Each moment that passes changes the Universe that we’re living in. It’s not the same now as it was yesterday and so on.
With each moment that passes by, there are various subtle but really important changes that are taking place even if most of them are not perceptible on the human timescales.
The Universe is expanding
For instance, the Universe is expanding, and this means that the distances between large cosmic structures are increasing as time passes.
As the Universe expands, the relative importance of radiation, matter, dark energy, or neutrinos – they are all changing.
The temperature of the Universe also changes as well, and the sky also suffers a lot of changes that can be seen by us with the naked eye.
Forbes notes the fact that there are six different eras that we can break the Universe into and the online publication and writes that we’re in the final one.
The six stages of our Universe
Here are the six stages of our Universe, cited from Forbes’ original article.
- Inflationary era: which preceded and set up the hot Big Bang.
- Primordial Soup era: from the start of the hot Big Bang until the final transformative nuclear & particle interactions occur in the early Universe.
- Plasma era: from the end of non-scattering nuclear and particle interactions until the Universe cools enough to stably form neutral matter.
- Dark Ages era: from the formation of neutral matter until the first stars and galaxies reionize the intergalactic medium of the Universe completely.
- Stellar Era: from the end of reionization until the gravity-driven formation and growth of large-scale structure ceases when the dark energy density dominates over the matter density.
- Dark Energy era: the final stage of our Universe, where the expansion accelerates and disconnected objects speed irrevocably and irreversibly away from one another.
We entered the final era of this universe billions of years ago, and most of the essential events that define the Universe’s history have already happened by now.