The paper explains why a rational number line must always be finite and, thus, the real number line is also finite, which is the basis for outer space.
If space were unbounded, the whole space would be beyond light's reach, meaning that light does not travel. However, we know light travels and it only happens when space is bounded.
Therefore, the set of real numbers is bounded, meaning the real number line must be bounded.
\[ \lim_{ts\to \infty} \frac{d}{ts} = 0 \]
Above limit means that, no matter how far you travel in space, it has no meaning relative to entire space. The ratio is exactly zero, meaning that you have travelled no distance relative to entire space regardless of distance you travelled within finite boundaries. Normally, you could find the distance you travelled with a ratio relative to entire space but if you assume that space is unbounded, that does not count. ts:total space , d: distance.