The hunt is now on for planets that closely resemble the Earth, and current indications are that worlds of the right size and at the right distance from their star may indeed be numerous. Less expected has been the discovery that many of the planets found so far look nothing like the familiar worlds of our own Solar System. Instead, a bizarre menagerie of Hot Jupiters, super-Earths, carbon planets, water worlds, gas dwarfs and even Tatooine-like worlds orbiting binary stars has replaced the neat division between small, rocky planets and frigid gas giants into which we had previously divided our planetary catalogue. If there’s a lesson to be learned it is surely that the Universe is still full of surprises.
Despite the abundance of these brave new worlds we are still in thrall to Fermi’s question. If the Universe is indeed full of planets, why do we see no signs of intelligent life?
Our galaxy is vast – more than 100,000 light years across – but the Universe is 13.8 billion years old. Even travelling at speeds well below that of light, it would not take more than a few million years to send self-replicating probes to visit every star in the Milky Way – and yet we see no credible signs of them visiting our Solar System. If the aliens were disinclined to embark on such a venture, they could stay at home and still notify the entire galaxy of their existence in just a few tens of thousands of years using radio signals – and yet, after decades of scanning the skies, SETI, the Search for Extraterrestrial Intelligence, has so far drawn a blank. Even if they have no desire to communicate at all we might still expect the aliens’ technology to leave its mark in other ways, modifying their planetary atmosphere with carbon dioxide emissions or changing the spectrum and brightness or their parent star through energy harvesting schemes – and yet as far as we can tell, the rest of the Universe appears resolutely natural.
Over the years many suggestions have been put forward to try to resolve Fermi’s conundrum. Broadly they fall into three categories: we really are alone – or the civilisations that do exist are so widely separated in space or time that we may as well be; the aliens are there but we’re not looking hard enough; they are there but we can’t see them because they are hidden from us or because the Universe is somehow stranger than we think.
Perhaps life is rare, either because the precise conditions necessary for it to occur are uncommon or because the chances of it arising are so vanishingly improbable that the Universe just hasn’t been around for long enough. Some scientists argue that the Earth may be a rather exceptional planet after all, with its large, stabilising moon and uncommonly well-behaved sun. We may even lie in a peculiarly habitable part of the galaxy, central enough to benefit from the chemical enrichment of previous generations of stars but safely distant from the harsh radiation of the galactic core. In this case we might not be the only life forms in the Universe, but we could be among the first.
Even if life is common, perhaps intelligence evolves only rarely and, when technological civilisations do arise, they only last for a few centuries – the blink of a cosmic eye – before disappearing. Our own planet has been around for about 4.5 billion years and the fossil record appears to show that simple microbial life established itself almost as soon as the Earth’s initial hellish conditions had settled into something more hospitable. Extrapolating from this single example it seems that life might get started quite easily – wherever the right environments exist. But it took another 3 billion years before complex plants and animals evolved, and intelligence like our own, capable of complex language and symbolic thought, has arguably only been around for a few hundred thousand years. Being smart has served homo sapiens well, enabling us to colonise the Earth and even sprinkle our technology lightly across the Solar System, but beetles, crocodiles, and horseshoe crabs have enjoyed much longer success, and all without feeling the need to build nuclear weapons or pump the atmosphere full of greenhouse gas. Intelligence may be useful to have but it comes with a self-destructive downside and it certainly isn’t the only way to dominate a planetary biosphere.
Perhaps aliens are everywhere but we’re not looking hard enough or in the right way? Since the 1950s we have had the ability to probe the skies for radio transmissions and, more recently, to look for other forms of artificially generated electromagnetic radiation such as directed laser pulses. But it is impossible for us to continuously monitor every likely star in every possible waveband – and these are only the signalling methods that we humans have thought of. Of course, since the early twentieth century we have been pouring our own signals into space in the form of radio and television transmissions and these now fill a spherical region about 100 light years in radius, encompassing hundreds of planetary systems. But the emissions become rapidly fainter with distance and even our most powerful radio telescopes would struggle to detect them from just a few light years away. In any case, as our broadcast technology shifts from analogue to more efficient digital systems, the strength of the signals we emit will dwindle and the Earth will fall silent once more. Our enduring contribution to the shared cultural heritage of the Milky Way could amount to little more than a brief pulse of twentieth century TV and radio.
Perhaps, biased by our own narrow perspective, we are looking in all the wrong places? A truly advanced species might shift its base of operations away from Earth-like worlds and Sun-like stars to regions where energy is in more abundant supply. The brutal environment beside an ultra-luminous star or the event horizon of a black hole could be an attractive proposition for such a civilisation. And, as we ourselves inch closer to creating artificial intelligence here on Earth, it raises the prospect that biological entities might be just a short phase in the lifetime of most civilisations, before they are superseded or uploaded into their own mechanical creations. Who knows where such machine minds might decide to live or how they might choose to communicate?
