Newton’s estimate of the distance to nearby stars was larger than any distance imagined before in human history. Even today, nothing in our experience allows us to relate to it. The fastest most of us have traveled is about five hundred miles per hour, the speed of a jet airplane. If we set out for the nearest star beyond our solar system at that speed, it would take about five million years to reach our destination. If we traveled in the fastest rocket ship ever manufactured on Earth, the trip would take one hundred thousand years, at least a thousand human life spans.
