Where We’ve Been: Flash edition
Hello, friends! I am here to offer a guided tour of my major Flash theories.
Let’s get started.
In the beginning, there was Speed Force.
Speed Force comes in three distinct forms: it behaves like a single sentient entity, occupies a “space” outside of the multiverse, and is accessible by crossing a “bridge” between the multiverse and the Speed Force. An analogy I like to use is a hollow marble in an ocean: the multiverse is the marble (a closed system), the ocean is the Speed Force (an “open” system).
The marble is an object: we know it has at least three spatial dimensions ( left-right,  forward-backward, and  up-down) and one temporal dimension ( past-future). Speed Force exists outside of the multiverse and is not an object: it has no defined spatial or temporal dimensions.
Photo: left to right, we have one-dimensional space (left-right), two-dimensional space (left-right and forward-backward), and three-dimensional space (left-right, forward-backward, and up-down).
To travel from the multiverse to the Speed Force, one must shift from four-dimensional space (multiverse) to zero-dimensional space (Speed Force). Conceptually, this is difficult: we’re so accustomed to three-dimensions (and an implicit fourth, time) that we can’t “picture” a zero-dimensional space. To cross over, you need a guide, a lot of luck, or simply brute force.
A guide would be The Flash, luck would be a Rupture event, and brute force would be a particle accelerator explosion.
Gif credit: justbarryallen.
Gifs: Barry meets The Flash in 2.21 The Runaway Dinosaur.
The Flash is a Speed Force entity which acts as a Speed Force emissary in the multiverse, and an ambassador of the multiverse in the Speed Force. It is most visible in The Runaway Dinosaur as the Ghost that various Speed-entities (including -Joe, -Iris, and -Henry) tell Barry to “catch.” Since The Flash is effectively the tie between Barry and the Speed Force, if Barry loses it, then he loses his direct connection to the Speed Force. He could obtain Speed by other means, but he would no longer have direct, limitless access to it. It would change his life profoundly.
Luck is a tricky term to use, as entering the Speed Force is on par with dying, but in desperate circumstances, the Speed Force can be a life-saving last resort. Speed Force lacks spatial dimensions: you can’t have a body in it. No body = no method to measure how alive or dead something is. In Rupture, Barry succumbs to the energy from the particle accelerator explosion: in essence, he is set on fire. His mass is converted into energy. (Think about a log burning up: mass [log] to energy [heat]. Einstein’s famous equation – E = mc^2 – is a formula for the conversion. [Einstein never actually wrote it in these terms, but the idea was his.]).
Photo: Barry facing his fate in 2.20 Rupture.
The conversion of mass – Barry’s body – into energy – Speed Force – was possible because Barry was already super-saturated: every cell in his body was infused with Speed. As a result, he was 100% human (who he was before the lightning strike) and 100% Speed Force (who he is after the lightning strike). He has a Speed saturation level of 100%.
Most speedsters, by contrast, are between the minimum critical threshold (25%) and the extreme critical threshold (75%).
During the Rupture event, Barry’s entire body was converted into energy. Bonded as he was to The Flash, he followed it “home:” to the Speed Force. That bond saved his life; without it, he would have died.
When it comes to Speed Force, Barry is the exception, not the rule. Barry is the prime speedster: the only speedster with a direct connection to the Speed Force. All other speedsters are secondary speedsters: they rely on the prime and other means of acquiring Speed.
The Flash acts like a tether between the two “worlds,” enabling a direct line between its multiversal counterpart (prime speedster) and its extramultiversal self (Speed Force). The Flash accompanies Barry and Barry alone; no other speedster has an actual Speed Force counterpart.
Photo: Say hi to Quick and Kid, left and right respectively.
Other speedsters have their own alter egos, which mimic more traditional heroic setups: Barry has a two-souls arrangement (himself and Flash), while other speedsters have a two-roles arrangement (themselves with and without the proverbial cape). Some of these alter egos are passive and friendly – Kid and Quick come to mind – but others are active and destructive. Reverse, the Speed-starved side of Eobard, wants to chase Flash until the bitter end to satiate its literally insatiable appetite. Trajectory was also Speed-starved, and the degree of her hunger was literally lethal, driving Eliza to inject herself with enough V9 to catch fire when she ran.
