The James Webb telescope has brought cosmology to a tipping point. Will it soon reveal new physics?

For the past few years, a series of controversies have rocked the well-established field of cosmology. In a nutshell, the predictions of the standard model of the universe appear to be at odds with some recent observations.

There are heated debates about whether these observations are biased, or whether the cosmological model, which predicts the structure and evolution of the entire universe, may need a rethink. Some even claim that cosmology is in crisis. Right now, we do not know which side will win. But excitingly, we are on the brink of finding that out.

To be fair, controversies are just the normal course of the scientific method. And over many years, the standard cosmological model has had its share of them. This model suggests the universe is made up of 68.3% "dark energy" (an unknown substance that causes the universe's expansion to accelerate), 26.8% dark matter (an unknown form of matter) and 4.9% ordinary atoms, very precisely measured from the cosmic microwave background — the afterglow of radiation from the Big Bang.

It explains very successfully multitudes of data across both large and small scales of the universe. For example, it can explain things like the distribution of galaxies around us and the amount of helium and deuterium made in the universe's first few minutes. Perhaps most importantly, it can also perfectly explain the cosmic microwave background.

This has led to it gaining the reputation as the "concordance model". But a perfect storm of inconsistent measurements — or "tensions" as they're known as in cosmology — are now questioning the validity of this longstanding model.

Related: Is the James Webb Space Telescope really 'breaking' cosmology?

Uncomfortable tensions

The standard model makes particular assumptions about the nature of dark energy and dark matter. But despite decades of intense observation, we still seem no closer to working out what dark matter and dark energy are made of.