I hope I am posting this on the right section..... In my Environmental Science Class, we are to design and build a solar oven(without using solar panels!). We will be baking a cookie. Me, being a "mathematician", remembered something about a parabola, that if light ray hits anywhere on the interior surface, it will reflect through its focus. I assumed for realistic three dimensions, this will work for a circular paraboloid(confirm that please). i.e. zr^2=x^2+y^2 If I put a cookie at its focus, it should cook well(or ignite). The surface of the circular paraboloid will be reflectable I have a few questions- 1. How exactly DO I create the frame of a circular paraboloid? I can't just stare at my calculator and yell "materialize!" 2. What material should I use that has a high albedo, but is cheap-ish? I will spend no more than $30 on this. 3. How will the size of the paraboloid effect the heat of the cookie? THE HOTTER THE BETTER. I want a high powered oven, if the cookie turns to ash, I'd be ecstatic.