14. Cardboard parabolic dish

<Intro>

When I was in 9th grade, I used to do a project for the physics class, in which we have to design a solar oven, and for this, my design is basically a reflective parabolic dish on an adjustable stand/base. The reason why I went with a parabolic design is that it has the ability to concentrate the sunlight to a point due to the curved shape of the dish. More specifically, because the dish is curved, as the beams hit the dish (assuming it's straight on), it reflects back to where the focal point is like a mirror. With all the angles that make up the dish, it makes sure that when the beams reflect, it aims to where to focal point was, thus allowing the point to reach high temperatures.

<Side view>

<Operation>

To start with, the whole dish is made out of cardboard, which is first cut into a circle (divided into 8 slices), and then cut up the slices with wedges of spaces in between, thus allowing enough room to bend the cardboard up until their sides fully touch one another, making a dish. Once the dish is secured with glue and then secured to a PVC stand setup, I added aluminum foil as a reflective material for the dish. Looking back, it doesn't seem reflective as a mirror, but that would do for now. 

<The shine>

When testing it out on an overcast day, I see that it does work, at least when shining my hand to where the focal point was (Don't try this), however, I can see that it's not hot enough to cook various foods like smores, which one of the disadvantages of using the parabolic oven is that you need to make adjustments to make sure it can focus the most amount of light to a point so it can cook the food more easily. With it, it seems that I would have to wait for some time till the day becomes sunny.

<Front view>

<Overall>

Despite the hurdles, seeing it work to begin with felt like an accomplishment, and I noticed that I was the only one who went with the dish design, while the rest of the students went with a more familiar solar box oven that used a reflector and a container with a plastic wrap to trap the heat in. With that, my dish oven seemed so unique that it was even displayed at my high school as a trophy.