I am trying to better understand one of my previous questions, and another.
Charged particle in uniform Magnetic field
Does a charged particle orbiting Earth radiate?
https://en.wikipedia.org/wiki/Paradox_of_radiation_of_charged_particles_in_a_gravitational_field
To the extent I understand the answers, it seems to me that a charged particle behaves differently if it is deflected by a gravitational or a magnetic field.
Even though the particle follows the exact same trajectory, it behaves differently.
In a magnetic field, it is a clear-cut radiation. If I lived in an almost massless magnetic field that mimics Earth's gravitational field on a very big scale (obviously, the magnetic dipolarity is an issue, so maybe mimic Earth's gravity in one half of the space), I could see the charged particles coming from the Sun radiating (with appropriate sensors).
In a gravitational field, there is a radiation, but it is hidden away by an event horizon from an observer on the surface of the Earth.
Could it be that a gravitational field is like a magnetic field and then something, something extra?
What does this tell us about the feasibility of a Grand Unified theory involving gravity?