January 19, 2015
“There was a young lady named Bright” – A summary of “A Brief History of Light”, relatively speaking
The first cafe of 2015 could not have been more interesting and well attended! And those present were particularly lucky, because thanks to technical issues, the video of the afternoon is slightly abbreviated.
2015 is not only the International Year of Light and Light Based Technologies (celebrations are in progress in Paris at the time of writing this), but it is also the 100 year anniversary of Einstein’s equations for General Relativity. While humans have known about light in some form from the beginning of time, understanding it and being able to harness its properties took an inordinate amount of time and effort, and was not without controversy. Although one may have heard the names of some of the physicists who profoundly influenced our understanding of light, the details are mostly known only to “insiders”. On Saturday, thanks to Professor Stone, Tilde Cafe attendees got a chance to peek into this relatively arcane realm, and get a sense of the breadth of the scientific contributions of these individuals, and also a little about the process of their discoveries. More importantly, an appreciation of the relationship between theoretical and experimental physics was evident – it’s what contributed to recognizing the dual wave and particle properties of light.
Doug Stone’s recent research is focused on lasers and their novel modifications and applications, for which he and his colleague Hui Cao received the Willis E. Lamb award for Laser Science and Quantum Optics just last week. A poorly appreciated fact, but one which long time Tilde Cafe attendees might have recalled from Steve Girvin’s talk in 2010, is that Einstein laid the foundations for lasers, the acronym for light amplification by stimulated emission of radiation. What few will have known before this cafe, is that lasers which produce light by themselves are actually oscillators and not amplifiers, rendering the acronym for them as LOSER – however, due to this unfortunate acronym, “laser” is used more broadly!
Many thanks, Doug, for an informative and entertaining afternoon. It was wonderful to see such a great turnout and while the video has been posted on the youtube channel, it doesn’t hold a candle (pun intended) to having been there that afternoon – https://www.youtube.com/user/tildecafe
To make up for the footage lost to posterity, we close the circle from the subject line for this email, with this limerick:
There was a young lady named Bright
Whose speed was far faster than light;
She set out one day
In a relative way
And returned on the previous night.
– A. H. Reginald Buller (from Punch, 1923)