Another thought. If space is spherical, and travelling in one direction for long enough brings you to the same point you started from, what happens when you travel straight up? Do you encounter the bottom of the earth and have to dig all the way through it? If so, why can't we see the bottom of the earth? What if you travelled at a 30 degree incline, or 1 degree incline? if the total distance you travel is the same to reach your starting point, then each angle has you ascending different amounts to reach that point?
The question marks in this diagram illustrate my confusion regarding what happens to the ground between you and yourself along inclined vectors. If one such vector was at an angle so shallow that when reaching my starting position, I would have only ascended 1 metre, at what point do I encounter the change in ground level as I aproach my starting position? Since there are an infinite number of possible angles, why am I not surrounded by an infinite number of gound levels?
Nolhekh, are you really a trigonometer? It looks more like you are just another of the countless trolls here. If you really know something about trigonometry, you should also know a little bit about spherical trigonometry. In order to get answers to your silly pseudo-questions take a globe and observe the behavior of any pair of great circles. In spherical space every point has a corresponding opposite point 180° apart, regardless of the direction one travels. So to answer your question, any movement along a straight line will first bring you to the point opposite the starting point (take a globe to visualize this, it's also called the antipodal point), and eventually back to your starting point. So if you move upwards in any direction you will after 20000 km (180°) come to the antipodal point on the total plane of the Earth's surface, and then enter the body of the Earth. After another 20000km or 180° digging through the Earth you will miraculously find yourself again at the point you started. You will never reach a "bottom" of the Earth, because none exists. Another question is whether the Earth is a massive body or whether it has cavities or is hollow, but that is not our problem here.
Why can't you "see the bottom of the Earth". Simple, because you can't see that far and furthermore in the real world light does not travel along straight lines. The only thing that is straight in the Cosmos is space itself. And yet it is closed!
If you can't imagine this explanation take a globe, start from any point on the equator and draw straight lines (that are great circles) in various directions, you will find they all "miraculously" meet the equator again at the same point. The Earth is a maximal sphere, so you can use a globe for visualizing its properties, however, keep in mind that the maximal sphere is one, whose surface curvature is zero.
Now, before blathering on with more nonsense here, people seriously interested in the true shape of the Earth should do a bit of reading and studying. Starting with the works of Ernst Barthel might be a good idea.
Lactantius