Chapter 28 The Structure of Space and Time

13) The formation of more protons than neutrons (at about a 7:1. ratio) was favored in the early universe because

A) it takes more energy to create a neutron from a proton than a proton from a neutron.

25) If the elliptical orbit of Mercury were more eccentric, its precession rate would be

A) larger than it is now.

9) Technically, its not mass that causes the curvature of spacetime, but

A) mass density.

2) Spacetime is curved by

A) mass.

4) In a flat universe parallel lines

A) never converge.

4) The "Big Bang" refers to the

A) point in time in which the known (and perhaps knowable) universe came into being.

1) Heat death refers to the universe

A) reaching the lowest energy state possible, which will mean the greatest level of entropy.

19) A clock on the surface of a shrinking star will run progressively

A) slower.

*16) A strong gravitational field

A) slows a clock.

15) The Big Bang is regarded as the expansion of

A) space.

*1) Relativity is the

A) study of how space, energy, and mass are related to time.

9) "Cosmological Redshift" refers to

A) the expansion of space itself.

3) Eternal Inflation refers to

A) the possibility that our universe is only a patch of a greater universe and that the process of universe spawning will continue forever.

5) According to inflation theory, parallel lines appear to remain parallel because

A) the universe is so unbelievably large.

*1) Cosmology is the study of the overall structure and evolution of

A) the universe.

2) The currently accepted reasoning for why the cosmic background radiation is so uniform in temperature is because

A) this temperature uniformity was achieved in the moments before cosmic inflation.

12) Cosmic background radiation refers to

A) uniformly distributed residual radiation that resulted from the Big Bang.

7) The difference between lightwaves approaching and lightwaves receding is

A) when approaching, lightwaves have higher frequency; when receding their frequency is lower.

8) Precession is

A) when the elliptical orbits of planets slip forward with each revolution.

13) Suppose at the surface of the Earth a person can do 20 pushups. In a spaceship far away from any gravitational influence, accelerating at g, the same person could do

B) 20 pushups.

6) Clocks on fast-moving spaceship shizzing past Earth appear to run slow when viewed from

B) Earth.

17) In a 1-g gravitational field, in 1 s, a light beam will curve beneath a perfectly straight line by

B) about 4.9 m.

3) Distant galaxies are

B) accelerating away from each other.

*1) What Einstein discovered about space and time is that they

B) are parts of one whole.

9) According to special relativity, two events that occur simultaneously in one frame of reference

B) can be non-simultaneous in another frame of reference.

*1) Dark Matter is matter that

B) cannot be seen or felt, but can be measured through its gravitational effects.

*18) Compared to a clock at the bottom of a very tall skyscraper, a clock at the top of this skyscraper will appear to run

B) faster.

2) Dark energy bends the curvature of spacetime

B) in the opposite manner of gravity.

*3) Einstein theories tell us that the speed of light

B) is constant in all frames of reference.

5) The Big Bang

B) marked the beginning of space and time.

7) According to cosmic inflation theory, the distribution of galaxies we see today is a consequence of

B) quantum fluctuations in the exceedingly small early universe.

10) A greater gravitational field causes time to

B) slow down.

15) A person on the ground floor of a skyscraper ages

B) slower than a person on the top floor.

6) According to Alan Guth, magnetic monopoles are not observed in our universe because

B) space expanded so much that they are exceedingly rare.

4) When we speak of time dilation, we mean that time

B) stretches with speed.

10) A four dimensional image of a coffee table is depicted in a

B) video.

*5) If you travel at high speed, then compared with your friends who "stay at home," you are

B) younger.

4) If heat death results in a maximum amount of entropy, then what does this say about entropy at the beginning of the universe?

C) The Big Bang was a moment of minimal entropy.

16) We are actually looking into the past when we look at

C) actually, both of these

14) Astronomers who subscribe to the Big Bang theory believe the Big Bang occurred

C) both of these

20) Light bends when it

C) both of these

21) The quantity that undergoes a red shift is

C) both of these

3) According to dark matter theory, most of the mass of a spiral galaxy is found

C) outside of the luminescent spiral arms.

1) Dark energy

D) All of the above

2) Evidence for dark matter is exhibited by the

D) All of the above

4) The theory of dark energy tells us that

D) All of the above.

7) If you were to travel at a speed close to the speed of light, you would notice that your own

D) Neither of these.

12) General relativity is most concerned with

D) all of these

*4) If dark matter were to be found on this planet it would likely be

D) at the center of Earth's core.

5) It currently appears that within this universe we have mostly

D) dark energy.

5) The modern theory of dark energy arises from observations showing that

D) galaxies are accelerating away from each other.

3) The universe as a whole is

D) has yet to be determined, although most astrophysical data points to a flat universe.

5) Where is dark matter found in the periodic table?

D) no where at all

22) The elliptical orbit of Mercury measurably precesses because

D) the Sun's gravitational field varies along Mercury's orbit.

2) In his special theory of relativity, Einstein stated that the laws of physics are

D) the same in all uniformly moving frames of reference.

23) According to relativity theory, it is possible to reverse time and grow younger when you

D) you can never grow younger.

24) If the orbit of Mercury were perfectly circular, its rate of precession would be

D) zero.

*11) According to calculations made by modern astronomers, the age of the universe is close to

A) 14 billion years.

3) How is it possible that today's diverse universe was able to arise from that which was very homogeneous at its first moments?

A) Inflation magnified ultrasmall quantum variations in position and momenta.

4) If the Sun suddenly became less massive, what would happen to Earth's orbit?

A) Spacetime around the Sun would become flatter, and the Earth, with its current momentum, would exit its orbit around the Sun.

7) Light is without mass, so how can gravity have an effect on light?

A) The space through which the light passes is curved.

2) The Big Rip refers to the

A) accelerating influence of dark energy, causing all matter to become completely ripped apart.

1) Cosmic Inflation refers to

A) an extremely rapid expansion of the early universe that occurred in an extremely brief period of time.

2) The Big Bang occurred

A) at the tip of your nose.

*8) The "redshift" of a galaxy refers to the rate

A) at which is receding.

*11) Space and time are

A) bound together.

10) How did Mr. Hubble calculate the age of the universe?

A) by measuring the rate of expansion of the universe

14) Fire a cannonball from a cannon and it curves due to gravity. Shine a light from a flashlight and it

A) curves per second the same as the cannonball.

6) Cepheids are types of stars that regularly change how bright they are over a period of a few

A) days.

5) According to Einstein, gravity is not the force exerted by one object on another, but rather the

A) effect we witness when a large mass causes a curvature in the shape of spacetime.

6) "Local observations made in an accelerated frame of reference cannot be distinguished from observations made in a gravitational field" is known as the principle of

A) equivalence.

*3) Edwin Hubble discovered that the farther away a galaxy is the

A) faster it is receding from us.

8) As a blinking light source approaching you gains speed, you see the frequency of flashes

A) increase.