With the help of the Hubble Space Telescope, astronomers have confirmed that the universe is expanding faster than predicted.
Adam Riess, Nobel Laureate and the leader of the research team, said that the community is having a hard time understanding what is going on. For the past six years, they have been using stars as a milestone and further refined their research. With this data, they made a new “Hubble constant”. It is a simple constant that calculates how fast the universe is expanding. Thanks to newer technology and ancient Greek geometry, Riess and the team can reach up to 10 times deeper in space than previous data.
The Planck satellite, on a mission from 2009 to 2013 mapped cosmic microwave background—lingering electromagnetic radiation from the Big Bang. This gave scientists an idea about the universe’s expansion from 378,000 years after it exploded from a tiny singularity.
And this is the part where the conflict comes. Riess and his team got a constant of 45.4 miles per second per megaparsec. But the results from the Planck satellite put the Hubble constant between 41.6 and 42.9 miles per second per megaparsec. Right now, the team has no definitive answer to why this is happening, but they do have a few “dark” theories.
One of them is dark energy, as it might pushing galaxies apart with greater and growing strength.
Another reason could be tiny sterile neutrinos. These tiny, subatomic particles travel almost at the speed of light and are only affected by gravity. These would form something called “dark radiation”. Dark radiation, in short, is still new to us and doesn’t really work with what we now know, that is, they do not work with any of the fundamental forces in the Standard Model of particle physics.
And lastly, it could be that darned dark matter. Dark matter is invisible, and it is not made up from neutron, protons or electrons.
Any one of these theories could change scientists’ understanding of the early universe and render the Hubble constant useless.