Being “plugged in,” Barry’s supply of Speed remains high all the time – no need to inject himself. Whenever he uses it, it’s replenished. Since the Speed Force contains an effectively infinite amount of Speed, as long as Barry maintains the connection he will never flat-out run out of Speed.
His connection to the Speed Force has been interrupted several times across the course of the series – including 1.07 Power Outage and 2.19 Versus Zoom – and attempts to “reconnect” him to his power source (1.07 Power Outage Speed treadmill electrocution, 2.20 Rupture particle accelerator explosion) failed.
Like a bad radio connection, spontaneous realignment was the best way to get the connection back, but that whole “bridging the four-dimensional/zero-dimensional” gap is a real challenge without The Flash. It’s like trying to tune the radio without a knob. Barry can do it – but only because it’s so intuitive it’s basically muscle memory. Try spontaneously levitating, and you’ll understand why Barry had the “yips.” It was within his grasp – barely – because he had already levitated for weeks. Still, he’s a human, and the Speed Force is an amorphous, undefined entity beyond the reach of the multiverse. It’s not an easy task.
PHoto: Barry (right) stands off with Farooq (left) in 1.07 Power Outage.
How did the connection break in the first place? To understand that, we need to talk about Speed saturation levels and critical thresholds. We’ll do so momentarily. Let’s wrap up this segment and talk about the third option to connect to the Speed Force: brute force.
Recall: the multiverse is like a marble. Normally, nothing gets in or out. That’s the definition of a closed system. Everything within it remains stable: energy and mass are constantly interchanging, but the amount of energy and mass always remains constant (this is the first law of thermodynamics: mass and energy cannot be created or destroyed).
However, powerful events can create bullet-holes in the multiverse, where that barrier between the multiverse and the Speed Force weakens enough to allow Speed Force energy to enter the multiverse. Since Speed Force – which, it is worth noting, is comprised entirely of Speed – has no definite shape, it is not, but acts like, lighting within the multiverse. It is energy with heat-like properties. It also has “massive” (mass-related) properties, including the Ghost itself and the tangibility of Speed bottled up and injected (or caught, as we see Zoom do in 2.06 Enter Zoom).
Photo: bullet holes in glass, showing “shatter points” where Speed can intrude into the multiverse.
If our hollow marble breaks open, it will be crushed by the surrounding ocean. As long as its integrity remains intact, it retains its own coherent shape, and the Speed Force stays outside. However, during the high-energy events where massive amounts of energy are effectively shot at the “wall” of the multiverse, shatter-points form. From these cracks, Speed can enter, and it does. It drifts in and coalesces in a storm near the point of contact.
It concentrates into “lightning” and sees out its lightning rods. And so The Flash as we know it – Barry-as-The-Flash – is born.
The breach automatically seals – the marble analogy unravels a little here; think of it more like putty, where it can shift slightly to cover the gap – and the storm disappears. But once the connection is established, there’s only one way to break it: take the Speed from the speedster.
This will happen naturally. After all, Speed is like heat: it diffuses. Diffusion is the process where a concentrated substance spreads into its surrounding environment and becomes more diluted throughout. Briefly: diffusion causes a dye to spread across a crystal clear container. It also occurs as heat moves from its source to the surrounding cooler air.
Another thermodynamic principle: heat always moves from the hot source to the cold sink. If I hold an ice cube in the palm of my left hand, the heat from my hand moves into the cold ice cube and melts it. As the heat leaves my hand, it cools: from the perspective of my hand, this is an exothermic (“heat exits”) reaction. If I hold a steaming cup of coffee in my right hand, the heat from the cup of coffee moves into my hand and warms it up. From the perspective of my hand, this is an endothermic (“heat enters”) reaction. Exo – exit. Endo – enter. Therm – heat.
