A Dark Matter Dream

T. M. A. Fruth

A note from the author:

Dark matter makes up about 85% of matter in the universe. Without it, the universe would look very different today, and we would not be here to observe it. Understanding its nature is a scientific priority, allowing us to understand how we got to where we are today. Yet, answering the question of how the discovery of dark matter would change the world is complicated. To write this story, I allowed myself to dream. Please take it as what it is, a piece of fiction imagined in conversation one evening. Maybe one day, there could be some truth to it. Or it might just stay a dream.

Lead (South Dakota, US), February 2023

Her panic is rising proportionally to the pressure in the detector. On a plot, the two would be perfectly parallel by now. What an unhelpful thought; Jess scolds herself and tries to adjust the temperature of the cooling instrumentation again. It has no effect. At this rate, we will start venting xenon into the underground cavern in less than two minutes. The screen in front of her goes blurry from her tears, and the electronic voice of the constant alarm is ringing in her ears. This is it. This is the end of this experiment. Why does this have to happen on her shift? Her career will end at 23 before she even finishes her PhD.

Jess opens her eyes, heart racing. It takes her a moment to realise that it was just a dream. A nightmare, probably triggered by the stress of the past months. She was so excited when she started her PhD at the University of Liverpool a little over a year ago. She would be part of an international collaboration trying to solve the dark matter puzzle. She would get a chance to figure out what 85% of the matter in the universe was made from. But she did not imagine that they would find it. Let alone in her first year of PhD!

At first, they thought it was an issue with the analysis; then, as the signal grew stronger over time, the preferred theory was a calibration source gone rogue. It was just too good to be true. But the signal passed all the tests, all the additional data quality cuts, and all the checks. And today is the day that the world will find out. There have been rumours for weeks about a discovery, but there were rumours before. This time it's the real deal. A simultaneous conference by their experiment in South Dakota and their colleagues in Italy – two independent experiments seeing the same signal. How lucky that her first onsite shift coincides with the announcement. She finally saw the detector four weeks ago during her first day at the underground lab. Well, she only saw the outside of the water tank containing the detector. The underground location and the water tank shield the detector against all the other radiation in the environment, so no chance to see inside. But still, it felt special being so close to what she had been working on for a year now.

A few hours later, she finds herself in the back of the meeting room, which has been converted into a makeshift conference room. She has never seen so many people at the lab. The presentation has just ended, and the room is buzzing with excitement. Her phone vibrates a message from Brian. Brian has become a good friend over the past month. He is a data analyst for a mining company and has been part of the little science bubble they form here. They weren't allowed to tell him about the discovery before, but clearly, he knew something big was happening. She reads his message. So - what does this mean for us, for our daily lives?

A question that will be asked so many times in the following days and weeks – the question she is worried about having to answer. The discovery of dark matter is huge; it impacts so much of our understanding, from the most fundamental building blocks of nature to the formation of galaxies. But it probably won't touch people's daily lives at all, Jess thinks. The thought gets pushed away by the excitement in the room.

Sydney (Australia) & Lead (US), March 2025

July Love sits in the shade looking out at Harbour Bridge. Who would have thought that dark matter would bring me to Sydney? She remembers the discovery day two years ago very clearly. As a science writer, she previously had her fair share of interactions with scientists and discoveries. But this was a different scale. Dark matter was just such a large fraction of the universe. It inspired people – hell, it inspired her. To finally sit down and write this book. It is about the search and discovery, what it means for our picture of the world, and how humanity fits into it all. She thought it was a story worth telling, but never would she have imagined the success of her book and that it would take her on a tour around the world. She has just come from Tokyo; next, she will fly to Melbourne and drive up to an underground lab called Stawell. Scientists are building a new precision experiment there now. After the initial discovery, that's what it is all about now testing dark matter's properties. Is there more than one particle? So many questions remaining to be answered. Her eyes wander over the harbour. Maybe she can squeeze in a short visit to the beach this afternoon.

On the other side of the world, in Lead, there's nowhere to go. Cars are stuck behind the protesters on Main Street. They are on their way up to the mine. Ever since the dark matter discovery a couple of years ago, a small but vocal group of conspiracy theorists from all over the world have come for these protests. They claim that dark matter is dangerous and that scientists create holes in reality by capturing it. Brian really doesn't follow their logic. Dark matter is not captured in the detectors; it simply passes through and leaves a signature. He has tried to reason with the odd protester he meets at the bar before realizing it would not make any difference. But in some way, he prefers these people to the worshippers who come around solar solstice to pray to the dark matter. You have to pinch yourself sometimes. Do people have no other problems in their lives?

