Newton's first law of motion. Did Newton wrote LONG mathematical proof for it, or was it simply a phenomenon?

Question

............. or was it simply a phenomenon observed many times?

"As Isaac Asimov goes on to explain, "Newton's laws of motion represent assumptions and definitions and are not subject to proof. In particular, the notion of 'inertia' is as much an assumption as Aristotle's notion of 'natural place.'.."

(http://en.wikipedia.org/wiki/Inertia)

If it is just an assumption, then it could be wrong. What if it's wrong? That's something puzzling me. I mean, what if there's some matter in the Universe which does not obey the law?

Was the three Newton's laws established through empirical methods or a priori?

Answer 1

Laws of physics must be mathematically consistent, but they are not proven mathematically. They are indeed not proven at all, ever. They can only be potentially disproven. All theories are subject to disproof if an exception is found experimentally.

Newton proposed a simple mathematical relationship for describing dynamics. He made no pretense that he could provide a deeper explanation for why they worked other than careful experiments showed they did. In his words, "I make no hypothesis" in regard to such things. That has been the template for the physical sciences ever since. Newton invented modern physics.

Incidentally, Newtonian mechanics has long been shown to be only an approximation for big slow moving things, although an extremely useful one since we ourselves are so big and slow moving. You can legitimately say, then, that Newton has already be proven wrong, at least for fast and small things.

Answer 2

Newton's Laws are based on intuitive thinking based on observation and experiment. They are not obvious because they depend on conditions that are difficult to set up under earth conditions, because we always have air resistance and friction under natural conditions. So Newton pointed to the problems and defined ideal conditions. Once those Laws defined perfect conditions, it became possible to look for what caused natural behavior that "violated" the Laws - for example in the case of One - a moving object slows down because of air resistance which is a force.

Answer 3

Every scientist or for that matter every intellectual first observes his surroundings carefullu, sees the various phenomena, then goes on find the whys and hows of it. It was the same with Newton aswell. First he experienced the things, scientific thinking being relatively new then, he went on to argue within himself and the others. Then he wrote his papers and did calculations, to support his observations an arguments.