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Time travel's physical limits and fictional opportunities: A review of Continuum

A police drama set in present-day and near-future Vancouver exploits the possibility of jumping back and forth in time.

Albert Einstein's theory of general relatively does not mathematically prohibit time travel. A variety of physicists over the years have calculated solutions to allow closed time-like loops that could allow for repeating space-time coordinates, most popularly in Michael Morris, Kip Thorne, and Ulvi Yurtserver's 1988 paper, 'Wormholes, time machines, and the weak energy condition.' Harnessing the energy created by a traversable wormhole could possibly produce a time machine. In Continuum , a new television series on Canada's Showcase and America's SyFy networks, that hint of plausibility sets the stage for exploring paradoxes, destiny, and morality.

Show creator Simon Barry's vision of the future is a technocracy, where corporations have replaced government. Dependence on ubiquitous technology has resulted in near-limitless surveillance and control by colluding corporations, with freedom sacrificed for economic stability and security. The future's rebels are militant extremists, determined to overthrow capitalism and re-establish a society prioritizing individual rights.

Continuum starts with a jailbreak in 2077 that releases the future's most notorious criminals and strands them, together with an ordinary police officer, 65 years in their past—our present day Vancouver, British Columbia. For the rebels, the situation presents an opportunity to start the revolution early and change the future by any means necessary. For the cop, it imposes a duty to recapture the fugitives and preserve the future. For Barry and his team of writers, it's a perfect platform for storytelling.

High-energy time travel

Morris, Thorne, and Yutserver start their paper by investigating the limits the laws of physics place on arbitrarily advanced technology. They conclude that if quantum field theory allows violations of the average weak-energy condition and a mass-to-charge ratio smaller than that of the electron, then traversable wormholes are technically possible. Under specific conditions that would render the Cauchy horizon stable, the wormhole could act as a diverging lens allowing for travel backwards through time.

Many physicists have continued this work, exploring the characteristics of the exotic matter required to create such a wormhole, and the limitations on various parameters for different styles of wormhole. A recurring theme is that generating a wormhole capable of transporting humans through time would require staggering amounts of energy.

Continuum's second episode follows our time-travelers seeking out high-energy sources to send them home. Finding BC Hydro and the municipal power grid woefully underpowered, they take a field trip to the campus of the University of British Columbia to visit TRIUMF, Canada's national laboratory for particle and nuclear physics. TRIUMF creates one of the most intense proton beams in the world, with 1000 trillion particles per second accelerated to speeds of 224 000 km/s in a highly cinematic collection of pipes and concrete.

As impressive as TRIUMF is for researching particle physics, it falls far short of the energy requirements set out to create traversable wormholes, even when multiplied by mysterious futuristic technology and flashy lighting. It's a moment where science and story are in agreement: Without enough energy, the time-travelers are stranded in time, unable to bounce around the timeline creating paradoxes.

More practically, as Barry confessed to me in a phone interview, 'While time-travel is a great platform for drama, if we were to engage in it as an ongoing weapon in storytelling we would probably dig ourselves into a very deep hole.' Trapped by both science and fiction for a one-way trip through time with no means to peek at the future, viewers and characters alike are left guessing about the consequences of their actions.

The paradox of free will

It appears that science and fiction concur when it comes to the challenge of interfering with the past. In physics, Igor Novikov's self-consistency principle for time travel theorizes that any closed time-like curve must be self-adjusting, cyclical, and self-consistent. The laws of physics remain the same for time travelers, thus reducing the probability of any event that causes a paradox to zero, yet still permitting free will.

Or, as Barry explained to me, 'We have a notion that we can control destiny and we behave accordingly. However, there are forces that tend to that get in the way of that for most people, and cause them to realize that control may be an illusion.' These themes are explored in a variety of ways as the time-travelers try to use their knowledge of the future to shape events.

