Mdthbs

In the comments for this question a dispute around around the question of "Have Newtonian Mechanics been falsified?"

That's a bit of a vague question, so attempting to narrow it a bit:

1. Are any of Newton's three laws considered to be 'falsified theories' by any 'working physicists'? If so, what evidence do they have that they believe falsifies those three theories?




2. If the three laws are still unfalsified, are there any other concepts that form a part of "Newtonian Mechanics" that we consider to be falsified?

"Falsified" is more philosophical than scientific distinction.
Newton laws have been falsified somehow, but we still use them, since usually they are a good approximation, and are easier to use than relativity or quantum mechanics.

The "action at distance" of Newton potentials has been falsified (finite speed of light...) but again, we use it every day.

So, in practical terms, no, Newton laws are still not falsified, in the sense that are not totally discredited in the scientific community. Classical mechanics is still in the curriculum of all universities, in a form more or less identical that 200 years ago (Before Relativity, quantum mechanics, field theory).

Most concept in physics fit more in the category of "methods" rather than "paradigms", so can be used over and over again. And all current methods and laws fails and give "false" results, when used outside their range of applicability.

The typical example of "falsified" theory is the Ptolemaic system of Sun & planets rotating around the Earth. However, philosopher usually omits the facts that:

• Ptolemaic system was experimentally pretty good at calculating planet motions


• Most mathematical and experimental methods of the new Heliocentric paradigm are the same of the old Ptolemaic

So the falsification was more on the point of view, rather than in the methods.

One of the problems of Newton's laws is that they can't describe the precession of Mercury's orbit. Mercury doesn't behave as predicted by Newton's laws and general relativity does a better job.

See
https://en.wikipedia.org/wiki/Tests_of_general_relativity#Perihelion_precession_of_Mercury

Newtonian Physics is accurate in the specific domain it was designed for

Physics is not about identifying the "truth" of the world around us. It's about creating mathematical models that allow us to accurately predict the behavior of the world.

Nobody is trying to create a perfect model, because the complexity of such a model would be infinite. Instead, we look for the boundaries of a model's accuracy - under what conditions it produces reasonable results, and the precision of the results it produces under those conditions.

You can see this more clearly with other physics models, such as the Ideal Gas Law. The Ideal Gas Law models a hugely complex system of particle collisions as a simple formula of ratios. It breaks down relatively quickly at high or low values of any of its quantities, but because we understand when and how the law breaks down, it is still useful.

At extremely large quantities (large speeds, large masses, high energies), the Newtonian model starts to break down, and we need to use a Relativistic model in order to get accurate results. But that doesn't mean that the Newtonian model is false, it just means that it is inapplicable for those conditions.