The time machine is, in itself, not much to look at. It consists of two chambers, each two meters wide and four and a half meters long, one next to the other, walled with transparent ceramic composites and containing a bench made of the same transparent composite. On the near end of each chamber, which is to say, the end nearest to me at the controls, is a door: one to enter the machine and one to leave it. At the far end is a portal. One takes the client away. The other brings them back.
To the observer, which is to say, me, the theoretical process is simple. The client enters the chamber to the left, through the door, carrying with them everything they have chosen to take on their journey, usually in a backpack. Inside the first chamber, everything they are taking is laid out on the bench and on the floor if space on the bench runs out. The chamber is flooded with sterilizing light and gas, a final attempt to keep the destination safe from any germ or disease the client might carry with them. The client closes their eyes and holds their breath. This is, for various reasons, biohazard theater, but regulations are regulations, and all it requires of me is to press a button to start the process.
Thus sterilized, the client repacks and moves to the portal. There is no dramatic transition; the client simply walks through. From my point of view, it is as if they walked through a small tunnel and disappeared from sight.
Roughly one second later, from my temporal point of view, they step out of the portal in the chamber to the right, and into the chamber proper. If they are carrying anything with them, they once again place it on the bench for sterilization. They once again close their eyes and hold their breath. I once again press a button. They once again gather up their belongings and leave through the door. Where they go after that, like where they go when they walk through the first portal, is not specifically my concern. I am here to run the time machine.
Presumably the client goes back to their life, where everyone they know has aged, like me, only that one second.
The client, however, has aged three days, or nine months, or twenty-seven years. They have been through a time machine, after all. This is how the time machine works.
What I have described is the theoretical process, a process I am meant to repeat three to six times a day, depending on the day. The theoretical process is almost never what actually happens. Theory is almost never practice.
It is not precisely three days, or nine months, or twenty-seven years. It would be, shall we say, suspicious if the temporal forces of nature deigned to accommodate our essentially arbitrary units of time. The retrieval intervals, as we call them, correspond to temporal resonances, ripples in the timestream, generated when we drop an object into it, in this case, the client. In the orientation session I received when I joined the organization as a technician, I was provided a brief gloss of the physics involved, and how the intervals were due to quantum fluctuations and nested dimensions and other such abstruse concepts.
I appreciated that the organization wanted me to understand these things, but at the end of the day I was hired to push buttons, move the clients through the exit and reentry process, and, when needed or desirable, call a supervisor. These tasks do not require an advanced degree. They barely require sentience. But the organization had learned over time that the presence of another human settles the clients (who are not told the internal name for them is “clients”—they are informed that they are referred to as “temponauts”). It is psychologically important, when traveling through time, to have another human be the last and first thing you see.
To that end, we technicians are given a basic education in the history and processes of time travel, enough to reassure the clients with general answers to their questions but not enough to worry them more with specific answers. We are told that the math and physics underpinning time travel were discovered and refined at ETH Zürich and not at MIT, as MIT has declared over and over again. MIT merely conducted the first real-world experiments that confirmed time travel was real and achievable on a larger-than-subatomic scale.
We are told of the great fears of the dangers of time travel and whether traveling to the past would warp and change the present, and how, not unlike the pre-Trinity concern that a nuclear blast could ignite the earth’s entire atmosphere, a human-scale test of time travel might wipe out the history of the planet. We did it anyway, because humans can’t not stick their fingers into wall sockets (this is a personal observation, not an organizational conclusion).
We are told we did not wipe out history. Instead we learned that reality branched at the juncture of the future meeting the past. Whether a new reality was created at the juncture or we plugged into one that already existed is still unresolved and, as a practical matter, immaterial. The point is that our present cannot and will not be changed by time travelers—they will change a reality we are not connected to in any way, except at the specific retrieval intervals.
