I’m blaming my fellow diarist Kate Blincoe. Recently, she extolled the joys of a UV torch, on the strength of which I bought one, have become addicted and now see the world entirely anew.
Ultraviolet is a shortwave, high-energy light normally undetectable to the human eye, but it is also damaging to many life forms. In the late Proterozoic ,most life flourished only under the sea, until the protective UV shield – the ozone layer – formed, 15km to 30km above our heads.
If a UV torch is pointed at plants and animals after dark, its photons interact at a molecular level, causing a lower-energy light to be re-emitted, but in the visible spectrum. In essence, the subjects fluoresce and the beam turns everyday parts of our world into a baroque psychedelia. A gritstone wall, for example, becomes a matt red sheet (algae) studded with glittering lime (any lichen patches).
Photography requires a before-and-after pairing of images to let any viewer appreciate the resulting transformations. Most miraculous is what happens to the golden saxifrage, a plant that smothers Lightwood’s banks in shining pastures of pure green, until the torch converts them to pools of carmine confetti scattered over the night floor.
I love most looking at the mosses on an old quarry face where there is a patch of spiky bog-moss. By day, it’s a superb cushion of freshest green, with each plant’s central floret fringed with seven or eight lateral shoots that droop around the head like huge vegetative spiders. See it under UV and the whole organism becomes a dancing troupe of lavender, aquamarine, turquoise, purple or pink.
On being sent these images, a friend asked: “But what does it mean?” Perhaps Henry David Thoreau put it best, when he witnessed a rainbow in December 1855. He pondered that what we see is only a fraction of the world’s possible radiance and that every raindrop in a storm has the potential to be a rainbow all by itself. “Beauty and music,” Thoreau wrote, “are not mere traits and exceptions. They are the rule and character [of life].” A UV torch just offers you new angles on the same old, same old sacred miracle.
• Under the Changing Skies: The Best of the Guardian’s Country Diary, 2018-2024 is published by Guardian Faber; order at guardianbookshop.com and get a 15% discount