"In science, you've got to go against what the elders are saying"

The string theorist Brian Greene has grown from maths prodigy to physics iconoclast. Now he hopes to

As a child, Brian Greene interpreted the story of Icarus differently to most people. "In my naivety, I thought that it was a story about a boy who was bucking authority, not doing what his father said and yet he was paying the ultimate price," he says. "As I got older and became a scientist, it seemed more off-base, because in order to have great breakthroughs in science, you've got to go against what the elders are saying."

Greene has spent his career as a physics professor doing exactly that, exploring the wild frontiers of superstring theory: an unproven, untested and possibly untestable outcrop of theoretical physics. It's an attempt to resolve a conundrum: that we have working explanations of the universe on a grand scale (Einstein's general relativity) and the subatomic scale (quantum mechanics) but no one can reconcile the two. String theory tries to provide a "theory of everything" by suggesting that all matter is, at its smallest level, made of one-dimensional, vibrating loops, whose oscillation patterns determine their mass and "flavour".

For more than a decade, this 48-year-old vegan has been its most compelling advocate. As he wrote in 1999, "String theory has the potential to show that all of the wondrous happenings in the universe -- from the frantic dance of subatomic quarks to the stately waltz of orbiting binary stars; from the primordial fireball of the big bang to the majestic swirl of heavenly galaxies -- are reflections of one, grand physical principle, one master equation."

Greene now lives in upstate New York but he was born in what was, in 1963, a rough district of Manhattan. His father, Alan, a high-school drop-out who became a professional musician and composer, spotted his son's precocious mathematical ability when he was just five and set him to work multiplying 30-digit numbers on huge sheets of construction paper. When that began to pall, he asked the young Brian to calculate the number of inches between the earth and the Andromeda galaxy. "That is a very straightforward calculation," he tells me now, sitting in the tea room of a London hotel, "because people know how far away it is in light years. Then you need to convert light years into miles, miles into feet and feet into inches."

His mother has always been less impressed by what he does. "My mom says: 'Why aren't you a doctor?' and I'm like, 'I am a doctor!' and she's all, 'No, I mean a real doctor.' She reads my books but she says they give her a headache."

His run-down school ran out of things to teach him when he was 11, so one of the staff sent him knocking on the doors of the graduate students at Columbia University, bearing a note: "Take this kid on, he's hungry to learn." Thankfully, one of them did. "For no money," he points out. "Because we didn't have any money. He just did this for the love of learning."

Time travel

It is fitting that Greene is now a professor at Columbia and co-director of its Institute for Strings, Cosmology and Astroparticle Physics. Every few years, he gives what he calls a "report from the trenches" of cutting-edge theoretical physics. In 1999, he wrote an introduction to the subject, The Elegant Universe, followed in 2004 by a book on space-time and the nature of reality. This year, it's parallel universes.

His latest book, The Hidden Reality, suggests that our universe could be one of many, "like slices of bread in a cosmic loaf" or "one expanding bubble in a grand, cosmic bubble bath". He explains the idea of a literal "fabric" of space-time by telling me that a spinning black hole exerts a drag on the space around it, "like a pebble in a vat of molasses -- as the pebble spins, the molasses spins with it". His relaxed, metaphorical prose style has got him into trouble before. One reviewer complained that he "indulge[d] in a pandering sort of lyricism", but of greater concern to Greene were those who read his clear explanations and then turned up at his graduate class expecting to understand the content. One man spent ten years in his basement trying to take his first book's ideas to the next level. "He wrote how his wife almost left him because he wouldn't come out of the basement," Greene tells me. "It was heartbreaking."

Asked to name his scientific hero, he picks Albert Einstein, along with Edward Witten, a Princeton physicist. At the start of the 20th century, Einstein overturned the principles of physics by rejecting Isaac Newton's theory of gravity because it conflicted with his discovery that nothing travels faster than the speed of light. "So many of us," Greene says, "revere [Einstein] but it needs to be said -- because I've seen it reported in an odd way -- that we don't revere Einstein like some gurus of New Age cults may be revered, or some religious leaders. We are constantly critical of everyone's contributions, even Witten's. We look at a given paper, we bang it around, knock it, try to break it."

The same goes for string theory, which could turn out to be completely wrong. "It's a highly speculative subject but I don't shrink from that," he says. "If you ask me: 'Do I believe in string theory?' The answer is: no, I don't. I don't believe anything until it is experimentally proven [and] observationally confirmed."

How would he feel if it turned out to be a blind alley? His answer is surprising. "I would be thrilled." He explains: "I don't mean that in an off-handed way. My emotional investment is in finding truth. If string theory is wrong, I'd like to have known that yesterday. But if we can show it today or tomorrow, fantastic . . . It would allow us to focus our attention on approaches that have a better chance of revealing truth."

