What do you think about space? do you think it ever ends? and if so what do you think would happen if you pass the edge? what do you think the end would look like? is it just an invisible wall?

Well, space is ever growing, so I'd say it's pretty slowly infinite. It may end at some point, but it would be hard, and take probably millions, if not, billions of years or more to reach the end with the limited technology we have. I would say that, like Earth, it would have it's own gravity, pulling us from ever reaching the outside fully, and that it would probably look like  just a black wall, with no stars or anything.

convex lenses are thicker at the middle. rays of light that pass through the lens are brought closer together (they converge). a convex lens is a converging lens. when parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus.

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