Hubble Tension Solved? Astronomers Race To Save Standard Model Of Cosmology

The universe is expanding at an accelerated rate, however, the nature of this expansion why it's expanding and why it's doing so at such an accelerated rate is uncertain. One culprit has been dubbed dark energy, a hypothetical form of energy that could be seen as anti-gravity. While what dark energy is precisely remains unknown, as a cosmological constant astronomers could roughly agree on its effects to measure the expansion rate of the universe, known as the Hubble constant. But not anymore.

Over the last few months, research has been published and news has followed about new measurements for the expansion rate of the universe. This is a Hot Topic in cosmology. Over the last several years, that earlier agreement has disappeared in the face of a gulf between the value depending on which method you use to measure it. The issue, dubbed the Hubble tension, took center stage, with cosmologists and astrophysicists arguing for one method of measurement and its resulting number over the other. But there is no clear winner.

How could it not become a core issue? The standard model of cosmology the universe started with a Big Bang, inflated exponentially, and has been expanding ever since (made up of regular matter, dark matter, and dark energy in a 5:25:70 proportion) is possibly at stake. The most advanced observatories humans have ever put into orbit to measure extraordinary phenomena can't agree on a single value for the expansion rate.

One, the Planck Observatory, looked at the cosmic microwave background (CMB). That’s the first light ever released in the universe. It is considered the light echo of the Big Bang, emitted once the universe was cool enough for neutral atoms to form, the light no longer shackled to them.