How does the light gathering power of the telescope compare to that of
the Keck telescopes?
To do this exercise you will need to measure or find the diameter of the objective lens of each telescope and then ratio the squares of the two diameters, since the area of a circle depends on the radius squared (since we are taking a ratio, the "2" in "2*radius = diameter" cancels).
Example: D_{1} = 10 cm, D_{2} = 200 cm
Ratio = 200^{2}/10^{2} = 400. That is, the larger telescope is 20 times as large, but has 400 times the light gathering power.
The 8-meter Keck telescope in Hawaii is one of the largest in the world.
Compare its light gathering power to our telescope (make sure you use the
same units for all quantities -- 1 meter = 100 centimeters).