Yes, one cannot reach the speed of light as their energy would be greater than the total energy of the universe, but one does approach it asymptotically.
To be sure we had it right I also asked Gemini:
"
An observer who has already fallen
inside the event horizon of a black hole would indeed be able to see light from outside, for a brief period. Here's why:
- Event Horizon is one-way for escape, not entry: The event horizon only prevents information (including light) from escaping the black hole, not from entering.
- Light cone dictates what's visible: Imagine a cone of light emanating from the observer. Any light within that cone is theoretically observable by them. Light from outside that hasn't yet crossed the event horizon can still fall within the observer's light cone, allowing them to see it.
However, there are some caveats:
- Limited view: The view wouldn't be the entire outside world. It would be restricted to a specific cone-shaped region behind them.
- Redshift and eventual darkness: As the observer falls deeper, the immense gravity would cause the light to redshift (stretch its wavelength) making it appear fainter and eventually invisible.
- Short-lived view: Due to the warping of spacetime near the event horizon, the light from outside wouldn't be visible for very long.
In essence:
An observer inside the event horizon would have a brief glimpse of the outside world through the light that entered before they crossed the horizon. However, this view would be limited, distorted, and fade away quickly."
So given a bit of time passing it seems you would be correct that we would see nothing when looking back. However, this discussion stimulates a thought that supports my idea that we live in a white-hole universe:
The white hole would act oppositely to a black hole so far as light passing the event horizon is concerned i.e. none would pass into the white hole from beyond the event horizon. Presumably though, light would pass from within to without.