Light can't escape a black hole and we can see it.
This is not technically accurate, and what follows may seem like semantics but it is important physics so hang on a moment.
We cannot and have not seen a black hole. We HAVE seen the effects of the existence of these objects, we have watched stars orbit these objects, we can measure their mass, and we can watch them eat stars and gas clouds.
What we CAN see is what is now known as the event horizon. 1 mm on this side of the event horizon, we can get data and light can, theoretically, escape to get to our eyes and instruments. At the exact point of that horizon, the universe divides by zero and our current understanding of reality breaks down. We have images of the chaos created by such deep gravity wells, but no images of the event horizon proper that I am aware of. The recent Japanese XRAY observatory, Hitomi, sadly had a malfunction, but one of the things it was supposed to do is increase the resolution of the images we have of the center of our galaxy. The James Webb telescope looks at the wrong kind of light, so we have to wait for another big XRAY scope to get better images.
The other thing I want to point at, also a technical reply is this:
I cannot prove a soul is real or tangible
Nor can anyone else. We can take an image of the electron shell of a hydrogen atom for example. We can now image individual photons of light energy. We can measure the temperature difference of the equator and poles of Pluto. You get the idea, I hope. If the soul was real, and existed within the laws of reality, we would have found it by now. Hell, they are using brain scans to pull dreams and individual memories out of people.
Whatever it is that makes human different than the other higher life forms on earth is not something supernatural. But something is different about us where we can speak, build, dream and ponder. I don't think it is a 'soul.' And in my mind that is something that makes us even more special and that we should spread sentient though through the universe and protect it.