Over on the Scientific American Guest Blog we have another non-historian trying his hand at the history of science under the title Newton’s Apple: Science and the Value of a Good Story. Our author, Ned Potter a Senior Vice President of an international communications firm and former science correspondent, tells us that Isaac Newton almost invariably tops any list of history’s greatest scientists and then poses the question, why? His answer is that Newton had a great story to tell:
It’s the one about the apple. You remember it – how the young Newton, sent home from school at Cambridge to avoid the plague of 1665, was sitting under a tree one day, saw an apple fall to the ground, and, in a flash of insight, came to understand the workings of gravity.
Right there in his retelling, Potter, reveals why Newton’s Apple is anything but a great story but before I explain why, I have other fish to fry. In a lackadaisical paragraph our intrepid author summarises Newton’s scientific career:
He published his Principia Mathematica in 1687. In his spare time he designed the first reflecting telescope, laid the foundations for calculus, brought us the understanding of light and color, and in his later years – it would be disingenuous to leave this out – tried his hand at alchemy and assigning dates to events in the Bible.
He did not design the first reflecting telescope in his spare time. Investigating the nature of light and colour was at the centre of his scientific endeavours twenty years before he composed the Principia Mathematicae and his design of the reflecting telescope was his answer to the problem of chromatic aberration in lenses that his new theories on colour had discovered and explained. It also wasn’t the first reflecting telescope but the first functioning one, as I’ve already explained elsewhere. Laying the foundations of calculus was also not a spare time activity. We now turn to something that I’m slowly getting tired of correcting. Newton did not try his hand at alchemy and assigning dates to events in the Bible in his later years but started both activities in his youth continuing them for many years. They also played a very central role in the heuristics of his scientific research, as I’ve said on more than one occasion.
My readers may ask themselves why the dating of Newton’s, by modern standards, non-scientific activities is such an important subject for me. It’s rather the other way around. By pretending that Newton only did these things in his dotage people like Potter came claim that Newton was a rational modern scientist in his youth who went off the rail in his old age, poor man. This is the creation of a myth in the history of science. Newton’s alchemy, theology and chronology are a central part of what made him the scientist that he was, to deny this is to deny the man himself and to put a mythological figure, who never existed, in his place. That is not doing history of science and should also have no place in the popular presentation of science. But back to Newton’s Apple!
The offending phrase is of course saw an apple fall to the ground, and, in a flash of insight, came to understand the workings of gravity. This is not what happened and it also creates a completely false impression of the scientific process of discovery. Nobody, not even Newton, understands a complex scientific theory such as the theory of universal gravity in a flash of inspiration and claims that they do misinform non-scientists about how science works.
Assuming the apple story to be basically true, and there are many historian of science who think that it is a myth, what Newton thought is very different to coming to understand the workings of gravity in a flash of insight. The sight of the falling apple led him to pose a question to himself, something along the lines of, ”what causes the apple to fall to the ground?” This led to another question, and herein lies Newton’s brilliance, is that which causes the apple to fall downwards the same as that, which prevents the moon from shooting off in a tangent to its orbit as the law of inertia say it should? Here we have the beginning of an idea that can only have taken place in a mind prepared by the requisite study to be able to form this particular idea. The idea alone is in itself useless unless one possesses the necessary knowledge to test it. Newton did possess this knowledge of dynamics, astronomy and mathematics, which he had acquired through intensive personal study over the previous years rather than from his university lecturers. He then applied this knowledge to testing his newly won hypothesis, a fairly complex and demanding mathematical calculation that required both time and effort. And see here the result! The two aren’t the same! Newton’s initial attack on the problem failed because of inadequate data. He put the problem aside and devoted himself instead to the study of optics (see above). However he did not forget that insight and many years later he returned to the problem with fresh data and showed that his initial insight had in fact been correct. The way was now open to the development of the universal theory of gravity. Note after all of the steps that we have already gone through we have not arrived at the workings of the theory of gravity, we have merely started down the road towards it. In fact Newton would have to invest two years of very intense work, to the exclusion of everything else in his life, between 1684 and 1687 in order to finally develop the theory in all of its glory, as published in his Principia. The process can hardly be described as “a flash of insight”.
I hope that I have made clear that, in the sense of Ned Potter, Newton’s Apple is anything but a good story, as it creates a complete misconception of the scientific process, a process that even in the case of a monster intellect such as Newton’s involves an incredible amount of study and sheer hard work.
The story as presented by Potter could however have its uses in teaching an introductory course in the history of science and in illustrating the scientific process. One presents the students with the myth of Newton’s Apple à la Potter and then have them research the real historical situation. To look for, read and analyse the original sources of the apple story, William Stukeley, as well as John Conduit and Voltaire, who both had the story from Catherine Barton, Newton’s niece and housekeeper as well as Conduit’s wife. Then have them study the real process by which Newton developed his theory of universal gravity, as I have sketched it, demonstrating how misleading such tales can be. As such I think that the Newton’s Apple story can be put to good pedagogical use, however as Potter wishes it to be considered:
Over the years, inevitably, the details have been embellished. Ask around today, and people may tell you that the apple bonked Newton on the head. But the point remains: if you have an important point to make, especially in science but also in other fields, there’s nothing like a good story to make it memorable.
I think it’s anything but a good story particularly if the important point being made is completely false.