1. Light travels at a certain speed. So what you are seeing in the space is technically in the past. The farther it is, the older it is, but it was also harder to see. The high resolution allows us to see much farther in the past with more data and precision, thus undertstand much more about the creation of the universe.
So you look at a closer younger galaxy then a farther older one and compare to see how they differ and draw conclusions.
2.But aside from the resolution, the biggest point about JWST is that it also has a very precise measurement on ranges of colors. Colors travel at different speeds. By isolating color ranges you can technically go back in time on a picture of the same object. Which is HUGE.
Latest Answers