One of my favourite things to do on a game drive at Londolozi is to park at the bottom of the airstrip on the way back home in the evenings and take a moment to gaze into the heavens. It’s the perfect time to slow everything down, to be fully present in the moment, and to let yourself be humbled by the enormity of it all. To acknowledge that poetic juxtaposition of how insignificant we are in the grand scheme of things but at the same time, how intimately connected we are to everything. As Carl Sagan famously quotes,

“The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies. These were all made in the interior of collapsing stars. We are all made of star-stuff.”

And I love that idea so I thought I’d share a tale of how you and I could be connected to stars and star systems in other galaxies on the other end of the universe.

As our closest star dips below the horizon, the universe unveils a myriad number of others.

The stars, ladies and gentlemen; billions upon billions of suns stretching further into the abyss than we can possibly fathom. We call it Infinity. But it is only as close to true infinity as anything will ever be; at least on this plane of existence. Because, as vast as the universe is, as unbelievably gargantuan as the scales involved are, there is an end. The edge of the universe is out there somewhere. But just what lies on the other side of that border we cannot know. Or rather we can know but none of us can truly comprehend the concept, nothingness. Absolute nothingness is what lies beyond. The universe cannot be described as a bubble floating through the water, for there is no water, there is no medium within which the bubble exists. Beyond the universal border, there is no void, there is no vacuum, there is no matter, no energy, no time, no space; there is nothing tangible or intangible, there is only…. Nothing.

Beyond us there is nothing.

But that’s a complicated and even somewhat terrifying concept to wrap our brains around so let’s rein it in a little and focus on what lies within the universal realm. And the answer to that is almost as mind-boggling; the answer to that is

Very little.

99,999999999999 (and so on) % of the universe is a vacuum; dark,  and cold, and empty.

But dotted throughout the vastness of space lie galaxies; gravitationally bound star systems trillions upon trillions of kilometres across and laden with hundreds of millions of stars.

There are an estimated 2 trillion galaxies in the Universe. That’s close on 70 Septillion Stars; 70 000 000 000 000 000 000 000 000 000 stars!! The odds are pretty long that our solar system is the only one that contains life.

A galaxy is formed of the dust of nebulae, massive clouds of “dust” made up primarily of helium but also tiny particles of solid matter and other gasses. These clouds span hundreds of trillions of km.

Coalescing at an increasing rate under gravitational pressure, this “dust” pulls itself towards itself making clumps, the light gravity of which pulls in even more dust. These clumps are pulled into each other and their mass gains exponentially, which in turn means that gravitational pressure gains exponentially, and that pressure and heat energy created thereof is so great that that mass combusts…

And a star is born.

Nebulae, colossal clouds of space dust. The birthplace of stars.

And this happens ten times, a hundred times, a thousand times, a million times over, again and again, and again, until these stars begin to coalesce around a galactic core which begins to draw stars in from the far reaches of the galaxy and this starts to spin, and these stars are drawn into a flattened disk which spins around the centre just as the 8 planets of our solar system spin around the sun. Now here I must note that there are a number of permutations of galaxy formation but what I have just described is a crude description of how our very own galaxy, the Milky Way, came into being. Other things happened too; at one point in time the Milky Way ripped apart at least one smaller galaxy, absorbing some of their stars and flinging out the remainder into the wider universe. This is evidenced by the fact that astronomers can actually see the leftover “Star Streams”, the remainder of absorbed dwarf galaxies, orbiting our galaxy away from the galactic plane.

At some point in the aeons-long history of the Milky Way, one very specific star was born. One star amidst an estimated 400 million; that star is our Sun. In its infancy, our Sun, like a curious and greedy child reached out into the deeper galaxy and began to drag more of that same matter and stardust that birthed it in toward itself. This matter, almost all of which was created in the hearts of collapsing stars in ages past, flattened into a spinning disk; similar to the rings of Saturn but on a far grander scale.

An edge-on view of the Milky Way showing the galactic core around which some 400 million stars spin.

Further aeons past and portions of this spinning disk began to separate and coalesce. And as these amalgamations of space debris grew, the gravitational pressure of their own increasing mass caused them to ignite and melt in on themselves. And within these balls of molten material, the heaviest elements began to sink into the depths of their cores while the outermost layer cooled and condensed into a planetary crust.

A young star creates an accretion disk around itself. The matter from this disk will eventually coalesce into planets.

Then something truly incredible happened, something that science still can’t explain. Some 3,7 billion years ago, on the crust of one of those 8 planets that just happened to find itself at the perfect distance from the Sun, carbon-based life happened. There are several theories as to how, none are definitive, but one thing is certain, life began on our little planet. And after it began, it exploded outward and swept over the Earth, finding its way into every possible nook and cranny, growing in complexity as it filled almost every available niche. And this evolution of the species continues to this day, almost 4 billion years later, to you and me.

First life emerged in the form of the simplest bacteria. Our most ancient ancestor.

And that is just a short tale to remind you that we are all part of one great whole. We are all built of the same elements, like everything else in the universe. And into that same universe, we will eventually return.

For we are dust. And unto dust, we shall return.

Picture Credits

Nebula – https://www.newyorker.com/humor/daily-shouts/exploring-universe
Milky Way – https://www.eso.org/public/images/eso1339a/
Planetary Birth – https://www.nature.com/articles/d41586-018-07591-8
Planets – https://commons.wikimedia.org/wiki/File:Solar_system_scale_edit.jpg