A MAGGOT-INFESTED MYTH?
“Eureka!” Physics Guru James Lloyd goes on a journey to find out whether an apple really struck Newton’s noggin. What he discovers could well rewrite the history books
We all know the story. A young Isaac Newton is sitting in his garden when – plonk! – an apple falls onto his head. As the scientist rubs his sore scalp, an idea enters his mind: could the same force that brought the apple plummeting to the ground also explain the motion of the Moon and the planets? In that instant the theory of gravity is born! At least that’s how the story goes… But did this cranial collision ever really happen? Physics Guru James Lloyd finds out. During my undergraduate physics days, there was an awful lot of stuff to learn. Quantum mechanics, relativity, particle physics – they were all subjects that I tried (and often failed) to wrap my head around. But there was one topic that we never broached: a fabled event that you could say actually kick-started modern physics. I’m talking, of course, about Isaac Newton’s famous apple. Did Newton really develop his theory of gravity after seeing a cascading Cox? Or is the whole tale just a maggot-infested myth that’s been passed down through the years? I thought it was finally the time to find out. Probably the most obvious place to start looking for evidence would be Isaac Newton’s own journals and notebooks. But, alas, I discovered that Newton never mentioned the apple in any of his writings. Instead, we must turn to a man named John Conduitt, who wrote about the incident some 60 years later. Conduitt, a politician by trade, was Newton’s assistant at
the Royal Mint and the husband of Newton’s beloved half-niece, Catherine Barton. It is here that we find some revealing clues to the truth of the apple event.
The case for the fruity legend
In his Draft account of Newton’s life at Cambridge, Conduitt describes a fresh-faced, 23-year-old Isaac Newton returning to his mother’s Lincolnshire home in 1666 – not because he missed his mum’s cooking, but because the plague had forced the University of Cambridge to shut down. There, Conduitt wrote, “whilst he was musing in a garden it came into his thought that the same power of gravity (which made an apple fall from the tree to the ground) was not limited to a certain distance from the Earth but must extend much farther than was usually thought.” So Conduitt may not describe Newton taking an apple to the head, or even that the scientist actually observed the falling fruit, but he at least makes a pretty strong reference to it. Around the same time, the French philosopher Voltaire was also helping to perpetuate the fruity legend. In An Essay Upon the Civil Wars
of France (1727), he wrote: “Sir Isaac Newton walking in his gardens, had the first thought of his system of gravitation, upon seeing an apple falling from a tree.” Voltaire probably heard the story from Catherine Barton, whom he described as Newton’s “very charming niece”, when he visited England in the 1720s. But the strongest evidence we find comes from another of Sir Isaacs’s close friends, an antiquarian called William Stukeley. In 1752, a quarter of a century after Newton’s death, Stukeley published his Memoirs of Sir Isaac
Newton’s Life. Truth be told, it’s a rather drab and long-winded account of the scientist’s life (though we do find out what the great scientist had for breakfast: “an infusion of orange peel in boiling water”, apparently, “with bread & butter”). But there on page 15, in a beautifully handwritten script, is an anecdote that makes the mouth water more than a freshly-baked apple pie: One spring day in April 1726, Stukeley visited
an 83-year-old Newton in Kensington, London. Unlike today’s London district, Kensington was then situated in the countryside, so the elderly scientist had rented a house there in the hope that the fresh air would improve his declining health. The two men spent the day together, and their conversations carried on into the evening. “After dinner, the weather being warm, we went into the garden, and drank thea [ sic] under the shade of some apple trees…,” recalled Stukeley. “Amidst other discourse, he told me, he was just in the same situation as when formerly, the notion of gravitation came into his mind. ‘ Why should that apple always descend perpendicularly to the ground,’ thought he to himself, occasion’d by the fall of an apple, as he sat in a contemplative mood. ‘ Why should it not go sideways or upwards but constantly to the Earth’s centre?’” So, while drinking this cup of ‘thea’ in the dusky evening light, Sir Isaac actually recounted the falling apple story to his friend Stukeley. The famous apple! From the horse’s mouth!
A mouldy tale
But can we really trust Stukeley? After all, he was a very good friend of Newton and may have been tempted to mythologise the scientist. As Scott Berkun, author of The Myths of Innovation,
writes: “biographers, certainly in 1720, are not objective reporters running around checking facts. They are often fans of their subjects, as Stukeley was of Newton.” And why would Newton have waited 60 years before sharing the story with someone? One explanation may be that he saw a falling apple in his youth and gradually embellished the story over time. It’s easy to see why it’d be such an attractive tale: a simple visual metaphor for his “Eureka!” moment; a humorous way to explain how gravity works. And then there’s the important fact that Newton was deeply interested in religion, so the nod to the Garden of Eden’s forbidden fruit might have appealed to him. One thing we can be sure of is that the apple never struck Newton on the head. That detail was added by a later writer, Isaac D’Israeli, who evidently had a penchant for slapstick comedy. But that hasn’t stopped the story from entering popular consciousness. Woolsthorpe Manor, Isaac Newton’s birthplace and the home he returned to in 1666, has since become something of a pilgrimage site. In the house’s garden, visible from Newton’s old bedroom window, is said to be the very apple tree that the young scientist sat under nearly 350 years ago.
As for the apple itself, the tree at Woolsthorpe Manor produces a rare variety of cooking apple known as ‘Flower of Kent’, which has been described as mealy, sharp, and quite flavorless. So if Newton really did see one fall to the ground, he probably didn’t enjoy eating it. Ultimately, we’ll perhaps never know the full truth behind Newton’s apple. Maybe we should trust those anecdotes provided by his friends. Maybe, in the grand scheme of things, it doesn’t really matter. After all, Newton went on to develop his theory of gravity in the end, apple or not. One thing’s for sure though – we should be glad that it was Newton sitting under that tree. Anyone else would have required a whole barrel full of fruit…
ABOVE: This apple tree at Woolsthorpe Manor grew up from the fallen trunk of another apple tree that existed in Newton’s day.