Grantham Civic Society column: How great ideas kept coming from Newton
350 years ago this summer, Isaac Newton left Cambridge when the plague overwhelmed the city. He returned alone to his childhood home, and took up residence in his hall chamber room in Woolsthorpe Manor.
His mind was overflowing with the readings he had been avidly absorbing. Not part of the traditional teaching of the day, Newton was exploring the works of new thinkers. In mathematics he continued his studies from Cambridge into “the method of fluxions”, this was a system to analyse changes in motion over time, now known as Calculus. The discipline of mathematics on Newton’s thoughts focused his widely ranging ideas from his list of “Quaestiones”.
He returned to Cambridge in March 1666, only to find a recurrence of the plague, so he returned to the Manor in June.
Now his thoughts were taken up with works by Kepler, Galileo, Huygens and especially Descartes. This led to his experiments with light, colour, and ways to improve the construction of the telescope.
He investigated what was actually taking place when the light from the Sun shone though a prism producing the rainbow colours. He ground a triangular glass prism “to try there with the celebrated phenomena of colours. And for that purpose having darkened my chamber, and made a small hole in my window shuts.... I placed my prism at his entrance that it might be thereby refracted to the opposite wall”. He drew a diagram of his experiment, and noted the length of the room as 22 foot. Imagine the recent excitement of discovering the length of his hall chamber room from window to wall to be exactly – 22 feet! In later life this was published in his book called Opticks.
So what about THAT tree?
Looking through the largest window in Newton’s room we can see the reclining form of an ancient apple tree, long named locally as Isaac Newton’s tree. Where does this fit into the burst of scientific thought of this Annus Mirabilis?
Newton told his story to four different people. One was an acquaintance from Grantham - historian William Stukeley. In his “Memoire of Sir Isaac Newton” he records that they were sitting together under an apple tree drinking tea, when Newton said, “It was in such a situation that he first took the notion of the gravitation of matter, from an apple dropping off the tree. Why should this apple always, and invariably fall to the earth in a perpendicular line. Why should it not fall upwards, sideways or obliquely....”
He extended these thoughts to the Moon.
What held it in place? Why did it not fall like the apple, to earth, or fly away? Newton remarked that “by thinking on it continually” he eventually calculated the Law of Universal Gravitation with the three Laws of Motion. His early musings at Woolsthorpe led to the publication of his great work, the Philosophiae Naturalis Principia Mathematica . This book can be seen at the Manor, along with an early edition in English.
Explore his scientific output in the Science Centre. Hear stories of his life and times in 17th century England and picture the scene on film.
Come and meet the 400 year old Flower of Kent apple tree. Wonder at the part it played in the development of scientific thinking that was used to land a man on the Moon.
Join the visitors who arrive here from around the world to see where Isaac Newton and his ideas originated.
Fifty years on he recorded “in those days, I was in the prime of my age for invention, and minded mathematics and philosophy more than at any time since.”