The Cosmic Perspective (9th Edition)
9th Edition
ISBN: 9780134874364
Author: Jeffrey O. Bennett, Megan O. Donahue, Nicholas Schneider, Mark Voit
Publisher: PEARSON
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Textbook Question
Chapter 20, Problem 20EAP
Decide whether the statement makes sense (or is clearly true) or does not make sense (or is clearly false). Explain clearly; not all of these have definitive answers, so our explanation is more important than your chosen answer.
21. After measuring a galaxy’s redshift, I used Hubble’s law to estimate its distance.
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Hubble's First Attempt. Edwin Hubble's first attempt to measure the universe's expansion rate was flawed because the standard candles he was using were not properly calibrated. Look at (Figure 1)
a.Estimate the value of Ho corresponding to the solid line in the figure. Express your answer kilometers per second per million light-years to two significant figures.
b.What is the approximate age of the universe indicated by that erroneous value of Ho? Express your answer in years to one significant figure.
An astronomer observed the motions of some galaxies. Based on his observations, he made the following statements. Which one of them is most likely to be false? Take Hubble's constant to be 67 km/s/Mpc.
A. A galaxy observed to be moving away from us at a speed of 70 km/s is at a distance of about 1 Mpc from us.
B. A galaxy observed to be moving away from us at a speed of 700 km/s is at a distance of about 10 Mpc from us.
C. A galaxy observed to be moving away from us at a speed of 7000 km/s is at a distance of about 100 Mpc from us.
D. A galaxy observed to be moving away from us at a speed of 70000 km/s is at a distance of about 1 Gpc from us.
Is the answer D? Thank you!
Suppose we look at two distant galaxies: Galaxy 1 is twice as far away as Galaxy 2. In this case,
A.
Galaxy 1 must be twice as big as Galaxy 2.
B.
we are seeing Galaxy 1 as it looked at an earlier time in the history of the universe than Galaxy 2.
C.
we are seeing Galaxy 1 as it looked at a later time in the history of the universe than Galaxy 2.
D.
Galaxy 2 must be twice as old as Galaxy 1.
Chapter 20 Solutions
The Cosmic Perspective (9th Edition)
Ch. 20 - Prob. 1VSCCh. 20 - Prob. 2VSCCh. 20 - Prob. 3VSCCh. 20 - Prob. 4VSCCh. 20 - Use the following questions to check your...Ch. 20 - Prob. 6VSCCh. 20 - Why do we need to understand the evolution of the...Ch. 20 - Prob. 2EAPCh. 20 - Prob. 3EAPCh. 20 - Prob. 4EAP
Ch. 20 - Prob. 9EAPCh. 20 - Prob. 10EAPCh. 20 - Prob. 11EAPCh. 20 - Prob. 12EAPCh. 20 - Prob. 13EAPCh. 20 - What is the cosmological horizon, and what...Ch. 20 - Prob. 15EAPCh. 20 - Prob. 16EAPCh. 20 - Prob. 17EAPCh. 20 - Prob. 18EAPCh. 20 - Prob. 19EAPCh. 20 - Decide whether the statement makes sense (or is...Ch. 20 - Prob. 21EAPCh. 20 - Prob. 22EAPCh. 20 - Prob. 23EAPCh. 20 - Prob. 24EAPCh. 20 - Prob. 25EAPCh. 20 - Choose the best answer to each of the following....Ch. 20 - Prob. 27EAPCh. 20 - Choose the best answer to each of the following....Ch. 20 - Prob. 29EAPCh. 20 - Prob. 30EAPCh. 20 - Prob. 31EAPCh. 20 - Choose the best answer to each of the following....Ch. 20 - Choose the best answer to each of the following....Ch. 20 - Choose the best answer to each of the following....Ch. 20 - Prob. 35EAPCh. 20 - Prob. 38EAPCh. 20 - Prob. 41EAPCh. 20 - Prob. 42EAPCh. 20 - Prob. 43EAPCh. 20 - Prob. 45EAPCh. 20 - Prob. 46EAPCh. 20 - Prob. 47EAPCh. 20 - Prob. 48EAPCh. 20 - Prob. 51EAPCh. 20 - Prob. 52EAPCh. 20 - Prob. 53EAPCh. 20 - Prob. 54EAPCh. 20 - Extremely Distant Galaxies. The most distant...Ch. 20 - Stretching of the Universe. The most distant white...
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