From years we have known that the universe is expanding since the big bang. Edward Hubble was the first to notice this, when he found that every distant galaxy was moving away from Earth. Also, there have been several high-end debates on how this expansion is calculated and whether it’s even correct or not.
The rate of expansion — The Hubble constant — has a huge flaw in measurement, its value changes depending on how the astronomers try to calculate it. But that’s an old flaw, according to a new study published in the Astrophysical Journal, results from the Hubble Space Telescope are now showing the Hubble Constant beyond a plausible level of chance.
There are several ways in which the rate of expansion is calculated, some use supernova information while some use cosmic microwave background — a method which uses distant radiation that we can detect. Both show that the universe is expanding at around 67.7 kms per second faster in every 3.26 million light years.
In the study, Astronomer Adam Riess and his team “SH0ES” — Supernovae H0 for the Equation of State — calculations didn’t match up and the team recalculated the expansion rate, this time with high accuracy using the Hubble Space Telescope. The team calculated near accurate distance to the nearby Large Magellanic Cloud and 70 new Cepheid observations, combined data from which estimated that the universe is expanding at 74 kilometres per second per megaparsec.
The difference between the old and new calculations is significant while also being quite impossible that its due to errors in the data or measurements. Maybe the experiments are measuring something that it yet to be found.
“We are measuring something different, one is measurement of how fast is the universe expanding while other is how fast it is expected to expand based on early physics calculations” said Riess.
Scientists are busy finding new ways to measure the Hubble constant, expectedly using colliding neutron stars and gravitational waves produced by them.
We still don’t know the actual expansion rate — all are just estimations — and we’ll leave the scientists to it.