The next startling discovery occurred when scientists discovered and then applied the idea that light, when passing through a prism, breaks down according to what elements are burning to produce that light. Upon further examination, this spectrum is not continuous as one might expect. Instead, it is broken up by thin lines. Armed with these signature lines within the spectral colors for an element, astronomers and physicists could accurately determine what materials even the most distant stars were made of.
But according to The Day We Found The Universe, next came the discovery that our universe is indeed expanding. The galaxies and their stars are subsequently moving away from what would have been a single vortex or ignition point. This happened when scientists noticed the spectral lines for a given element were indeed there, but were shifted.
When burning elements on earth are examined through a spectroscope, their elemental colors appear with their spectral lines. When distant stars are examined with a spectroscope, their signature elemental colors and lines are present, but the tell-tale lines are shifted toward the red end of the color spectrum. The only logical conclusion is that these burning bodies are moving away from a central point at tremendous speeds.
And where are they going? Father Georges LeMaitre, believing that space time is stretching, proved to Einstein and other astronomers and astrophysicists that "The galaxies are not rushing through space but instead are being carried along as space-time inflates without end."
Thus, astronomers now believe they've uncovered the universe for what it is. It is not infinite. But it is vast; so vast that our species will never reach even the nearest star. Even IF somehow a spaceship could be built to travel at the speed of light (186,000 miles per second), many generations would have to live and die on that spaceship before finally reaching the nearest star which may or may not have a planet favorable to human life.