Particles, dust and me

“Ashes to ashes, dust to dust . . .” For me, the words of the Anglican funeral rite, taken from Ecclesiastes 3:20, underline not only our fragile hold on this planet but our essential oneness with the universe. It seems we are made of stardust.

The elements that go to make up the human body did indeed start off in stars, or the Big Bang to be more correct (1).

What I just found out is that three elements had a different origin and started off inside either a black hole, a supernova, or a neutron star. One, in particular – Boron – is essential to life on earth and is vital to formation of the cell wall of plants (2). (The other two are beryllium and lithium.) In other words, without black holes, there would be no life on earth as we know it. Quite a thought.

The incredibly fine balance of our life on Earth often draws me up short. If the Earth were just a little closer to the sun, all the water would evaporate, a little further away and we would become a desert planet. Likewise, if the Earth were a bit smaller than it is, the gravitation pull would be weaker and our atmosphere would leak off into space. Much bigger and we would have a great deal of trouble standing upright. . .

Then there’s the nature of the earth’s core, formed of molten iron. The rotation of the Earth causes this molten iron to rotate, which produces electric currents that create the magnetic field from which we derive magnetic north (3). This magnetic field has an essential function for life, in that it creates a forcefield, shielding us from the impact of the solar wind, comprising mainly protons, electrons and alpha particles. Without it, the bombardment of the Earth by these cosmic particles from the sun would irradiate all life, destabilising DNA which would mutate at a frightening rate. Life as we know it would never have evolved. As an aside, if you’re interested, the solar wind also includes a host of ions, atomic nuclei and isotopes (4). Space dust.

Due to the polarisation of the magnetic forcefield, the solar wind is attracted to the poles. When this stream of electromagnetic particles hits the thin atmosphere at these points, the particles are deflected, often producing a spectacular display of fireworks we know as the aurora borealis. So the extraordinary combination of our atmosphere and the unlikely magnetic field produced by of our planet’s core protects all life day and night.

Yet that thin layer of atmosphere that protects us, and at the same provides the essence of all life in the form of oxygen and rain, is so very thin that if Mount Everest were at the North Pole it would protrude two kilometres above its canopy (the atmosphere is just seven kilometres thick at the poles, it is more than twice that at the equator).

Aurora borealis over the Northwest Territories, Canada (6)

Not all the cosmic particles bombarding us from the sun are stopped by the forcefield shielding us and our atmosphere. Some carry right on to reach the Earth’s surface, for instance, in the form of ultraviolet light. This is what causes us to tan. It can also cause sunburn. And cancer. A few, neutrinos and muons among them, carry on right through us. Some of the neutrinos are even thought to pass right through the Earth and come out the other side. Quite amazing – we are being bombarded night and day by a cosmic ray machine. (C-Ray rather than X-Ray?)

But some do stop, thankfully. Among those are the photons detected by our complex, built-in electromagnetic detectors – our eyes. The sensors triggered by the bombardment of photons enable us to interpret our world visually. Thank goodness they do, otherwise we wouldn’t be able to see the glories of the night sky or the aurora borealis.

It is quite a thought that some of those electromagnetic particles and cosmic dust can sometimes be part of you and me, albeit momentarily.

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