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| 'It is obvious this is not like looking at a snapshot of the Higgs boson at a party, grinning for the camera between a couple of gurning gluons.' |
Yellow lines shoot in wavy, wire-like radiations through a field of multitudinous blue dots. A few green and red lines are in there, too. These lines and points shine against darkness. Around the edge of the bright pattern, glowing rectangles define the perimeter of a circle.
"Picture that changes the way we see the universe for ever", said the headline above this image on the front page of Thursday's Guardian. The picture suggests a revolutionary frontier of knowledge. It fizzes with energy and mystery. If it is reasonable to call the Higgs boson a "God particle", this image certainly conveys the Sistine Chapel awe, the electrified sense of wonder, that has greeted its apparent discovery.
And that is probably about as much as a "photograph" of science at this level can communicate or record. Since the Higgs boson has taken prolonged experiments in the world's greatest particle accelerator to glimpse at all, and given that to do so the Large Hadron Collider had to recreate conditions in the universe just after the big bang (remember when it was switched on and people worried it would implode the universe?), it is obvious this is not like looking at a snapshot of the boson at a party, grinning for the camera between a couple of gurning gluons.
It has been released along with similarly mind-boggling images to convey the drama of collisions and energies that has enabled scientists to claim the discovery of the particle that is thought to create much of the mass of the universe. The fabric of reality suddenly looks less threadbare. It is a vindication of decades of theory and research, of modern science itself. So of course we want to see a picture. Show us the Higgs.
Everyone knows the information in this photograph would be as hard to explain in words as quantum mechanics itself, but our urge to see a picture is irresistible. That is not only natural but recognises what has been achieved at Cern. For this is a triumph for the human urge to see the truth.
The history of science is a dialogue between theory and experiment. The great insights of modern science start with Copernicus and Galileo: in fact the discovery of the Higgs boson, which started as pure theory and has now been "seen", re-enacts their discovery of the solar system. Copernicus was like Peter Higgs and the other physicists who hypothesised the existence of a particle that gives other particles mass. He theorised. At the start of the 16th century he argued that the Earth orbits the sun. It was pure hypothesis. Copernicus never picked up a telescope. Galileo did. Galileo was the first truly empirical scientist who put every hypothesis to the test.
Galileo's 1610 book The Starry Messenger contains his own drawings of the moon as it looked through his telescope. He could see mountains, craters, a planet-like surface. This showed the moon cannot be just a light revolving in the sky, as medieval cosmology had it. Therefore the sky is not a canopy over our heads, it is a vast field of moving objects – space – in which the Earth is a moving object, too. Galileo gave an empirical basis to the strange idea proposed by Copernicus – just as, four centuries later, the LHC experiments have given an empirical basis to the strange idea of Higgs and his fellow physicists.
The way science works – with theories that are tested against evidence, through experiment – was not the invention of one great philosopher. It was born out of the practical-minded curiosity of the Renaissance and was arrived at by trial and error. The scientific method was understood by Leonardo da Vinci, who said all true knowledge comes of experience – the evidence of the senses. The scientist who practiced it most beautifully was to be Charles Darwin, who delayed publishing his theory of natural selection until he had amassed enough evidence to make The Origin of Species as much a miracle of observation as of radical thought.
By contrast, Albert Einstein's theories of special and general relativity seemed completely remote from "experience" — yet experiments have repeatedly confirmed them.
In his painting An Experiment on a Bird in the Air Pump in London's National Gallery, the 18th-century artist Joseph Wright of Derby shows the wonder and terror of experiment. A moonlit gathering is held enthralled – and horrified – by a spectacular demonstration of the reality of the vacuum.
This week's discovery means the vacuum is not so empty after all. But it also means we are the true heirs of Wright of Derby's Enlightenment and Galileo's Renaissance. These may be troubled times, but this week, reason reasserted itself.