Continuum embraces some of the classic tropes of time-travel, with escaped convict Matthew Kellog gleefully embracing his knowledge to scam the stock market to fund a hedonistic lifestyle impossible in the future. His colleagues take a more sinister approach, and test René Barjavel's grandfather paradox by attempting to exterminate the would-be family of their foes. In a standoff of mutually assured destruction, the outcome satisfies both the physicist's self-consistency principle, and the writer's determination to preserve drama for a good story.

Loops of cause and effect

Displaced officer Keira Cameron's primary objective upon finding herself in the past is to continue her duties as a police officer (euphemistically termed a 'protector' in 2077) to uphold the law, while simultaneously preserving the future she remembers. Her choices are complicated by fuzzy memories of history in her own time: knowing what vital technologies are but not who invented them, or the dates of major events but forgetting the details.

Her presence at events that change the life paths of other characters and reshape society may counter the action of her contemporaneous rebels, or may itself destabilize the future she's working to preserve. Without any way to check her impact on the timeline, her actions have unknown reactions.

The fugitives' plan is to foment rebellion against corporate greed and control early, hijacking the 99% movement by escalating street protests into violence, and starting a propaganda campaign that recycles messages from the future into the present day, borrowing phrases and branding yet to be developed.

Continuum explores a loop of influence, with Robert Heinlein's bootstrap paradox applied to ideology and marketing. The words of a time-traveler influence a politically active boy in the present. That boy will grow into a leader of the movement, in turn directly inspiring that time-traveler to join the rebellion. It's a twisted loop of cause and effect, a chain of images, arguments, and ideals whose origins are obscured within a muddled timeline.

Alec Sandler, the first present-day character Kiera meets, is central to another bootstrap paradox. An inventor, his prototypes are potentially influenced by seeing commercial implementations of the same technology carried back from the future. At 17 years old, the only paper notes Alec takes appear in his high school notebook. A peek inside reveals a few jotted down momentum equations, but in a habit common to bored students of any era, it appears Alec mostly doodled potential logos instead of taking notes during class. Glimpses of the future through Kiera's memories confirm he founds his company, growing it into a successful corporation responsible for the key technology used by the futuristic police to maintain control and order. A variant of his doodled logo ends up illuminating the Vancouver skyline.

Alec's idealism in the present paired with his success in the future raise even more questions of cause, effect, and the impact of choices to change the future. In his conversations with Kiera, Alec learns of the future that already was. From the business advantage of learning what products are bound to be successful to the moral dilemma of inventing the tools used in the destruction of personal freedoms, it is unknown if Alec's path is predestined, or if his interactions with the time travelers will change and shape how and what he creates, influencing society to come.

Shades of dystopia

Glimpses into the time traveler's memories offer a future that is both strange and familiar. Vancouver's iconic SkyTrains have been refurbished, and the high-rise construction projects in Chinatown currently subject to heated public debate have been approved, built, and upgraded many times over.

Continued species loss is assumed. Keira encounters her first horse at a public protest attended by Canada's Mounties, and again while visiting a working farm. Her delight at encountering what for her is a long-extinct species brings up echoes of current debate in ecological circles about the practicality and ethics of reviving extinct species through genetic modification and cloning.

Society is highly ordered and strictly controlled with advanced police technology and omnipresent surveillance; however, flyovers of slums reveal escalating economic divide. Corruption within food distribution networks drive desperation and theft. The continuing erosion of personal freedom leads to escalating violent protest by an organized rebellion with charismatic leaders. Law enforcement protects and colludes with corporate interest, while militant extremists use questionable methods in a quest for basic freedom. The mix of means and ends precludes the clear labeling of hero and villain, a moral dilemma that can spark conversations about real current events and future impact.

The direct science in Continuum is understated, implied through activity and consequence rather than jargon and equations, yet the problem of how technological advancement impacts culture drives the themes of the entire series. Between metaphors, moral uncertainty, paradoxes, and loops of action and reaction, it's no surprise when Barry laughs, 'We're trying to cram an incredible amount of information into forty-four and a half minutes.'

Mika McKinnon is a disaster researcher, entertainment science consultant, and irrepressible educator. She writes about disasters at, and science in fiction at .

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