Speed is hot. Very hot. The hottest substance in the multiverse, in fact: without fail, it diffuses into whatever is surrounding it.
Photo: Speed is like heat: it diffuses.
The universe seeks equilibrium. This is where the expression “nature abhors a vacuum” comes from. A vacuum is empty space. Like our hollow marble. It’s an anomalous state: everything wants to spread out evenly, not in random pockets. Something has to be holding this equalizing force back to prevent the even distribution of mass (or diffusion of energy, in this case). Think of a bowl of water: unless you put a barrier in the middle, it’s highly improbable (but not, technically, impossible) for all of the water to stay on one half of the bowl.
Nature wants to fill the multiverse with Speed warmth and bring the whole system – Speed Force and multiverse – to the same “temperature.” With the barrier between them, this process cannot occur: they’re distinct. If I put my ice in a cooler, then the warmth of my hands wouldn’t be able to bleed through the plastic insulation and melt it. However, once contact has been established, it’s irreversible, and Speed starts spreading. The multiverse warms up, however imperceptibly.
Speed is the source of all of a speedster‘s powers. It is the blood in their veins and the thunder in their beating hearts. It is the reason they can do extraordinary things. There are two types of speedsters: active and dormant. Active speedsters can perform Speed-related tasks. To have the minimum amount of Speed required to perform any Speed-related tasks, one must meet the minimum critical threshold.
We can talk about critical thresholds quantitatively (aka numerically; in numbers) using Speed saturation levels. Speed saturation levels are measurements of the amount of Speed that a human being has in their body at any one time. This ratio defines the amount of Speed to non-Speed a person possesses.
Photo: Barry’s levels plummet from 100% Speed saturation level to 1% in 2.19 Versus Zoom.
Speed saturation levels vary over time. Remember Speed diffusion? Speed is always moving away from the hot speedster to the cold surrounding multiverse. Therefore, one’s Speed saturation is falling continuously. In just one case – Barry-as-The-Flash – it’s also being continuously replenished. Therefore, Barry’s Speed saturation level is almost always 100%. When he uses large quantities of Speed for long periods of time, it falls, sometimes dramatically. When other speedsters steal from him (e.g. Zoom in 2.19 Versus Zoom) or even other metas (1.07 Power Outage, Farooq), he can lose enough Speed that he no longer meets the minimum critical threshold, and his connection to the Speed Force is severed.
Arbitrarily, the minimum critical threshold is a Speed saturation level of 25%. A 25% Speed saturation level literally translates to 25% of a speedster’s body weight being Speed-saturated cells.
These mutant cells are technically cancerous, and they destroy formerly healthy human cells at a spectacularly high rate. It’s only the equally rapid production of healthy cells (thanks to a sped-up metabolism) that outpaces the destruction of Speed-infected cells. Speed affects every aspect of a speedster’s physiology, for better or worse. Unless one keeps up a constant supply, the damage can become fatal.
(One can imagine what a spectacularly awful conversation it would be to have with a speedster once the dots were connected. “You have cancer.” The closest we came to a conversation of this type occurred in 1.04 Going Rogue, when Felicity asked Caitlin, Cisco, and EoWells’ if Barry “was going to age faster.” The most probable answer is yes. But the rapid replacement of healthy cells cancels it out, so the potential answer is no. In essence: a speedster can live an exceptionally long time, if they maintain a constant supply of Speed.)
We know that Zoom – Hunter Zolomon – faced a death sentence. The logic behind it: he had used a fatal quantity of Velocity 9 to boost his Speed saturation levels. For speedsters without that absolutely precious connection to the Speed Force, life is tough: one has to obtain it from other sources, or risk losing all of it and becoming a dormant speedster. After a certain point, dormancy is a death sentence. Speedsters can’t revert to their old lives; once they’re affected by enough Speed over a long enough period of time, they’re locked in. Find more – or die.
Gif: Not doing so hot, huh, big guy? Zoom in 2.14 Escape from Earth-2.
