Laboratory Manual for Introductory Geology 4e

FIGURE 1.6 The white cliffs of Dover, England, seen at two different scales.
(a) The towering chalk cliffs of Dover, England stand up to
110 m (350 ft) above the sea.
(b) Microscopic view of the chalk (plankton shells) that the
cliffs are made of. The eye of a needle gives an idea of the
minuscule sizes of the shells that make up the cliffs.
EXERCISE 1.7
The Challenge of Perspective and Visualizing Scale
Name:
Course:
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The enormous difference in size between ourselves and our planet gives us a limited perspective on large-scale features
and makes understanding major Earth processes challenging. To appreciate this challenge, consider the relative sizes of
familiar objects (use Appendix 1.1 for conversions):
2 m
1 mm
1 m
12,800 km
Relative sizes of a dog and a flea.
Relative sizes of the Earth and a tall geologist.
(a) Assume that a flea is 1 mm long and that a dog is 1 m long.
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To relate this to our U.S. customary system of measurement, how long is the flea in inches? inches
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How many times larger is the dog than the flea?
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How long is the scale bar representing the flea?
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How long would the bar representing the dog have to be if the dog and the flea were shown at the same scale?
(b) Now, think about the relative dimensions of a geologist and the Earth.
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How many times larger than the geologist is the Earth?
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How large would the drawing of the Earth have to be if it were drawn at the same scale as the geologist? Give your
answer in kilometers and in miles. km miles
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Based on the relative sizes of flea and dog versus human and the Earth, does a flea have a better understanding of a
dog than a human has of the Earth? Or vice versa? Explain.
16 CHAPTER 1 SETTING THE STAGE FOR LEARNING ABOUT THE EARTH