Cool Pic Archive Pages
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These images have been chosen for their uniqueness. Subject matter ranges from
historic events, to really cool phenomena in science and engineering, to relevant
place, to ingenious contraptions, to interesting products (which now has its own
dedicated Featured Product
category).
 A decade ago, I featured a quilt made by
Sara Schechner
that depicted the 26-inch Alvan Clark telescope. She later contacted me about having
learned of its appearance on RF Cafe. Sara is the curator of the Collection of Historical
Scientific Instruments at Harvard University, and holds a PhD from Harvard. She
wrote a book in 1997 entitled, "Comets, Popular
Culture, and the Birth of Modern Cosmology." It includes an extensive collection
of ancient drawings and etchings of astronomical events such as comets, meteors,
super novae, and solar system conjunctions, as well as implications of such phenomena
in significant world events. Astrologers made a pretty good living in the day by
convincing rulers and potentates that they had privileged insight into the significance
of such things.
While reading it, I ran across this etching (left) depicting "Archimedes (c.250
BC) beholding both [planets and comet] in his Jacobs Staff." The first thing that
struck me in the image is that the Jacob's Staff looks an awful lot like a log periodic
antenna. Compare the rendition to the log periodic antenna structure shown in the
Wikipedia image (below left). The physical size suggests its use is designed for
maybe the 900 MHz ISM band, or even higher bands. Could Archimedes actually
be pointing a directional radio frequency antenna at the comet in an attempt to
communicate with alien beings in a starship, rather than using it to determine the
celestial coordinates of the object? Maybe aliens provided it to him ;-)
 Log Periodic Antenna
 Jacob's
Staff
According to Wikipedia's explanation of how the Jacob's Staff was used, "The
navigator places one end of the main staff against his cheek just below his eye.
He sights the horizon at the end of the lower part of the transom (or through the
hole in the brass fitting) (B), adjusting the cross arm on the main arm until he
or she can sight the sun at the other end of the transom (C). The altitude can then
be determined by reading the position of the transom on the scale on the main staff.
This value was converted to an angular measurement by looking up the value in a
table."
OK, you might conclude given the context of the drawing that Archimedes was doing
just that. However, note that the bottom of the picture seems to be missing. Well,
with a little sleuthing in Cyberspace, I was able unearth the rest of the original
picture (right). It appears to support my theory - what do you think?
 This quilt, made by
HAD (Historical Astronomy Division,
of the American Astronomical Society) past chair Sara Schechner, is a copy of a
well-known photograph of the 26-inch Alvan Clark telescope as first set up at the
original USNO site in
Foggy
Bottom, c.1873. Simon Newcomb is at the eyepiece. Details of the quilt (size,
length of time to make, where displayed, etc.) are hard to come by.
Posted December 14, 2022
(updated from original
post on 4/26/2012)
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