Silicon is the 14th element on the periodic table and one of the most common elements in the Earth’s crust. It is also a primary component of sand. Other than filling our deserts and seas, silica (silicon dioxide) is also mostly what makes up glass. Where does it come from? The answer lies in massive, ancient stars.
Where Elements Are Born
According to our current knowledge, all of the building blocks for the universe around us and the energy contained within it came from the Big Bang. Hydrogen, the lightest and most plentiful element in existence, is the first on the periodic table. It has a simple structure of a single electron orbiting a single proton (and sometimes a neutron). Next is Helium, made of two electrons orbiting two protons and two neutrons.
Helium is created when two hydrogen atoms are fused in stellar cores. Their centers are nuclear fusion factories, creating heavier elements out of smaller ones. This process also releases a tremendous amount of energy, powering the star. What elements a star can fuse depend on how massive it is and how hot it’s burning. When a star runs out of fusible elements, its power fades, and the star begins to die.
At the start of the universe, hydrogen, helium, and lithium were the only elements present, as far as we’ve been able to observe. As you make your way along the periodic table, the elements get heavier and require more extreme conditions to form. More massive reactions produce more energy, resulting in a flashier source. Though it’s not a linear progression, many elements can only be created when cataclysmic cosmic events occur or in the hearts of massive stars. Among those elements are aluminum, silicon, potassium, and calcium.
Most of the heavy metals form when two neutrons stars collide. Nearly every element on the periodic table was forged inside a star, either during its lifetime or in the moments of its death. Scientists can study the composition of distant stars and celestial events by analyzing the light they give off. The discovery of silicon inside a massive supernova is one of the most recent advancements made using spectroscopy, adding to a long and ever-growing list.
What We’re Made Of
The results of nuclear fusion in stars that have long-since died are what make up Earth today. Carbon, oxygen, nitrogen, silicon, and of course hydrogen are among the most abundant. The gold that we use in wedding rings and other personal adornments was born from the fusion of neutron stars. The windows on your house and in our telescopes all came from the supernovae of massive stars and white dwarfs.
Carl Sagan once wrote, “we are made of star-stuff,” and it’s true. Every element that makes up our bodies exists inside of or originated from the death of a star. We share so much with the universe around it, but our Blue Marble is a unique oasis adrift in space, and with every scientific step forward, we come closer and closer to learning how we came to be.