Why are speedster rivalries so fierce? Because it’s life and death for the rivals contending for that most revered of thrones: the prime speedster’s seat. I have a theory (all of the above is part of my theory, but this is a theory-within-a-theory, if you will) called capture the prime.
The idea is simple: if one can’t create a direct connection to the Speed Force, then one can capture the prime speedster, steal a certain percentage of their Speed, allow a rest period for the Speed Force to naturally replenish the prime’s Speed, and repeat the process indefinitely, becoming an artificial prime.
It’s not a perfect arrangement – break the connection that a prime has to the Speed Force and they’re useless to you; the stress of the process can also easily kill a prime, especially over time – but it is the next best thing for a secondary speedster. It’s the strategy Zoom employs in 2.14 Escape from Earth-2 and Eobard subtly employs throughout Season 1 by using Barry’s limitless supply of Speed as his own rocket fuel for traveling home to the 23rd century.
Velocity 9 is just one alternative to natural Speed found on the speedster’s black market. Another alternative is tachyons, which are utilized by EoWells from 1.09 The Man in the Yellow Suit onward. Eobard fell beneath the minimum critical threshold during the March 18, 2000 time-traveling event. Expending that much Speed was disastrous for him: he had to spend the next fifteen years raising his rival just so Barry could give him the boost he needed to get home. Using the last of his reserves, Eobard fought Barry and persuaded Team Flash to pursue the tachyons to capture the Reverse Flash. The plan backfired – the Reverse Flash got the tachyons – but for Eobard, it was a raging success.
It wasn’t enough, however, to get him back home.
Natural Speed is volatile, diffuses fast, and has major health consequences for speedsters. It only comes from one source: the Speed Force. Artificial Speeds, like tachyons and Velocity 9, mimic natural Speed, but are not actually Speed. They’re compensation. Enough to keep a dying speedster alive long enough to hopefully find a way to the Speed Force to “refuel.”
Artificial Speeds are not designed for long term use. They are highly volatile and diffuse so fast they can’t be accumulated for more than a few hours. Even though Eobard loads up on tachyons, he never reaches the extreme critical threshold, or the minimum amount of Speed required to perform extreme Speed-related tasks, like time-traveling. His Speed saturation level spikes, but it never reaches the 75% Speed saturation level required for these kinds of extreme Speed-related activities.
For speedsters, time travel is made possible because the Speed Force has no specific temporal location and therefore encompasses all time. One can thus jump to any point in the multiverse’s history by hopping into the Speed Force and hopping out at the desired location. This Speed Force highway bridging different multiverses is called Limbo.
Limbo is the interstitial space between the four-dimensional multiverse and the zero-dimensional Speed Force. It appears as a bluish tunnel in 1.23 Fast Enough. It’s also a tunnel during time traveling events such as 1.15 Out of Time and Arrow’s 4.08 Legends of Yesterday events. It is invisible to outsiders. (Which makes sense: zero-dimensions.) It’s only during the crossing over itself that others can see it.
To get to Limbo, one needs to be burning hot and running fast. You have to essentially break through the barrier: fly at such a rate that the boundary between the two “worlds” (multiverse and Speed Force) blurs. You’re not just trying to break the speed of sound; you’re trying to break the barrier of space-time. That’s pretty impressive.
Barry has a fast pass: he’s already connected to the Speed Force, so he can hop in and out of Limbo as he pleases. He’s always burning hot, and in desperate circumstances he can run very fast. He doesn’t need to be running as fast as other speedsters who have to brute-force their way into it: in essence, The Flash has a key to Limbo, but Eobard and Hunter have to literally break down the door to get the same results.
Once in Limbo, you can go wherever you like. If you’re Barry, you can hop out at will: same deal, just unlock the door. Eobard and Hunter (and all other non-prime speedsters) take a tremendous risk whenever they time travel because they could permanently become trapped in Limbo: if they can’t break the door down twice, they’ll get stranded. And stranded speedsters go insane.
