“The people that walked in darkness,” goes the third lesson, “have seen a great light.”
And there we have it. Two polar extremes: darkness and light. An ancient metaphor born of a tiny spinning ball in a vast universe.
One of the earliest concepts in our school science curriculum here in the UK is night and day, and how the whole globe gyrates in a kinky sun-dance which leaves some places in darkness for six months at a time, and others with white nights and seemingly endless daylight.
It is no wonder that night and dark are such powerful symbols, for there they are at our spiritual fulcrum. Look at Stonehenge, an ancient mechanism for harnessing the solstice sunlight; or the way iron age houses were so often built to allow in the light of the rising sun. Remember Candlemas, and the feast of the blessing of the candles, with the mediaeval beliefs that just the light of a candle could cure the plague.
These days, real darkness is hard to find. There are few places in Britain where you can get a truly black velvet night where stars and planets can be properly viewed. The interference of electric light is relentless.
And, where one can get a switch and flick it to produce instant light, we value it less. It is no longer thought a miraculous healer – though its place as a supplier of Vitamin A is now recognised. But somehow, we take it for granted. It is commonplace. For now.
But whilst science has laid bare light, it has made dark yet more velvet and mysterious. Scientists are going to extraordinary, flamboyant lengths to create the ultimate darkness.
Around the middle of Italy there is a fabulous range of mountains named in English, Great Stone, and in Italian, Gran Sasso. It was where Mussolini was imprisoned in 1943 before a crack team of Nazi troops set him free, and on its peaks sits a station of the Rome Observatory.
But in its bowels is a place where scientists have sought and created darkness as thick as velvet. Thicker, and more profound. Its highest peak has a tunnel cutting through the mountain, And deep in that tunnel is a thick steel door. 1,400 metres of rock prevent any cosmic rays reaching through to pierce the dark. In three cavernous halls there, scientists are conducting experiments
They’re looking at dark energy. And dark matter.
We know about roughly 4% of the stuff in the universe, because light bounces off it: so we can perceive it. But of the rest, about 73 per cent is a dark energy which acts to keep the universe in its shape, and stop it contracting in on itself.
And then there’s dark matter. Light doesn’t bounce off it, says Dr Chamkaur Ghag, a particle physicist from University College London, so we don’t perceive it.
There are more things in Heaven and Earth, as someone once said, than are dreamt of in our philosophy. And there are even more things than we dream of under mountains.
So these days the people who walk in a busy, frenetic light can, if they stop and but consider it, see a great and wonderful darkness. Darkness which reminds us that there is still, in this universe of ours, a vast and undiscovered country.