> the twin at the speed of light that remains younger
Neither of these are actual scenarios in relativity. I'm not sure where you are getting them from but your information appears to be garbled.
There is a so-called "twin paradox" in relativity (not actually a paradox so the name is a misnomer), where two twins who take different trips (in the original scenario, one stays at home and one travels out to a distant star and back again at high speed) can end up with one younger than the other when they meet up again. But neither twin can travel at the speed of light; that's impossible for an ordinary object like a person. And neither twin can fall into a black hole, because if they did they could never come back out to meet up with the other twin.
Nice, I'm glad you got the reference despite my lack of proper terminology. It's a thought experiment, no one actually wants a twin paradox, but it is worth thinking about it. I'm sure you get my point.
> the twin at the speed of light that remains younger
Neither of these are actual scenarios in relativity. I'm not sure where you are getting them from but your information appears to be garbled.
There is a so-called "twin paradox" in relativity (not actually a paradox so the name is a misnomer), where two twins who take different trips (in the original scenario, one stays at home and one travels out to a distant star and back again at high speed) can end up with one younger than the other when they meet up again. But neither twin can travel at the speed of light; that's impossible for an ordinary object like a person. And neither twin can fall into a black hole, because if they did they could never come back out to meet up with the other twin.