We are told that there are more retrieval intervals than those at three days, and nine months, and twenty-seven years, but that they are impractical in terms of time travel. There is one interval at one second, more or less, which no one ever uses, because they literally just walked through to their destination and need to take a moment to get their bearings. There are additional resonances at (again, not precisely) 810 years and 243,000 years. Humans can’t use those. We are told to stress to the clients that the twenty-seven-year resonance is, practically speaking, their last chance to come home.
The first client of the day was heading to October 13 in 1066, and to England, to the eve of the Battle of Hastings, where King Harold’s infantry was defeated, and Harold himself killed, by the army of William, Duke of Normandy, who would be crowned the new king of England on Christmas Day that year. The client, an accountant left a bequest by a childless aunt, planned to change the course of history by assassinating William before Harold could fall to the invading army. The client proposed to do this through the cunning use of a sniper rifle, with which, I was informed by said client, he was now a crack shot after nearly a year of practice and training.
To this, I nodded and smiled. This was not the first client to attempt to change history, nor the first client to invade the Battle of Hastings with advanced technology. Sniper rifles and machine guns were common. Once a client brought an RPG. A particularly ambitious client hauled over a maser weapon. As long as it could fit into the exit chamber, it could be brought along. William the Conqueror, as our history would know him, in this new timeline would become a mere historical footnote, headshot by a sniper round, exploded by a propelled grenade, or parboiled in his own armor by focused microwaves. The world would proceed from there with Harold still king, the Norman threat repelled, and a new narrative for the future of England to be written.
The client, disinfected and ready to change someone else’s world, saluted jauntily to me and started toward the portal. I made a small salute in return. The client was dressed in clothes that would camouflage him among the common people of eleventh-century southern England, his sniper rifle, currently collapsed, hidden in a bag carried on his back. As part of our services, the organization, once it booked the client’s tour, offered to equip him with appropriate garb and accoutrements and to get him up to speed in (our) history of the place and time, and gave him the option of remedial lessons in the local language, in this case Old English. Our client was as prepared as we could make him, or at least as prepared as he wanted to be.
The accountant strode through the exit portal and a second later stumbled through the return portal in the right-hand chamber, screaming. He carried nothing with him but his clothes, ragged to the point of disintegration. He wailed, revealing gums without most of their teeth. He gestured frantically with his left arm, his right one a stump. His hair was wild where his scalp was not shiny from burn tissue. He may have been speaking Old English, or he may have simply been babbling. He gibbered, wailed, and screamed for several more moments, tearing at his hair and clothes, before collapsing onto the floor, weeping.
I gassed the client. Not with the disinfecting gas, although that would come presently, but with a tranquilizing spray the organization developed to allow us to process clients returning with notable and visible mental or physical trauma. The gas would settle the client long enough for me to do a visual and instrument-based initial assessment, and then allow our security and medical technicians to remove the client from the return chamber to continue their reentry process. The client breathed in the gas in hyperventilating gulps and less than a minute later was passed out, whimpering himself into unconsciousness.
A button press, and the medical assessment machinery unfolded itself from the chamber ceiling and began its scans and samples. In three minutes I knew that our accountant was suffering from malnutrition and the early stages of leprosy; that most of his ribs had been broken at some point, as had his feet; that his liver and kidneys were in an advanced stage of decline; and that both of his eyes were clouded with cataracts. He was infested with fleas, lice, and intestinal parasites.
The client had not made his three-day return resonance, nor his nine-month. He had been there the full twenty-seven years, and by the evidence—scrapes and scratches on his knees and gnarled remaining hand—had literally crawled into the resonance so as not to miss it.
I checked the client information on my screen and noted that the client had opted for the full recovery package prior to his departure, which in his case was about to be a very good thing for him. Not all clients went for the full recovery package, opting instead for the required but minimal base recovery package, whether due to overconfidence, or the belief that they would not be going far enough back in time to require a full recovery, or simply because at the tail end of signing up for a very expensive experience, they decided to economize.
