Astronomy ch. 1
Consider a rain cake expanding uniformly in an oven. Views from one of the raisins, you would see ___________________.
All other raisins moving away from you, with more distant raisins moving faster
Which of the following is not a general difference between a planet and a star?
All planets are made of rock and all stars are made of gas.
What do we mean when we say that the universe is expanding?
Average distances between galaxies are increasing with time
List these smallest to largest: a. Solar system b. Milky Way Galaxy c. cluster of galaxies d. Earth e. Sun
Earth, Sun, solar system, Milky Way Galaxy, cluster of galaxies
How are galaxies important to our existence?
Galaxies recycle material from one generation of stars to the next, and without this recycling we could not exist.
Which of the following statements does not use the term light-year in an appropriate way? a. A light-year is about 10 trillion kilometers. b. It will take the Voyager spacecraft about 20,000 years to travel just 1 light-year c. The Milky Way Galaxy is about 100,000 light-years in diameter d. It will take me light-years to complete this homework assignment e. It's about 4 light-years from her to Alpha Centauri
It will take me light-years to complete this homework assignment
Using the ideas just discussed in what sense are we "star stuff"?
Nearly every atom from which we are made was once inside of a star
On a scale in which the distance from Earth to the Sun is about 15 meters, the distance from Earth to the Moon is __________________.
Small enough to fit within your hand
The term observable universe refers to _______________.
That portion of the universe that we can see in principle, given the current age of the universe
Our solar system consists of ______________________.
The Sun and all the objects that orbit it
An astronomical unit (AU) is _________________.
The average distance between Earth and the Sun
What is the ecliptic plane?
The plane of Earth's orbit around the Sun
What is nuclear fusion?
The process of combining lightweight nuclei to make heavier nuclei
The total number of stars in the observable universe is about:
The same as the number of grains of sand on all the beaches on Earth
What best describes what we mean by the universe?
The sum total of all matter and energy
Suppose we look at two distant galaxies: Galaxy 1 is twice as far away as Galaxy 2. In that case________________.
We are seeing Galaxy 1 as it look at an earlier time in the history of the universe than Galaxy 2