This isn't a discipline for the faint-hearted. When Greene was studying for his PhD at Oxford in the 1980s, he was tackling one of the fundamental ideas required to make the maths of string theory work: that there are more than three spatial dimensions. "Our eyes only see the big dimensions but beyond those there are others that escape detection because they are so small," he says. "Yet the exact shape of the extra dimensions has a profound effect on things that we can see, like what the electron weighs, its mass, the strength of gravity."

When he began his doctoral research, there were five possible shapes, one of which he ruled out by mathematical analysis. "The problem was, when I turned back to the list of shapes to look at the second, the list had grown. It was 100. Then 1,000, then 10,000. Ten thousand is still potentially doable -- it would keep an army of graduate students busy for a while -- but, nowadays, it has reached ten to the power of 500, which is an unimaginably huge number; the number of the particles in the observable universe is about ten to the power of 80."

Faced with this abundance, some physicists have decided to abandon the search, while others (including Greene) are trying to find equations to narrow down the field. A third group has a more radical proposal. "Those physicists have said we should take seriously the failure to pick out one shape from the many, because maybe that's telling us there is no unique shape. Maybe the maths is telling us that there are many universes and in each universe one of those shapes is in the limelight."

Mind the gap

Physicists can be an iconoclastic bunch but is there not a danger that their conviction gives fuel to the climate sceptics and creationists who say that science is a belief system, too? "Science is a self-correcting discipline that can, in subsequent generations, show that previous ideas were not correct," Greene counters. "When it comes to climate change . . . [and] the preponderance of data is pointing in a given direction, your confidence needs to rise proportionate to that. The data is very convincing."

He also has trenchant views about religious belief. "My view is that science only has something to say about a very particular notion of God, which goes by the name of 'god of the gaps'. If science hasn't given an explanation for some phenomenon, you could step back and say, 'Oh, that's God.' Then, when science does explain that phenomenon -- as it eventually does -- God gets squeezed out. I think the appropriate response for a physicist is: 'I do not find the concept of God very interesting, because I cannot test it.'"

Before I leave, I raise the idea of the "infinite multiverse", where every possible outcome of an event spins off a different universe. Dropped your piece of toast, buttered side down? There's now a universe where the opposite happened and you didn't have to scrape the fluff off your breakfast. It's one way of dealing with the fact that although a given outcome might have 30 per cent probability, and another might have 70 per cent, nowhere in the laws of physics is there a reason why one happens and not the other.

Doesn't that render the idea of free will redundant? "Yes," he says baldly. "We do not see free will in the equations: you and I are just particles governed by particular laws. Every individual, faced with five choices, would make all five -- one per universe. And all of the choices would be as real as the others." Don't we deserve credit for picking the choice that keeps us in this universe? Greene shakes his head. "Not really, because you are following one trajectory of choices. It is not as though there was a place in the mathematics where your free will dictated that particular set of choices. You are knocked around by the laws of physics, just like all your copies in the other universes."

I look at the preppy professor sitting opposite me drinking a cup of chai and wonder if there is a Brian Greene in another universe who was turned away by every grad student he asked for help. "And joined some gang and just been a street thug?" he says, smiling. "It is possible."

Brian Greene's "The Hidden Reality" is published by Allen Lane (£25)

Helen Lewis-Hasteley is an assistant editor of the New Statesman

Helen Lewis is deputy editor of the New Statesman. She has presented BBC Radio 4’s Week in Westminster and is a regular panellist on BBC1’s Sunday Politics.

This article first appeared in the 06 June 2011 issue of the New Statesman, Are we all doomed?

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The cult of clean eating in a fast-food nation

In Britain, it used to be vulgar to comment on one’s food. Now, it’s a bit weird not to.

These are the top food trends that the British media predicted for 2016: seaweed, parsnip puddings and sprouted seeds. And yet what was the most popular recipe on BBC Good Food, the country’s biggest cooking site? Lemon drizzle cake. When it comes to the food that we eat, the gulf between fantasy and fact has never been wider.

A third of British children are overweight, yet from the pictures tagged as “kids’ food” on the photo-sharing platform Instagram you would think they lived on pumpkin muffins and raw breakfast cereal. The same site boasts 290,229 posts on #avocadotoast and a mere 7,219 for #baconbutty, but I would bet my best spiraliser that we eat more of the latter.

Food trends have always been the preserve of those wealthy enough to enjoy the luxury of choice. If social media had been around in the 18th century, the exotic pineapple would have been trending heavily even as the majority of Britons subsisted on bread and gruel. Yet rarely have these fads been so hard to ignore: right now, we are a society obsessed with our stomachs . . . or, at least, our eyes, given that these seem to do much of the consuming.

The average British adult spends five hours a week watching, reading about, browsing and posting about food – and just four cooking it. A record 14.8 million of us tuned in to the final of The Great British Bake Off – almost as many as saw England’s dismal performance against Iceland in last year’s Euros – yet the most commonly eaten meal in the UK is a sandwich. That conjures a depressing image of each one of us sitting in front of a screen, scrolling through endless pictures of kale smoothies and activated quinoa as we tuck in to a floppy BLT.

