?

A the age of the Earth.

B the age of the solar system.

C the size of the galaxy.

D the average density of the universe.

E all of the above would help about equally.

which of the following do not constitute a part of the observational evidence supporting the big bang theory of the universe?

A Hubble's law.

B the 3k microwave background radiation.

C the chemical abundances in the universe.

D all of the above support the big bang theory of the universe.

the most common view of the universe among astronomers is that we live in

A an infinite universe

B a finite but unbounded universe

C a finite and bounded universe

D no choice

according to the big bang model

A all matter expanded from a point.

B radiation fills the universe.

C matter formed from radiation.

D all of the above.

the 3k microwave background radiation:

A is the one bit of evidence that seems to contradict the big bang theory.

B is about what was predicted as the residual thermal radiation from the big bang.

C was a complete surprise and still cannot be explained.

D is apparently the "whimper" from the onset of galaxy formation.

separation of the unified superforce into gravitational, electromagnetic, and nuclear forces:

A released enormous amounts of energy that fueled early universe inflation.

B caused the immediate formation of hydrogen and helium.

C caused the neutrons to decay into protons, electrons, and antineutrinos.

D broke the early universe into fragments which later formed galaxies.

at the time of the big bang explosion

A the universe was definitely a black hole

B remnants of previously existing intelligent life could have survived

C all the observable matter and energy of the universe was concentrated in a small volume

D all of the above

according to the big bang theory, an oscillating universe would result if

A the original velocity of expansion was low

B the original mass of the universe was low

C the original mass of the universe was high

D external forces act on the universe

according to the big bang theory about how old is the universe?

A about 100 million years.

B about 13 billion years.

C about 500 billion years.

D the big bang theory does not predict the age of the universe.

according to the big bang theory, the age of the universe is about

A 20,000 years

B 20 million years

C 20 billion years

D 20 trillion years

which of the following must be explained by the hot big bang model?

A expansion of the universe

B thermal history of the universe

C formation of galaxies

D grouping of matter in clusters and superclusters

E all of the above

which of the following forces may halt the expansion of the universe?

A nuclear forces.

B electrical forces.

C gravitational force.

an important tested prediction of the big bang theory is

A matter is continuously created

B the universe is expanding

C the universe is mostly hydrogen and helium

D gravity will cause the universe to collapse again

which of the following was not produced in significant quantities during the big bang

A helium

B carbon

C hydrogen

D light

the universe is said to be closed if

A gravity is strong enough to stop the expansion in a finite time.

B the density is greater than the critical density.

C it is finite.

D all of these.

the scientific study of cosmology assumes that

A light can travel infinite distances

B space travel to other galaxies will eventually be possible

C the laws of nature discovered on the Earth must apply throughout the universe

D giant galaxies all have the same actual brightness

the discovery of the cosmic microwave background radiation supports the standard big bang model because it implies

A a hot state in the past.

B an isotropic universe.

C a homogeneous universe.

D all of these.

E none of these.

if the universe is observed to be expanding, then it must

A have exploded at some definite time in the past

B have definite, observable boundaries

C have a definite center

D none of these

according to the big bang theory which of the following objects began to condense last

A clusters of galaxies

B clusters of stars

C stars

D galaxies

as matter left the big bang, which element was formed in the greatest abundance

A hydrogen

B carbon

C iron

D uranium

a finite universe must

A have observable boundaries

B be a black hole

C be impossible

D have a definite volume

according to the standard big-bang model, what elements are synthesized in the big-band itself?

A hydrogen only.

B helium only.

C hydrogen through lithium.

D all elements up to iron.