(Once, and only once, Barry is locked behind a Speed door he can’t open. Tracy Brand’s Speed Force trap is essentially a door that opens to the same room, ad infinitum. There’s nowhere to go. Breaking it down makes no difference. It’s a temporal loop: there’s no sense of moving forward or backward in time because all of time already exists. The loop will go on forever. For Savitar, it might as well have; for thousands of years, he was trapped in Limbo, unable to get home – but just close enough to interact with home, luring Julian and Wally into his plan. The Flash works both ways: connection to the Speed Force, connection to the multiverse.)
The more energy you expend, the more Speed you expend. For non-prime speedsters, this is a risky game. They have to keep their “next fix” in mind. Where are they going to find it? Creating it is one method. That’s costly – both fiscally and physically. It’s not easy to create artificial Speeds (recall: Velocity 9 is the ninth edition). Stealing it requires the technology’s existence in the first place. It has to be a preexisting condition: you can’t steal something that isn’t there.
But … by an extension of the very same logic, you can steal something that is there.
Which brings me to a personal favorite, and one of my earliest theories-within-a-theory: why speedsters steal Speed.
There are two perspectives: Barry, the prime speedster, who doesn’t need to worry about his next fix because he is already hooked up to it; and all other non-prime speedsters, who are constantly thinking about their next fix because it’s never a guarantee. For Barry, it’s a painful mystery why Eobard and Hunter chase him so ferociously; he doesn’t understand the hunger. (He understands the short-term pain – in 1.07 Power Outage and 2.19 Versus Zoom – but not the long-term hunger.) He doesn’t understand their motives because he thinks every other speedster is like him.
That’s exactly what Eobard wants Barry to think. He doesn’t tell Barry why he hates him in 1.23 Fast Enough. He chooses his words carefully. To admit “because you’re stronger than me, and I want that strength” is a doomed move. Once you concede to your enemy, there is no reclaiming that psychological high ground. Barry perceives Reverse Flash and Zoom as faster than him.
(It makes me think of Savitar’s comment in 3.09 The Present: “The only thing you have to do to become a God is to make people believe you are one.” Guess he finally learned something from Eobard and Hunter.)
In actuality, they’re sprinters: they use a lot of Speed in high-energy, targeted bursts, creating the illusion that they’re much, much faster. Barry, a jogger, uses his Speed much more sparingly over a longer period of time. He doesn’t have their desperation, and he doesn’t have their strategies in mind. He doesn’t need to use his Speed aggressively, so he doesn’t push himself. That’s why Eobard pushes him throughout Season 1.
Again and again, Eobard tells him: “Run, Barry, run.” Barry thinks, I am. But relative to other speedsters, he’s moving slowly. He’s not running. And he can’t keep up with speedsters running for their lives. He’s running to win the game. They’re running to stay alive.
Barry has tremendous potential – he’s the most powerful speedster in existence – but he also lacks the same driving desperation that forces him to use whatever he has at its maximum potential. He’s jogging. Eobard uses some of his precious remaining Speed to push him, to bully him into getting faster. It still isn’t enough; it takes more than half a season before Barry is really fast enough to do what he needs. It has to be frustrating for Eobard, knowing fully well that Barry can be so much faster.
Eobard can’t tell Barry that he is faster because it undermines his psychological advantage. When the physical cards are stacked irreversibly against you, a mental victory is all you’ve got. Eobard achieves it, and so does Zoom. Instead of creating desperation, their attacks bruise his confidence and knock him down without building strength. He doesn’t get faster without “cheating:” tachyons are like caffeine to him, kick-starting his system without actually stemming from a mental shift.
The physical games aren’t enough. Barry needs to be running for his life to beat his enemies.
(And it still isn’t enough to beat himself: Savitar kills “Iris” in 3.22 Infantino Street. Barry’s mental block was still in place: he’d seen himself lose this fight, time and time again, and even running as fast as he was, he was too desperate, lacking the control needed to really throw his weight into it. He was running clumsily instead of strategically: he needed to cover ground from the second he realized the Speed bazooka wasn’t working. Instead, he waited, and he lost the game.)
