Monday, October 05, 2009

Pre-Keplerian Keplerian

Here's an interesting discussion of paintings by Jan Brueghel the Elder (son of the famous Pieter Bruegel the Elder) that depict telescopes in larger scenes, including a Keplerian refracting instrument previously thought not to have existed until a couple of decades later. The original study is by Paolo Molaro and Pierluigi Selvelli at L'Istituto Nazionale di Astrofisica in Trieste. It notes that one painting in particular - a collaboration between Brueghel and Peter Paul Rubens titled "The Allegory of Sight" of 1617 - shows a Keplerian telescope that predates the first reference to a Keplerian telescope in 1631. Kepler first theorized in 1611 that a convex eyepiece would be a large improvement on existing telescopes. Physics arXiv blog explains:

The evidence is twofold. First is the length of the instrument: Molaro and Selvelli estimate that the extended instrument would be some 180 cm or so long. Keplerian designs are longer than the earlier Galilean designs (a misnomer, since Galileo did not invent them). Second is the size of the eyepiece, which appears to limit how close the eye can get to the eyepiece lens. That would only make sense in a Keplerian design.

The question then is who built this telescope, and what was it used for. Keplerian designs can achieve much higher magnifications than their Galilean cousins. That would have given its owner a significant advantage over anyone else scanning the heavens... If they'd troubled to look, that is.

Raising the question:

...Could it be that the owner of one of the most powerful telescopes on the planet failed to point it skywards? And in failing to do so, missed a chance at the kind of scientific immortality that Galileo was later to achieve?


Anonymous said...

Too busy checking out the neighbors...and naked angles?

MT said...

I think Galileo was pretty well primed for immortality before he built his telescope, and maybe the owner did point it at Saturn. It's conventional that credit for the find goes to the person to discover what's been found.