Stars are far apart, especially compared to the everyday distances in human experience.  The fastest a human being has ever travelled is just shy of 40 Km/s, and even at that incredible speed it would take 30,000 years to reach the closest star.  That is an incredible distance no matter how you slice it.  Taking it a step further, most stars in the sky are 20-200 times further away, and that’s just the population of stars we can see.  So if we go beyond and talk about galaxies and the distances between them, we are literally talking astronomical quantities.  Yet even with...