Infinity is forever. You might hope that your relationship with your high school boyfriend will last into infinity, but, realistically, you know that's not likely to happen.
You've probably come across infinity in mathematics — a number, like pi, for instance, that goes on and on, symbolized as ∞. Astronomers talk about the infinity of the universe, and religions describe God as infinity. A more earthbound example is an infinity pool — a swimming pool designed to trick the eye and look like it doesn't have an edge, so the water goes on forever. You may know the Latin phrase ad infinitum, which means "and on and on."