Afraid of the dark
I've never been afraid of the dark. When it's all you've ever known, it seems a rather silly notion. But now... well, this seems different somehow. Now we're all frightened.
It wasn't always like this. We all grew up with the stories about the old times, when there were colonies every few parsecs, all set on planets (artificial or otherwise) around healthy stars, and supply stations strung along the major trade routes likes beads of water on an invisible web. The galaxy thrived back then, or so the stories go. Civilisation reaching ever outwards, colonising, trading, cooperating, and fighting, naturally. There was rarely ever total peace, not in our nature say the historians. But it's all long gone now.
Slowly, imperceptibly at first, night began to fall across the universe. Complete and total darkness, the end of all things. Our own star (we knew it as Suryan) faded from glory long before I was born. I've never known real daylight, never felt the warmth of the midday sunlight on my skin. Growing up, we were all told the stories and legends of the light times, when Suryan made the sky glow from horizon to horizon and stars filled the sky when Suryan herself slipped below the edge of the world.
But all that has faded with the generations. Long ago our star melted away into the darkness and we were left clinging to this rock, digging ever deeper into its crust just to reach the feeble warmth of the planet's ancient cooling core. At least we had that, other colonies were not so lucky. Those who had settled on artificial planets didn't last long when their stars faded, their power systems were never designed to cope with such extreme cold. The cold metal constructions lost their heat quickly and their inhabitants (those unlucky enough not to make an escape on whatever ships they might have had) froze in a matter of months. There are those who say that was a better way to go.
Suryan isn't completely dead of course, that takes billions of years. When she ran out of material to fuse, her outer atmosphere expanded, reaching almost as far as our colony here on the fourth planet. Protected under the colony's thick-walled domes, the inhabitants watched from safety as the star put on its last and greatest show. While the core began to shrink, those burnt-orange layers continued to expand, becoming a fading wisp-like shell centred on the dying remains of what had once been a giant nuclear fusion reactor. That remnant core still sits at the centre of this system like the last dying ember of a fire. It still produces light and heat of course but not enough to be useful, not by a long way.
It's been some decades now since the last ship left this system. When Suryan burnt its last, up there in the sky, there was widespread panic. People were desperate to leave, to go somewhere else with a star that was still viable. But there wasn't anywhere to go. Slowly but surely, the stars were dying everywhere and there was no more gas left to create new ones. These are the last days of the Universe, but people refused to believe it. Somewhere there's another star, they said, somewhere. The ships left, heading out towards whatever points of light they could see in the sky, and those who stayed behind attempted to carry on as normal. We've known what was coming for generations but there was nothing we could do. You either accept it and get on with life as best you can, or panic and most likely hasten your demise. While we have no ships any more, nor the capabilities to construct any, we can still communicate with other colonies although that happens rarely these days. There isn't anything left to communicate, and it uses power we can little afford to waste.
I often wonder what happened to those ships that left. The records show that they kept in communication with the colony for some time after they set out, promising to return for survivors when they found a new home in the sunlight. But then the logs stop. When I was younger I assumed they just stopped transmitting, that they were saving energy or something. But now, well, I've heard the stories from other colonies of madness and chaos and I wonder if the same fate befell those ships we dispersed into the night like seeds.
That's the problem with space flight of course. It takes time. Those ships leaving Suryan would each have headed towards a distant glimmer of light, some far-off star that hadn't yet reached the end of its days. But in the mean time, the light from those little balls would have been travelling for centuries before it reached our system, if not longer. What would happen to the crew if, after using all of the fuel they could spare to send them rushing onwards towards some distant star, keeping just enough to slow down again at their intended destination, they suddenly saw that their promised Eden was disappearing, fading away before their very eyes? By that point there would be nothing they could do, no way of changing course without using up the precious fuel they would need in order to slow down once they reached somewhere habitable. Game over. What then?
I ask myself: what would I do in that situation? It would be tempting to open an airlock, destroy the safety interlocks and just let everything be pulled out into the vacuum. Not a pleasant way to go, certainly, but quicker than most options available on a tug. We were never an exploration colony, merely a mining outpost, and those craft had never been designed for long-term use. Your options were starvation (water was recycled, even on the tugs, so no problem there), carbon dioxide poisoning (the filters worked pretty well, but were usually replaced every couple of years), or some manner of your own choosing. Most colonists would rather chose their way out rather than go slowly - we'd all seen it happen, read the case studies. It was part of basic schooling on these outposts. Harsh, may be, but the sooner you realised the realities of colony life the better.
