What the NEW black hole discovery tells us!

geodesics and GR are one way of observing the phenomenon.  You could also say 'gravity ian't a force, and doesn't require a mass to operate... gravity modifies the velocity vector towards itself.'   Gravity doesn't care what a thing's mass is... EVERYTHING falls at the same rate (granted light is going a LOT faster than a feather or hammer, but none the less for the same amount of time the light is in a gravitational field it will still get accelerated the same way.  Except along it's forward/backward path, then its frequency is modified (red/blue shift).  This gravitational lensing has been proven time and again, and it's not based on any different knowledge, just a different operation.

If space is stretching, then distant galaxies would be closer together than galaxies are near to us.   (but then that's assuming we're in the middle of this 14B ring and therefore we're the center of everything)  Even if we aren't,the distance something 10B years ago would have changed would be gthe same...

OR - does... no... when space stretches, does the matter in that space also stretch, because it's really the same metric to stuff in the space?  So the only thing that manages to sense the change is light in its frequency?... like somehow to the light the path is now longer than it was Then it would have to be basically the same size... which they aren't, red shift is larger in every way possible, except amplitude - or strentgth - but a single photon's amplitude seems to always be the same.

BTW; a recent realization is that photons transmit rotation, while gravity transmits linear velocity change... but then we'd have to be in a 7D universe - time, 3 linear space (4), and 3 rotational inertia/not just momentum) (7).... and we have basically 2 forces - gravity and light that transmit deltas from one body to another across space.