On Tuesday, October 6th, the Nobel Prize in Physics 2009 has been awarded to Willard S. Boyle and George E. Smith, the fathers of digital photography. In 1969, the two scientists from Bell Laboratories, in New Jersey, USA, invented a device able to capture light without using photographic film — the so-called CCD (Charge-Coupled Device).
The technology behind the CCD exploits the photoelectric effect, through which light is transformed into an electric signal. The explanation of the photoelectric effect won Albert Einstein the Nobel Prize in 1921. Boyle and Smith faced the challenge of converting this effect into a practical application, and designed a sensor able to catch light at several different points (called pixels) and to transform it, over an extremely short time lapse, into electric signals to then be transported and reproduced on a monitor or stored in a file.
The CCD has revolutionised photography and our approach to it for ever, as it is the very heart of tens of millions digital cameras produced in the world, including those integrated into many mobile phones and other gadgets. However, digital photography meant an even more remarkable revolution for science, and for astronomy in particular, a field which literally lives off the images of the sky.
All current professional telescopes are in fact equipped with digital sensors, vastly more sensitive than the old photographic plates astronomers made use of until only a few decades ago. Furthermore, CCDs can be used again many times and their output signal, being already in digital form, is ready to be stored and analysed by computers. In fact, without this new technology, it wouldn’t have been possible even to conceive the massive catalogues containing detailed information about hundred of millions of far-away galaxies, which allowed astronomers to understand the properties of the Universe better and better.
Boyle and Smith shared the most prestigious of all scientific awards with physicist Charles K. Kao, for his work concerning the transmission of light signals through optical fibres. Optical fibres, just like the CCD, also contributed to the digital revolution, making the sharing of data and information possible over increasingly short time intervals. Without them, the internet as we know it could not exist.
It is interesting to note how, during the International Year of Astronomy 2009, the Nobel Prize in Physics has been awarded to three scientist whose research focussed on light and has contributed to the production of vital tools for astronomers, professionals and amateurs alike.
Image credit: NASA
Translated from Il Denaro, 08.10.2009
