Yesterday's mail brought a surprise from the blogosphere:
Gary Santoro, of the Mediaburn Radio Weblog sent me a copy of John Walsh's 1958 Photometry, a survey of the art of light measurement forty five years ago. As many great technology books of that era, this one is lavishly illustrated with line drawings in ink. This style of technical hand drawing has been left behind by modern typefaces and computer generated graphics.
None-the-less, there is a romantic quality to the old style that conveys a quiet confidence that the artist or the scientist can comprehend every last detail of the subject. Today, we know our limits.
I am especially interested in the sections on sky photometry (above), stellar photometry (right) and of course, colorimetry (below). These instruments - photometers - are superseded by much more advanced techniques that can image and make light readings at the same time. In the fifties however, another antique device, silver halide/gelatin film, was the only means of obtaining a permanant image from a telescope. I guess it still is.
Thanks Gary!!!
Nasa has put up their picture of Mars taken last night from the Hubble orbiting telescope. Lucky dogs - they don't have any clouds.
