Life in the Universe (4th Edition)
4th Edition
ISBN: 9780134089089
Author: Jeffrey O. Bennett, Seth Shostak
Publisher: PEARSON
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Textbook Question
Chapter 3, Problem 46IF
Alien Technology. Some people believe that Earth is regularly visited by aliens who travel here from other star systems. For this to be true, how much more advanced than our own would the space travel technology of the aliens have to be? Write one to two paragraphs to give a sense of the technological difference. (Hint: The ideas of scale in this chapter can help you contrast the distance the aliens travel easily with the distances we are now capable of traveling.)
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Group of answer choices
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Tutorial
A radio broadcast left Earth in 1925. How far in light years has it traveled?
If there is, on average, 1 star system per 400 cubic light years, how many star systems has this broadcast
reached?
Assume that the fraction of these star systems that have planets is 0.30 and that, in a given planetary
system, the average number of planets that have orbited in the habitable zone for 4 billion years is 0.85. How
many possible planets with life could have heard this signal?
Part 1 of 3
To figure out how many light years a signal has traveled we need to know how long since the signal left Earth.
If the signal left in 1925, distance in light years = time since broadcast left Earth.
d = tnow - tbroadcast
d =
light years
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Chapter 3 Solutions
Life in the Universe (4th Edition)
Ch. 3 - List three major ideas of astronomy that help...Ch. 3 - Briefly define and describe each of the various...Ch. 3 - Describe the solar system as it looks on the...Ch. 3 - Prob. 4RQCh. 3 - Prob. 5RQCh. 3 - Prob. 6RQCh. 3 - Prob. 7RQCh. 3 - What do we mean when we say that Earth and life...Ch. 3 - Imagine describing the cosmic calendar to a...Ch. 3 - Prob. 10RQ
Ch. 3 - Prob. 11RQCh. 3 - Prob. 12RQCh. 3 - What is the difference between matter in the...Ch. 3 - Define and give examples of kinetic energy,...Ch. 3 - Prob. 15RQCh. 3 - Prob. 16RQCh. 3 - Briefly describe the four major features of our...Ch. 3 - Briefly describe the nebular theory and how it...Ch. 3 - What was the close encounter hypothesis for our...Ch. 3 - How have recent discoveries led scientists to...Ch. 3 - Prob. 21TYUCh. 3 - At a middle school talent show, 14-year-old Sam...Ch. 3 - SETI researchers announced today that if they...Ch. 3 - A noted physicist today announced that he has...Ch. 3 - Prob. 25TYUCh. 3 - Astronomers have discovered a galaxy in the far...Ch. 3 - Inventor John Johnson has patented a device that...Ch. 3 - Prob. 28TYUCh. 3 - Prob. 29TYUCh. 3 - Using new, powerful telescopes, biologists today...Ch. 3 - Prob. 31TYUCh. 3 - Prob. 32TYUCh. 3 - A television advertisement claiming that a product...Ch. 3 - When we say the universe is expanding, we mean...Ch. 3 - Prob. 35TYUCh. 3 - The age of our solar system is about (a) one-third...Ch. 3 - Prob. 37TYUCh. 3 - How many of the planets orbit the Sun in the same...Ch. 3 - Prob. 39TYUCh. 3 - Prob. 40TYUCh. 3 - Explaining the Past. Is it really possible for...Ch. 3 - A Strange Star System. Suppose that we discovered...Ch. 3 - Prob. 44IFCh. 3 - Alien Technology. Some people believe that Earth...Ch. 3 - Atomic Terminology Practice. a. The most common...Ch. 3 - Prob. 49IFCh. 3 - Prob. 50IFCh. 3 - Patterns of Motion. In one or two paragraphs,...Ch. 3 - Two Kinds of Planets. The jovian planets differ...Ch. 3 - Pluto and Eris. How does the nebular theory...Ch. 3 - Rocks from Other Solar Systems. Many leftovers...Ch. 3 - Prob. 55IFCh. 3 - Prob. 56IFCh. 3 - Scale of the Solar System. The real diameters of...Ch. 3 - Prob. 58IFCh. 3 - Prob. 59IFCh. 3 - Prob. 60IFCh. 3 - Prob. 61IFCh. 3 - Prob. 62IFCh. 3 - Prob. 63IFCh. 3 - Prob. 67WPCh. 3 - Tour of the Solar System. Visit one of the many...
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