THE HUMBLE TELESCOPE
\n David Daye
\n Columbus, OH<\/p>\n
A quick, fun telescope project for kids and lazy adults is the
\nHumble Telescope, a solar viewer that can produce foot- to yard-
\nsized images of the sun, including sunspots down to a few earth
\ndiameters. And although far simpler than a similarly-named
\ninstrument, the Humble Telescope may be a more reliable, cost-
\neffective way of viewing of detail on a heavenly body.<\/p>\n
Since a pinhole camera works not by refraction but by simple
\ngeometry, it follows that a tiny MIRROR should create as good an
\nimage as a pinhole in a lightproof box. The advantage of the
\nmirror is that you can shoot its image anywhere you please, into a
\ndarkened room far enough back to produce big if somewhat dim
\nimages. You can only do that with a pinhole by making a barn-sized
\nviewer.<\/p>\n
As with the Other telescope, the key element here is a special
\nmirror — but this one only needs to be a flat FRONT-silvered one,
\nin almost any shape of 1 square inch or more. While you, too, can
\nhave one specially made by a government contractor, you can also
\npick one up in any shopping mall parking lot, where they are
\nproduced by the timeless forces of automobile fender-benders.<\/p>\n
The shiny part has to be on top, because the image is ruined
\nif light has to pass in and out of glass. Clamp the mirror to your
\ncamera tripod (kids: stick it on a dry rock with bubble gum). Now
\nmake the pinhole “mask” that does the actual imaging. Take your
\nbusiness card (the gum wrapper) and poke a 1\/8″ to 1\/4″ hole with
\nyour executive pen (rusty nail).<\/p>\n
Open the window of your viewing room–glass, screen and all–
\nand block off most of the opening with shades or towels. Go out
\ninto the sun and use the light of the full mirror to aim the image
\ninto the room. (Prop your mounting rock into position.) Gently
\ntack the mask over the mirror with tape so that only the pinhole
\narea is exposed.<\/p>\n
Dash in and watch or photograph at will! Sunspots appear as
\ndim smudges that wiggle and move along with the image of the disk.
\nYou have about a minute before the disk tracks away from the
\nwindow. The farther the mirror from the wall, the bigger but
\ndimmer the image. The bigger the pinhole, the brighter but
\nblurrier the image.<\/p>\n
For better viewing: 1) Set up a flat, white cardboard or
\nscreen for the image. 2) Keep the room the same temperature as
\noutoors to minimize heat distortion. 3) Keep the room dark as
\npossible so as to see more dim sunspots. 4) Have parent or teacher
\ndo the aiming so you can keep your eyes used to the dark.<\/p>\n
