At our Stellar Summer Days – School Holiday programme, we have been learning all about stars, sunlight and solar energy.
One of our activities has been using home-made solar ‘pinhole’ viewers to peer at a reflected image of the Sun. You can never look at the Sun directly, but if you use a correct solar viewer, you can view it’s disk safely without burning your eyeballs off! You may have seen solar viewing gasses before (especially with all the hype around the 2017 Great American Solar Eclipse). These glasses work by filtering out light. In comparison, the pinhole viewer projects the sunlight onto another surface, so you’re actually looking at a reflected image of the Sun rather than directly at it.
If you came along to the holiday programme and use our projection viewers and now want to recreate it at home, or if you’ve got young ones to entertain (or you’re young at heart) then follow the steps below and make your own. Happy viewing!
What you’ll need:
- Empty cereal box, or shoe box
- White paper
- Aluminium foil
- Small pin
What to do:
- Trace the bottom of the box on paper
- Cut out the traced rectangle
- Tape the paper to the inside bottom of the box
- Close and tape the top of the box
- Cut two holes in the top of the box
- Cover one hole with the foil, and tape it to the box
- Poke a small pinhole in the middle of the foil
- Take your pinhole projector outside and catch a glimpse of the Sun!
- If there are extra images in the box it means there are small holes in the box you didn’t notice when making it. You can block them off with tape.
How to use it:
Head outside and turn your back to the Sun, so that the sunlight shines into the pinhole foil.
Look through the hole that you did not cover, and you’ll see the Sun projected on the paper inside the box.
Note: Be careful not to put too much aluminium foil on the box, as if it’s very sunny outside the foil may reflect the sunlight. Always be careful and protect your eyes. Children should be supervised when using their viewers.
See this how-to video below on making your viewer. This video was made for viewing the solar eclipse, so please note that you won’t see that occur on your reflected screen BUT you will still see the disk of the Sun – and we think that’s pretty cool!
For more on our Solar System’s star, check out this Crash Course Astronomy episode with Phil Plait –