Eobard and Hunter want Barry’s Speed because natural Speed is superior to artificial Speed in every way. Natural Speed is also almost infinitely abundant – outside of the multiverse, where it is largely inaccessible. When it enters the multiverse, it’s a spectacular fluke. Speedsters are lightning rods, and they absorb the escaped Speed before it can diffuse. So, you can take natural Speed from the source – almost impossible – or you can take it from other speedsters.
Non-prime speedsters thus have three sources for Speed: their point-of-origin (the “lightning strike”), artificial Speed, and other speedsters. For non-prime speedsters, this is a zero-sum game: I win, you lose, or vice-versa.
Hunter stole most of Jay’s natural Speed, but like all Speed, it still diffused. Riding the high, he chose to attack Earth-1 and eliminate its Flash, indubitably thinking he would top off his Speed and eliminate competition at the same time. (Again: zero-sum game mentality. Competition is deadly to you. Get rid of it, or risk it coming back to destroy you.)
At first, the plan went very well: he absolutely destroyed Barry. He even stabbed him in the chest in a Speed-stealing gesture, identical to the move he made in the false flashback with his fight with “Jay Garrick.” Granted, Barry had been hit with not one but two Speed suppressant darts, so he was running lower than usual, but he still had plenty to offer. To cover up the gap, Hunter made a show of hoisting Barry higher and saying goodbye.
Then the plan derailed: Cisco shot him with a Speed-suppressing dart. It might not have seemed like much – to the prime, it certainly wasn’t – but for a non-prime speedster, it’s a terrible blow. Hunter retreated to Earth-2, effectively badly wounded. His extended absence from Earth-1 was not part of the original plan.
Jay was out of Speed, and now Hunter was running on fumes, too.
So he enlisted help. He convinced Harry to steal Barry’s Speed for him. (Why? If Zoom was clearly faster, why else would he have someone else step in for him? For that matter, why else would he have fallen off the radar for so long when he had a clear advantage?) He needed it: the game plan had shifted radically. Hunter didn’t want to kill Barry anymore, his potentially last source for natural Speed. He wanted to use him.
He also dabbled into artificial Speed to make it possible to keep up the whole Jay/Zoom charade, but he was clearly in trouble and starting to show it. The Big Bad exterior faltered. He seemed reasonable, negotiable – far different than the monster who swept in and broke Barry’s back months before – but he was suffering under the surface. He was dying.
And Hunter knew he was dying.
He invested in Caitlin, more than he planned to (just as Eobard invested in Cisco more than he planned to), but even her help wasn’t enough. No artificial Speed was going to get the job done. When Barry came to him, Hunter kidnapped him (once again, using lackeys. If we lacked this dying Hunter perspective, we wouldn’t know why he wouldn’t do the work himself). For a brief serendipitous episode, it even seemed like Hunter might come out on top; he finally had the prime in his grasp. But he misjudged exactly how much Speed Barry had to offer and he left him alone too long.
And Barry got loose.
Hunter was approaching point-of-no-return territory. Some damage is too deep to be underdone. Thoroughly but not yet mortally irradiated, Hunter made one last powerful attempt to gain the upper-hand: he attacked Barry where it hurt, kidnapping Wally and ransoming Barry’s Speed.
Photo: “Your Speed for Wally.” Zoom, left, holds Wally, right, hostage.
It might be enough. If he could get enough Speed, he could purge the damage the artificial Speed had done and revive the still-healthy cells. He could survive. He could make it.
Injecting himself with Barry’s Speed, we see an invigorated Hunter, but the high would wear off, and with it, the terrible realization that no amount of Speed was going to be enough to kick this sickness. He was terminal. He was going down.
And he was going to take everyone with him.