So, here lies the remains of a once busy and reasonably prosperous colony. Mirroring the downfall of the empire, it withered with the dying of the light. There were those who refused to believe it would happen, others who proclaimed it as the ultimate test of faith in whatever deity they served, still others who maintained that we'd find a way out somehow. But the truth was that we'd known for generations that this was coming. Ways of restarting stars were proposed, but they all required more energy than the empire could spare, just for a single star. Society crumbled, the trade routes grew silent, colonies began shutting off their contact with the outside world. Where colonies were close enough, wars broke out.
The stars didn't all go out at once. It takes time for a star to use up its fuel, and that depends on many things, but larger stars burn up faster. Despite the dangers, the empire loved placing colonies around massive stars because they were the most profitable. You could have several large artificial colonies around a massive star where they could harvest huge amounts of energy, and stellar mechanics was developed enough that the onset of a catastrophic supernova explosion, so characteristic of these massive stars, could be predicted to an accuracy of a few months. Smaller stars like our Suryan were far more sedate. Not massive enough to go supernova, they took many billions of years to use up their fuel. While our colony was never rich, we lasted longer then many others simply because our star was a comparative weakling.
But even by the time this colony was founded, the universe was old. Really, it was a wonder our species had lasted as long as it had without destroying itself from within. Galaxies formed new stars at the rate of a few per standard solar year, but they have to come from something, you need gas to create them. No more gas, no more stars. We knew, as a species, that this was what would happen someday but, like countless cultures before us had done throughout history, we always assumed it would be far enough in the future that it would be someone else's problem. For the most part that was right, but now we are that someone else, and we are scared.
Most of the colony, those who didn't leave in the tugs, have chosen to carry on as normal. Each year we just dig a bit deeper towards the dying heart of the planet to keep the thermal plants supplied with enough energy from our world's cooling interior. None of us alive now really knew Suryan as anything other than the dying ember that hangs in the sky today, so to us the sight is normal. I once saw a holograph of an Earthscape - its open spaces and vivid blue sky were nauseating. There were no stars in that picture either, apart from Sol of course, now long gone.
That's the difference. Their sky was bright and harsh. Ours is black and cold, as if oblivion had been given form. I look out every day at that sky and my eyes wander, searching for the last faint pinpricks of light - something I know I'll never see again, now. Last night, the last star in our sky faded forever. We knew it had to happen sometime, but it was still something of a shock when it finally came. None of us can claim to be astronomers, but we all knew the movements of that last star. We watched it grow fainter and fainter, occasional bursts of light giving unwarranted hope of a reprieve. Every one of those upward-gazing eyes knew what those fits meant, but still the soul hopes.... may be.
The last star. The final vestiges of warmth are gone from the sky. Those photons will continue on, travelling out into the darkness long after this little colony has gone. For all we know, we may be the last, interstellar communication is a luxury that we can no longer afford. But what's left now? There will be no more stars, no more colonies, just endless darkness and cold like the long-dead surface of this planet.
There's still time for a walk before lights out. I've never been outside the dome before, may be the air isn't as poisonous as they say.... I'm not afraid of the dark.
This is really going to happen, eventually. Galaxies only form stars from their own gas reservoirs, supplemented by the gas which falls onto them from their own halos, the surrounding intergalactic medium, or from galactic cannibalism where a merging galaxy provides a fresh injection of gas (often triggering a massive burst of star formation). Eventually though, this gas will run out and stars will stop forming, but not for billions of years. Stars will only shine while they have sufficient fuel in their cores for nuclear fusion to proceed; when that fuel runs out, the star dies. The ultimate fate of a star is determined by its mass, but they all stop shining eventually. The story above is based on the following paper by Braun et al. What Braun et al do in this paper is study a sample of particularly luminous galaxies known as ULIRGs, Ultra-Luminous InfraRed Galaxies, investigating their molecular gass mass. Studies of these galaxies can tell us about the evolution of molecular gass mass over time which can help in our understanding of the evolution of star formation rate density, both past and future. This particular sample is interesting because they sample a particular redshift range (0.2<z<0.5) where data is currently sparse. Coincidentally, I spotted the associated this press release from CSIRO a week after I wrote this story. You can find the paper here:
Braun, R., Popping, A., Brooks, K., & Combes, F. (2011). Molecular gas in intermediate-redshift ultraluminous infrared galaxies Monthly Notices of the Royal Astronomical Society, 416 (4), 2600-2606 DOI: 10.1111/j.1365-2966.2011.19212.x