Perhaps they just don’t want to talk to us? There may be good reasons why aliens wish to actively conceal their presence: if just one civilisation in the galaxy possesses genocidal tendencies alongside the technology to put them into practice it could make sense for everyone else to keep their heads down. Most terrifying of all, although we are naturally convinced of our own intrinsic fascination, advanced alien minds might simply find us too primitive, too violent or too boring to bother with. At the end of the day, aliens could just be incomprehensibly alien.
After centuries of speculation, debate and methodical searching we still don’t know if we’re alone in the cosmos. A message from the stars could arrive tomorrow, answering Fermi’s question once and for all, but even if conclusive evidence continues to elude us it seems unlikely that we will ever completely give up the search.
For now, we have an unsolved scientific mystery with profound implications for the human race – what better starting point for a science fiction anthology? Science might have to wait a little longer for a definitive resolution to the Fermi Paradox but who knows, one of the stories in this volume may already have the answer.
Marek Kukula & Rob Edwards
Royal Observatory Greenwich,
June 2014
Catching Rays
David L Clements
Sarah shuffled in her seat, conscious that the Director was hovering nearby, waiting for the interview to finish.
“When do you expect to announce your results?” asked Horst. Sarah thought he looked relieved, sitting across the table from her in the canteen, nursing a bulb of fresh coffee. He was due to head back to Earth on the next lunar shuttle.
“It will take some time,” she replied. “The collector’s finished, but we need to install the traps before running a final test. Then we have to ramp up the power before we can collect the highest energy cosmic rays.”
“A few months?”
Sarah smiled. “Longer than that. Even when we have things fully running it’ll take a while to collect and analyse the data. A year at least, maybe longer.”
“Thank you for your time,” said Horst, closing his tablet. “That was great, and a fine way to end my
visit. And if you find anything interesting, please contact me.” He stood, rising too quickly and briefly leaving the floor. “Damn,” he muttered as he flailed in mid-air. “How do you cope with this?”
Sarah laughed. “Practice, which visitors like you never have time for.” She steadied him as he drifted back to the floor. “Have a good trip home, and we’ll see you back on Moonbase Three in, what, eighteen months?”
Horst sighed, and nodded. “I guess so.”
“I’m sure you’ll do better next time.”
The Director chose that moment to force his way into the conversation. “All done here I see,” he said, smiling at both of them. “I hope you had a good chat with our latest brilliant researcher?”
“Oh yes,” said Horst, while Sarah squirmed. “Very informative.”
“Excellent. Let me walk you to the shuttle, there are a couple of things I’d like to discuss.” Horst picked up his bag, and the two men left the canteen.
“Enjoy it while it lasts,” said Petra. She was sitting at one of the other tables, behind a partition, listening to the whole interview.
“What do you mean?” asked Sarah.
“Being Moonbase Three’s latest poster child.”
Sarah didn’t know what to say. Petra had been on the base for a while, doing development work on nanotechnology. “Happens to us all at the start. But it will soon change if you don’t deliver successes, or they take too long to come. When your funding is cut nobody will want to know you.”
Sarah’s project had got most of the funding in the current round, beating the nanotechnologist’s bid and several others. Petra stood with the gentle, smooth movements of an experienced lunar resident. “You’d better get your results before you’re out of the spotlight, otherwise you’ll end up on your own, far from home, making do with leftover equipment that isn’t even appropriate.”
“What about your postdoc?” Sarah asked, sure she had seen him only a few days ago.
“Gone. On the same shuttle as Horst. And our great Director has made it clear I will be joining him if I don’t make a breakthrough soon.”
Petra turned her back and walked out of the canteen.
Sarah exhaled slowly and left in the opposite direction, heading along one of the narrow white corridors to the small office she shared with Max, her postdoc.
“How are the final checks?” she asked as she slid open the door.
“Looking good. We can install the traps and start low field, end-to-end tests as soon as the Sun sets.”
Their tiny office’s only saving grace was the broad picture window dominating one wall. Outside, across the dark grey landscape, the infinitely slow lunar sunset was under way. The Sun hung on the horizon, slipping with glacial slowness behind black basalt mountains casting long, unnaturally sharp shadows across the regolith.
“Another eight hours. Then a few more for passive cooling to kick in,” said Sarah. She checked her watch for the time back home in the Eurozone. “I’m off to bed. See you in the morning.”
Black, airless lunar night surrounded them. Each suited figure had headlamps, one on each side of their helmet. Navigation lights and indicators blinked on shoulders, helmets and backpacks. Scattered construction floodlights brought further light and the semblance of warmth wherever they stood, but they only served to remind Sarah, Max and the rest of the crew they were working in one of the most hostile environments known to man. A coronal mass ejection, or other harsh space weather event, could catch them in a hail of lethal radiation, while the smallest micrometeorite could pierce a suit and deliver a high velocity bullet’s worth of damage.
There were warning systems, but they were never perfect. Physically roaming the lunar surface was a calculated risk, but the final stages of construction and calibration could not be done with drones or remotes.
