Extremely precise measurements of the distance between the Earth and the Coma cluster of galaxies provide new evidence for the Universe’s faster-than-expected rate of expansion. (Photo courtesy NOIRLab)
Marie Claire Chelini, Trinity Communications
The Universe really seems to be expanding fast. Too fast, even.
A new measurement confirms what previous — and highly debated — results had shown: The Universe is expanding faster than predicted by theoretical models, and faster than can be explained by our current understanding of physics.
This discrepancy between model and data became known as the Hubble tension. Now, results published in the Astrophysical Journal Letters provide even stronger support to the faster rate of expansion.
“The tension now turns into a crisis,” said Dan Scolnic, who led the research team.
Determining the expansion rate of the Universe — known as the Hubble constant — has been a major scientific pursuit ever since 1929, when Edwin Hubble first discovered that the Universe was expanding.
Scolnic, an associate professor of Physics at Duke University, explains it as trying to build the Universe’s growth chart: we know what size it had at the Big Bang, but how did it get to the size it is now? In his analogy, the Universe’s baby picture represents the distant Universe, the primordial seeds of galaxies. The Universe’s current headshot represents the local Universe, which contains the Milky Way and its neighbors. The standard model of cosmology is the growth curve connecting the two. The problem is: things don’t connect.
“This is saying, to some respect, that our model of cosmology might be broken,” said Scolnic.
Measuring the Universe requires a cosmic ladder, which is a succession of methods used to measure the distances to celestial objects, with each method, or “rung,” relying on the previous for calibration.
The ladder used by Scolnic was created by a separate team using data from the Dark E
