Missing Lithium
While until recently most people were unaware that lithium even existed, today this element is a daily topic in the media.
It is a crucial component for manufacturing batteries not only for mobile phones but also for the increasingly popular electric vehicles.
There is not an abundance of lithium on Earth, and the same is true for the universe.
However, research on the Big Bang suggests that there was much more lithium at the beginning of the universe, up to three times more. It remains a mystery where all the missing lithium has disappeared to.
Of course, there are various hypotheses. One suggests that a large amount of lithium was consumed in the formation of stars. Another possible culprit could be dark matter.
It should be added that none of these hypotheses can yet be reliably proven.
The Size of the Universe
If there's one thing we can say with absolute certainty about the universe, it's that it is indeed very large. Under ideal conditions, one can see up to several billion light-years from Earth. Yet, this might only be a small part of the cosmos.
There is a pretty good reason to believe that the visible universe is just a small slice of something much more massive. This conclusion is mainly drawn from the movements of galaxies, which are never entirely static.
Many of these galaxies, located at the edge of the known universe, are moving beyond the reach of our telescopes. They are likely being pulled by the gravity of other galaxies, which we can no longer observe.
There are theories suggesting that the universe is still expanding today. In such a case, it is highly unlikely that we will ever be able to map the entire universe. Not even in the distant future.
What Happened to Antimatter?
At the very beginning of the universe, antimatter was created alongside matter. Both types of matter were theoretically supposed to fill the universe in equal amounts, yet today there is no trace of antimatter in the cosmos.
And for that, we can be grateful.
Otherwise, we would witness unprecedentedly large explosions that would occur upon contact between the two types of matter. And that could have very unpleasant consequences for us.
The most likely explanation for this mystery is that at some point, at least some antimatter transformed into matter, which then began to dominate the universe.
It is possible, then, that the current universe is at least partially composed of remnants of antimatter.