Yesterday, there was a solar eclipse that came across the continental United States for the first time in 99 years. As a physics major with an astrophysics focus, obviously I was not only aware of it but I was definitely going to watch. I had originally thought about traveling the 8+ hours from home to make it to an area in totality, but with PAX West being about a week away I couldn’t really afford the time off. However, my office was in a location of about 82% coverage, which while that is not totality it was definitely enough to be excited about.
Since I couldn’t take the day off of work, I had to figure out how to view the eclipse at the office safely. While I had a coworker who brought his Celestron solar binoculars, and solar rated welding goggles I wanted something that wouldn’t require me to trade back and forth. Naturally it was arts and crafts time to make a shoebox viewer!
While the physics and optics behind pinhole cameras is a bit detailed, construction of one is surprisingly simple. In order to make my viewer I just needed a shoebox sized box, a piece of aluminum foil, a piece of white paper, a thumb tack, tape and scissors.
First, I cut a section out of one of the short sides of the box. I then covered this section with the foil, and poked one small hole in the foil with the thumb tack. This makes the aperture of the pinhole viewer, and is the side of the box that will face the sun. The light from the sun will pass through this hole and hit the opposite side of the inside of the box.
Next, on the inside of the opposite side of the box I taped the white paper to create my projection screen. You don’t have to have paper on this side of the box, as the image will project on the box either way, but a white backing is helpful as it increases the contrast and helps make a clearer image.
Once the screen was in place I put the lid back on the box and cut my viewing window. In order to do that I simply cut a section about a quarter of the length of the box out on the side that the screen was attached. This way, when the pinhole was facing the sun, I was able to face away and look at the screen to see my projection.
While my viewer was very low tech, and not particularly pretty, it worked beautifully. Only about a minute after first contact I was able to see in my projection the shape of the moon crossing the circle of the sun. I was able to watch as more than 80% of the sun was blocked, and was even able to get photos of the projection. I was definitely thankful for my coworker sharing his goggles and solar binoculars for short periods so I could look directly at the eclipse, but there was something extremely satisfying about such a simple physics based craft allowing me to watch such a unique celestial experience.
RPG...IRL 