- #1

Shirish

- 214

- 24

Apologies in advance if this is a naive question. From what I've understood, it's not particularly meaningful to talk about gravity as a force, since it induces the same acceleration (

Whatever device or accelerometer we use, every component of that too will be accelerated the same way as the observer will (at least classically speaking), since classical gravitation force is proportional to the inertial mass and everything will thus be subject to the same force/mass relation. The observer will not be able to measure (provided they or the measuring device are under no other influence other than gravity) any acceleration whatsoever. This makes it meaningless to talk about gravity-induced "acceleration" since we can't measure it.

One central idea underlying this is the equivalence principle (gravitational mass = inertial mass) that makes sense to me. But I wonder -

(I'm not claiming any such thing might or should exist - just trying to clarify my understanding)

*classically speaking*) in everything.Whatever device or accelerometer we use, every component of that too will be accelerated the same way as the observer will (at least classically speaking), since classical gravitation force is proportional to the inertial mass and everything will thus be subject to the same force/mass relation. The observer will not be able to measure (provided they or the measuring device are under no other influence other than gravity) any acceleration whatsoever. This makes it meaningless to talk about gravity-induced "acceleration" since we can't measure it.

One central idea underlying this is the equivalence principle (gravitational mass = inertial mass) that makes sense to me. But I wonder -

**is the fact that gravity acts on everything also fundamental to this**? If there were anything at all that's not acted on by gravity, would the whole "gravity as a force doesn't make sense" premise (or maybe GR itself) break down? Is this question related to Mach's principle in any way?(I'm not claiming any such thing might or should exist - just trying to clarify my understanding)

Last edited: