In the rarified circles of analog computing, today is a
somewhat reverent anniversary. On June 14, 1822, Charles Babbage first proposed
his difference engine to the Royal Astronomical Society, which many view as the
birth of computing as a formal, widespread scientific pursuit.

That’s probably overstating things a bit.

For those who don’t know, Babbage’s difference engine was an
analog, mechanical computer similar to a limited-use adding machine—effectively
an ancient ancestor of the modern computer. What most techno-geeks fail to
realize is that Babbage never actually built his original difference engine.
Despite a healthy series of grants from the British government, Babbage’s first
design never came to fruition—and the failure led to some minor scientific
controversy during the early 19th century.

Babbage did eventually produce a revised, superior design,
known as Difference Engine #2. Though some modern scholars were skeptical about
the plausibility of Babbage’s later designs, a 1989 London Science Museum
project largely allayed those skepticisms, when the organization constructed a
contemporary difference engine based on Babbage’s blueprints for Engine #2. It
worked perfectly (and continues to do so), validating Babbage’s place as
perhaps the foremost analog computing visionary of the 1900s.

Of course, this is not the same as being the inventor of the difference engine. While
Babbage certainly made the difference engine famous, and his designs are
arguably the first viable concepts for such a device, Babbage merely
rediscovered the concept of analog computing.

In fact, history often credits J.H. Mueller, a German
military engineer, with first conceiving of a mechanical difference engine in 1786.
But Mueller’s speculations never led to the creation of an actual working
difference engine, which places him in the same company as Babbage.

Several inventors took Babbage’s designs and built their own
analog computing engines in the mid 1800s. Perhaps most notable among this group
was Per Georg Scheutz, a Swedish inventor who exhibited a working difference
engine at the 1855 Paris World’s Fair.

All of these devices were descendents of the clockwork
timepieces that came before them, which demonstrated that mechanical devices
could accurately incorporate and represent mathematical functions and
expressions. This tradition stretches back to the complex clocks of
18th-century Europe—and from there back to the mechanical celestial models of
13th-century Arabia.

However, in 1900, an artifact recovered from a Mediterranean
shipwreck suggested that this timeline of clockwork computing may stretch back
even further—to ancient Greece.


What ancient artifact recovered from a Mediterranean
shipwreck forced a radical rethinking of the development of clockwork devices
by suggesting that ancient Greeks could have constructed primitive ancestors of
19th-century analog computers?

The so-called Antikythera
is a crudely preserved mechanical device that appears to have
modeled the movements of the sun, moon, and several planets—and its origin
dates back to the 1st century BC.

The device comes from the 1900 discovery of a shipwreck between
the Greek islands of Crete and Antikythera. Sponge divers recovered several
artifacts from the wreck, including a number of statues.

The chunk of “rock” that would come to be known as
the Antikythera Mechanism originally appeared to be among the least remarkable
items found on the sunken vessel. It wasn’t until 1902 that archaeologist
Spyridon Stais noticed something irregular about the artifact: a gear poking out
of its corrosion-encrusted form.

Flash-forward a few years, after X-ray scans of the artifact
revealed the remains of a complicated internal gear system, and you have what
looks to be an ancient analog computer. The gears resided in a long-lost wooden
box, the face of which likely contained astrolabe-like images of the solar
system that moved in sequence, likely giving ancient astronomers and
astrologers a reasonably accurate tool for predicting planetary positions
months and years into the future.

Scholars are still fighting about the exact level of
mechanical complexity the original device likely employed, but most agree that
the Antikythera Mechanism was a working clockwork model of the Greek concept of
the solar system—based on a flawed epicyclic principle, well before the days of
Copernicus and Kepler—but was of sufficient technical sophistication to reset
the entire presumed timeline of mechanical technology.

In one extreme analysis, the Antikythera Mechanism appears
to employ a differential gear—a clockwork component that historians previously
believed didn’t emerge until the later stages of the Renaissance. Suddenly all
those apocryphal accounts that Archimedes (who was Carthaginian, not Greek, but
why quibble?) had a working mechanical planetarium don’t seem so far-fetched.

In any case, it seems that Babbage’s quest for a difference
engine began not in 18th-century Germany, but in 1st-century BC Greece. That’s
not just a major reset of the computer historian’s clock, but also some
time-quaking Geek Trivia.

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The Quibble of the Week

If you uncover a questionable fact or debatable aspect of
this week’s Geek Trivia, just post it in the discussion area of the article.
Every week, yours truly will choose the best post from the assembled masses and
discuss it in the next edition of Geek Trivia.

This week’s quibble comes from the May 24 edition of Geek
Trivia, “A
bridged version,”
which was a rerun of a Classic Geek from Feb. 4,
2004. TechRepublic member Grax
busted me on my poor geographic terminology.

“The article says: ‘[Da Vinci’s] original bridge plan
called for a massive, 240-meter-wide stone structure that would span the Golden
Horn inlet of the Bosphorus River in present-day Istanbul.’ The Bosphorus is
the strait that joins the Black Sea with the Sea of Marmara. It is not a ‘river’ or even a

Alas, you’re right, dear reader—I’ll never make it as a
cartographer. Thanks for the correction, and keep those quibbles coming.

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The Trivia Geek, also
known as Jay Garmon, is a former advertising copywriter and Web developer who’s
duped TechRepublic into underwriting his affinity for movies, sci-fi, comic
books, technology, and all things geekish or subcultural.