A nation in which it was once considered vulgar to comment on one’s food has turned into one where it’s a bit weird not to. The current feverish interest in all things culinary feels, I imagine, like the Sixties must have done after Britain discovered sex “Between the end of the Chatterley ban/And the Beatles’ first LP”. And as with the sexual revolution and its fantasies of free love and cosmic joy through tantric chanting, perhaps the idea is more popular than the reality: increasingly, this endless parade of recipes cooked and meals eaten seems to be about more than the food itself.

While sex has (largely) thrown off its ancient shackles of judgement and shame, our diets are increasingly becoming their own morality tale. Once upon a time, “bad food” meant adulterated food – cheese dyed using lead, bread bleached with chalk – or perhaps cruel food, such as battery-farmed eggs. Occasionally someone who seemed to take too much pleasure in their meals might feel the weight of the country’s Protestant past, but wholesome food was generally seen as good rather than sinful.

Social media can’t be wholly to blame for the demonising of simple nourishment in the 21st century. Writing in the Observer last year, the philosopher Julian Baggini cited Salman Rushdie’s “naughty but nice” cream-cake advertising slogan from the Seventies as an early example; but “wicked” food was once a largely playful concept. Now, it is hard to find the humour in the modern idea of clean eating or, indeed, in its “dirty” dark side.

Clean eating, if you’ve been lucky enough to have avoided the torrent of smoothie bowls and bone broths pouring forth from screen, billboard and printed page in recent years, is a way of life (most adherents reject the word “diet”) with many rules – the Hemsley sisters’ “simple, mindful and intuitive” approach for “a long-term lifestyle change” takes up six pages of their bestselling recipe book Good + Simple. But there is little consensus among its advocates as to what these rules are.

Although clean eating is often described merely as a movement that champions minimally processed, “natural” foods, one of the few things that unites its various congregations is the need to eliminate what they deem to be unclean alternatives. Gluten is a popular target for dismissal, because it can be “hard to digest”; legumes are sometimes blamed for “bloating”. Cane sugar is definitely out, but consumption of dates and honey is actively encouraged, often served with a generous spoonful of coconut oil or nut butter (but not peanut butter, because that “gives you cancer”).

Given the often spurious scientific grounds for these strictures (tomatoes are said to cause inflammation; dairy steals the calcium from your bones), it’s little wonder that clean eating stands accused of promoting what the food writer Bee Wilson described recently as a “twisted attitude to food”, valuing certain ingredients as pure and cleansing, while others come with an unwanted side order of guilt and anxiety.

The backlash wasn’t long in coming – and on social media, the crucible of the eat-clean craze, nothing is served in moderation. “Dirty” food, which revels in its own naughtiness, is the inevitable flip side of the clean-eating coin, a world where adherents compete to outdo each other in crimes against cookery. Online audiences encourage such extremes; they like their food, to misquote Longfellow, either very, very good or horrid. In short, a simple spag bol is never going to get as much attention on Twitter as an “Italian-style” beefburger, dripping with Bolognese sauce, drenched in Parmesan, and served between two slabs of deep-fried pasta (this does exist).

Such fantastical foods are fine online; as with pornography, the problem comes when they influence the way people eat in real life. Bee Wilson, who was subjected to a barrage of online abuse when she dared to question the thinking behind one clean-eating guru’s “philosophy” at last year’s Cheltenham Literary Festival, cites growing evidence of the dangers of clean eating from those working with people who suffers from eating disorders. One specialist in London told the Sunday Times in May that between 80 and 90 per cent of his patients were following so-called clean diets.

At the other end of the spectrum, an ­Oxford University study published last year in the journal Brain and Cognition explored the possibility that “exposure to images of desirable foods can trigger inhibitory cognitive processes such as self-restraint”. The researchers concluded that our brain has to make a great effort to resist temptation when looking at “food porn”, in order to “maintain a reasonably healthy weight”. And not everyone succeeds.

It remains to be seen whether this appetite for public displays of ingestion endures. I can’t imagine the world needs any more pictures of fried eggs but others disagree: 264 have been added to Instagram in the time it has taken me to write this piece.

Technology will decide – work is already under way on virtual-reality headsets that allow diners to eat one food while looking at an image of another. This is a significant development, as evidence suggests that changing the appearance of food can affect our perception of its taste and flavour.

It is possible to imagine, in the not-too-distant future, chowing down on a plate of steamed fish while gazing lasciviously at a bacon cheeseburger. Or we could just learn the old-fashioned art of moderation. Is there a hashtag for that?

Felicity Cloake writes the New Statesman’s food column

Felicity Cloake is the New Statesman’s food columnist. Her latest book is The A-Z of Eating: a Flavour Map for Adventurous Cooks.

This article first appeared in the 16 February 2017 issue of the New Statesman, The New Times