Explain how Eratosthenes used the rays of the Sun to estimate the circumference of Earth and to demonstrate that the planet was spherical


Eratosthenes read about a well in Syene where sunlight reached the bottom at noon on the summer solstice, meaning that the Sun's rays were perfectly vertical. He measured the angle of a shadow cast by a column in Alexandria on the summer solstice, and used this angle to calculate the distance between the two cities, as a fraction of Earth's circumference. As the distance was already known, he could solve for the total circumference of Earth.

Environmental & Atmospheric Sciences

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A portion of the continental crust may move upward after a period of significant erosion to maintain balance through the process of ________.

A. lithification B. volcanism C. sedimentation D. metamorphism E. isostatic adjustment

Environmental & Atmospheric Sciences

Name three bodies in the solar system other than Earth that exhibit active volcanism

What will be an ideal response?

Environmental & Atmospheric Sciences

If you wanted to study the various shapes of different kinds of bacteria, you could use

A. a light microscope or an electron microscope. B. an electron microscope, but not a light microscope. C. the unaided eye. D. a light microscope or the unaided eye.

Environmental & Atmospheric Sciences

When rivers flow over a fairly uniform substrate with a uniform initial slope, they usually develop what type of drainage pattern?

a. Arc-shaped network b. Perpendicular network c. Dendritic network d. Parallel network

Environmental & Atmospheric Sciences