But I suppose an accountant, of all people, would understand the actuarial probability of needing the full recovery experience.
The medical technicians had arrived, sealed into biosuits, hauling a containment cot. They entered the return chamber, dragged the unconscious client onto the cot, and sealed it for the journey to the organization’s return ward, where the client would spend the next week in quarantine, and likely a few weeks after that recovering from his journey and the suite of therapies required to bring his body, if not his mind, back to some semblance of normal.
As the accountant was carried out, I wondered idly whether he had been successful in his attempt to change the course of history. When he recovered, if he recovered, he would have to tell us, otherwise there would be no way to know. Once the client returned, the connection to the other reality was severed, and no further information would pass between there and here. Our client would be the only witness to events. Sometimes clients brought a recording device, but if this one had, he’d left it behind. His experience existed now only in his memory, if at all.
I pressed another button and began the process of decontamination of both chambers. Another client would be ready at the top of the hour. The chambers had to be prepared and ready for her.
The thing that made time travel useless for historians is what made it profitable for tourism: Introducing information from one reality to another alters the second reality irrevocably.
“Information” here is the time travel term of art for anything sent back through time: humans, drones, probes, cameras, gases and small particles from our atmosphere, photons from light, anything and everything down to the level of quantum entanglement. The minute any of that arrives in a past moment, from our perspective a new branch of reality is created, and everything that proceeds from that moment will be different from, and have no effect on, what we consider our own time. The butterfly effect is correct, but the butterfly is in another reality entirely.
This was not a problem for some types of science. Drones sent back to sample DNA from species extinct for millions of years were able to extract that genetic information and bring it back. Observations of the supernova that created the Crab Nebula were broadly accurate and useful. Anything that relied on noting or sampling things that had already existed prior to the point of “informational insertion” was, generally speaking, sound enough for science.
But everything from that point of insertion could no longer be trusted to be accurate to our own timeline. The drone that obtained the ancient DNA sample, by interacting with the creature to get it, changed its behavior and set it on a different path than it would otherwise have gone on. The camera recording the supernova blocked photons and cosmic particles from completing the path they took in our own timeline. The average person does not understand or care how a lizard going one direction and not another, or an energized particle hitting a sensor rather than a rock, matters at all in the grand scheme of things. A scientist, however, knows that initial conditions are everything, and that small differences at the outset make for huge differences in results down the line. The observer and the observed always interact. Everything changes.
Send a historian to observe, say, the assassination of Julius Caesar, and their presence changes the scene. There is one more person present at the murder who wasn’t there before. The historian interacts with Roman citizens on the way to the assassination and after it. Every single action spins out novel reactions that compound from that moment. Jostle a random Roman on the way to the Senate, and 1600 years later a different pope is named. Jostle a different one and the assassination doesn’t happen at all. “History” stops being accurate the moment you observe it.
Send a different historian! Two things will happen. First, this new historian will not find the previous time-traveling historian at all; every intrusion in time creates a new branch in reality. Second, this other historian will affect events differently from the first one. They will take different steps to the Senate. They will directly and indirectly interact with different Romans and those interactions will subtly change the scene. Who stabs Caesar and in what order. Where the knives fall. What Caesar says to Brutus, or if he says anything at all.
Each historian you send to observe a past event will return and report a slightly different version of events. Which means, historically speaking, that the results are junk. The reportage of the event is accurate only for that reality. You can’t be “careful” and attempt to interact only minimally; one can’t know which actions, however seemingly trivial, will be directly consequential, immediately or over time. Every step changes everything, always. It took years, and many arguments about the truth, before historians accepted that time travel could not tell you what “really” happened in the history of our own reality, and that, as every trip back branched into a different reality, every trip back would likewise produce differently inaccurate results.
