An Introduction to the Astrolabe, the Medieval Smartphone

Image by Anders Sand­berg, via Wiki­me­dia Com­mons

Asked to imag­ine the char­ac­ter of every­day life in the Mid­dle Ages, a young stu­dent in the twen­ty-twen­ties might well reply, before get­ting around to any oth­er details, that it involved no smart­phones. But even the flashiest new tech­nolo­gies have long evo­lu­tion­ary his­to­ries, and, in cer­tain notable respects, even the smart­phone has a medieval ances­tor. That would be the astro­labe, an espe­cial­ly fas­ci­nat­ing eleventh-cen­tu­ry exam­ple of which was recent­ly dis­cov­ered at the Fon­dazione Museo Minis­calchi-Eriz­zo in Verona. It was iden­ti­fied by Uni­ver­si­ty of Cam­bridge his­to­ri­an Fed­er­i­ca Gigante, who’s been mak­ing the media rounds to explain the con­text and func­tion of this strik­ing and his­toric device.

“It’s basi­cal­ly the world’s ear­li­est smart­phone,” Gigante says in an NPR All Things Con­sid­ered seg­ment. “With one sim­ple cal­cu­la­tion, you can tell the time, but you can also do all sorts of oth­er things.” In a visu­al New York Times fea­ture, Franz Lidz and Clara Van­nuc­ci add that astro­labes, which resem­bled “large, old-fash­ioned vest pock­et watch­es,” also allowed their users to deter­mine “dis­tances, heights, lat­i­tudes and even (with a horo­scope) the future.”

Gigante tells them that, when she got the chance to pay the Minis­calchi-Eriz­zo astro­labe clos­er scruti­ny, she could iden­ti­fy Ara­bic inscrip­tions, “faint Hebrew mark­ings,” and West­ern numer­als, which made this par­tic­u­lar arti­fact “a pow­er­ful record of sci­en­tif­ic exchange between Mus­lims, Jews and Chris­tians over near­ly a mil­len­ni­um.”

In the video above, Seb Falk, author of The Light Ages: The Sur­pris­ing Sto­ry of Medieval Sci­ence, demon­strates how to use an astro­labe to cal­cu­late the time. It is, admit­ted­ly, a more com­pli­cat­ed affair than glanc­ing at the screen of your phone, analo­gies to which have become irre­sistible in these dis­cus­sions. “Like the smart­phone, the astro­labe came into being dur­ing times of eco­nom­ic pros­per­i­ty — in that case, like­ly dur­ing the height of the Roman Empire,” writes Smith­son­ian ‘s Lau­ra Pop­pick. Though func­tion­al astro­labes were made of ordi­nary wood or met­als, the sur­viv­ing exam­ples tend to be ornate­ly engraved brass, which pro­vid­ed sta­tus val­ue to the high-end mar­ket. In that respect, too, the astro­labe resem­bles the “con­cep­tu­al ances­tor to the iPhone 7” — a device that, in the eyes of technophiles here in 2024, now looks fair­ly medieval itself.

Relat­ed con­tent:

How the Ancient Greeks Invent­ed the First Com­put­er: An Intro­duc­tion to the Antikythera Mech­a­nism (Cir­ca 87 BC)

Watch an Accu­rate Recon­struc­tion of the World’s Old­est Com­put­er, the 2,200 Year-Old Antikythera Mech­a­nism, from Start to Fin­ish

Behold the Astro­nom­icum Cae­sareum, “Per­haps the Most Beau­ti­ful Sci­en­tif­ic Book Ever Print­ed” (1540)

The Ancient Astron­o­my of Stone­henge Decod­ed

The World’s First Mobile Phone Shown in 1922 Vin­tage Film

Based in Seoul, Col­in Marshall writes and broad­casts on cities, lan­guage, and cul­ture. His projects include the Sub­stack newslet­ter Books on Cities, the book The State­less City: a Walk through 21st-Cen­tu­ry Los Ange­les and the video series The City in Cin­e­ma. Fol­low him on Twit­ter at @colinmarshall or on Face­book.