Hydrogen · Science
Hydrogen, the most abundant element in the universe
About three quarters of the universe's ordinary matter is hydrogen, formed after the Big Bang. It's in stars, in water and in 62% of your body's atoms.
bairogonzalez.com team, drawing on Bairo's story · Published
If you could gather all the ordinary matter in the universe, that of stars, planets, gas clouds and people, and sort it by element, about three quarters of the pile would be hydrogen. Almost all the rest would be helium. Everything else we know, the iron in blood, the calcium in bones, the silicon in sand, the gold in a wedding ring, would fit into less than two percent.
Counting atoms rather than weight, the lead is even bigger: out of every hundred atoms in the universe, about ninety-two are hydrogen.
The simplest and the oldest
Ordinary hydrogen is the simplest atom possible: one proton and one electron. There's nothing more elementary to be made out of matter.
It's also the oldest. In the first minutes after the Big Bang, the universe was too hot and dense to hold whole atoms. In that very short interval, the light nuclei formed: a lot of hydrogen, quite a bit of helium, a trace of lithium. Cosmologists call this moment primordial nucleosynthesis, and the proportions it predicts, about 75% hydrogen and 25% helium by mass, match what is measured in the sky.
Only hundreds of thousands of years later did the universe cool enough for electrons to bind to nuclei. That's when the first true hydrogen atoms were born, the same ones that still float between galaxies today.
The furnace of the stars
From hydrogen came almost everything that followed. Gas clouds contracted under gravity, heated up, and at their centers hydrogen began to fuse into helium. That's how stars ignite. The Sun is doing it right now, every second, and that work is where the light warming your skin comes from.
In bigger stars, fusion continues: carbon, oxygen, nitrogen. When those stars die, they scatter into space the elements they made. The carbon in your cells and the oxygen you breathe once passed through the interior of a star that began its life burning hydrogen.
Inside you
Hydrogen is in water, which is made of two of its atoms and one of oxygen. It's in fats, in proteins, in DNA.
In the human body, it accounts for about 9.5% of the mass. That seems little, because it's an extremely light atom. But, counting atoms, about 62% of the atoms in your body are hydrogen. Most of the atoms that make you up are the same element that formed in the first minutes of the universe.
That's why the 21 cm line is so valuable to astronomy: listening to hydrogen is listening to the main ingredient of everything.
Sources: Abundance of the chemical elements · HyperPhysics, Big Bang nucleosynthesis · Composition of the human body · Hydrogen line
In Bairo's view
For Bairo, few facts in science are as spiritual as this one, even though science doesn't say it in those words. The simplest element is everywhere: in the stars and in the air, in the sea and in the blood. Discreet, almost invisible, present from the beginning.
He says he sees God in hydrogen. It's his faith, spoken as poetry, and not a claim of chemistry. The chapter The voice he follows tells where that image comes from. Chemistry explains what hydrogen is. What it means to a man who found faith at rock bottom belongs to him.
And there's a detail that moves him: the most abundant is also the simplest. For him, abundance doesn't begin with the complicated. It begins with the elementary, repeated faithfully, atom by atom.
For you
It can be a relief to know this on a bad day. You are made, for the most part, of the oldest material there is. The hydrogen atoms in your body have already crossed billions of years, clouds, stars and oceans before getting here. You aren't a last-minute accident. You're a recent stage of a very long story.
And hydrogen teaches a second thing: greatness doesn't require complexity. The brightest star in the sky burns the simplest atom. Perhaps the next step in your life doesn't need to be sophisticated either. It needs to be simple, and repeated.