E all elements up to uranium.

a circle drawn to represent the "size" of a big bang universe represents

A the critical radius of a black hole universe

B the maximum extent of the known galaxies

C the maximum distance light could travel since the big bang

D a completely arbitrary boundary

an argument in support of the big bang theory is that

A the universe is so large

B the background radiation has been detected

C heavy elements do exist

D the universe is so young

a background radiation was first predicted by

A the big bang theory

B steady state theory

C Einstein's theory

D electromagnetic theory

which of the following was not created in the big bang

A hydrogen

B helium

C light

D carbon

from outside, the primeval fireball would have looked small, hot, and dens

A correct

B wrong: it would have looked large, hot, and dense

C wrong: it would have looked large, cool, and dense

D misleading: the fireball filled all space, and could not be viewed from "outside"

if the universe has an open geometry, it will

A expand forever, more and more slowly.

B stop expanding in the future and stay that size always.

C stop expanding in the future and then contract.

D expand forever, faster and faster

the background radiation is believed to be

A the combined light from distant stars

B the combined light from distant galaxies

C light from the time when atoms became neutral

D the red shifted radiation from quasars

if the age of the universe were finite, then

A light from distant stars might not be here yet

B quasars would not exist

C the speed of light would have to be infinite

D the number of stars in the universe would have to be finite

it is impossible for an object to cross the edge of a big bang universe because

A gravity would pull it back

B its average speed since the big bang would have to be greater than the speed of light

C the chances of it escaping without colliding with something are very small

D not enough time exists

the "objects" which existed at the big bang explosion were

A similar to stars and galaxies

B quasars

C individual atoms

D tiny fragments of atoms unknown on the Earth

which of the following is not important to modern cosmology?

A everything appears to revolve around the Earth.

B lines in the spectra of distant galaxies are red-shifted.

C we detect an isotropic microwave radiation which appears to be cosmic in origin.

D there is a particular ratio of hydrogen and helium abundances in very old celestial objects.

in the expansion of the universe,

A the galaxies are not expanding into empty space

B all distances in the universe are increasing

C the universe must eventually heat up again

D helium is transformed into hydrogen due to the decrease in temperature

if the big bang theory is correct, the explosion must have occurred

A about one billion years ago

B about 15 billion years ago

C more than a trillion years ago

D an infinite length of time in the past

conditions before the big bang

A can be discovered by studying the chemical composition of the universe

B can be discovered by studying quasars

C are described by a generalized version of Hubble's law

D can never be known because of the complete destruction that took place

for any type of universe the age is less than the Hubble time because:

A observations simply do not provide enough evidence for seeing far enough back in time.

B geometry works that way.

C our part of the universe is not near the site of the big bang.

D gravitational attraction of galaxies for each other has slowed the expansion.

nearly all of the elements heavier than hydrogen and helium were formed:

A during the first few minutes after the big bang.

B immediately after decoupling.

C after about 100 thousand years.

D only after stars formed.

according to the big bang theory of the universe, the universe will collapse in on itself if

A the current density of the universe is large enough

B the current rate of expansion is slow enough

C space is not curved too much

D all matter is in the form of galaxies or quasars

the existence of an intergalactic medium would favor

A the open big bang theory

B the oscillating universe theory

C the steady state theory

D the black hole theory

which of these is observed about the cosmic background microwave radiation?

A it has a thermal spectrum.

B it varies in intensity in different directions in space.

C it has a temperature of about 3 k now.

D (a) and (b).

E (a) and (c).

according to the big bang theory, clusters of galaxies

A cannot occur

B can be formed only much later after all other processes are complete

C occur naturally in the theory

D are formed before the big bang

which of these is not a basic assumption of cosmology?

A expansion of the universe.

B universality of physical laws.

C homogeneity of the universe.

D isotropy of the universe.

evidence now available points to which kind of universe?

A open.

B flat.

C closed.

D Euclidian.

if h is larger at great distances, then

A the universe must be older than we suspect.

B the matter in the universe is not important to its motion.

C the expansion is slowing.

D all of these.

the background radiation is believed to be

A light emitted by nuclear reactions in the early universe

B the combined light from distant galaxies

C the light in the universe at the time when matter became neutral

D the red shifted radiation from quasars

the conclusion that the universe is expanding can be deduced from

A the existence of galaxies

B the red shift of star light from almost all stars

C the big bang theory

D nothing, it is an assumption

in addition to the expansion of the universe, the big bang explosion must have created

A quasars

B time

C a flash of light which still fills the universe

D a brief flash of light that has long since disappeared

what evidence indicates that an explosion took place at the beginning of the universe?

