Dr Dan Credgington spoke at the Royal Society about the future of light on earth in his Café Scientifique: Are you seeing clearly? While the ability to create light has transformed our lives, here Dan asks what more we could dream for light-emitting technology.

An archaeologist unearthing ancient treasure is looking for windows back into the past, to understand the people of that time, how they lived and what they hoped for. The snapshot we gain is always imperfect, which is one reason why the modern tradition of leaving time capsules for others to discover is both a recognition of impermanence and a display of generosity to future generations. How could our children’s children understand our lives as we might want them to, if we don’t help them? Can we give them a leg-up in their own trawl through some future ancestry website?

Time capsules come in many shapes, and one that I find most interesting is a list produced by the scientist Robert Boyle over 300 years ago. It’s a wish list, which already tells us a great deal about the constants of human nature. I write mine on the screen of my smart phone, he wrote his with a quill, but the content is all too familiar. In this case, the wish list is of things he hopes science and technology might make possible, which naturally begins with “The Prolongation of Life” and “The Recovery of Youth“. You and me both, Robert. More interestingly, it tells us of the challenges of his day – making scientific instruments more precise (“The making of Parabolicall and Hyperbolicall Glasses”) the dangers and unpredictability of travel (“A Ship to saile with All Winds”, and “A Ship not to be Sunk”), the need to understand and control the chemistry, physics and biology of the world around him (“The Transmutation of Metalls” and “The Transmutation of Species in Mineralls, Animals, and Vegetables”) and the ever-present need to improve the productivity of agriculture (“The Acceleration of the Production of things out of Seed”).


People have long imagined what can be done with light. What’s on today’s wish list for light technology? © The Royal Society http://ow.ly/QbkBb

A couple of weeks ago, I asked the audience at a Royal Society’s Café Scientifique discussion a question: If you could do anything at all with light and lighting, what would it be? For the past hour or so we had been talking about the rapidly spreading technology of light-emitting diodes (LEDs) – a more focussed theme than Boyle’s, but still the same idea: tell me your wish list. They were given a piece of paper with the question and a large, imposing blank box, and left to their own devices. At the end of the event, more than half had tried their hand at inventing something new, of imagining what could be done beyond the familiar and the everyday. The answers were all very interesting, and some quite surprising.

Some related to the possibility that new LED technologies will be cheap, non-toxic and disposable: LED lipstick for the ultimate cyberclub look, LED greetings cards (if tinny jingles can sell, won’t videos be even better?), edible LEDs (taking birthday cakes into the 21st century?) and pens which write with glowing ink. Several imagined glowing bicycles and illuminated cycle gear to protect the growing numbers switching petrol for pedals. Changing the technology of the everyday, as it were.

Some gazed further over the horizon to imagine new technologies: modified eyes, for example, for perceiving the world beyond the visible spectrum – would this have occurred to people in an age before space telescopes and night vision cameras? Body-powered lighting, using humans as batteries and recognising how much energy first-world citizens have to spare. And of course, the Star Trek Holodeck – creating a communal virtual reality to trick the senses.

Others were inspired by problems of the here and now. One example (and not a new one) was the search for higher food productivity – coloured LED lighting to grow plants using much less energy, and so much more efficiently, than is done currently.  Another was cutting down on wasted energy with innovations like motion-activated street lights.

Perhaps the most interesting of all tell us something about how we relate to one another. In an age of emojis and avatars, maybe we shouldn’t be surprised by the idea of colour-changing clothing that reveals to others our emotional state, or that broadcasts our level of concentration to those we are talking to. Or even the person we are listening to…

I won’t venture to analyse what future generations might make of such a list, or what it tells them about us. It’s obvious though how much our wishes reflect our present, and that the genius of the creative mind rests in the difficulty of imagining something truly out-of-place or out-of-time. It is reassuring, though, to look at some of the other wishes on Boyle’s list and realise how much of what we hope for comes to pass:

The practicable and certain way of finding Longitudes”, solved by John Harrison, with his prize eventually awarded in 1773.

The Cure of Diseases at a distance”, the first smallpox vaccine produced in 1798 and the first antibiotic in 1928.

Potent Druggs to alter or Exalt Imagination, Waking, Memory, and other functions, and appease pain, procure innocent sleep, harmless dreams, etc”. Morphine was produced in 1804, followed by caffeine (1819), anaesthetic ether (1846), LSD (1938), Ritalin (1944), and Valium (1963).

The Art of Continuing long under water”, how much Boyle would have enjoyed finding out about the first commercial SCUBA in 1878…

Or “The Art of Flying” realised in 1903 at Kitty Hawk…

Or “The making Armor light and extremely hard” becoming the invention of Kevlar in 1965…

Then there’s “The use of Pendulums at Sea and in Journeys, and the Application of it to watches”. In 1969 the first quartz wristwatch went on sale.

Varnishes perfumable by Rubbing”, don’t forget the 1970s and 80s – scratch-and-sniff’s heyday!

The Cure of Wounds at a Distance”, remember 2001’s Operation Lindbergh.

And finally, “A perpetuall Light” celebrated in 2014 as the inventors of blue LEDs win the Nobel Prize for Physics.

Listen to Dr Dan Credgington’s Café Scientifique: Are you seeing clearly? audio now available on the Royal Society website.