The universe is about 13.7 billion years old. The universe is expanding. The universe is filled with matter. The universe contains stars and galaxies. The universe is made up of atoms.
Inflation was a period of exponential growth that happened when the universe first began. This process caused the universe to expand exponentially. The number of light-years is increasing because of inflation. Scientists believe that inflation slowed down over time. Dark energy may have affected the expansion of the universe.
The universe is much bigger than we thought. We used to think that the universe was about 13 billion years old. But now we know that it's actually at least 250 times older than that. And if you add up all the matter and energy in the universe, it adds up to more than 10^80 joules. That's enough energy to power every star in our galaxy for billions of years!
That's big, but actually much tighter than most models.