You are likely aware that a total solar eclipse will be viewable
in the United States on Aug. 21 (hours and locations vary), but
"viewable" does not mean with the naked eye. Staring directly at the
sun can cause blindness, of course, but there are ways to safely watch the
eclipse.
Let's get clear on things you cannot use to watch the
eclipse: sunglasses are out, as are 3D movie glasses (what are you thinking?!)
and binoculars. Even those glasses you ordered from Amazon specifically for
this event might not be safe, and at this point, eclipse glasses for sale
online are expensive or not available until after the eclipse (tres helpful).
But don't despair; you can make a pinhole camera from easily
obtainable items. There are a few kinds of pinhole cameras, some made with
boxes and cylindrical containers, but you can also make do with two sheets of
card stock or paper. Let's start there.
Getting Started
Get two pieces of card stock, the kind that you used for
projects in grade school, or plain paper, though if you go with paper, your
camera will be far flimsier. Then get either a sewing needle, paper clip, or
thumbtack.
Viewing
Before the eclipse, take out your pierced piece of card
stock or paper. Put the plain piece on the ground. Stand with your back to the
sun and hold the card stock or paper with the hole in it above your shoulder so
that the sun shines through it and projects onto the plain piece on the ground.
Look at the piece of card stock or paper that is on the ground during the
eclipse.
Take a sheet of stock and make a small round hole right in
the middle of it with the sharp object of your choice from the list above. Or,
if you have aluminum foil, cut a small square in the middle of the piece of
paper, tape over it with aluminum foil, and make a small hole in the foil.
You can adjust the size of the image by moving the card
stock or paper that is over your shoulder closer or further away from the piece
on the ground. Closer makes the image smaller and further away makes it larger.
Is it a little like Plato's cave in that you're experiencing a shadow of the
thing and not the thing itself? Yes, but you will not be blind, so there's
that.
