Notes 5 Exam

Question 1

1. The unit of distance called the parsec is equal to how many light years?

Answer 1

3.26156 light years

Question 2

A parsec is equal how many kilometers?

Answer 2

30.857 x 10^12

Question 3

A parsec is equal to how many Astronomical Units?

Answer 3

206.26 x 10^3 astronomical units

Question 4

How many Astronomical Units is Earth from the Sun?

Answer 4

1

it is the distance between the earth and sun

Question 5

How big is the Sloan Great Wall?

Answer 5

400+ mega parsecs long

Question 6

How does the size of the Sloan Great Wall compare to a cluster of galaxies?

Answer 6

Virgo cluster is about 2.2 Mpc

Question 7

Approximately, how many galaxies are gravitationally bound in the Local Group of galaxies?

Answer 7

1300-2000 members

Question 8

Where in the universe is the Milky Way located?

Answer 8

-

Question 9

What is Olber’s paradox?

Answer 9

The paradox is that a static, infinitely old universe with an infinite number of stars distributed in an infinitely large space would be bright rather than dark.

Question 10

How did Hubble’s Law resolve Olber’s paradox?

Answer 10

HUBBLE’S LAW DEMONSTRATES THAT THE UNIVERSE IS NOT STATIC. THE UNIVERSE IS DYNAMIC. IT CHANGES IN TIME.

Question 11

What observations suggest that the universe is expanding?

Answer 11

The observation that galaxies are moving away from each other is interpreted as the expansion of space.

Question 12

What is Hubble’s constant?

Answer 12

H_o is Hubble’s constant

Question 13

The measurement of the cosmic background radiation describes a universe with which properties (/implies what about our universe)?

Answer 13

The universe is homogeneous and isotropic

Question 14

What do the observations of Type I supernovae suggest regarding the expansion of the universe?

Answer 14

Studies of Type Ia supernovae demonstrate that the universe’s expansion (Hubble law) isn’t just a simple expansion at a constant rate. These supernovae imply that the acceleration rate is increasing in time!

Question 15

Is the matter identified in the periodic table of elements a form of dark matter?

Answer 15

no

Question 16

What is the relative abundance of different kinds of energy in the universe in the Big Bang cosmological model?

Answer 16

It contains 4.6% ordinary matter, about 23% dark matter and 72% dark energy

Question 17

How old are the dimensions of space and time?

Answer 17

about 13.7 billion years ago

Question 18

Does science have a successful model to describe the universe during the Planck era?

Answer 18

No

Question 19

Do hydrogen nuclei form before or after the first second of the evolution of the cosmos?

Answer 19

before the first second

during one millisecond

Question 20

Did fusion reactions in the early universe stop because the temperature of the universe was too great or too low?

Answer 20

too low

Question 21

Did light energy dominate the dynamics of the evolution of the universe before or after matter dominated the dynamics of the universe?

Answer 21

after

Question 22

What is the Sloan Great Wall?

Answer 22

the largest known structure in the universe

Question 23

Does the universe contain more dark matter or more ordinary matter (atomic)?

Answer 23

more dark matter

Question 24

What is the Planck time?

Answer 24

It is the time required for light to travel, in a vacuum, a distance of 1 Planck length

Question 25

How have the forces of nature changed over time?

Answer 25

During the Planck time all four forces of nature are unified. At the end of the Planck epoch, gravity breaks from the electronuclear force (electromagnetism, weak force and strong force combined) and Grand Unification models describe the evolution of the universe.