A the density of matter in the universe.

B low intensity radiation from all directions.

C the big bang theory.

D the steady state theory.

E the existence of supernovae.

if our universe is a big bang universe, the existence of other big bang universes is

A ruled out by observations

B possible but not indicated by observations

C impossible

D definitely observable

since the time of decoupling, one million years after the big bang, matter has ______ and light has ______.

A clumped, blue shifted

B clumped, red shifted

C smoothed out, blue shifted

D smoothed out, red shifted

E cooled off, heated up

if our universe is a big bang universe, the amount of matter in the universe must be

A variable depending upon the age of the universe

B indeterminate

C infinite

D finite

the cosmic background radiation is

A the flux of cosmic ray particles always falling upon the Earth's surface f every direction in space

B the radio noise generated by Earth-bound transmitters, spreading out into space (since about 1920)

C low intensity radio noise, spread throughout all space, originating in the original explosion of the universe, and having a spectrum similar to that of a 3 k black body

D the flux of visible radiation contributed to empty space by all visible stars in the universe

according to the standard big bang model, the abundance of helium in the universe now

A can be any percentage of the total.

B cannot amount to less than 25 to 30 percent by mass.

C must be less than 25 to 30 percent by mass.

D is mainly made in stars.

to say that the early universe was causally connected implies:

A that early events caused subsequent events in a continuing string.

B that causality requirements prevent us from telling what happened during the first 10-43 seconds.

C that the relative abundances of hydrogen and helium in the early universe can account for current chemical abundances.

D that light travel time was such that all parts of the early universe were at the same temperature and all of the universe has the same origin.

immediately after the big bang explosion the matter began to

A condense into stars and galaxies

B cool

C be created

D move faster than the speed of light

in the universe as a whole, the effect of gravity is

A to try to pull everything together

B to try to push everything apart

C so random that no net effect is present

D negligible because of the immense distances involved.

knowledge of the state of the universe before the big bang is impossible because

A everything was antimatter then

B all elements and structures were destroyed during the big bang

C nothing existed before the big bang

D relative to us, everything before the big bang was moving faster than the speed of light

knowledge of the nature of the universe before the big bang is impossible to obtain because

A nothing existed before the big bang

B all objects which existed before the big bang are now outside our observable universe

C all ordinary elements and particles were destroyed during the big bang

D too much time has passed since the big bang

the inflationary model copes with the horizon problem by

A asserting that the universe foes not have a horizon.

B a short period of rapid expansion in the cosmos' size.

C keeping all regions of the universe separated completely.

D allowing the universe to expand faster and faster.

the fact that a residual temperature of 3k is observed in all directions implies an early universe that had a very high temperature and that:

A the radiation is all thermal.

B the universe is now infinitely large.

C all parts of the universe had a common origin.

D our knowledge of what went on in the early universe is severely limited.

suppose we lived in a time when the universe was contracting. we would observe

A that as we looked out in space we were looking forward in time

B new galaxies continuously appearing

C the greater the distance of a galaxy the greater its blue shift

D all of the above

the apparent expansion of the universe is or was caused by

A a universal repulsive force, stronger than the gravitational attraction between matter in the universe

B the centrifugal force upon all matter in the universe, caused by motion around its center

C a single, very large explosion at the beginning of the universe

D our point of view, with the expansion being a projection effect resulting from the Earth's motion in the galaxy

the temperature of the microwave background radiation has been determined from the

A strength of its emission lines

B strength of its absorption lines

C short wave length of its emission maximum

D long wavelength of its emission maximum

the first local condensations to form in the universe eventually became

A stars

B clusters of galaxies

C galaxies

D planets

the Hubble law graph early in the history of the universe, compared to current observations, would have been

A exactly the same

B a totally different sort of relation

C much steeper

D less steep

which of the following is not a basic assumption of the big bang model?

