Question

To Rabbi Michael Abraham,
Greetings,
I saw an idea of the Rabbi’s regarding the question of whether the basic principle of evolution, survival of the fittest, is falsifiable. Following that, I started thinking about Newtonian mechanics, and I mean Newton’s three laws. Is mechanics falsifiable? Take the law of conservation of momentum: the conservation law states that if the system is not subject to an external force, then the total momentum in the system is conserved. Suppose we performed an experiment and the total momentum was not conserved. We would not say that the law of conservation of momentum is invalid, but rather that there is some external force acting on the system. Maybe we would begin looking for that force; perhaps we would conclude that it is a “real” force or a d’Alembert force, but we would not claim that the conservation law is invalid. The same applies to the law of conservation of energy.
The same thing would really be true for any experiment in mechanics. We perform an experiment that predicts a certain kinematics of the system; if that kinematics is not obtained, we would say that there is some additional force or some additional unknown mass, and so on. I am a student at the Technion, and a physics professor here told me, after I presented this argument to him, that I am right, and that this is one of the problems physics is currently facing with regard to dark matter/dark energy.
Another question: is Newtonian mechanics in its current form necessary? That is, Newtonian mechanics connects the concept of force to acceleration. Could I have constructed another complete mechanics that connects the concept of force to velocity? I admit that this would be a very inconvenient and computationally cumbersome mechanics; it would give me forces that vary over time and other inconvenient phenomena. But if this is indeed possible, it would follow that Newtonian mechanics, especially in the second law, mainly gives us a language and nothing more.
If that is true, I still do not think that mechanics as a whole is unfalsifiable, but only the three laws. For example, when I determine that gravitational acceleration at the surface of the earth is 9.8, that is certainly a falsifiable claim. But on second thought, how do I know? Can I not say that gravitational acceleration is 10 and that there is some unknown force giving me -0.2? I think not, and here I think a distinction should be made between an essential inability to falsify, as I mentioned regarding the three laws, and this claim, where I have only come up with excuses for why it does not have to be so, etc. And by the way, there really is a change in the gravitational field, a tiny change, between someone located on the side of the earth closer to the sun and someone on the other side, because of the sun’s centrifugal force.
One more point: I do not think Newtonian mechanics is entirely unfalsifiable, because apparently relativity refuted it. I think it assumes two things: continuous time and Euclidean geometry of space, and there it can be refuted. But the three laws overall only define the concept of force; they define a language on which we dress the forces of nature.
Still, the importance of mechanics, even if it is only a language, is that it helps us quantify causality in physics, and that it is amazingly convenient for calculation.
And since we mentioned d’Alembert forces, what is the Rabbi’s opinion regarding Newton’s bucket experiment and Mach’s principle? That same professor introduced me to it בעקבות the conversation we had. At the end of the conversation, although he agreed with me, he argued that this is the difference between physics and philosophy: in physics, what matters is that things work, even though he agreed that this is an important principle.