YOU can accelerate in a jet fighter to the very frontiers of space; you can plumb the depths of the Pacific in a mini submarine; you can help three million viewers' imaginations to cruise the cosmos, but there's nothing quite like a full nappy to bring a globe-trotting TV physicist's feet back down to Earth.
• Things have only got better for Brian Cox, whose TV series saw him take off in a Lightning jet. Picture: Complimentary
Thus it is that I agree to break off my telephone interview with Professor Brian Cox, the "rock star physicist" who has been boosting BBC2's prime-time viewing figur
The days on the road as a keyboard player with pop bands Dare and D:Ream may be far behind him, but as the engagingly youthful face of TV science, most recently in Wonders of the Solar System, and highly vocal critic of government spending – or dearth of it – on science, not to mention his day job as a physics professor at Manchester University and researcher on the particle-bashing Large Hadron Collider, Cox hasn't been home too much over the past year. When I phone him at home in his native Oldham, the 42-year-old scientist is looking after young George while waiting for his American wife, TV presenter and website producer Gia Milinovich, to return home.
He'll be away from home next week, too, when he presents a special screening of Wonders… at the Filmhouse on Monday as part of the Edinburgh International Science Festival.
George, he tells me, once communication has been resumed, was born in May last year (Cox also has an older stepson with Milinovich), "and we started filming Wonders… in March and finished in September. I had a month off around the time he was born, but I was gone a lot of the time, flipping backwards and forwards".
Flipping backwards and forwards is the least of it. The lavishly produced five-part BBC2 series, in which Cox visited extreme environments across the globe to demonstrate how the laws of physics operate across our solar system, saw the boyish-featured boffin climb into a vintage English Electric Lightning jet fighter for a near-vertical take-off into the wide blue yonder – or more precisely, 18km up to where he could see the curvature of the Earth and what he termed the "thin blue line" that is our atmosphere.
He also hopped about on Alaskan glaciers, viewed a solar eclipse from the holy city of Varanasi on the Ganges in India and camped out on a rumbling Ethiopian volcano.
Finally, in Sunday's concluding episode, he descended into the abyss of the Pacific where, amid eternal night and a pressure of 200 atmospheres, he watched "extremophile" life forms thriving around hydrothermal vents on the ocean floor – with the implication that if life can exist there, it should be able to exist in other similarly inhospitable parts of the universe.
If the Lightning flight was your proverbial short ride in a fast machine, the submarine descent vies with it in Cox's most vivid memories of filming the series.
"Beautiful aircraft," he says, in the soft Lancashire tones brimming with unfeigned enthusiasm for his subject, which make him a natural communicator but have also earned him his fair share of spoofs, from the Jonathan Ross show to Harry Hill.
"I grew up thinking they were the most beautiful aircraft – there's one in the Manchester museum, so flying in one had always been an ambition of mine."
Beautiful, but risky: the privately owned Lightning he flew in crashed at an air show a few months later; the pilot was killed.
"But while the Lightning was 40 minutes of sheer excitement, the nine hours of floating about in the Pacific was probably the closest, psychologically, you can get to going into space. You're an hour and a half away from anything. If anything goes wrong, you're completely on your own, and the submersible cabin is about the same size as an Apollo spacecraft."
The giant tubeworms and other life he witnessed two kilometres down, around undersea vents, were, he says, "wonderfully complex", and he speculates that the conditions there may be similar to those on Jupiter's moon Europa, which, scientists suspect, harbours a 100km deep ocean under its icy shell.
It wasn't all thrills, however. He recalls camping near a lava lake on the active Erte Ale volcano in Ethiopia, with daytime temperatures of 40C. "The only water we had was this stuff in plastic containers dumped by helicopter and (it] had these military chlorine tablets in it, and because it's so hot you have to drink 11 litres of water a day. It's like drinking 11 litres of swimming pool."
