Backyard Energy

Besides electronics, electricity is used to create heat or motion.  This dish can focus heat.  I still have to see if it will cook a hot dog.  A sphere can also focus light like a parabola.

To collect and store mechanical wind energy, add up the energy of pinwheels and store energy in a grandfather-clock-style pendulum.

To make a pattern for a parabolic dish, divide the dish into 3 or more sections called “lunes” which will be hemispheric.  The height of each pattern will be the length of a parabolic curve, from “further links” below.  The width will be width w to a circle (w x 2 X pi X radius) / number of sections.

The CRC Handbook of Chemistry and Physics calculus formula for the derivative of a curve #274 for some reason produces a straight line.

Further links:

Math Forum
Wolfram Alpha > see parabolic curve or lune
numericana.com > Parabola