Hence the Magnetar. Not only did Hunter want to destroy the multiverse – this is shatter the multiverse sub-theory in action – he wanted to destroy Barry. He eggs Barry on in 3.23 The Race of His Life. He even tries to get Barry to kill his time remnant (from a first-person perspective, no less; he snarls at Barry to “do it!” as Barry holds a vibrating hand aloft). He wants Barry to snap, to follow him down, to suffer like he is. He wants to kill Barry, mentally and physically.
He fails, but he does win to some extent: in desperation, Barry goes back in time less than a second, hijacking a one-second-younger universe and meeting his one-second-younger self, and together, they stop the Magnetar and Hunter. The Magnetar Barry – the one-second-younger doppelganger – dies the first time.
He does not die the second time, post-Flashpoint, as events domino and pieces fall in different configurations. The one-second-younger Barry – the future Savitar – is rejected by the time traveler Barry, and his one-second-younger family. His universe is thoroughly hijacked: taken over by a time traveler masquerading as the original inhabitant.
And so the Savitar/Barry rivalry begins.
Every doppelganger matters is a simple statement with a complex application. It means every universe Our Barry goes to contains valid, independent, life-loving versions of himself. These are not Barrys who want to lie down and die. They want to live just as badly as Our Barry does. They are just as full-fledged and important as Our Barry. Since we observe the series over the shoulder of Our Barry, it can sometimes carry the impression that these are just clones, Xeroxes, Barrys who lack the rich inner life Our Barry has.
Just because they’re younger than him – or, indeed, older; in which case, they could look at him with the same dismissive attitude – does not make them less real. “Real” does not begin at the finish line. At every point in his life, in every universe, Barry was a person who deserved the full regard as one.
A large part of Savitar’s bitterness stems from the fact that Our Barry has historically treated his time remnants – his temporal doppelgangers, as opposed to spatial doppelgangers, which we’ll come back to – as disposable. We’re spared the moral dilemma of wondering what happened to the 1.15 Out of Time and 4.08 Legends of Yesterday Barrys, and we can pretend that 2.17 Flash Back Barry is alive and well (even though, like 3.23 The Race of His Life Behind-the-Door Barry, he was potentially erased). We can turn a blind eye to these other universes and focus solely on this one Barry.
That’s the peak of selfishness. It’s a self-centeredness that astounds. It’s a lack of empathy that horrifies. Our Barry would fight for his life if a doppelganger tried to take it from him; why should other Barrys not be permitted the same regard? 2.17 Flash Back Barry ran for the hills when Our Barry tried to stab him with the tranq dart. (He ultimately succeeded and 2.17 Flash Back Barry had to have wondered for a moment if it was a fatal drug before he passed out.)
Each of these “other Barrys” has their own temporally unique universe. In one moment, there are two Barrys: the uninterrupted Barry, who will time-travel; and the interrupted Barry, who is present when the time traveler arrives. The uninterrupted Barry passes by the arrival point without incident, but the interrupted Barry’s life comes to a halt when his older doppelganger appears spontaneously. Up to the arrival point, the two Barrys are identical: they share the exact same preceding history. They’re the same person.
After this arrival point, they will never be the same person again.
I liken this scenario to Schrödinger’s cat. Erwin Schrödinger, professional geek, once created a though experiment to explain the unpredictability of where electrons are in space. It’s a little wordy to explain the whole experiment here, so I’m boiling it down to its simplest, most relevant components. You have a cat in a closed, blacked-out box. You also have a jar of lethal poison in the same box. In a set time period, there’s a 50% chance the jar will break and kill the cat, but until you open the box, you can’t determine whether the jar has broken yet. Therefore, the cat is both dead (the jar has broken) and alive (the jar has not broken). The weird part: until you open the box, the cat is statistically both, even though once the box is opened, we can clearly see the result. One result.
There’s always an alternative. Open the box again at the exact same instant, and you would see the dead cat. It’s not possible to do this – you would have to time travel.
So, uninterrupted Barry’s original universe is dead cat, but interrupted Barry’s original universe is live cat. They take place at the exact same time but they have very different results. The universe is essentially one massive binary system, where one means “yes” and zero means “no.” You ask questions, and the number of yes-no responses it takes to get to the right answer are “bits.” (Bit is short for “binary digit.”)