Cox is nothing if not a practising exponent of what he preaches – that we must explore. He likes to quote one of his heroes, the 18th-century English chemist and inventor Sir Humphry Davy: "Nothing is so dangerous to the progress of the human mind than to assume that our views of science are ultimate. That there are no mysteries in nature, that our triumphs are complete, and that there are no new worlds to conquer."
In fact, there's a bit of the Enlightenment savant about Cox. "I should have been around in 1780, really, those great times – Stevenson, Brunel and all the rest. America had that attitude in the 1950s and 60s and went to the Moon. It's not that all that's gone now, but I do think we need a kick up the backside now and again," he laughs. "The estimated costs of a Mars mission vary from 40 billion to 400bn, but those are sums that we've spent on our banks."
Which brings us to his recent, much-publicised criticism of proposals by the Westminster government and the Conservatives alike to cut the UK's budgets for education and scientific research. It's clearly a matter close to his heart. "Although many of us don't think of it in these terms, the UK economy is really quite dependent on knowledge-based industries – something like 45 per cent of the GDP. The basis of that is the science budget and the university budget – and you need a skilled labour force. We spend less on that than the European average, less than the Scandinavian countries, less than the US.
"Our science budget is about 3.3bn a year. I would argue that, for that tiny investment, which is below average, we punch way above our weight. My argument isn't based on any sort of special pleading for scientists to mess around and explore the universe. I think it really is one of the fundamental foundations of our economy."
So affronted is he at the two main Westminster parties' plans to cut science spending he has said he'll vote Liberal Democrat, as it's the party with the greatest commitment to science spending. It's a far cry from Cox's days noodling at the keyboard with D:Ream, the 1990s synth-pop band whose hit single Things Can Only Get Better was adopted by Labour for its 1997 election campaign.
His days on the road as a musician started when he joined the rock band Dare at the age of 18, touring with it for five years until the group broke up after a punch-up in a Berlin bar. Cox went off to study physics at Manchester University, where he remains as a research fellow, and joined D:Ream while still a student.
Did he ever have to sit down and make a hard choice between physics and music? "I think just briefly," he replies. "I remember being in my second year at university and I had no money, and D:Ream were flying high at that time and there were American and Australian tours I couldn't do because I was studying."
He finds the "rock star physicist" label an asset when, as an ardent science evangelist, he gives talks to schoolchildren. "I always tell kids that if you just get your A-levels when you're 18 to get into university, then it's pretty easy for you to do something else for a couple of years. But if you mess up that time up to when you're 18, it's very difficult to recover it."
Events such as the Edinburgh Science Festival he regards as essential. "I think it's so important for our country to be scientifically literate, and events like this help immeasurably."
As a researcher involved with the Large Hadron Collider, the huge particle accelerator complex run by the European Organisation for Nuclear Research near Geneva, he is unabashedly enthusiastic about the success of the recent experiment which saw the machine colliding beams of protons at the highest energy levels yet.
But is particle physics a harder concept to put over on popular television than, say, space exploration or the possibility of extraterrestrial life? "With all these things, it's a case of finding a narrative," says Cox, who will return to television next year in a new series, Universal, about how the laws of nature apply throughout the universe and humankind's place in it.
"In particle physics, a lot of that story is bound up with the way the complexity of the universe today crystallised out of the simplicity of earliest time, the Big Bang. And one of the things about the Large Hadron Collider is that it can recreate these really high-energy conditions. So, yes, we'll be doing particle physics in the series."
He may continue to whet our interest in Life, the Universe and Everything, but he also insists he'll be spending a little more time at home.
"I'm going to make the next series, but I'm not going to keep popping up on every other television programme. I'm not a TV presenter; I'm an academic, really. I just happen to have this extra thing that I like to do."
• Brian Cox presents a special screening of Wonders of the Solar System at the Filmhouse, Edinburgh, next Monday, 12 April. He also takes part in Why Does E>MC? on Sunday, 11 April, and Hi Energy! on Monday, 12 April.
• For more details about the Edinburgh International Science Festival, log on to: www.sciencefestival.co.uk