close my eyes and turn my face to the sun’s radiance and the world becomes pink. It’s easy to see why so many pagan cultures threw themselves before it and trembled with fear at the dark gasp of an eclipse. In seconds I am drowsy with the sun’s deception; lying back is irresistible.
Just what is happening does not bring comfort. Everything around me is grabbing its chance for renewal. In that sense spring is a celebration, a triumph of survival of the long winter. But a survival for what? Where are we all headed under this exuberant star we call Sol? The revelations of physics and the assurance that the sun is 93 million miles away, that it is halfway through its calculated life cycle and will one day run out of heat, plunging us all into ice and gas, reveal no more answers than my jam jar. The knowledge that the glow on my face is a magnificent nuclear engine driving life on Earth, delivering energy through space via photons captured by the very green plants I am sitting on and the result of unthinkable nuclear reactions at the sun’s core, consuming 5 million tonnes of matter every second and releasing 3.9 x 1026 watts of energy, hasn’t helped me a jot. I’m still in deep shadow, and I know it.
And survival at what price, and for whom? It’s not by birth and rebirth alone that we survive, but also by the relentless scythe of the Reaper. We inch our way forward over the piled corpses of the dead. No amount of romantic imagery or poetic licence can balm either the fact or the pain. They were right, those pagans, to worship the sun in dread. These warming rays, these beams that seem to ruffle the very essence of the air, that load the great tits’ and chaffinches’ breasts with jubilation, are where it all begins. Deceptive and unimaginable though it may be, the sun’s energy – so vast that we can express it only in a mathematical formula – is systematically sending us out to kill. It is the power source that kick-starts the whole girning, churning conundrum of life into violent alert. We are, every one of us, its slaves and its utterly merciless militia.
I well remember doing photosynthesis back whenever it was so long ago. It gripped me; it seemed such a fiendishly good idea. Beam down the solar energy, fire up the chlorophyll to hang onto the light, suck in the carbon dioxide and water and – Hey Presto! A bag of sugar emerges at the other end. With a wag of the finger and a shake of his bald pate, Tommy Wallace insisted of us languid adolescents never to overlook that this could happen only in the presence of protoplasm in living cells. Ah yes, of course, life – living and meeting. That’s you and me. And what, dear, kind, generous-spirited, eye-twinkling, pipe-sucking Director of Biology, is life? What is it that sparks back and forth in this wonder gel we’ve named protoplasm? And what is it for? Just what is it, precisely, that makes you you and me me? In his book The Immense Journey, Loren Eiseley seems to sum it up:
Through how many dimensions and how many media will life have to pass? Down how many roads among the stars must man propel himself in search of the final secret? The journey is difficult, immense and at times impossible, yet that will not deter some of us from attempting it. We cannot know all that has happened in the past, or the reason for all of these events, any more than we can with surety discern what lies ahead. We have joined the caravan, you might say, at a certain point; we will travel as far as we can, but we cannot in one lifetime see all that we would like to see or learn all that we hunger to know.
Had I possessed the wit and the courage, aged thirteen, to press the point, I fear that I would have been disappointed. There were no answers in his biology department (despite having it endlessly banged into us that bios logos meant the ‘reasoning of life’), nor were they in his long shelves of books gathering dust beneath the lab windows; not even, I suspect, inside that wise old head. The answers I sought were then and are to this day back in my jam jar – dreams and sunbeams mingling.
Back in 1953 (only six years before I discovered the joys of photosynthesis) Stanley Miller hit lucky. The young Stan, of whom I have a photograph in front of me on my desk, is dutifully dressed in a collar and tie and an immaculate white lab coat. He looks serious, with trim ’50s short back and sides and horn-rimmed glasses. He seems to be posing: holding up a flask at the University of Chicago, where he conducted his groundbreaking experiment. He looks a little nervous, which is hardly surprising since at the raw age of twenty-three he had just been catapulted into the global forefront of organic science. Nervous or not, he is every inch the chemistry student. I get the impression he’s never been shopping in his life, that he has an over-protective mother, folds his pyjamas every morning and persistently ducked out of games at school.
He is standing in front of a grid of retorts from which hangs a tangle of apparatus: a flask and a pressure vessel, pipes, valves, U-tubes and cables. This is the young man who set the science world a-buzzing with what the world’s press headlined as ‘Finally ringing the death knell on Creationism’ – a final blow added to the still-haemorrhaging wound of iconoclasm inflicted by Darwin and the Evolutionists back in the 1860s. Miller had, they proclaimed, handed science the unequivocal proof for the origin of life on Earth. The question was inevitable. At a seminar presenting his results to rows of famous faces in the internationally acclaimed and predominantly sceptical audience of scientists, he was asked if he thought this was how life started. Miller’s professor, Harold Urey, leapt to his student’s defence. ‘If God didn’t do it this way, then he surely missed a trick!’
What the young graduate student had actually done was nothing of the sort – he hadn’t proved a thing. But he had managed to simulate in his flasks and vessels the primitive conditions that probably existed on Earth about 3,000 million years ago, roughly when life might first have emerged.
The Earth is about 5,000 million years old; for the first 2,000 million it was too hot and all the oxygen was tied up in rust – bonded into oxides with other elements such as iron and silicon, which form much of the Earth’s crust. The atmosphere consisted principally of four gases: methane, ammonia, hydrogen and water vapour from volcanic eruptions. Then along comes the irreversible influence of the sun.
Somehow, somewhere, all those billions of years ago, in some anonymous mist of eye-stinging, nauseous vapour swirling through the Earth’s electrically crackling atmosphere, lightning, together with ultraviolet and gamma radiation from the sun, bombarded those four gases until they metamorphosed, brewing themselves into a stew of amino acids. Bang! (or perhaps it was Fizz! – the first building blocks of proteins had arrived on our planet.
Stanley L. Miller rigged up his pipes, tubes and electrodes with the water flask, pressure vessels and a cooling jacket, sealing the vital ingredients within a bell jar. He sucked out the air, creating a sterile vacuum. Then he pumped in the mix of gases and boiled up the water in the flask so that steam circulated throughout. Once he was satisfied that they were all in place in the sparking chamber he gave it a kick of home-made lightning.
He ran it for a week. The solution in the flask turned yellow-brown and an oily tar formed on the walls of the sparking vessel. As the water cooled he found that fifteen different amino acids had condensed out in the U-tube. This was laboratory-induced prebiotic synthesis.
The experiment was opened to peer review with publication in Science – one of the leading journals of the scientific world – on May 15th 1953. It was an experiment, no more than that – a shot in the almost-dark of inspired guesswork. It had not proved how life did start, but it did demonstrate how life could have started. Later, Melvin Calvin did much the same thing using gamma radiation, shunting Miller’s work a quantum leap further forward. As well as a mix of amino acids, Calvin’s experiment produced simple sugars, and some of the purines needed for nucleic acids. Nineteen fifty-three was an extraordinarily productive year in the world of organic chemistry. Only a few months later Watson and Crick would publish their double-helix model of DNA.
If, in fact, these primitive organic molecules were synthesised in the atmosphere, it is likely they were washed down to Earth by rains, which in time accumulated
