Four Centuries of Optical Zoom

August 25, 2009 on 5:40 pm | In astronomy, culture, people, science, technology | No Comments

Today marks  another landmark scientific anniversary – the 400th anniversary of Galileo’s first telescope.  It was on this day in 1609 that Galileo presented his prototype 8x-magnification telescope to the assembled Senate of Venice.  It was not the first telescope—that forgotten honor belongs  to Dutch astronomer Hans Lipperhey who built a simple telescope just one year earlier, in 1608—but it was the one that captured the attention of the Venetian merchants (who were most interested in its practical applications for shipping and navigation) and lit the candle of modern astronomy.  Galileo’s telescope allowed him to make precise observations that confirmed Copernicus’ heliocentric hypothesis and dispatched the notion of an Earth-centered universe.  Galileo’s published defense of this view in 1632 led directly to a papal trial in 1633, in which he was declared “vehemently suspect of heresy” and, after recanting his scientific views under threat of torture, his imprisonment sentence was commuted to house arrest.  Galileo remained in home near Florence (he was allowed one trip to seek medical advice near the end of his life) and was closely watched by church authorities until his death in 1642.  For a laugh, you can read the Catholic Church’s position on the Galileo controversy.

I, for one, am overwhelmed with humility by the science that Galileo’s telescope revolutionized.  It has brought us the likes of Carl Sagan, Maria Mitchell, Giovanni Cassini, and Stephen Hawking.  It brought us NASA and the space program, which will launch the space shuttle Discovery (STS-128) tomorrow at 1:10 AM EDT on a mission to the International Space Station.  There are no words that can, for the casual observer, capture the immensity of the expanding universe that telescopes have uncovered.  There is, at least, an image that comes close.  I am referring to the Hubble Ultra Deep Field, which is a composite image of a tiny region of space in the constellation Fornax, captured by the Hubble Space Telescope between 2003-2004.  It looks back over approximately 13 billion years, showing in just a tiny speck of sky that appears dark to the human eye the multitude of galaxies that existed only 400-800 million years after the Big Bang.  Every spot, blur, smudge, and speck on the image is an entire galaxy containing millions or billions of stars.  I will say no more about it, for if you’ve never seen it, this image deserves quiet reflection.  You can click on this small image to view the entire high-resolution version (18.1 MB).  In honor of Galileo, and without further blabbering from this blogger: