When Isaac Newton inscribed his renowned laws of motion onto parchment in 1687, he could only have marveled at the enduring impact these principles would have on our understanding of physics. Centuries later, these laws are still the cornerstone of mechanics and our interpretation.
Newton, writing in Latin, outlined three critical principles that govern the motion of objects in the universe. These principles, which have been translated, discussed, and debated over the years, define how objects move and the forces that affect them.
A New Perspective on Newton’s First Law
However, a recent analysis by Virginia Tech philosopher Daniel Hoek suggests that we may have been misinterpreting the precise wording of Newton’s First Law of Motion all along. Hoek, who aimed to set the record straight, discovered a mistranslation of the original 1729 English translation of Newton’s Latin work, the Principia Mathematica.
Traditionally, Newton’s First Law of Motion has been interpreted as stating that an object will continue in a straight line or remain at rest unless an external force acts upon it. This interpretation has served well in educational contexts, yet it overlooks the constant presence of external forces.
Upon revisiting the archives, Hoek realized that this common interpretation had overlooked the word “quatenus,” meaning “insofar,” which was mistakenly translated as “unless.” This single word dramatically changes the meaning of the law.
The Misunderstood Meaning
According to Hoek, this nuance means that Newton intended the First Law to imply that every change in an object’s momentum is caused by external forces, rather than describing how objects maintain momentum in the absence of forces.
“By restoring the word ‘insofar’ to its place,” Hoek explains in a blog post, “we bring Newton’s original principle back to its intended splendor, emphasizing that all changes in an object’s motion are due to external forces.”
Hoek’s interpretation was first highlighted in a 1999 scholarly analysis, yet it hasn’t gained wide traction. This lack of recognition may be due to the resistance against changing deeply ingrained scientific concepts.
“Some find my reading too wild and unconventional,” Hoek admits, while others believe it to be “so obviously correct that it barely needs arguing for.”
Despite its unconventional nature, Hoek counters that the reinterpretation doesn’t alter the fundamental laws of physics. Instead, it offers a deeper insight into Newton’s original intentions.
The Implications of Inertia
The prevailing interpretation raises questions: Why would Newton describe a state free of external forces when such a state doesn’t exist in the universe? Gravity and friction are omnipresent.
According to George Smith, a philosopher at Tufts University and expert in Newton’s writings, “The whole point of the First Law is to infer the existence of the force.” This interpretation aligns more closely with Newton’s intention to illustrate the influence of external forces.
Newton provided three examples to clarify his point. The most compelling, according to Hoek, is the spinning top, which gradually slows down due to air resistance. This example demonstrates that the First Law applies to real-world objects subject to forces.
Hoek underscores that this revised interpretation reinforces Newton’s revolutionary idea that celestial bodies and terrestrial objects adhere to the same physical laws, bridging the gap between Earthly and heavenly mechanics.