Here’s a fun weekend project for the do-it-yourself-ers among us: Burning a log using only sunlight!
The most efficient way to do this is by using a parabolic mirror, which channels the sun’s light into a single point and makes it intense enough to generate a significant amount of heat. YouTube user NightHawkInLight decided to take a stab at making one himself, and he did so with great success.
The best part of this build is that it seems relatively accessible to the everyman who has basic access to supplies and a limited amount of money with which to buy them. The reflective surface is a material you’re probably familiar with, especially if you’ve been watching Better Call Saul: Aluminized mylar, which is most commonly sold as space blankets.
The process is relatively simple: The reflective surface is created by creating a sealed circular edge on the surface of the space blanket so it can be inflated. Then, that bubble is locked in place with a few layers of fiberglass, and that shape is further solidified with a plastic frame. As the video shows, this particular build was not without its missteps, but he thought on his feet, learned along the way, and ended up with a result that was super effective.
As for the science behind why a parabolic mirror works, it’s pretty basic: The shape, which is called a paraboloid, reflects rays of light (or sound, radio waves, or other kinds of energy) that enter the mirror parallel with each other to a central point. Here’s what that looks like with a two-dimensional parabola, so just picture this happening in 360 degrees:
Check out the video above, and let us know if you think this build could be improved in any way, be it with better materials, stronger design, or whatever else you can think of.