One of the great advantages of science compared to technology, which generally only travels into the future, is that science also allows us to travel back in time. But for one as remote as the origin of the universe. A team led by Gan Zhao of the Chinese National Academy of Sciences has made a major scientific breakthrough by discovering the chemical signature of the first generation of stars, believed to be the first in the universe.
Its study is essential to understanding the origin of the elements of the universe because it is there, in the stars, where they are born. It’s not for nothing that we are called stardust: the calcium in our bones, the oxygen we breathe, the phosphorus, the iron… all of them are born in the stars. But let’s go in parts.
An element is a substance that is made up of atoms that have the same number of protons. Chemical elements, like the ones these scientists had previously discovered in stars, are the raw material of the universe. Its atoms are made of three “basic building blocks”: protons, neutrons, and electrons. What makes an element, for example oxygen, oxygen and not, let’s say iron, not what they are made of because they both have an atom made up of protons, neutrons and electrons, but how many of these “bricks” have protons Are. For example, oxygen has 8 and iron has 26. This explains the difference.
In nature, once we get to 92 protons, uranium, the element is depleted. The simplest element is hydrogen, as it has only one proton. But inside a star, heat (energy) drives them very fast and hydrogen atoms collide and fuse together. In doing so, they convert into a helium atom (which has two protons) and release energy in the process, which further increases the temperature and causes new atoms to fuse: two helium atoms, When fused, an atom of beryllium is produced, which has four protons. This is how elements are created inside a star. The younger it is, the fewer metals it contains, and this can give us an idea of ​​its approximate age. And that’s what these experts analyzed.
