26.5.0 The Expanding Universe

25. Edwin Hubble was able to show that (with the exception of our nearest neighbors) the farther a galaxy is from us, the a. brighter it looks b. bluer its color c. the later in its life we are seeing it d. the larger its halo is e. the faster it is moving away from us

e. the faster it is moving away from us

33. The astronomer who assisted Edwin Hubble at the Mount Wilson Observatory and helped him establish the expansion of the universe was: a. Vesto Slipher b. Harlow Shapley c. Milton Humason d. Immanuel Kant e. James Kirk

c. Milton Humason

31. Why is the use of Hubble's Law to measure distances to galaxies so important to astronomers? a. They have NO other way of measuring distances to galaxies - absolutely none b. Many galaxies don't move away from us, so when we find one that does, it's really a big deal c. Most galaxies are so far away, the only way to get distances to them is to use Hubble's Law d. The other ways of getting distances only work for really far away galaxies; so the Hubble Law is the only way to measure distances to nearby galaxies e. It's stretching the truth to say that Hubble's Law is a really important way to get distances to galaxies; really, it's no more important than any other method

c. Most galaxies are so far away, the only way to get distances to them is to use Hubble's Law

26. In a distant galaxy, whose light is just arriving from 10 billion light years away, our spectroscope should reveal that the most common element is a. helium b. carbon c. hydrogen d. iron e. Einsteinium

c. hydrogen

30. Which of the following statements about the implications of Hubble's Law is FALSE? a. the law implies that the whole universe must be expanding b. the law can be used to measure distances to remote galaxies for which we can measure a Doppler shift c. the law does NOT require us to be at the center of the expanding universe d. if you were observing the universe from a distant galaxy, you would NOT see all the galaxies (except those in your own group) moving away from YOU e. although galaxies move away from each other, they themselves are not expanding in size

d. if you were observing the universe from a distant galaxy, you would NOT see all the galaxies (except those in your own group) moving away from YOU

28. Which of the following was not done by Edwin Hubble? a. measuring the distance to the Andromeda "nebula" b. classifying the galaxies by their shapes c. establishing the expansion of the universe d. discovering the law that the motion of the galaxies away from us follows e. discovering the relationship between period and luminosity of a cepheid variable

e. discovering the relationship between period and luminosity of a cepheid variable

24. The first astronomer to show that spiral nebulae (today called spiral galaxies) have large Doppler shifts was a. Edwin Hubble b. Vesto Slipher c. Percival Lowell d. Christian Doppler e. Harlow Shapley25

b. Vesto Slipher

27. The Andromeda Galaxy (our nearest spiral neighbor) has spectral lines that show a blue shift. From this we may conclude that: a. the universe is no longer expanding b. this particular nearby galaxy is moving toward us c. this galaxy has merged with the Milky Way and is now part of it d. this particular nearby galaxy is moving away from us e. this galaxy has an unusual number of very bright and hot O-type stars in it

b. this particular nearby galaxy is moving toward us

32. Before you can use Hubble's Law to get the distance to a galaxy, what observation must you make of that galaxy? a. you must find a Cepheid variable star in the galaxy b. you must take a spectrum of the galaxy and measure the red shift c. you must measure how strongly the galaxy emits radio waves at a wavelength of 21 centimeters d. you must find a Type Ia supernova that is exploding in that galaxy e. all you need to do is look at the galaxy through any telescope

b. you must take a spectrum of the galaxy and measure the red shift

29. According to Hubble's Law, if two galaxies are not part of our Local Group, and galaxy B is three times farther away from us as Galaxy A, then Galaxy B will a. move toward us three times faster than A b. move away from us nine times faster than A c. move away from us three times faster than A d. move toward us nine times faster than A e. move away from us at about the same speed as A

c. move away from us three times faster than A