Anyways, he'll be out of here next week. He pulled together all his savings to return to graduate school and took a sabbatical from work. He's not sure yet whether he'll just do a masters and go back to work after or whether he'll stay for a PhD. Since the discovery, he has felt inspired to learn more about the fundamental laws of nature. And now he is going to do it. Traffic is finally moving again, the cars behind him are honking, and Brian starts his engine.

London (UK), November 2050

It's quarter past eight on a Friday night when Jess opens the fridge in her apartment. Empty. At least she only has to feed herself tonight. The kids are at a friend's house, and her husband is on travels. She selects pizza from the display on her fridge door. It'll be here in 10 minutes. A long weekend of exam marking is ahead of her, and then from Monday, she can focus on the grant proposal. 27 years have passed since the first dark matter particle had been discovered. Since then, they have identified three different types of particles in the dark matter sector.

There is now a multi-tonne detector on every continent on Earth to make precise measurements and further determine the properties of dark matter. She was lucky to be at the right place and time, she thinks. Her career as a professor is built on the discovery and the hype surrounding dark matter. It has not only impacted her life. The number of physics undergraduates has exploded in the years following the first discovery and thankfully has stayed high, even once the conspiracy theories had died down. Their research had found application in industry, with data analysis algorithms for the healthcare sector, and some hardware techniques being adopted in manufacturing – but they are still missing a direct application of dark matter. This proposal they are putting together is the first step towards changing that. Sometimes she wonders whether it is too crazy, too much out there. But then her colleagues seem convinced. You can't win if you don't try.

Their working title is "dark matter batteries." The choice is simple, the concept hard, and whether this will be feasible is far from obvious. The energy market has changed a lot in the past 20 years. Finally, it is all renewable energy. The big challenge that remains is efficient energy storage. Rarely a week goes by without news of a battery exploding or discussions about how the expanding space travel sector needs new solutions. This proposal could solve that. If they can focus the galactic stream of dark matter enough into a small space, they can cause dark matter particles and antiparticles to collide and disappear, while releasing energy during the process. And that energy could then be harvested. Creating such a strong gravitational field would cost a lot of energy – if achievable. That's why they will pitch it as "batteries" rather than as energy source. But it has promises; the efficiency could be phenomenal if done right. Jess chuckles: her 23-year-old self would have loved this. Her mind wanders back to the societal impact they have already seen in the years since the discovery. Honestly, it has surprised her. The fascination she meets in her daily encounters with students, friends, and even politicians, has shown her that understanding the world around us a little better can impact our worldview and inspire everyone. Maybe that is enough, she wonders. That's when the doorbell rings.

London (UK), January 2200

Ben Free puts his contact lenses in, blinks a few times, and says, "Go to Cygnus Station I." His South London apartment disappears in front of his eyes, and the outer parts of the Milky Way appear. In front of him is the rendering of Cygnus Station. Today he will be reviewing the commissioning mechanisms of this project. Ben comes from a long line of civil engineers. His grandfather had his own vessel manufacturing company in Bermondsey. When the dark matter batteries came up, his dad sold the company and ventured into this new direction. While it was a long process, the batteries were a major success – helping with the efficient distribution of energy and enabling exponential growth. Ben is still struggling with the name batteries. Really these are large-scale factories with lots of shielding on the outside. Only dark matter particles and neutrinos can enter through the shield and encounter the strong gravitational field at the centre. Once a critical mass is achieved, the gravitational field increases, focusing the dark matter into a small cavity and initiating annihilation reactions. The resulting high-energy radiation is collected in detector modules surrounding this central region and converted into electricity feeding straight into the grid.

There are 6 GESG (Gravitational Energy Storage and Generation) stations on Earth. His colleagues are working on a near-term project, a GESG on Mars ground station. That would allow enough energy generation to go beyond the solar system. But he has volunteered for the long-term dream project Cygnus-I – a space station in the outer Milky Way with its own GESG. The optimistic timeline is 100 years, even with the latest quantum health care that might be far-fetched for him in his 50s. But his daughter might see it. She is in the astronaut class of 2202. And in the meantime, he gets to enjoy the view of the very realistic simulation. He initiates the first sequence, and an alarm starts ringing.

Epilogue

Jess opens her eyes. It takes a moment for reality to set in. An alarm is echoing through her small Liverpool studio. After yesterday's remote shift, she must have left the detector control terminal open on her laptop. Suddenly there is silence. Someone probably acknowledged the alarm. Jess checks her phone - November 20, 2022, 6:55 am. She jumps out of bed; the shift handover is in 5 minutes. One last round of calibrations before the detector is ready to start looking for dark matter. As she reaches her bathroom door, she pauses for a second. Did she dream about dark matter? She tries to remember, but the dream has quietly slipped away.