Astronomy Ch. 1 Final

Which of the following is a general difference between a planet and a star? All planets are made of rock and all stars are made of gas. Planets are brighter than stars. Planets are larger than stars. Stars glow in infrared and visible light, while planets glow only in the infrared.

OuOur solar system consists of _________. a few hundred billion stars, bound together by gravity the Sun and the planets, and nothing else the Sun and several nearby stars, as well as the planets and other objects that orbit these stars the Sun and all the objects that orbit it

Which of the following best describes what we mean by the universe? the sum total of all matter and energy our Milky Way Galaxy a vast collection of stars that number as many as the grains of sand on all the beaches on Earth all the galaxies in all the superclusters

What do astronomers mean by the Big Bang? the explosion of a massive star at the end of its life the event that marked the beginning of the expansion of the universe the event that marked the birth of our solar system a gigantic explosion that blew all the galaxies in the universe to smithereens

What do we mean when we say that the universe is expanding? Within galaxies, average distances between star systems are increasing with time. Everything in the universe is gradually growing in size. The statement is not meant to be literal; rather, it means that our knowledge of the universe is growing. Average distances between galaxies are increasing with time.

A television advertisement claiming that a product is light-years ahead of its time does not make sense because _________. a light-year is an astronomically large unit, so a product could not possibly be so advanced it uses "light-years" to talk about time, but a light-year is a unit of distance it doesn't specify the number of light-years light-years can only be used to talk about light

The term observable universe refers to _________. the portion of the universe that can be seen by the naked eye the portion of the universe that is not hidden from view by, for example, being below the horizon that portion of the universe that we have so far photographed through telescopes that portion of the universe that we can see in principle, given the current age of the universe

On a scale where the Sun is about the size of a grapefruit and the Earth is about 15 meters away, how far away are the nearest stars besides the Sun? 100 meters about the distance across the state of Delaware about the distance across 50 football fields about the distance across the United States

If the 14 billion year history of the universe were compressed to one year, and "now" is exactly midnight December 31, approximately how long ago were your grandparents born? 1 second ago 0.15 second ago 1 hour ago 1 minute ago

What is the "Raisin Cake model" intended to explain? that all the raisins in the cake move away from one central raisin, just as all galaxies are moving away from one special galaxy (ours) that raisins, like galaxies, expand with the rest of the universe that every raisin in a raisin cake moves farther away from every other raisin: there is no special central raisin (and no special central galaxy) that the universe heats up as it expands, just like the raisin cake heats and expands