Einstein
Temporal Engineer
Well Einstein what causes objects to attract each other? Are you implying centrifugal force produces attraction between stellar bodies? Centrifugal force flies outwards repelling objects. Centripetal motion(only found in fluids) causes them to fly together(like down a drain, etc)
The only reason anyone believes in mass is due to energy equivalence. They don't know how to explain mass other than as a scalar value. So I wouldn't worry about it much. Just means the amount of energy in a massless gamma photon is equivalent to a scalar energy equivalent in 1 positron and 1 electron.
I'm sure mass has other behavioral characteristics as yet undiscovered but for now the equivalence math works.
They show mass is real when they do the energy balance sheet for a nuclear explosion. Just means equivalence. So you can call it mass or angular momentum if you like or anything else. Some people say all particles are really swirling vortexes of energy that converts into gamma photons when annihiliated by it's anti-spin antimatter particle.
Mass just means photon energy in a different form that has resistance to acceleration. So when you say it doesn't exist you're saying resistance to acceleration doesn't exist.
Real question is why doesn't a gamma photon have resistance to acceleration just like the particle? Or a particle have no resistance to acceleration like a photon. So when they say a photon is massless that's what they're saying. Same can be said for gravity. It's just a set of behaviors. Stuff accelerates towards each other while experiencing weird time dilation.
Of course this doesn't explain anything. Still doesn't explain the why.
Wait a minute. You wrote: "The problem with momentum is that you have to accept the concept of mass. So how do you measure an inertial mass? My physics instructor just said to use gravitational mass. I never did buy that story. And to date no one has ever found a way to measure an inertial mass. WTF! Mass is the foundation of Physics. And no empirical facts exist to show this is even real. So you either decide to abandon ship or go down with the boat. I would recommend abandoning ship. Or sail along side to watch the mistakes being made that hastens its sinking."
Ya measure inertial mass by how much an object blows up another when stopping suddenly. Or by how many photons an accelerated charged particle in a cyclotron or betatron are emanated. So, measure the gravitational mass(weight) and then accelerate and measure the kinetic energy for it's speed on impact or it's radiation and presto, inertial mass.
Since we don't know how fast the earth is moving in interstellar space exactly(it's a rough estimate) some of our gravitational mass could really be inertial mass but who cares. They're obviously interchangable.
I think I understand what you're saying, no way to measure inertial mass in real time without first slowing it down to measure it's momentum.
What I was trying to get you to realize is the real world of empirical facts was left behind in favor of a theoretical universe that is not the one we exist within.
I chose to explore the universe we are in where there is no mass at all. Instead there are basic forces. I notice you have been taught that a vector has a third attribute called duration. When I was in school a vector was just magnitude and direction. Of course direction doesn't have to be a spatial direction. It could also be a time-like direction.
Centrifugal force is just the flip side of the gravitational force. The plus and minus. And the inertial force is the one they are attempting to hide. There is a minus version. But there is some indication that the direction of time that associates with inertial force is what has changed direction. I need to point out that I have empirical facts to support these statements.
I notice you made reference to gravitational mass and inertial mass as being the same. Einstein made a similar blunder with his principle of equivalence. Newton also made a blunder with his F=MA equation.