“To every action there is always opposed an equal reaction.”
- January 4, 1643 – March 31, 1727
- Born in England (UK)
- Natural philosopher, mathematician, physicist, astronomer, theologian
- Proposed the laws of universal gravitation and motion, built the foundations of modern science, and systematized theories of natural philosophy and mathematics.
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Quote
“To every action there is always opposed an equal reaction.”
Explanation
In this quote, Isaac Newton is articulating his third law of motion, which states that for every force exerted on a body, there is an equal and opposite force exerted in response. This fundamental principle of physics explains how forces act between objects and is crucial in understanding the behavior of objects in motion. Newton’s third law is central to a wide variety of phenomena, from the way rockets launch into space (where the force of the exhaust gases pushing downward results in an equal reaction that propels the rocket upward) to the interaction of objects in everyday life, such as the force of a person pushing on a wall and the wall pushing back with an equal force.
Newton’s formulation of this law was revolutionary in the 17th century because it provided a clear and predictable framework for understanding the dynamics of motion. Before Newton, the nature of force and how objects interacted was not as well understood. The third law established the idea that forces are always mutual, and no object acts in isolation. This law also laid the groundwork for future discoveries in mechanics and physics, influencing the development of both classical and modern physics.
In modern physics, Newton’s third law continues to be a cornerstone of classical mechanics, and it applies to a wide range of fields, including aerodynamics, fluid dynamics, and even quantum mechanics. The principle of action and reaction is essential in understanding the conservation of momentum, where the total momentum in a closed system remains constant because of this equal and opposite reaction. The law also applies in fields like engineering, where force and reaction forces are critical in designing structures, machines, and vehicles. Even today, Newton’s third law remains a simple yet profound statement about the inherent symmetry of nature and the relationship between forces in the universe.
