Hydrogen
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Hydrogen

When we think of the word ‘universe’, we should probably think of hydrogen.

Hydrogen is a colourless, odourless, tasteless, but highly flammable gas. It’s the element that makes up 74% of all ordinary matter, lights the stars and in doing so illuminates the universe.

All hydrogen comes directly from the Big Bang, as quarks coalesced into atoms in the first few seconds of the universe. Hydrogen is the simplest atom to make with just one proton and one electron, and because of that simplicity a lot of it was made.

Along with helium and trace amounts of other elements, it formed huge clouds in space and under the influence of their own gravity, they slowly formed the galaxies, dust clouds, and stars throughout the universe.

When a cloud of hydrogen coalesces into a dense ball, it’s own gravitational weight fuses together hydrogen and other atoms at its centre, creating heat, light, and waste products like iron, which turns the ball into a star.

Hydrogen is star fuel. In our Sun, 600 tons of hydrogen are fused in every second. Through hydrogen and gravity, stars like the Sun heat and light the universe.

The light and heat of stars come from fusing elements, mainly hydrogen, in their cores.
The light and heat of stars come from fusing elements, mainly hydrogen, in their cores.

After billions of years waste products like iron build up, and a star will reach the end of its life. Many stars then erupt in a giant explosion called a supernova. The resulting shockwave creates a multicoloured gas cloud called a nebula, and they look absolutely stunning.

Some of the most beautiful shapes in space are nebulas. This is the Omega Nebula, which is about 90% hydrogen, unused by a long dead star.
Some of the most beautiful shapes in space are nebulas. This is the Omega Nebula, which is about 90% hydrogen, unused by a long dead star.

Nebulae are also known as ‘stellar nurseries’, because even though they are the remnants of dead stars, they still contain enough hydrogen to form the next generation of stars, as well as the planets that orbit them.

Our own Sun, as well as many of the stars nearest to us formed from a long-gone, ancient nebulae of unknown shape and colour.

In our solar system, most of the material coalesced into the Sun and the biggest planets in the solar system, the gas giants; it’s why Jupiter, Saturn, Neptune, and Uranus are about all 90% hydrogen.

Down on Earth, we still have plenty of hydrogen and we’ve invented a number of creative uses for it.

Fuel

When hydrogen burns, it gives off very few pollutants and zero carbon dioxide. Some energy companies are promoting it as an emissions-free alternative to gasoline.

We sometimes used as rocket fuel, but it takes up a lot of volume for its weight, so we cool it into a liquid to fit more into a container. But this usually creates its own complications. The containers have to have thick heat-resistant walls that must be maintained, which makes it an expensive fuel to use.

The Delta IV rocket used liquid hydrogen mixed with liquid oxygen as a propellant.
The Delta IV rocket used liquid hydrogen mixed with liquid oxygen as a propellant.

Buoyancy

Considering that hydrogen is literally rocket fuel, it’s bizarre that it was also used last century as the gas that gave lift to airships and zeppelins.

Predictably enough, it caused a massive explosion in the airship Hindenburg in 1937 when it was lit by a static spark.

The Hindenburg explosion
The Hindenburg explosion

Nowadays we use helium to lift blimps and airships, even though it’s rarer, more expensive, and weighs more than hydrogen. But it also doesn’t explode.

But in 1937, the production of helium was monopolised by the United States, who refused to export it to any other country (including the German-based company that made the Hindenburg) under the probably not unfounded concern that it might be used for military purposes, considering WWII erupted just 2 years later.

So although the zeppelin engineers at the time were aware of the explosiveness of hydrogen, they decided to go ahead with it as it was the only option available.

Acids

The concentration of hydrogen ions in a solution is what makes something acidic.

But the most interesting thing about hydrogen is that everything around you, from the skin and bones of your hands to the metals in your phone, was once hydrogen gas.

Check out how this happened in our two-part article called The Story of Your Atoms.