After four hours on the surface Sarah hoped everything was finally done. At least the cold trap in front of her was fully operational. “How are we doing?” she called on the group radio net.
“A few minutes more for me, but basically done,” replied Max.
The rest of the crew needed more time.
Sarah joined Max and gazed at the sky until he had finished. She brought her gloves to her helmet, shading her eyes from light scattered from her headlamps, trying to see the pin-sharp stars that filled the sky.
“It’s so empty,” Sarah said over their private radio link to Max. “We’re so alone.” She shivered, despite her suit heating system. This was a recurring train of thought for Sarah while on the surface, looking away from the blue jewel of Earth at the vast black emptiness of the rest of the sky. “A sky full of stars, but empty of minds – as far as we can tell.”
“That’s not our job, boss,” replied Max. “Leave that to the guys with the big radio ears and optical eyes down on Earth.”
“Maybe,” said Sarah. “But it doesn’t seem right. We’re spreading out into space, but there’s no sign anybody else has done that. Ever. In the whole history of the universe.”
“We’ll find them,” said Max. “They have to be out there, we’re just not looking the right way.”
Sarah was ready to argue the point, to deliver the kind of authoritative philosophical argument expected of a senior academic. The head contractor’s voice interrupted on the communal band. “We’re all done, I think.”
Sarah switched channels, a little relieved she wasn’t going to dent Max’s naive enthusiasm today. “Great!” She said. “Time to head back to the barn.”
Bright lights, white nanofibre walls, a crowded room filled by a hot and humid yet breathable atmosphere. They stood inside the small habitat dedicated to running Sarah’s cosmic ray experiment. It was a huge contrast to the surface. Sarah always felt a twinge of claustrophobia when she came back inside, but this time she ignored that in the excitement of, at last, having an experiment to run.
As soon as she was out of her suit, she headed to the control console. While she began the startup procedure, the rest of the crew gathered around.
“All traps running nicely,” she announced. “Great work people.” There were nods of appreciation and handshakes.
She typed more commands, checked more indicators. “E-mag scoops initialising.”
High above the surface of the Moon, the other part of the system started up, a series of superconducting cables forming a network of fields filtering charged particles to the surface and Sarah’s cold traps. “Looking good,” reported Sarah. “A few minutes and we should have the first low energy captures!” There was scattered applause across the room, and one of the engineering contractors moved towards the fridge.
Sarah spotted the movement. “Hey,” she shouted. “No champagne until we know it’s working.” Max and Sarah’s closest colleagues laughed nervously, but the contractors looked disappointed.
Tension filled the room. Scattered attempts at conversation died away as they waited for the first crucial results.
At her console, Sarah watched the displays, monitoring instrument health and performance, awaiting the first chime that would announce the successful collection of low energy cosmic rays.
She made some calculations in her head, factoring in event rates, efficiencies, collecting volumes, once again checking calculations she had done years ago and knew by heart. “Yes,” she nodded to herself, “if we don’t have anything in a few minutes then we have a...”
A loud ping broke her train of thought. She smiled, and rose from her chair.
“Friends, colleagues, the cosmic rays have landed!”
Then came cheers, applause, and popping corks, as they celebrated success after years of effort.
Speeches followed, and an even greater throng of Moonbase Three personnel came down the long tunnel to Sarah’s control centre. The Director welcomed a project that was certain to be a new, great success for Moonbase Three, and congratulated Sarah on getting it started on time and slightly under budget. She even caught a glimpse of Petra at one point, standing quietly
by one of the consoles and looking out onto the lunar surface, a glass of wine untouched in her hand. She wondered what the other woman was looking at, and suppressed the urge to smile when she saw it was one of the cold traps. They were Sarah’s invention, a unique technology that made the array possible. I guess Petra has a right to be envious, she thought.
Hours later, when the celebrations had ended, Sarah was the last person left in the control room as usual; clearing up glasses, collecting half-finished plates of food for recycling. Quickly deciding to leave the last of the debris to the operations crew to clear up, she went to the main console for a first look at her results.
She frowned. “No. That can’t be right.”
“I agree,” said Max. “This doesn’t make any sense at all.”
The collector had been running for several days. They were in Sarah’s office, hunched over a work station screen, looking at telemetry from the cold traps. The results she’d seen that first evening had not gone away, despite her hope they were a technical artefact.
“You agree the mass is too high, and the charge too low?” she asked. She should know more than Max about the experiment, and everything else, but wanted him to find a hole in her thinking.
He frowned. “High mass could mean a multiple hit, but that wouldn’t explain the charge.”
Sarah nodded. “More like a few thousand hits for that mass. So, something has gone seriously wrong.” She sat back and shook her head. “We’ll have to purge the collectors, do a total restart and hope this goes away.”
“That would take weeks!”
“Quite. But this makes no sense. The Director isn’t going to like it – his great new project taking a giant leap backwards.”
Paradox: Stories Inspired by the Fermi Paradox Page 2
