To put it very simply, astrophysicist Edwin Hubble in the early 1930s noticed that galaxies were moving. Get away. This strange discovery led him to understand that the universe was not a static entity, but was expanding.
Today our cosmological model is of course more complex than it was then and we have the tools to predict the expansion rate of the universe. The problem with this calculation is that the value of the Hubble constant predicted by the cosmological model differs from the one measured experimentally. This discrepancy is known as the “Hubble effort,” and it doesn’t seem to get better with time.
A recent study published in The Astrophysics Journal concluded that the expansion rate of the universe is 73.3 km/sec/million blocks. This roughly means that the universe is expanding at 73.3 kilometers per second every megaparsec (3.26 million light-years).
Pantheon+, an improved dataset in collaboration with another data analysis method, SH0ES, helped the researchers with their calculations. The other piece of information we got from this analysis is that the universe is made up of 66.2% dark matter. The remaining 33.8% is divided into a much larger portion of dark matter and a small portion of normal matter.
“With this combined Pantheon+ dataset, we get an accurate view of the universe from [quando] Dark matter dominated it until dark energy dominated the universe. This dataset is a unique opportunity to see how dark energy ignites and drives the evolution of the universe on the largest scales yet.”
In the future, these new methods will help us fix the discrepancy in the Hubble constant and better understand the past and future history of the universe.