There are several equations left over from my talk on light last Thursday – and I thought this splendid dinner might be an ideal occasion to present them. But I’d like to say a few words first.

These dark days in Stockholm emphasize the importance of light in our lives. It is equally important in our literature. The word, “light”, has vastly many meanings. Shakespeare, in Love’s Labours Lost, has one of his cleverer characters make fun of that by speaking the line, “Light, seeking light, doth light of light beguile …” Loosely translated, that means: Intellect, seeking understanding, easily fools reason. – Or perhaps it’s the other way around.

Among these meanings for light you have lightness of weight or burden. In fact, when I read John Hall’s and Ted Hänsch’s huge lists of people they thanked for help in building lasers, I couldn’t help recalling a Chinese proverb: “Many hands make light work.” Our experimental friends must wonder in turn how theorists collaborate. How many theorists does it take, for example, to screw in a light bulb? The answer is three: One to climb the ladder and hold the bulb, a second to rotate the ladder, and a third to write about the rotation group and its double-valued representations.

There are many celebrations centered on the transcendent theme of light. I think of the Summer Solstice, in which I understand some picturesque northern folk spend Midsummer’s Night dancing around Maypoles. But then there are also several celebrations, clustered around this darkest time of the year, that share the magical motif of light – the observance of the rebirth of the sun in many early cultures, the miracle of the oil lamps of the Maccabees, the Christians’ new star shining in the East, and the candles of the martyred Santa Lucia,… But if this is the season to celebrate the rebirth of the sun, logic would tell you that Midsummer’s Night must be the opposite. Still, you might have a hard time persuading the dancers on Midsummer’s Night that they are celebrating a funeral. The sun, of course, doesn’t have to die in order to be reborn every year. Now, that is also a metaphor for the way science progresses. Every field of study has its summer seasons, but must also be reborn from time to time.

We three physicists, a theorist and two experimental luminaries, are grateful to the Royal Academy and the Nobel Prize Committee for choosing this year to honor work on optics. Our work, we hope, is part of a rebirth of that science of light, and we are very pleased to see it rewarded in this most appropriate of seasons.