Retroreflector

I had some spare mirrors from [this project](https://www.thingiverse.com/thing:4622866), so I decided to make a retroreflector. Retroreflectors reflect incoming light back to its source. This is done regardless of the light source orientation related to the reflector. This is super useful since it does not require that the mirror is orientated in a special way to reflect light back to the source. In fact, they have some mirrors like this on the moon to measure the distance to the moon by shining a laser on the reflectors and measuring the round trip time. When you look into it, you can see your eye centered where the three mirrors come to the corner. For cameras, you can see the lens centered in the corner no matter the orientation of the retroreflector.

This project uses 2-inch mirrors. My mirrors were .067 inches thick. The results are not too good because the cheap craft mirrors are not [first surface mirrors](https://en.wikipedia.org/wiki/First_surface_mirror), but the result