Galileo for a Day

January is the month that Galileo made his most monumental discovery: spotting the four moons of Jupiter through his twenty-power spyglass.

Representatives of Instituto e Museo Nazionale di Storia della Scienza in Florence, Italy place the Galileo telescope into the display at the Franklin Institute in Philadelphia, Pennsylvania April 1, 2009.

It reminds me of a visit I made three years ago to the Franklin Institute in Philadelphia, when they had one of Galileo’s telescopes on display.

It looked rather mundane, like an extra-long paper-towel tube: a blotchy brown cylinder about three feet long and two inches wide made out of wood and varnished paper, all held together by rings of metal wire.  This instrument is one of only two still in existence made by Galileo.

Scheduled to give an evening lecture, I was fortunate to be at the Institute during the exhibit. Arriving early, I had time to peruse the Galileo exhibition and to my delight found the rooms, filled with astronomical artifacts from the Renaissance, deserted. Walking by the astrolabes, compasses, and quadrants, I turned a corner, and there it was: Galileo’s telescope, perched at an angle on two transparent rods. It was enclosed in a tall glass case, standing solitary and majestic on the polished wooden floor. I was alone with one of the greatest artifacts in astronomical history.

Despite the instrument’s plain appearance, it took my breath away. No one is sure what discoveries Galileo made with this specific telescope (he constructed many), but the aura of fame still surrounds it. I was able to kneel down to position my eye within an inch of the eyepiece, separated only by the glass case. Peering down the tube, which holds Galileo’s original lenses, I saw a blurry white spot. Alas, just the museum ceiling. But in my imagination, I was sighting the phases of Venus, mountains on the Moon, and Jupiter’s satellites for the very first time, just as Galileo did four hundred years earlier.