A the universe is infinite.

B physical laws are the same everywhere.

C the universe is isotropic.

D the universe is homogeneous.

if the mass of the universe is smaller than a critical value, it would be

A open

B closed

C steady state

D oscillating

which of the following cosmological theories is correct

A big bang

B oscillation

C steady state

D the answer is unknown but possibly none of the above

which of the following is an observed property of the microwave background radiation?

A it comes from the direction of the Andromeda galaxy.

B it's spectrum contains many absorption lines.

C it is Doppler-shifted towards shorter wavelengths.

D its spectrum matches that for a black body at a temperature of 2.7 k.

the 3 degree background radiation is direct evidence that

A the Earth formed 4.6 billion years ago.

B galaxies formed 10 billion years ago.

C the big bang took place.

D cleaning pigeon droppings from your radio telescope can earn you a Nobel prize.

when George Gamow developed his theory of element production he found that theoretically there was a block to building elements at masses of 5 and 8.the block was caused by:

A a lack of theoretical background.

B a misunderstanding of the details of pair production.

C the very rapid expansion of the early universe.

D the short half-life of elements with masses at 5 and 8.

in a single big bang universe, the Hubble law graph would curve upward because

A distant objects were closer together

B the expansion of the universe is rapidly slowing down

C the velocity of expansion of the galaxies is increasing

D of observational errors

which of these is not an observation with cosmological import?

A red shifts of galaxies.

B cosmic microwave background radiation.

C abundance of deuterium in the interstellar medium.

D abundance of helium in the oldest stars.

E red shifts of stars in the milky way galaxy.

what do most astronomers think about the evolution of the universe?

A the universe has always been like it is now with no beginning or end.

B it doesn't make sense to talk about the evolution of the universe.

C the universe was created at 6:00 p.m. (Jerusalem time) on Wednesday, march 22, 4001 B.C.

D the universe stared about 15 billion years ago with a "big bang."

the idea of a finite but unbounded universe implies that

A no physical object can experience a boundary to the universe

B a boundary exists only when an abstract mathematical four dimensional geometry is envisaged

C any physical boundary is moving away from any other physical object at the speed of light

D all of these

an observation in support of the big bang theory is

A the background radiation

B the expansion of the universe

C the existence of galaxies

D the existence of life

the cosmic background radiation is

A caused by cosmic nucleosynthesis

B the remnant of the big bang radiation field

C what remains of neutron decay

D generated by the decoupling of radiation and matter

strong evidence for a big bang theory is the observation of

A quasars

B black holes

C Hubble's law

D the helium abundance of the universe

in the standard big-bang model, the formation of galaxies faces the problem that

A stars must form first.

B not enough matter exists in the universe.

C the abundances of elements is not correct.

D angular momentum must be conserved.

E galaxies should form very, very slowly.

what is the "cosmological principle" which is assumed by all cosmologies?

A the universe looks essentially the same from any point in space.

B the universe looks essential they same from any point in time.

C all galaxies are about the same as the milky way galaxy.

D both (a) and (b) above.

E both (b) and (c) above.

which of the following is not a basic assumption made in modern cosmology?

A the law of gravity works the same way in distant galaxies as on Earth

B both matter and radiation are spread out uniformly throughout the universe

C the universe looks the same in all directions from Earth

D the universe is infinite in extent

to determine the deceleration of the universe requires

A observing very faint galaxies

B observing very bright galaxies

C observing nearby galaxies

D observing the microwave background radiation

the cosmic background radiation is

A the faint glow along the ecliptic, caused by sunlight scattering from dust particles

B the radio noise caused by cosmic rays moving through magnetic fields in sp

C the electromagnetic remnants of the explosion in which the universe was bo

D the result of the radioactive decay of heavier, unstable elements produced in supernova explosions

an observation which supports the big bang theory is the existence of

A planets

B clusters of galaxies

C the background radiation

D an expanding universe

the idea of a finite universe is

A a natural result of our finite nature

B a unique requirement of the big bang theory

C contrary to modern observations

D established by the darkness of the night sky

an observation in support of the big bang theory is

A the existence of planets around other stars

B the existence of other galaxies

C the existence of the radio background radiation

D the existence of photons of light.

