Cox is keen to point out that he’s not just about undergraduate recruitment. His hero, the late American astronomer Carl Sagan, once said that the reason the library at Alexandria was burnt down by the Barbarians – destroying all the knowledge of the ancient world for ever – was because the scientists in that library never tried to engage with the public.
“They sat in an ivory tower. So when the Barbarians came, there was no one there to defend them. Knowledge is valued when it’s democratised, when it’s the property of all.”
It was this defence of knowledge that first put Cox on our TV screens. He was politicised by some savage funding cuts to research budgets when Tony Blair left office and Gordon Brown took over. “They did some ridiculous things to funding in Britain, in physics in particular. Made a real mess of it. I never understood whether it was Machiavellian or incompetence.”
He’s aware that knowledge has to be spread in the right way. When you look at climate change denial and parents turning down the MMR jab, he explains, it’s often the sense that they don’t like being preached at that’s at the core.
“It’s like: ‘Who are these scientists, and why should we listen to them?’ The motto of the Royal Society is: ‘Take nobody’s word for it’. Scepticism has value. But if you get an infection, you go to the doctor… With climate scientists you have people collecting data and building models to explain it. That’s what they do.”
With a deft conversational wriggle he brings us back to Stargazing Live. “It’s the data that make this a terrifically exciting time in cosmology, because we have precision data. Data about the oldest light in the universe, new telescopes going up to look at the very first galaxy…
“General relativity is having its 100th anniversary this year, and we still don’t understand what’s causing the universe to accelerate in its expansion. The stuff we understand is just five per cent of the universe. Even the Higgs particle raises more questions than it answers – and the Large Hadron Collider is just about to switch on again. We are standing on the edge of the known. Who knows what there is to discover?”
Eclipse Live: A Stargazing Special Friday 20 March, 9.00am BBC1; Stargazing Live Wednesday, Thursday, Friday 8.00pm BBC2