Star-watching Diversion with Mr. Pulfrich

[P3D <doerfler@xxxxxxxxxxxxxxxxxxxx>]

The September, 1996, Astronomy magazine mentions on page 81
an alternate use of the Pulfrich Effect for bored astronomers,
to wit:

    Astronomy is a great hobby that evolves throughout your
    lifetime.  As you gain experience with your telescope, you
    may find yourself falling into the ranks of the so-called
    serious amateur astronomers.  Serious work is okay, but don't
    forget astronomy's fun side.  For autumn skygazing that's pure
    fun, check out Epsilon ([Greek letter epsilon]) Pegasi, the 
    Wiggle Star.  Viewed with a magnification of 50x to 75x,
    Epsilon proves to be a wide, unequal double star, hardly
    the visual treat to match any of the Gamma Gang.  But wait.
    Something magical happens when  you gaze at this pair while
    jiggling the telescope tube back and forth (be sure it's in
    a direction perpendicular to a line joining the two stars).
    The companion seems to sway to and fro like a clock pendulum.
    What's happening?  Its light takes longer to register on your
    eye's retina.  Each time the field reverses direction, the
    faint star seems to continue briefly in its original direction.
    The Wiggle Star provides an amazing illusion, and a pleasant
    change-of-pace from serious skygazing.

Now if you had two eyepieces (one for each eye) with a sunglass lens
over one, and wiggled the telescope (or binoculars) while watching a
single star, imagine how the single star would be flying around in 3D...

Or if you wore glasses with somewhat different lens distortions--
hey, maybe this explains how UFO sightings happen...  8^)

Ron Doerfler
(waiting for a clear night sky to haul out the binoculars)


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