ITT: discuss monads

>modern physics still uses Newtonian gravity

It's used to simplify the process of deriving results on macro scales, as newtonian mechanics is approximately correct at that level, but philosophically and physically, it is not a true account of how the world functions and Leibniz was smart enough to understand that Newton's conception of "occult qualities" in nature posed a serious philosophical challenge to Newtonian metaphysics, something that Einstein later picked up on. Today, there are three competing notions:

1. Gravity is mediated by bosons (gravitons)
2. Gravity results from the curvature of the metric tensor
3. Gravity is a field

We currently do not possess the answer. One thing we do know is that it is not an unmediated force that acts instantaneously at a distance.

That unmediated force?

God's pre-established harmony

Precisely what it is not, as pre-established harmony relies on local causality in order to function. Every state depends on some other state local to it. Something cannot influence something else where it is not.

Does the concept of the monad have any practical or scientific value or is it just a historical curiosity cooked up by this brilliant oddball?

I guess you could call the hidden particles in the debroglie-bohm interpretation monads if you wanted to

I bet it's one of those ideas that seems useless but probably has some far-flung application in quantum mechanics or some other esoteric field.

this is about as far-fetched as Bohr calling mathematical symbols Platonic forms

I said if you really want to