A long time ago, in a galaxy far, far away… No, it’s not Star Wars, but a real galaxy far, far away, very similar to ours, the Milky Way, when it was formed. It was observed by James Webb Telescope who never rests, was called Firefly Sparklehas a mass of ten million solar masses, and we see it as it was just six hundred million years after the Big Bang.
There was also the stroke of luck… er… of being able to see it through a gravitational lens, i.e. a deformation of spacetime due to clusters of galaxies that allows us to see what’s behind an observed region. To make you understand, if you didn’t know, Einstein’s first proof of relativity happened just like this: if Einstein was right, the stars behind the Sun would have been seen moved to the side, because the solar mass would have bent spacetime and consequently light. would follow the deformation. When Einstein published general relativity in 1916, few believed it, but in 1919 Arthur Eddington organized an expedition to Africa. On May 29 of that year, a total solar eclipse was predicted in São Tomé and Príncipe, and the result was that the stars normally hidden by the Sun were outside. To everyone’s amazement, the theory of relativity received its first incredible confirmation, the first of many others (this Einstein was a genius, did you know that?).
The same thing goes for the cluster of galaxies that created a gravitational lens making this galaxy visible to the JWT at its first formation, a galaxy very similar to ours. You can observe the formation of new stars, gas, dust, nitrogen, oxygen, a laboratory in ferment. We are also looking at something that happened more than thirteen billion years ago.
Astronomers are rightly cheerful and you can also see it in onomastics, Firefly Sparkle means sparkle of fireflies, a name that Fabio Volo, Gramellini or Heidi (not Heidegger) could have chosen, fireflies that would shine very little if it weren’t for the effect of aforementioned gravitational lens. Personally, I find new discoveries about the universe more and more surprising, fantastic, and also the confirmation of how terrifying all this is, even though people look at the starry sky and find it beautiful.
Of course, many answer that we still don’t know what la is dark matternor the dark energy that pushes the universe to accelerate its expansion, its disintegration.
One day we will know what dark energy is, what dark matter is, but I can guarantee you one thing: don’t worry, they won’t be anything reassuring for us. For now enjoy the Firefly Sparkle, it also sounds good for a Christmas song.