Originally a test pilot for Overwatch, Lena Oxton — callsign Tracer — was the finest pilot of the worldwide taskforce that protected the world. One day, while testing a new teleporting jet, she vanished. Months later, she appeared, but was ghost-like, unable to interact with corporeal matter or sustain her form for long. After it was discovered she was suffering from chronal disassociation, a chronal accelerator was created to anchor her in time, as well as giving her the power to speed up, slow down and even reverse time.
That first paragraph was more or less paraphrased from Tracer’s Wikipedia entry, but what does it mean? Well, for that, it’s time to talk a little about time. We all know about the first three dimensions of space-time: it’s the underlying structure that makes our world what it is; it is what allows us to walk around in circles, climb up ladders and just generally move around in, well, three directions. The fourth dimension of space-time is (at least according to a man by the name of Hermann Minkowski) time.
While we have full control over the first three dimensions of space-time, at least according to the reference frame of Earth, we have very little control over our movement of the fourth dimension. Sure, we can slow it down a bit by going very fast or chilling out near a black hole, but those are very hard things to do, the change is nigh imperceptible unless you have an accurate atomic clock on you and, well, we’re still going ‘forward’ in time, we’re just dragging our heels a little bit.
Think of a four-dimensional world as some people standing on an endless conveyor belt. We can walk side to side on this conveyor belt and jump up and down, but other than that, it just keeps going forwards. We can walk backwards, slowing down our speed a little bit, or run forwards — but as before, we are still simply going forwards. Now with Tracer, think of her being attached to a large robotic arm. At the start, it was wiggling around, jerking her around back and forth through time. Her chronal accelerator is a remote control for this robot arm, making it stay still in relation to everyone else, but also making it take her back and forth, allowing her a level of control over time.
To get the full scoop on Tracer’s powers, it’s time to break out the game and the accompanying shorts about her. Her basic powers are fairly simple: her blink ability makes her jump forwards a bit, quickly moving her forward several meters. Now this isn’t time travel — it can take her on a flat trajectory into the middle of the air, with no momentum afterwards, and she can shoot and interact the whole time whilst moving — it’s simply spatial manipulation. Her reload is much more interesting, though: she reverses the time of her guns slightly, resetting them to an earlier time before she used up all her ammo. And that’s the interesting bit — she can turn back time to an earlier point, for a specific thing, then play back from that point.
Her recall ability functions the same way; it reverses Tracer backwards three seconds in time, resetting her health, ammo, status and position to their t-3 positions. One very interesting point is that if the t-3 position is on a moving platform, the recall won’t just drop you in the air; it puts you on the platform wherever it is in the current time. So this is not just time and space travel, it’s timeline swapping, Tracer is switching herself with another universe’s version of her who didn’t do anything in those past three seconds and instead just stayed standing on the platform. Going back to the conveyor belt analogy, not only is her chronal accelerator moving her back and forth along the belt, it’s also picking her up and swapping her with alternate versions on parallel tracks, or alternate timelines. This is both really weird and really complicated, because anything regarding alternative and parallel timelines is weird and generally messy.
This, thankfully, does give a slight limit to Tracer’s powers, because Tracer doesn’t do bonafide time travel. By instead timeline swapping with slight time-travelling during these switches, it confines Tracer to the timescape boarded by the activation of the chronal accelerator and, presumably, her death, if she ever dies. Sadly, although my roommate wishes it to be true, Tracer cannot go back in time and kick it with Cleopatra.
The most terrifying thing about Tracer is her recall ability. When recalling, her health and ammo returns to full, with no indication of any limits to this power. Doing a bit of mental thinking, it makes sense that any ammo lodged in her body, or presumably any food that Tracer has eaten, would disappear when she recalls. So Tracer, having had a very tiring match, eats a delicious Mars bar. Then, for some reason she recalls three seconds. Then, to the best of my knowledge, the mass energy from that Mars bar disappears into an alternate universe.
That is scary.
See, our universe has a set amount of mass energy, contained within whatever started off our universe. According to the first law of thermodynamics, that energy can neither be created nor destroyed. We get a set amount of stuff and that’s all we have, theoretically until the end of time. Tracer screws all that up.
Overall, there are three options for how our universe will end up. They are, in order of terrifying:
1: Perfect Balance, in which the dark matter repelling everything in our universe and all the matter in our universe balance each other out and everything stays the same forever.
2: The Big Crunch, in which there is more matter than dark matter in the universe, and over billions of years everything slowly pulls each other together until it all ends up crushed together in one supermassive black hole.
3: The Heat Death of the Universe (AKA The Big Yawn), in which there isn’t enough matter in the universe, and over the course of unimaginable amounts of time, everything drifts apart until the entire universe becomes an empty void of equal temperature; entropy has won.
Now you’d think that Tracer couldn’t do much on her own, eating Mars bars, but theoretically, if Tracer was seduced by Talon and wanted to destroy the world, she could do so quite effectively. Working out the energy of an object is very easy: simply plug the relevant numbers into E = mc2, then we get the energy in a Mars bar.
E = mc2
where E is energy, m is the mass of the Mars bar and c is the speed of light in a vacuum.
m = 0.058
E = 0.058 × 299,792,4582
E = 5.21×1015 J
Now that’s a large number, so first let’s try to simplify that down a little bit. The easiest way is just sticking a prefix at the end of it — thankfully, Peta is perfectly placed at ×1015, so the energy contained in a Mars bar is 5.2 PJ, or 5.2 PetaJoules.
Then, to get a good number to play with, we need to change it into Watts, or energy over time (power). Checking the wiki for the snitch on Tracer’s recall, we can find that it takes her back three seconds in time and takes exactly 1.25 seconds to take her back in time. So, if Tracer can unwrap the Mars bar and shove it in her gob in three seconds, it takes 4.25 seconds to ‘use’ 5.2 PJ, so:
5.21×1015 / 4.25 = 1.22 PW
But we can go one even better and convert into the lovely, Watt-hours unit, so we divide our number by 3,600, the number of seconds in an hour:
1.22×1015 / 3,600 = 338×109
= 338 GWH
That’s nearly three-hundred times the amount of energy to send a Delorean back in time!
That’s an insane amount of energy. On the scale of national power grids, it’s approximately equivalent to 845 million kettles all being run at the same time. This incredible amount of energy is constantly removed from our universe, time and time again. And this is completely wrong in every single sense of how our world works — there’s a fixed amount of energy and you can’t keep taking and removing it over and over. It just doesn’t work like that.
Therefore this ‘superpower’ of Tracer is really interesting. There are two possibilities, from what I can see. First, this power is being taken from somewhere else in the universe and chucked out into a parallel universe. Or, secondly, the energy is being created from ‘somewhere’ before being inserted into these parallel universes, leaving us with a net increase of energy across the multiverse.
So, overall, Tracer just wrecks the entire multiverse, just by eating a Mars bar.