Hi! Thank you so much for answering my question!
I was wondering if anything could travel through a black hole or would it be "stretched". If so, do black holes lead anywhere, or do they just lead into complete darkness? Do we even now where they lead?
Hello again, Amanda...
"...I was wondering if anything could travel through a black hole or would it be "stretched"..."
If all our theory about the intense gravity of a black hole is correct then nothing can travel through a black hole. You may already know that when you stand up here on Earth there's a difference in the gravitational pull between your head and your feet. That's because your feet are closer to Earth's center of gravity than your head so your feet are more attracted downward than your head. If you multiply that difference billions of times, like in a black hole, that difference in gravity would literally tear your very atoms apart.
"...do black holes lead anywhere..."
Totally unknown. We have no way of directly examining what's going on in a black hole. There are any number of theories, like a black holes leads into other universes, or into other dimensions, but we have no way of verifying any of those ideas.