Maybe a year ago, possibly here, I finally saw gyroscopic precession demonstrated in a way that didn’t invoke magic thinking. The person simply pointed out that the mistake is in thinking of the rotating mass as a stationary object, when in fact you are applying the lateral force to a different spot on the object at each time interval, leading to very strange vectors.

The most eye-opening thing I've learned about relativity in the past few years is that the notion that space has no preferential direction is an axiom in the theory.

There's nothing about the way we measure the speed of light that would disambiguate if light traveled instantaneously in one direction and at half the measured speed of light in the other. We just don't have a way to know, because time measurements require information to re-converge at the original site of the experiment's beginning.

It's a pretty good axiom, because we also have no reason to believe there's a preferred direction in space... But it's an axiom.

I really appreciate articles that don't just say what a new thing reveals, but puts it in a context of what we still don't know.

From a layman's perspevtive I've never understood the existence of angular momentum as anything other than a mental model or abstraction. My intuition tells me that all momentum is only linear (except maybe at the fundamental particle level), and perceived rotation is really just a huge amount of linear interactions by individual particles that make up a larger object. This is similar to how a gas is not really a singular thing but really a bunch of particles bouncing against each other, but can still be described by ideal gas laws as if it were a singular object.

What is the flaw in my thinking?

This might be an easy question, but it's always bothered me...

If gravity is caused by curvature of space-time (like I'm a train on a curved rail), doesn't that mean that space-time itself exerts forces?

But if that's the case, why doesn't space exert a retarding force against all moving objects, like a form of friction or wind resistance?

In a total vacuum, an object would move through space-time with zero resistance forever... As if space-time is incapable of exerting any force of its own.

Why does spacetime only exert force when curved?