I present to you: the astrolabe!

First in our “forgotten instruments of science” series, the astrolabe was once the astronomer’s multitool. You can still get them today; of course, most of the results when you google “astrolabe” may be astrology-related, but there are some artisans out there who make awesome scientific reproductions of historic instruments (and there’s some neat DIY projects to be found, too!). Here’s how one such artisan explains the astrolabe:

“The astrolabe is a model of the heavens. Based upon the assumption that the earth is the center of a spherical universe, this instrument reproduces on a flat surface the positions of the Sun and many of the major stars, as seen by an imaginary observer, outside the sphere looking upward . . . Because the astrolabe can be set to show the positions of these heavenly bodies at different times of day or night, on different dates and for different latitudes, the instrument is also a computer.”

from “THe Astrolabe,” by Norman Greene

In fact many astrolabes can do even more than show the positions of stars. Common functions include:

  • measuring the altitude of the sun
  • finding the time
  • finding the time of sunrise or sunset
  • navigating (by use of stars)
  • calculating angles (often used in surveying)
  • proving to your guests that you are a Bonafide Scientist

And certainly many more, over the years. We’re not sure who actually invented the astrolabe, but there’s evidence the Greeks and Romans were using them — essentially, as one article puts it, the astrolabe was the “smartphone” of ancient history. However, it was overshadowed by the clock and other instruments which were seen as more rational; because of its association with astrology, the astrolabe was discarded by western scientists around the 18th century. But today you can rediscover this neat instrument and always know where the stars are! (Unless, of course, you already have an app for that. 🙂 )

Selected Sources

Norman Greene’s website can be found here.

Poppick, Laura. “The Story of the Astrolabe, the Original Smartphone.” Smithsonian Magazine. Find it here.