In 1726, writer William Stukeley had a conversation with Isaac Newton (1634-1727) in Kensington during which Newton recalled “when formerly, the notion of gravitation came into his mind.” Later, Stukeley writing in his Memoirs of Sir Isaac Newton’s Life, recorded that Newton said, “It was occasioned by the fall of an apple, as he sat in contemplative mood. Why should that apple always descend perpendicularly to the ground?
Genesis of Newton’s Gravitational Insight
This sounds very grand however Newton was helped on his way by two of the laws of the “Giant” Johannes Kepler (1571-1630). Namely that the planets orbit the sun in elliptical orbits with the sun at one focus and that the square of the periodic time of revolution of a planet around the sun is directly proportional to the cube of the mean distance from it.
Prior to this Newton would have had access to the work of the immortal Galileo Galilei (1564-1642) and the work of the Greeks of antiquity who studied and elucidated the seven conic sections (circle, parabola, ellipse, two branches of the hyperbola, the line, the two parallel lines and the point) and who defined the closed curves as our well known loci. Newton also had a famous quarrel with one of my favourite (but unfortunately unsung heroes of Physics). Robert Hooke (1635-1703) regarding gravity who is mainly remembered for the law of springs. The Micrographia and for coining the term cell as used today in Biology for what he saw using his microscope resembling prison cells.
Gravity and Beyond
Returning to Isaac he also discussed the inverse square law with Edmond Halley (1656-1742). Prior to publishing it and who incidentally paid for its publication. And history claims that a famous conversation ensued between Halley and Newton leading to the inverse square law; which went something like this:
Halley (H): “What would give rise to Kepler’s r cubed T squared law?”
Newton (N): “An inverse square law”
H: “How do you know?”
N: “Because I hath showne it”
And the rest is history with the publication of the Principia.
Science as an Iterative Process
Thus the gravitational revelation was as many scholars claim “in the air” when he stated it as was Newton’s development/invention of the calculus. Newton’s claim to calculus should also be viewed in detail as two of my good “old friends” R. Descartes (1598-1650) and P. Fermat (1607-1665) were finding equations of tangents to curves using techniques that greatly resemble what we call today differentiation and then we have the two Greek “Giants” Eudoxus (337BCE) and the immortal Archimedes that were using mensuration techniques (e.g. the method of exhaustion) to compute areas and volumes. I cannot mention Archimedes without quoting one of the most famous statements in Science:
“Give me a lever long enough and a fulcrum on which to place it, and I shall move the world.”
-Archimedes.
So one must take many events into consideration when giving precedence to one scientist over another in predicting/stating theories, and we can no doubt deduce that Science is iterative.
