Galileo for a Day

It looks 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. Now on display at the Franklin Institute in Philadelphia, this object is, in reality, a telescope made by Galileo, one of only two still in existence.



I was fortunate to be at the Institute last week, scheduled to give an evening lecture. 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 ago.


Above image: White-gloved representatives of Instituto e Museo Nazionale di Storia della Scienza in Florence, Italy, place the Galileo telescope into its glass display case at the Franklin Institute in Philadelphia, Pennsylvania. (Reuters)