Four millimeters. Not something you'd notice, not in a summer, not in a lifetime. But run the film in reverse and in 200 million years the floor of the Atlantic Ocean would be squeezed back into the toothpaste tube and the continents would snuggle together, like pieces of a jig-saw.
Everyone knows this now. Plate tectonics. Continental drift. But I remember when it was a thrilling new theory, bang, apparently (but not quite) out of the blue, back in the Sixties. It was so beautiful, so concise in its ability to explain so much, that we knew at once that it must be true.
And the infinitesimal widening has been subsequently measured, directly, with millimeter accuracy, using a method called Very Long Baseline Interferometry, recording radio signals from distant quasars, reaching across the universe to reveal the drift of continents on Earth.
Two millennia ago, an Irish poet wrote (or recited) what is traditionally considered to be the first verse made in Ireland:
I am the wind on the sea.It is a thoroughly pantheistic poem, in keeping with the druidic nature of early Celtic spirituality. To which we might seamlessly add new verses:
I am the ocean wave.
I am the sound of the billows.
I am the seven-horned stag.
I am the hawk on the cliff.
I am the dewdrop in sunlight.
I am the fairest of flowers.
I am the raging boar.
I am the salmon in the deep pol..
I am the lake on the plain.
I am the lava in the sizzling rift.And give the final lines back to that unknown Irish poet:
I am the scattering of continents.
I am the wet sea filling the gap.
I am the measuring quasar.
I am the abyss of years.
I am the meaning of the poem.
I am the god that makes fire in the head.