Not long after the James Webb Space Telescope began beaming back from outer space its stunning images of planets and nebulae last year, astronomers, though dazzled, had to admit that something was amiss. Eight months later, based in part on what the telescope has revealed, it’s beginning to look as if we may need to rethink key features of the origin and development of the universe.
Launched at the end of 2021 as a joint project of NASA, the European Space Agency and the Canadian Space Agency, the Webb, a tool with unmatched powers of observation, is on an exciting mission to look back in time, in effect, at the first stars and galaxies. But one of the Webb’s first major findings was exciting in an uncomfortable sense: It discovered the existence of fully formed galaxies far earlier than should have been possible according to the so-called standard model of cosmology.
According to the standard model, which is the basis for essentially all research in the field, there is a fixed and precise sequence of events that followed the Big Bang: First, the force of gravity pulled together denser regions in the cooling cosmic gas, which grew to become stars and black holes; then, the force of gravity pulled together the stars into galaxies.
The Webb data, though, revealed that some very large galaxies formed really fast, in too short a time, at least according to the standard model. This was no minor discrepancy. The finding is akin to parents and their children appearing in a story when the grandparents are still children themselves.
It was not, unfortunately, an isolated incident. There have been other recent occasions in which the evidence behind science’s basic understanding of the universe has been found to be alarmingly inconsistent.
Take the matter of how fast the universe is expanding. This is a foundational fact in cosmological science — the so-called Hubble constant — yet scientists have not been able to settle on a number. There are two main ways to calculate it: One involves measurements of the early universe (such as the sort that the Webb is providing); the other involves measurements of nearby stars in the modern universe. Despite decades of effort, these two methods continue to yield different answers. [Continue reading…]