Where Do Galaxies Come From?
We’ve almost got the entire story. James Webb will put the last piece into place.
In all of science, there are really only two ways that something can be “known” to humanity. The most solid knowledge comes when we can observe or measure it directly, giving us incontrovertible, factual knowledge of the phenomenon in question. The second way we can know about something is theoretically: where we understand the laws, properties, and conditions that must have been in place to give rise to the phenomenon we then observe or measure later on. This latter form is an indirect form of knowledge, and we always seek experimental or observational confirmation of those ideas wherever we can.
When it comes to many questions in the Universe — the nature of dark matter, the origin of the matter-antimatter asymmetry, or the existence of the very first stars of all — we have strong evidence that certain events must have occurred, but we don’t have the direct evidence we want to understand them fully. One of those questions, simple though it may seem, is “where do galaxies come from?” There’s a tremendous amount of information we know about them, but plenty of gaps as well. Remarkably, the James Webb Space Telescope may wind up filling them all in, leading to a more complete understanding of galaxies at long last. Here’s how.