the observation of gravity waves and the diffuse x-ray radiation favors

A the big bang theory

B the oscillating universe theory

C the steady state theory

D no choice

the concept of a finite but unbounded universe implies that

A no physical object can experience a boundary to the universe

B the universe is a black hole

C equal amounts of matter and antimatter exist

D the age of the universe is finite

the elements which formed after the big bang explosion were

A destroyed in later generations of stars

B predominantly light elements

C mostly heavy elements

D mostly heavy elements which were later broken down into light elements

the assumption of isotropy states that the universe looks the same

A at all times.

B in all locations.

C in all directions.

D all of the above.

which of the following is not a basic assumption made in modern cosmology?

A the law of gravity works the same way in distant galaxies as on Earth.

B both matter and radiation are spread out uniformly throughout the universe.

C the universe looks the same in all directions from Earth.

D the universe is infinite in extent.

the cosmic microwave background radiation

A is composed of greatly Doppler shifted photons from the instant the big bang started

B is composed of greatly Doppler shifted photons from the time when the big bang's temperature was 3000k

C is a measure of the current temperature of the universe

D more than one of the above

the intensity of the microwave background radiation is greatest in the direction of

A the galactic center

B rich galaxy clusters

C the sun

D nowhere; it is the same all over

if the universe actually is closed, then

A it will expand forever

B the edge of the universe is only 50 billion light years away

C the actual density of the universe is less than the critical density

D we are, in effect, inside a black hole

which of the following was created in the big bang?

A oxygen

B carbon

C plutonium

D none of the above

the "big bang" refers to the moment when

A matter in the universe had a near-infinite density

B the stars in the universe began to shine

C galaxies collided with titanic fury

D the universe began to contract

the universe will eventually collapse on itself if

A its average density is above some critical value

B it is an open universe

C it is negatively curved

D it expends its energy too rapidly

the critical density is

A the density of matter in the milky way

B the density at which an object becomes a black hole

C the density at the center of the big bang

D the density of a flat universe

which of the following was not created in the early big bang

A hydrogen

B helium

C light

D carbon

the photons in the "cosmic microwave background" that now reach the Earth have

A low energies because they were produced with low energies

B low energies because of their large Doppler shifts

C high energies because they come from the early moments of the universe

D high energies because they were produced in high-energy collisions

the temperature of the background radiation is nearly

A 3 k

B 30 k

C 100 k

D 1,000 k

the reason why the universe continues to expand is

A galaxies are being pushed apart by the Hubble force

B the initial "kick" of the big bang was sufficient to keep galaxies flying away from each other for billions of years

C gravity does not act over intergalactic distances

D the laws of physics demand it, since the universe is infinite

the microwave background has a spectrum similar to that of

A thermal radiation from a hot body

B thermal radiation from a cool body

C an emission nebula

D the sun

according to the big bang theory, as the universe expands

A more matter is continuously created

B the matter cools

C the rate of expansion increases

D it gets darker

the future of the overall universe, in terms of its ultimate evolution and whether it will expand forever or eventually contract again, is determine by which of its parameters?

A the present volume of the universe

B the intensity of cosmic microwave background radiation

C the average density of matter within it

D the temperature of the gas within it

the big bang theory says the universe has expanded

A quietly except for a few periods of rapid change

B and contracted several times since the big bang

C without any significant change in the basic state of matter

D infinitely far since the big bang

the present consensus has ruled out the theory of

A a closed and finite universe

B an oscillating universe

C a universe expanding forever

D none of the above

the background radiation

A comes to us from all directions in space

B comes to us from a single direction indicating the center of the universe

C is the remnant of a supernova explosion

D none of the above

the assumption we make concerning the cosmological principle is that

A the universe can never change

B different laws of physics apply in different regions of the universe

C all observers of the universe see the universe appearing and acting in the same manner

D there is no beginning and no ending of the universe as we presently know I

except for hydrogen the most abundant element formed in the big bang was

A helium

B oxygen

C nitrogen

D carbon

in the present theory of the big bang in the universe, what significant event occurred at about 1 million years after the initial big bang?

