According to modern science, Earth is 4.5 billion years old and written human history extends about 10,000 years back. Suppose the entire history of earth is represented with a 1000 meter long timeline, with the birth of earth on one end and today on the other. What distance represents 4 billion years? How far from the end of the time line does written human history begin?

Question

Mathematics

Alexandria Reynolds

8 May, 11:59

According to modern science, Earth is 4.5 billion years old and written human history extends about 10,000 years back. Suppose the entire history of earth is represented with a 1000 meter long timeline, with the birth of earth on one end and today on the other. What distance represents 4 billion years? How far from the end of the time line does written human history begin?

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Answers (1)

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Chaim Callahan · Answer 1

888 8/9 meters 2 2/9 millimeters

Step-by-step explanation:

Length is proportional to time, so ...

1. (4 billion) / (4.5 billion) = L / (1000 meters)

... L = (1000 meters) * 4/4.5 = 888 8/9 meters

2. Using the same idea as in problem 1, the length is ...

... L = (1000 meters) * (10^4) / (4.5*10^9) = (2 2/9) * 10^-3 meters = 2 2/9 mm