You are stardust and lightning

Did you know that the stars gave their life for you and that you’re actually powered by trillions of tiny lightning bolts? It’s not outlandish science fiction. It’s plain old scientific fact.

Now, if the “S” word usually sends you into a narcoleptic boredom coma, you’re not alone. But I really think you should read on. And that’s because I’m going to attempt to explain the fundamentals of how the atoms in your body were formed and what provides your life force – using only some basic, easily understandable facts about the world you live in.

It all started with a bang…a really really big one! Although it’s a fascinating tale, the story of how the universe came into being is not especially important to this article. What is important to understand is that this colossal explosion eventually created only two elements: hydrogen and helium. These two gasses are the simplest known elements in the universe and are definitely not the only thing you and I are made of. So where did all the rest of the stuff come from?

Hydrogen and helium might be no good for making people but they’re the perfect ingredients for creating stars. A star, like our sun, spends its entire life locked in a battle for balance: there is the crushing, implosive force of gravity on the one hand, and titanic, explosive force of nuclear fusion powering its core on the other. Victory of one over the other would most certainly result in the star’s demise.

What you’re seeing here is the inside of a next-generation experimental nuclear fusion reactor, also known as TOKAMAK reactors. The eerie light you see is formed by the same process that operates in centre of our sun. The phenomenal amount of energy given off by nuclear fusion has the potential to provide an almost unlimited amount of clean energy.

The fusion that takes place in a star’s core is not some ungraspable concept.  In simple terms, it’s caused when two hydrogen atoms smash together to from a helium atom under the immense heat and pressure caused by the eternally ruthless force of gravity. (The process of nuclear fusion also happens to be responsible for humanity’s most potent weapon of mass destruction [the H or Hydrogen Bomb], but could also offer a solution to the world’s destructive dependency on fossil fuels – maybe within the next two decades).

Archive footage showing the largest, most powerful explosion ever created by humanity.  the Russian Tsar H-bomb.

So now you know where the star gets its power. But a star cannot have an infinite source of hydrogen fuel. What happens when it’s all used up? Well here’s the clever bit. The fundamental laws of nature are frugal to the extreme: nothing is wasted. As a great friend of mine once said, “Matter is energy waiting to happen and energy is but liberated matter. They are two forms of the same thing.” A star takes this rule to full effect by using the ashes of its previous existence to fuel a new life. As its hydrogen runs out it starts to smash helium molecules together instead, creating carbon and oxygen. From here it ascends through the periodic table, creating magnesium and neon then silicon and sulphur and so on. So before the formation of stars, our entire universe was made up of the two stalwarts, hydrogen and helium. The other elements were created thanks to some “smashing” efforts from the stars.

Back to the point. After ascending up the periodic table the star eventually reaches a critical point when it attempts to fuse iron. Iron is a fantastic material for creating girders but sadly it’s a death sentence for the star. You see, all the previous ‘smashing’ reactions have liberated energy: when you smash hydrogen atoms together, for example, you get helium plus a great big dollop of energy. In contrast, smashing iron together requires more energy than it gives off – which is a massive problem for the star. As the iron accumulates within its core, the star starts to become unstable, until (when the mass of the iron core reaches about 1.5 times the mass of our sun) it collapses, causing what is surely one of the most spectacular, beautiful and violent natural events to occur anywhere within the universe: a supernova.

The Crab Nebula

NASA, ESA, J. Hester and A. Loll (Arizona State University)

As the core collapses a gigantic shock wave shreds the star’s outer layers, which are composed of the remnants of the star’s former lives. All the elements, hydrogen through to iron, are ejected at phenomenal speeds out into the cosmos where they will create the building blocks for new planets (which is how our Earth came to be a very long time ago).

Out of a terrifyingly violent supernova the elements of life are born. Literally. If you could trace the origin of every carbon atom in your body (bear in mind that every living thing on our planet is a carbon-based life form) you would find that each one originated within a star. This applies to everything: from the oxygen you breathe to the calcium in your bones and the iron that forms the fundamental core of every red blood cell. As the great astronomer Carl Sagan once said, ”We are all made of Star Stuff”.

So now that we have established that you’re made entirely from the remnants of some long-dead star, we must take a journey from the mind-numbing vastness of outer space to the minuscule world of the mitochondria. This may well be an unfamiliar word to you but without it you certainly would not have stepped off the plateau of bacterial life to become the complex and inspiring being that you are. Mitochondria are the powerhouses of every single one of the 100 trillion (or 100 million million) cells within your body. It is worth pausing for a moment to appreciate the enormity of this number. It is estimated that there are about 300 billion stars in our galaxy (the Milky Way), of which we can actually see only the tiniest proportion, even on the darkest and clearest night. This means that there are at least 1,000 times more cells in your body that there are stars visible in the sky…Another reason to feel special!

But I’ve digressed. Back to our internal powerhouses, the mitochondria.

Mitochondria are tiny “cells within cells” and are responsible for 90% of the energy generated from the sugars that you, me and every other complex cell consumes.

A CGI representation of the mitochondria and the mechanism by which it converts food (i.e. sugars) into energy in the form of ATP.

Mitochondria have one role in life: to convert sugars into a tiny molecule known as ATP (adenosine triphosphate). This essential molecule is the basic energy currency of life and can be thought of as the “$1 bill” of energy. To create these “$1 bills” the mitochondria perform a series of complicated chemical reactions with funny names such as oxidative phosphorylation and the electron transport chain. But again, we don’t need to delve into the complex details here. The key fact you need to know is that one of these processes pumps tiny, positively charged ions (known as protons, which are basically hydrogen atoms with no electrons) across the internal membranes of the mitochondria causing a potential difference, or voltage, to arise.

One of the things we must bear in mind here is the scale. The membrane itself is only about 5 nanometers (nm) across. Think about this number for a minute. To get 1nm you would need to divide one millimeter into 1 million equally sized chunks…so this is seriously tiny! Even though we’re dealing with such a tiny distance, the voltage created across these membrane by the tiny hydrogen nuclei is about one tenth that of a normal torch battery. When we convert this number to a more human scale we end up with a number of 30 million volts per metre. This is the same as the amount of electrical charge needed for lightning to strike over a distance of 10 metres! So, within every cell of your body, from the tip of your tongue to the ends of your toes, a force equivalent to a bolt of lightning powers your every movement and thought.

And so to conclude. You are a truly wonderful being. Every one of your 100 million million cells is powered by a force equivalent to a bolt of lightning and some distant star has given its life in the most beautifully ferocious explosion just so you could exist. Just think about that for a second the next time you witness an electrical storm, feel the warmth of the sun on your skin or peer up at the twinkling lights in the night sky…You should feel very, very special.