Terrible for historians, but great for our organization. If time travel cannot affect our own history, and every trip back branches a new reality, and those new realities have no effect on our own, then as a practical matter, from our point of view, there are no consequences for intruding into this new reality. Yes, anything one of our clients did would affect them, but that was a them problem, and also, from a philosophical point of view, anything that happened in that reality was meant to happen in that reality, otherwise it would not have happened, or could not have happened.
And so the organization opened up time travel to tourism.
The appeal was simple: Travel back in time to a historical event you’ve always wanted to see. Visit a distinguished ancestor or a beloved celebrity. Change the course of history with a well-placed intervention. See the world before humans arrived on it. All of it was possible, and without repercussion in this reality—we would never know of your adventures elsewhere, except what you chose to record or tell.
(The organization never said this part explicitly and in its operating agreement made the clients agree to hold themselves to the highest ethical standard while achieving their particular experiential goal. But it was understood that this clause was unenforceable. We could not follow you to make sure you behaved yourself, you did not need to disclose when you returned, and in any event, the organization not only allowed clients to make trips to assassinate world historical figures, it would sell them the weapons to take along on the trip. If you didn’t tell, we wouldn’t ask.)
In the earliest days of temporal tourism, governments, activists, and philosophers protested the practice and suggested shutting the organization down. The organization responded by making the point that the tourism was funding the organization’s laudable scientific goals, pointing to its expanding library of prehistoric DNA and plant seeds, and calling upon leading biologists and physicists to testify to how the organization’s discoveries and practices were allowing us to develop new medicines, combat global catastrophes, and expand our awareness of the structure and majesty of the universe. If the cost was a millionaire spending three days in the Chicago of the Roaring Twenties, drinking bathtub gin and trying to make time with a flapper, that was fair price for progress, especially when the price would be paid by an entirely different reality, not ours.
The politicians, activists, and philosophers asked these scientists how they would feel if people from another reality time-traveled to ours and changed the course of our own history. The answer was: It probably hasn’t happened, because our history shows no evidence of temporal visitation. But if it was going to happen, then it already happened. If it happened, we don’t know that it happened. If we don’t know that it happened, then the impact of it happening must have been so negligible that it doesn’t matter that it happened. But it probably hasn’t happened. Some reality had to be the first to figure out time travel. It was probably ours.
Some politicians and activists were still skeptical. The organization solved that problem with bribes. It did not bribe the philosophers, since very few people listened to them anyway, and those who did were politicians and activists. Who were bribed. And thus temporal tourism became a real, and really profitable, business.
The second client of the day was pleased to inform me that she was a historical novelist doing research on eighteenth-century Sri Lanka, which I was informed is a terribly exciting time in the history of the nation, what with the crisis of succession in the Kingdom of Kandy and the on-and-off struggles against the Dutch, who were the European colonizers of the island at the time.
I smiled and nodded as the ostensible author went on and I prepped her travel. I personally know next to nothing of Sri Lanka, either in current or historical time. I know very little about many of the specific times and places our clients wished to visit. This is less about a lack of interest as it is a lack of time; there are several clients in a day, and my job is to manage their exit and return, not to worry about the interim between those two events. That is their concern.
To be fair, it’s a rare client who shows interest in my work. Very few ask how it is I fine-tune the portal to deposit them not only at a specific time but at a specific place on the globe. This is not a problem for me, as I don’t have a great knowledge of it myself; for me, it is a matter of inputting coordinates, largely on a graphical interface, and letting the machine itself handle the details from there.
Nevertheless, from time to time a client might show more than casual interest. A year or so ago, one client asked to come into my control room and watch the process, which I refused because that would break pre-exit quarantine and cause cross contamination, and also because I don’t like people looking over my shoulder. The client asked how we compensate for the fact that the earth is not a static object, either in space or time, and how we could manage dialing in the planet when it had moved billions upon billions of kilometers away from where it had been at the time of his temporal destination. I told him the answer was too complicated to explain in the time he had left before his exit, which was probably true and a convenient way to cover my own ignorance.
