making popcorn by parabokic antenna
In English
At long distances, radio waves are essentially traveling in parallel. When the waves hit a parabolic reflector, they are reflected and concentrated into a single point called the focal point of the reflector. When a receiving device is placed at that point, more waves and a stronger signal can be collected.
Today, we will apply this principle to solar heat energy. We will collect sunlight with a parabolic antenna to make popcorn.
Here is a converted parabolic antenna covered with reflective tape. It has a radius of .8m. A pan placed or held near the focal point can collect the solar heat energy from the parabolic reflector..
The question is, "Can we gather enough heat to pop popcorn?"
This uses the same principle that we use when we light paper on fire with a magnifying glass.
Let's calculate how much energy we can obtain from the sunlight collected by our parabolic antenna.
First let's look what is called the Solar constant, that is the amount of incoming solar radiation per unit area of a plane perpendicular to the sun's rays. It is about 1370W/m2
The the plane perpendicular to the sun's rays formed by our parabolic antenna is 2.0m2: S=πR2 = 3.14×0.8×0.8=2.0m2
Don't forget the heat energy loss to the surrounding air and absorbed by the surface of the reflector. Here we will make a conservative estimate that half of the energy is lost. Only 50% of the energy gets to the pan. So we will multiply our equation by 0.5, So....Let's calculate, .... multiply the solar constant 1370W/m2 ×the area perpendicular to the suns rays 2.0m2× the portion of total energy reaching the pan 0.5 = that gives us.. 1370 W!!!
This is over 500 watts more power than the electric popcorn popper! Now watch the next segment and see how our experiment turned out.