Astronomers frequently say that "there are more stars in the universe than there are grains of sand on all the beaches on the earth". Given that a typical grain of sand is about 0.5 – 1.0 mm in diameter, estimate the number of grains of sand on all the earth's beaches. The diameter of the Earth is 12,742 km. a) About 1011 b) About 1016 c) About 1021. 6. Assume that a typical galaxy contains about 200 billion stars and that there are more than 150 billion galaxies in the known universe. Estimate the total number of stars in the universe. b) About 1022 a) About 1010 c) About 1016. 7. Compare the values of the number of grains of sand in all earth's beaches (from problem 5) with the number of stars in the universe (from problem 6) – which is greater? a) Number of sand grains b) number of stars c) they are about the same.

Astronomers frequently say that "there are more stars in the universe than there are grains of sand on all the beaches on the earth". Given that a typical grain of sand is about 0.5 – 1.0 mm in diameter, estimate the number of grains of sand on all the earth's beaches. The diameter of the Earth is 12,742 km. a) About 1011 b) About 1016 c) About 1021. 6. Assume that a typical galaxy contains about 200 billion stars and that there are more than 150 billion galaxies in the known universe. Estimate the total number of stars in the universe. b) About 1022 a) About 1010 c) About 1016. 7. Compare the values of the number of grains of sand in all earth's beaches (from problem 5) with the number of stars in the universe (from problem 6) – which is greater? a) Number of sand grains b) number of stars c) they are about the same.

Astronomy

1st Edition

ISBN:9781938168284

Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff

Publisher:Andrew Fraknoi; David Morrison; Sidney C. Wolff

Chapter20: Between The Stars: Gas And Dust In Space

Section: Chapter Questions

Problem 21E: One way to calculate the size and shape of the Galaxy is to estimate the distances to faint stars...

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