Can kinetic energy be reconverted to work?
122. Does any location get the same number of sunshine hours per year? Is the period of light and dark the same for every place on earth over the course of a year? Example: Do Nome, AK and Rome, Italy get the same number of hours of light and dark per year (ignoring intensity differences). Big question in our family recently!! Thank You !! Reply A good question–and congratulations for having a family with such wide-ranging interests! Intuition seems to say “yes”, but the challenge is to demonstrate it without any calculations. Below is one try. Certain approximations are necessary. You ignore the actual size of the Sun’s disk–but count as “light” times when the center of the Sun is above the horizon and as “dark” times when it is below the horizon. Also we ignore the ellipticity of the Earth’s orbit, which causes the speed of the Earth’s motion around the Sun to vary, but assume that it moves at constant speed. (About that variation, see Skepl2A.htm. With those assumptions the Sun, t