A the temperature of the cosmic background radiation had cooled to its present level of about 3k

B protons and neutrons became stable

C the primordial helium in the universe was produced

D the universe became transparent to photons of radiation

if the average density of the universe is less than the critical density

A the universe will expand forever

B the universe will eventually collapse

C the universe is bounded

D the universe must be static

the center of the universe

A is located in the direction of the constellation Sagittarius

B could be located if we could find a galaxy which is not moving

C is in the fourth dimension

D can be said to be everywhere

evidence that there may have been an exploding primeval fireball that initiated the expansion of the universe comes from

A the discovery that the universe is bathed in low energy microwave radiation (2.7 k)

B the observed explosions of certain galaxies

C the nonthermal radiation (synchrotron radiation) of the quasars

D the discovery of antimatter in distant space

the amount of visible matter observed in the universe

A assures that the universe must eventually contract

B can eventually increase the universe's rate of expansion

C falls about ten times below the density needed to assure that the universe will eventually contract

D assures that the universe cannot possibly contain enough matter ever to contract

the universe became transparent when electrons and protons formed hydrogen atoms because

A atoms only absorb certain wavelengths of light

B the density of matter was so low

C nucleosynthesis finally ceased

D there is less chance that a photon will hit an atom than an electron

at the time of the big bang the universe was

A cool with a low density

B cool with a high density

C hot with a high density

D hot with a low density

if the density of the universe is greater than the critical density the universe will

A continue to expand forever

B eventually stop expanding

C eventually stop expanding and begin contraction

D continue to contract forever

according to the oscillating universe theory

A new hydrogen is being created to replace that which is being consumed by the stars

B the galaxies are presently rushing in toward the center where a big bang will eventually occur

C the universe at some time in the distant future will begin to contract

D the universe will be recreated in precisely the same way and with the same results when it burns itself out

in discussions of cosmology, the "critical density" refers to

A the density of matter at the time of the big bang

B the present-day density required for the universe to eventually collapse

C the density of the universe derived by summing the masses of all visible galaxies

D the density of the universe at the point of maximum expansion

why was one million years after the big bang an important point in the history of the universe?

A nuclei of helium could form first then

B carbon, nitrogen, and oxygen could form then

C atoms could remain neutral then

D galaxies could form then

good evidence for an original big bang which "created" our universe come from

A the rapid motions of some nearby stars, such as Barnard's star

B a background "glow" of microwaves, with black body temperature of about 3 k

C the measurement of the rotation of our galaxy

D the density of galaxies in the universe

the universe is closed if

A the big bang theory is correct

B the mass of the universe is great enough

C the current rate of expansion of the universe is fast enough

D Hubble's law remains a straight line

as the material from the original primeval fireball spread out in all directions, it became

A more and more magnetic

B cooler and cooler

C hotter and hotter

D more and more dense

if the universe has a closed geometry, it will

A expand forever, more and more slowly.

B stop expanding in the future and stay that size always.

C stop expanding in the future and then contract.

D expand forever, faster and faster

if the universe is closed

A galaxies will eventually begin moving toward each other

B an infinite sequence of big bangs will occur

C it is a black hole

D all of the above

if the universe is expanding now

A it will continue to expand at the current rate forever

B it will expand forever, but at a constantly decreasing rate

C it will eventually contract again

D all of the above are possible

a few minutes after the big bang

A heavy elements like iron formed.

B hydrogen and helium formed.

C stars and galaxies formed.

D Geraldo Rivera was born.

an observation which supports the big bang theory is the observation of

A the microwave background radiation

B dark lines in stellar spectra

C the existence of clusters of galaxies

D the existence of planets