Jacob Hoover – Projects

A random idea turned into over a month of work and all I’ve done is what has already been done, but I did it my way.

There’s a unique position of the sun for every time of day on every day of the year. Sundials operate on this principle by projecting a shadow onto a plane (typically) which then has markings to indicate the time. The sundial I devised here skips the shadow step and instead projects the sunlight itself.

The idea is simple, point a bunch of fiber optics toward the sky and use the output of these fibers to tell the time. In practice, this is challenging. The number of fibers, their placement and geometry, the acceptance angle of the fibers, the installation process, and finally generating useful information out the other side is an intense bit of work that, as usual, required multiple iterations before a functioning prototype was generated.

Fiber Optics

When light passes from one medium to another, like air to water, it will bend or refract. This is why a straw in a glass will appear in two different locations. The caveat here is that refraction only works at certain angles. If the light hitting the air-water boundary is at a very shallow angle, instead of moving into the other medium it will instead reflect. It is this reflection that fiber optics use to transmit light efficiently. As long as the fibers are not bent in such a way as to make that shallow angle too large, the light will almost perfectly reflect back into the fiber – total internal reflection.