[Diapositivo]

Because you can walk at the surface of a sphere (assuming it is big enough for the experiment, of course!) in any direction without finding something to stop you. Said differently, there is no edge. Different from another surface like a field.

So, the surface has no limit even if it is finite (you can calculate it).

It is finite and you are infinitely going in circles over it. Saying it is infinite is playing with the meaning of words. By this token one might say that a rollercoaster is infinite because one can "advance" in one direction in it without ever reaching its end. But it isn't. That's regardless of how big the rollercoaster or the sphere is. The bigger it is the less I have the perception I am going in circles, yes.

But perception is not "truth". The Earth is big enough that people can walk it for a life without ever realizing advancing in circles, but nobody says it is infinite. That if we agree that infinite = without limits.