Perhaps unsurprisingly, that client’s destination for the trip was the 1911 Solvay Conference in Brussels, where the client intended to rub elbows with Einstein, Madame Curie, Max Planck, and Ernest Rutherford, among others. He returned, annoyed, at the three-day resonance; he had been arrested by the authorities for entering the invitation-only conference under false credentials and harassing the attendees. He spent most of his sojourn in a Belgian jail cell. The client asked to go back immediately and try again, saying he could avoid getting arrested this time, but that’s not how it works, and he hadn’t paid for a second trip, in any event. Temporal tourism, as it happens, is not cheap.
This was not a problem for today’s client. My display of her account showed that this was her tenth temporal excursion, and that this would be her seventh to eighteenth-century Sri Lanka. In fact it was her seventh to a specific date and place in eighteenth-century Sri Lanka.
Both of these are rare. Most people can only afford a single time travel trip in their lifetime, if they can afford it at all. Scientists have their travel subsidized by the organization, but in truth much of that “travel” isn’t a human traveling at all, but rather autonomous drones and robots trained for specific missions, a solution that is both cheaper for the organization and safer for the scientists, especially when dealing with prehistoric megafauna.
Either way, scientists are a special economic case and a tax deduction for the organization. Clients pay full freight, both for their travel and for everything around the travel. When it comes to temporal tourism, the organization learned from the very best: cruise lines, which sell a base service—the actual travel by ship—and then pile on extra services for an additional cost. Drinks packages. Spa packages. Upgrades to cabins. Port attractions. If one is not careful, and cruise lines make it easy not to be careful, one can spend more on the extras than one pays for the basic service.
The organization took this to heart. Access to a different reality is the basic service. Add on to that informational classes about the time and place to which one is traveling, language lessons, outfitting appropriate to the era, etiquette and customs training, weapons (obvious and hidden), medical services both before and after travel, reorientation upon return, and, of course, gifts and merchandising. There are houses that can be bought for less than what one of our higher-end packages might cost. Modest houses, but even so.
For today’s client to be on her tenth trip suggested that penny-pinching was not a thing she worried about. She was either indeed a tremendously successful novelist, or more likely, considering the finances of most novelists, had wealth from other means, either generational or provided by an indulgent spouse or partner.
There are other clients who have made repeat trips—the record is thirty-eight, by a billionaire industrialist who liked to go back in time and hunt previous billionaire industrialists for sport, until Cornelius Vanderbilt shot him in the lung and he barely caught the three-day resonance alive—but the vast majority of the clients who make multiple trips do as the billionaire hunter did, which is to visit multiple times. The usual multi-tripper will hit a series of historical highlights, to see, for example, the World’s Columbian Exposition of 1893, and then the destruction of Pompeii in 79, and then the Battle of Gettysburg in 1863. Or, not unlike the billionaire, will go back in time to hunt various extinct animals. Variety is the essence of tourism.
The fact that this client went back multiple times to the same place and the same time was unusual, and to an experienced technician like myself, it suggested certain probabilities, which in this particular case were largely confirmed when the client stepped through the exit portal and then a second later came through the return portal visibly pregnant. The client had come back through their nine-month resonance at least six months along.
The client, knowing I would register the pregnancy, confessed that on her first trip to eighteenth-century Sri Lanka, she had become enamored with, and had a tryst upon, a merchant there, and each subsequent visit deepened her feelings, even if, from the merchant’s point of view, they were meeting for the first time every time they met. The client decided that this trip would be her final one and was determined, for this last visit, to leave with something to remember the merchant by.
I nodded and otherwise said nothing. Clients do not need to explain themselves to me, and I do not care to judge them for their actions or their ethics in dealing with those in different realities. Part of me thought that there were less expensive ways to get pregnant, but another, better part of me thought that having a child by someone you love is not a thing you could put a price on, in this reality or any other.
Besides, this client was not the only one who had ever used a time machine for selfish, or at least, self-interested purposes. I know that for a fact.