The James Webb Space Telescope has produced some truly stunning results, and its first full year of observations is still ongoing. But among the astounding pictures and ground-breaking discoveries, there was a perplexing assertion: that the telescope had seen galaxies in the incredibly young universe.
According to the headlines, those galaxies were so enormous and emerged so early that they “broke” the Big Bang theory of cosmology.
Although the claim gained widespread attention, it is untrue, like with many things found online. There is now more evidence supporting the Big Bang.
“CDM cosmology” in Brief
The James Webb Space Telescope’s discoveries of far-off galaxies were recently confirmed to be entirely consistent with our current knowledge of cosmology by experts who examined the data more carefully.
It’s not that faraway galaxies exist that could be problematic. In reality, the CDM cosmology (short for “cold dark matter”), a contemporary version of the Big Bang hypothesis, anticipates the emergence of galaxies in the incredibly early cosmos.
This is due to the fact that stars and galaxies were completely nonexistent billions of years ago.
Everything was far more uniform and densely packed when our universe was much smaller and denser than it is now, with only minute density deviations arising at random. But over time, the disparities in density increased as the slightly denser pockets attracted more material to them.
What then is the conflict?
The estimated masses of those galaxies are what caused the apparent tension. Many of them were quite large—far in excess of 1010 solar masses.
Although they are presently much smaller than the Milky Way, they were fairly large in the early cosmos. These galaxies’ high masses, according to the researchers that discovered them, are thought to conflict with a number of hypotheses of galaxy origin and evolution.
The researchers even went so far as to say that no galaxy formation model within the CDM framework could be able to produce such massive galaxies so soon.
A Subject of some contention
However, their assertions depended on determining a precise distance to those galaxies, which is exceedingly challenging at such great distances.
The researchers used a technique known as a “photometric redshift,” which matches the general light spectrum of a galaxy to a model to determine a distance, for the record-breaking galaxies that might be at odds with cosmological models.
The galaxies can appear to be farther away than they actually are using this method, which is notoriously unreliable due to simple phenomena like extra dust surrounding them.
Uncertainty Related To “The Big Bang”
Webb was used by a new research team to locate galaxies using spectroscopic redshift, a considerably more exact and trustworthy method of measuring distance, to determine whether the Big Bang is in peril.
In order to determine the redshift and, consequently, the distance to the galaxies, this method identifies the spectral lines of known elements emitted by the galaxies. The team discovered four galaxies as a sample using this more precise method.
These galaxies were all equally far away as the ones that had already been found, but their distances were confirmed and trustworthy. These galaxies, nevertheless, had masses that were significantly smaller—between 108 and 109 solar masses.
The concern that arose was whether or not the CDM would permit the existence of these tiny galaxies at such a young time in the universe’s history, given the tension that existed at the time.
Now The Simulations start.
Creating galaxies is a difficult task. While the overall history and evolution of the cosmos within the CDM model can be traced using pen-and-paper mathematics, galaxy formation involves the complex interaction of many different types of physics, including gravity, star formation and supernova explosions, dust distribution, cosmic rays, magnetic fields, and more.
Supercomputer simulations must be used to generate artificial galaxies based on the universe’s raw, primordial form as it existed billions of years ago in order to account for all of these interactions.
That is the only method to link the fundamental CDM model parameters to what we observe in the real world (galaxies) (like the amount of normal and dark matter in the cosmos).