Wrote this elsewhere

wonder how infalling matter is seen from a event horizon?

Assuming light to blueshift everything outside the event horizon should speed up, locally measured from the Event Horizon, and infalling mass should then seem to arrive, as good as, instantly. That is if it speed up, locally defined? You can also imagine yourself accelerating, to get that effect, which then close to light speed would mean, what? Just think of some other frames trajectory or geodesic, then accelerate, if now your local clock slows down relative a universe, will those geodesics mass move faster, as defined by you? It's also a question of your motion relative theirs naturally, but what I'm wondering about is how a local clock will define other frames motion, when close to 'c'.

If you think it will, is there a point where that trajectory or geodesic, for you accelerating, will seem to move ftl? It can't be , unless 'c' is wrongly defined. Because we define it locally. We can also assume a uniform motion, after such a 'final' acceleration. Will your clock still 'tick' slower relative other frames of reference, equivalent to your accelerating, or do you expect that local clock to become of one rhythm, same for all uniform (relative) motions?

=

There is a paradox hidden here as it seems to me. 'c' puts a limit on everything I measure, and let's assume me close to 'c' in a uniform motion for this, But if my clock moves slower I can just as easily define yours to move faster. And that goes for all motion. Infinitely close to 'c' I would expect a universe's lifespan to pass me by in a twinkling of my eye.

Shouldn't that mean a 'infinite blue shift' for me, locally measured. As well as me assuming that as much light should be able to reach me, as if my clock hadn't slowed down, alternatively, the universe 'speeded up'. As I'm still part of the universe, no matter what speed I measure relative other frames of reference. Either you assume a equivalence between your clock slowing down, represented by your outside universe 'speeding up', or you stop at the definition of your local clock slowing down.

So, slowing down your clock, but not assuming the equivalence of a universe to speed up, what effects would that give you? Think of lights speed in a vacuum, should it change? Would you expect it to blue shift or red shift. How about mass (planets etc) moving, would they speed up? Is there a way to differ those two, either assuming a equivalence allowing me to define my 'slower clock', as yours 'faster'? Relative defining it as 'one universal clock' versus your 'slow'. To use such a definition from a acceleration may work, but from a uniform motion?

And this one was one weird example

But it may work for me? Although it is not symmetric.