Life in the Universe (4th Edition)
4th Edition
ISBN: 9780134089089
Author: Jeffrey O. Bennett, Seth Shostak
Publisher: PEARSON
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Chapter 13, Problem 41POS
To determine
Write the opinion for the assumption that neither the planet Earth nor its species are considered to be special.
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Which of the following seems least reasonable regarding life on Earth?
Group of answer choices
There is much scientific evidence suggesting that all creatures living on Earth today appear to have evolved from a common ancestor.
Louis Pasteur discredited the concept of spontaneous generation by demonstrating that even bacteria and other microorganisms arise from parents resembling themselves.
There is ample physical evidence that the earliest life forms on Earth were multicellular creatures, perhaps resembling some of our primitive fish.
When the earth formed some 4.6 billion years ago, it was a lifeless, inhospitable place.
Before the mid-17th century, most people believed that God had created humankind and other higher organisms and that insects, frogs, and other small creatures could arise spontaneously in mud or decaying matter
About billion years into its development, the Earth it was teeming with organisms resembling blue-green algae.
Tutorial
A radio broadcast left Earth in 1923. 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 0.50 and that, in a given planetary
system, the average number of planets that have
orbited in the habitable zone for 4 billion years is 0.40.
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 1923, distance in light years =
time since broadcast left Earth.
d = tnow - broadcast
d = 97
97 light years
Part 2 of 3
Since the radio signal travels in all directions, it
expanded as a sphere with a radius equal to the
distance it has traveled so far. To determine the
number of star systems this signal has reached, we
need to determine the volume of that sphere.
V, =
Vb…
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
Submit
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Chapter 13 Solutions
Life in the Universe (4th Edition)
Ch. 13 - Prob. 1RQCh. 13 - How does the speed of light affect the possibility...Ch. 13 - Prob. 3RQCh. 13 - Prob. 4RQCh. 13 - What is the rocket equation used for? Based on the...Ch. 13 - Prob. 6RQCh. 13 - Discuss a few ways of reaching the stars (other...Ch. 13 - How would time dilation affect space travel at...Ch. 13 - Prob. 9RQCh. 13 - What is the Fermi paradox? What two seemingly...
Ch. 13 - Why does it seem that other civilizations, if they...Ch. 13 - What arc Von Neumann machines? How do they affect...Ch. 13 - Describe the coral model of galactic colonization....Ch. 13 - Briefly discuss possible motives for galactic...Ch. 13 - Summarize the three general categories of possible...Ch. 13 - Briefly discuss the profound implications of the...Ch. 13 - What known problems were solved when Einstein...Ch. 13 - Prob. 18RQCh. 13 - Besides the idea that you cannot reach the speed...Ch. 13 - Prob. 20RQCh. 13 - Prob. 21TYUCh. 13 - Prob. 22TYUCh. 13 - Each of the following describes some futuristic...Ch. 13 - Prob. 24TYUCh. 13 - Prob. 25TYUCh. 13 - Prob. 26TYUCh. 13 - Prob. 27TYUCh. 13 - Prob. 28TYUCh. 13 - Prob. 29TYUCh. 13 - Prob. 30TYUCh. 13 - Prob. 31TYUCh. 13 - The amount of energy that would be needed to...Ch. 13 - The rocket engines of our current spacecraft are...Ch. 13 - Suppose that a spaceship was launched in the year...Ch. 13 - Prob. 35TYUCh. 13 - Prob. 36TYUCh. 13 - Which of the following questions best represents...Ch. 13 - Prob. 38TYUCh. 13 - Which of the following is not relative in the...Ch. 13 - Prob. 40TYUCh. 13 - Prob. 41POSCh. 13 - Prob. 42POSCh. 13 - Prob. 44IFCh. 13 - What's Wrong with This Picture? Many science...Ch. 13 - Large Rockets. Suppose we built a rocket that...Ch. 13 - Prob. 47IFCh. 13 - Solution to the Fermi Paradox. Among the various...Ch. 13 - Prob. 50IFCh. 13 - Cruise Ship Energy. Suppose we have a spaceship...Ch. 13 - Prob. 52IFCh. 13 - The Multistage Rocket Equation. The rocket...Ch. 13 - Relativistic Time Dilation. Use the time dilation...Ch. 13 - Testing Relativity. A + meson produced at rest has...Ch. 13 - Prob. 57IFCh. 13 - Prob. 58IFCh. 13 - Prob. 59IFCh. 13 - Prob. 60IFCh. 13 - The Turning Point. Discuss the idea that the...
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