James Webb Space Images Challenge How the Universe Evolved
The James Webb Space Telescope (JWST) has been unlocking many mysteries, and now it’s finding multiple galaxies that grew massive too soon after the Big Bang if the standard model of cosmology is to be believed.
In a study published in Nature Astronomy, Mike Boylan-Kolchin, The University of Texas at Austin, found that six of the earliest and most massive galaxy candidates observed by JWST contradict the prevailing cosmology thinking.
Other researchers estimate that each galaxy is seen from between 500 and 700 million years after the Big Bang yet measures more than 10 billion times as massive as our sun. One of the galaxies is even more massive than the Milky Way, even though our galaxy had billions of more years to form and grow.
Boylan-Kolchin believes that we’ll require something new about galaxy formation or a modification to cosmology. An extreme possibility is that the universe expanded faster shortly after the Big Bang than predicted. For galaxies to form so quickly at such a size, they would need to convert nearly 100% of their available gas into stars.
While 100% conversion of gas into stars is technically right at the edge of what is theoretically possible, this would require something to be very different from what we expected. JWST provides an unsettling dilemma. If the masses and time since the Big Bang are confirmed for these galaxies, fundamental changes to the reigning model of cosmology—what’s called the dark energy + cold dark matter (ΛCDM) paradigm, which has guided cosmology since the late 1990s —could be needed. If faster ways to form galaxies than ΛCDM allows, or if more matter was available for forming stars and galaxies in the early universe, astronomers would need to shift their prevailing thinking.
