tillingborn wrote: ↑Tue Feb 09, 2021 10:36 am
You're making the same mistake as Immanuel Can, in that both of you attribute particular ontological qualities to what are abstract nouns. A force is whatever changes the acceleration or shape of and object, basically any change that can be measured in Newtons; it is not a 'thing' in a material sense.
I am not making any such mistakes. You just believe that I am.
You can't say "a force is whatever changes the acceleration"... without being explicit about the theory/reference frame from which you are measuring "acceleration".
Newton distinguishes gravity from acceleration, Einstein says gravity and acceleration are the same thing. Thus gravity is an illusion.
tillingborn wrote: ↑Tue Feb 09, 2021 10:36 am
General Relativity is just one of the ideas that account for the acceleration that massive objects experience.
Yes, but acceleration with respect to what?
tillingborn wrote: ↑Tue Feb 09, 2021 10:36 am
A gravitational field is another abstract noun to which you are attributing ontological qualities, when for the purposes of science a gravitational field is simply anywhere that an object will experience an acceleration, as in it will measurably change velocity or direction. Like gravity and force, a field is not a material thing.
You are indeed confused. Within each respective theory "forces" and "fields" are reified in the Mathematics. And they are represented (modeled) by different mathematical objects.
And their interpretation thus differ because of the different ontological assumptions of each model.
tillingborn wrote: ↑Tue Feb 09, 2021 10:36 am
Here you are mixing up Newton's worldview and his mathematics. It is his mathematics which is falsified. His general approach was that physics is about the maths rather than what qualities to attribute to abstract nouns. That is still the dominant approach, hence the dictum 'Shut up and calculate'.
You have some fundamental misunderstanding of what Mathematics expresses.
Newton's model-theoretic assumptions/definitions were encoded in his equations. So the semantics of "acceleration" in Newton's mathematics is not the semantics of "acceleration" in Einstein's mathematics. Because they assume a different geometry.
Subsequently the English abstract noun "acceleration" means one thing in a Newtonian universe, and another thing in Einstein's universe. In Einstein's universe "acceleration" is synonymous with "gravity".