It shows us the universe is behaving like a driver who slows down approaching a red stoplight and then hits the accelerator when the light turns green. Billions of years later, when the light left more recent supernovas, the universe had begun accelerating, stretching the expanse between galaxies and making objects in them appear dimmer. Due to the Doppler Effect, light waves are compressed when a light source is moving toward you and stretched when it's moving away. This happens to sound waves too, which is why the pitch of a police car's siren drops as the car passes you. With light, however, frequency equates with color, not pitch.
Higher frequencies look bluer and lower frequencies look redder.
Only if the universe itself is expanding, as demonstrated by the balloon below. Later this year astronauts will install a new camera on Hubble that will give us 10 times better resolution than the current camera, which will give us even better capability to find answers to grand cosmic questions like this. Astronomers say the new Hubble findings rule out other explanations. Nearly a century ago, Einstein's Law of General Relativity concluded the universe must collapse under the relentless pull of gravity. However, like many scientists of his time, he assumed the universe to be static and unchanging.