astr homework 1

Our universe is approximately 13.7 _________ years old. Select one: a. million b. thousand c. billion d. trillion

C. billion

According to the figure, if you were to specify your address in the universe, listing your membership from the smallest to largest physical structures, it would be: Select one: a. Earth, Local Group, Solar System, Andromeda, the universe. b. Earth, Solar System, Local Group, Milky Way, the universe. c. Earth, Solar System, Milky Way, Local Group, Laniakea Supercluster, the universe. d. Earth, Solar System, Milky Way, Laniakea Supercluster, the universe. e. Earth, Laniakea Supercluster, Milky Way, Solar System, the universe.

C. earth, solar system, milky way, local group, Laniakea supercluster, the universe

In science, an idea that cannot be tested is Select one: a. a hypothesis. b. a theory. c. not a scientific idea. d. a fact e. a principle.

C. not a scientific idea

Which of the following statements about the celestial sphere is NOT true? a.The celestial sphere does not exist physically b. Earth is placed at the center of the celestial sphere. c. The "celestial sphere" is just another name for our universe. d. When we look in the sky, the stars all appear to be located on the celestial sphere. e. From any location on Earth, we can see only half the celestial sphere at any one time

C. the "celestial sphere" is just another name for our universe this is false

which number is bigger? Select one: a. 1.2 b. -9.8 c. 9.8 x 1012 d. 1.2x1013 e. 1.2 x 10 -13

D. 1.2x 10^13

Briefly explain what we mean by the statement "The farther away we look in distance, the further back we look in time."

It means that when we look at a distant object, we see it as it was some time in the past, rather than as it is now. This is because the light we see has taken time to travel from the object to us.

Which of the following is false? a. A scientific theory is an undisputed fact. b. A scientific theory may eventually be proven wrong when scientists acquire new data. c. A hypothesis must always have one or more testable predictions d. If continual testing of a hypothesis shows it to be valid, it may become an accepted theory. e. Scientific observations are used to test a hypothesis

a. a scientific theory is an undisputed fact

Which of the following best describes the Milky Way? Select one: a. a spiral galaxy with a disk about 100,000 light-years in diameter and containing between 100 billion and 1 trillion stars b. a spiral galaxy with a disk about 1 billion kilometers in diameter and containing between 100 million and 1 billion stars c. a spiral galaxy with a disk about 100,000 light-years in diameter and containing about 100,000 stars d. a spherically shaped collection of stars including our solar system and about a dozen other solar systems, stretching about 4 light-years in diameter e. Our star and all the material that orbits it, including its planets and moons.

a. a spiral galaxy with a disk about 100,000 light years in diameter and containing between 100 billion and 1 trillion stars

Suppose we look at two distant galaxies: Galaxy 1 is twice as far away as Galaxy 2. In that case, ________. a. Galaxy 2 must be twice as old as Galaxy 1 b. Galaxy 1 must be twice as big as Galaxy 2 c. we are seeing Galaxy 1 as it looked at an earlier time in the history of the universe than Galaxy 2 d. we are seeing Galaxy 1 as it looked at a later time in the history of the universe than Galaxy 2

c. we are seeing Galaxy 1 as it looked at an earlier time in the history of the universe than Galaxy 2

If an event were to take place on the Sun, how long would it take for the light it generates to reach us? a. 1 day b. 10 hours c. 1 second d. 8 minutes e. It would reach us instantaneously

d. 8 minutes

The direction directly overhead of an observer defines his or her a. celestial pole b. nadir c. circumpolar plane d. zenith e. meridian

d. zenith

Which of the following best describes the modern definition of a constellation? a. a collection of stars that are near one another in space b. a Greek mythological figure c. a group of stars that all lie at about the same distance from Earth d. a pattern of bright stars in the sky e. a region of the celestial sphere

e. a region of the celestial sphere

A person located on the equator is orbiting the center of the Earth to the East at 1670 km/s. Relative to the center of the Earth, a person on the North Pole is Select one: a. moving toward the South at the same velocity. b. not moving at all. c. moving at the same velocity to the East, since they are both on the same planet in space. d. experiencing weightlessness. e. stationary, except spinning in place once per day.

e. stationary, except spinning in place once per day

Because of _____________, we can conclude that gravity works the same way on Mars as it does on Earth. Select one: a. Sagan's planetary principle b. the hypothetical statute c. Newtons theory of relativity d. Einsteins special theory of relativity e. The cosmological principle

e. the cosmological principle

Rank the following in order of smallest to largest: -size of a typical galaxy - the width of a human hair - size of Pluto's orbit - distance to nearest star (other than the Sun) - one (1) light year

the width of a human hair, size of Pluto's orbit, one (1) light year, distance to nearest star (other than the Sun), size of a typical galaxy

A "light year" is a way to measure distance. t/f

true

While, night after night, the stars seem not to move relative to each other, they are actually moving in random directions with relative to each other with typical velocities of about 70,000 km/hr. t/f

true