Astronomy Ch. 1

Which of the following statements about scientific theories is not true? A) A theory cannot be taken seriously by scientists if it contradicts other theories developed by scientists over the past several hundred years. B) A theory is a model designed to explain a number of observed facts. C) If even a single new fact is discovered that contradicts what we expect according to a particular theory, then the theory must be revised or discarded. D) A theory can never be proved beyond all doubt; we can only hope to collect more and more evidence that might support it. E) A theory must make predictions that can be checked by observation or experiment.

A) A theory cannot be taken seriously by scientists if it contradicts other theories developed by scientists over the past several hundred years.

All the following statements are true. Which one follows directly from Kepler's third law? A) Venus orbits the Sun at a slower average speed than Mercury. B) Venus is larger than Mercury. C) Venus has a thicker atmosphere than Mercury. D) Venus is more massive than Mercury.

A) Venus orbits the Sun at a slower average speed than Mercury.

About where is our solar system located within the Milky Way Galaxy? A) about two thirds of the way from the center of the galaxy to the outskirts of the galactic disk B) near the far outskirts of the galactic disk C) in the halo of the galaxy above the galactic disk D) at the center of the galaxy E) about 10 percent of the way from the center of the galaxy to the outskirts of the galactic disk

A) about two thirds of the way from the center of the galaxy to the outskirts of the galactic disk

How long would it take to count all the stars in the Milky Way Galaxy at a rate of one star per second? A) several thousand years B) hundreds of thousands of years C) several days D) several years E) several weeks

A) several thousand years

Modern telescopes are capable of seeing bright galaxies up to about A) 1 billion lightyears away. B) 10 billion light-years away. C) 1 trillion light-years away. D) 10 million light-years away. E) 1 million light-years away.

B) 10 billion light-years away.

Roughly how many stars are in the Milky Way Galaxy? A) 10 billion B) 100 billion C) 100 million D) 1 billion E) 100 trillion

B) 100 billion

How are galaxies important to our existence? A) Galaxies prevent planets from leaving their orbits around stars; e.g., our galaxy prevents Earth from leaving its orbit of the Sun. B) Galaxies recycle heavy elements produced in stars into future generations of stars. C) Without galaxies, there could not have been a Big Bang. D) Galaxies provide the gravity that prevents us from falling off Earth. E) Without galaxies, the universe could not be expanding.

B) Galaxies recycle heavy elements produced in stars into future generations of stars.

Imagine that we put a raisin cake into the oven, with each raisin separated from the others by 1 cm. An hour later, we take it out and the distances between raisins are 3 cm. If you lived in one of the raisins and watched the other raisins as the cake expanded, which of the following would you conclude? A) All raisins would be moving away from you at the same speed. B) More distant raisins would be moving away from you more slowly. C) More distant raisins would be moving away from you faster. D) It depends: If you lived in a raisin near the edge of the cake, you'd see other raisins moving away from you, but they'd be coming toward you if you lived in a raisin near the center of the cake.

C) More distant raisins would be moving away from you faster.

If you represented each star by a grain of sand, how much sand would it take to represent all the stars in the universe? A) all the sand in a typical playground sandlot B) all the sand on the beaches in the United States C) more than all the sand on all the beaches on Earth D) all the sand on the beaches of California E) all the sand on Miami Beach

C) more than all the sand on all the beaches on Earth

How many galaxies are there in the observable universe? A) about as many as the number of grains of sand on all the beaches on Earth B) an infinite number C) roughly (within a factor of 10) the same as the number of stars in our galaxy D) roughly a thousand times more than the number of stars in our galaxy E) about as many as the number of stars we see in the sky with our naked eyes

C) roughly (within a factor of 10) the same as the number of stars in our galaxy

What do scientists mean by verifiable observations? A) observations that can be interpreted in only one way B) observations that support a scientific theory C) statements that a person can, in principle, verify for himself or herself D) observations that a model does not have to predict E) statements that anyone would agree are obvious

C) statements that a person can, in principle, verify for himself or herself

From the fact that virtually every galaxy is moving away from us and more distant galaxies are moving away from us at a faster rate than closer ones, we conclude that A) the universe is shrinking. B) the Milky Way Galaxy is expanding. C) the universe is expanding. D) the farthest galaxies will eventually be moving faster than the speed of light. E) we are located at the center of the universe.

C) the universe is expanding.

How long does it take our solar system to complete one orbit around the Milky Way Galaxy? A) 100 million years B) 10 thousand years C) 1 million years D) 230 million years E) 230 thousand years

D) 230 million years

By studying distant galaxies in the 1920s, Hubble made which of the following important discoveries that led us to conclude that the universe is expanding? A) All galaxies contain billions of stars, and all galaxies have spiral shapes. B) All galaxies were born at the same time, and all will die at the same time. C) All galaxies outside the Local Group are moving away from us, and all are moving away at nearly the same speed. D) All galaxies outside the Local Group are moving away from us, and the farther away they are, the faster they're going. E) All galaxies outside the Local Group are orbiting the Local Group.

D) All galaxies outside the Local Group are moving away from us, and the farther away they are, the faster they're going.

What is meant by a hypothesis? A) a pseudoscientific idea B) a historical theory that has been proved inaccurate C) a natural phenomenon that requires explanation D) an explanation for a phenomenon that makes a prediction E) a tentative understanding of a natural phenomenon

D) an explanation for a phenomenon that makes a prediction

What is the meaning of the word cosmos? A) the Milky Way B) the dark sky C) the light from a distant astronomical object D) the sum total of all matter and energy, that is, everything within and between all galaxies E) the origin of Earth and life upon it

D) the sum total of all matter and energy, that is, everything within and between all galaxies

Approximately how fast are you moving with the rotation of Earth? A) 130 km/hr B) 13 km/hr C) not moving at all D) 13,000 km/hr E) 1,300 km/hr

E) 1,300 km/hr

Earth is made mostly of metals and rocks. Where did this material come from? A) It was made by our Sun. B) It was made by nuclear fission of uranium and other radioactive materials. C) It was created by chemical reactions in interstellar space. D) It was produced in the Big Bang. E) It was produced by nuclear fusion in stars.

E) It was produced by nuclear fusion in stars.