A quick demonstration: let’s say I’ve chosen a letter in the alphabet, K, and I want a machine to guess the letter. The machine asks its first question: “Is it in the first half of the alphabet?” Yes – I punch in a 1. The machine asks a second question: “Is it a vowel?” No – I punch in a 0. The machine asks another question: “Is it in the first six letters of the alphabet?” No – I punch in a 1. At this point, the machine knows it’s between letters 7 and 13, and it’s not I. That narrows the field down to six letters. “Is it in the first ten letters?” No – I punch in a 0.
Now the machine is going in for the kill: with only letters 11 through 13 left, there are just three letters to choose from: K, L, and M. “Is it the 11th letter of the alphabet?” Yes! I punch in a 1. It took five yes-no questions to get to our final answer. It could have taken up to seven in this scenario (if our letter was M, for example). This five-question process takes five bits of information. Your computer works by communicating in these kinds of 1s and 0s all the time. Twenty questions is literally a binary system question game. (And the smarter you are about your questions, the fewer “bits” you’ll need to get the right answer.)
So, one universe – dead cat universe – might be our 1, “yes” universe, while the other universe – live cat universe – might be our 2, “no” universe. (If you want a binary question: “Is it the original universe?” Yes – 1. Dead cat. No – 2. Live cat.)
Each scenario, you must understand, is equally valid. All twenty-six letters of the alphabet were equal targets. K is not a superior letter to U, and vowels are not better than consonants. The questions will pan on the same neutral way: “Is it in the first half of the alphabet?” K – yes. 1. U – no. 0. “Is it a vowel?” K – no. 0. U – yes. 1.
Neutral. The machine’s feelings aren’t chuffed if it’s a vowel or consonant, first half or second half of the alphabet. The multiverse is similarly magnanimous – or perhaps egalitarian – when it comes to these multiple temporal universes. To distinguish them from overlapping universes set in the same time but resonating at a different frequency, I define overlapping universes resonating at the same frequency but set in a different time as divergent universes.
Why divergent? Because the interruption – the time traveler’s arrival – causes events to diverge from their original pattern. The time traveling event literally diverges from the uninterrupted track of the original universe. (It looks like a staircase. It’s pretty cool.) The “interruption” is a divergence. Inhabitants of these divergent universes are equally valid. K and U are equally valid letters.
To keep things relatively simple, I’ve assigned numbers to the different Barrys. Our Barry is Barry-2. He’s originally from Universe 2. His origin story begins with Barry-1, the Future Barry who fought Eobard on March 18, 2000 before rescuing Barry-2. Barry-1 is the uninterrupted Barry from the original version of this night; Barry-2 is the interrupted Barry from the new version of this night. Both are continuous – Barry-2 doesn’t spontaneously appear, he always had the potential to exist. If we only opened the box once, he never would have appeared to, and The Flash as a show wouldn’t exist.
The number system gets fun. I use Barry-3 as the Kid Barry in 1.23 Fast Enough because he’s the “third Barry in the room” that night. I use Barry-5 and Barry-6 for 1.15 Out of Time (1.15 –> 5) and 4.08 Legends of Yesterday, respectively, because Barry-5 derives from 1.15, and Barry-6 has an identical time-traveling story. Barry-4, being the next in the line up of time-traveling events, goes to 2.17 Flash Back Barry. Barry-7 is 2.23 The Race of His Life Magnetar Barry (Barry-D7, the divergent version, is Savitar). Barry-8 is the 2.23 The Race of His Life Barry Behind-the-Door, aka a divergent version of Barry-2 in 1.23 Fast Enough.
Something really interesting happens to Barry-8: he disappears. That’s a euphemism: he actually dies. He’s erased from existence just like Eobard was in 1.23 Fast Enough. The reason only Barry-8 died has to do with ancestors and descendants. Since doppelgangers are identical up until the divergence, you’re safe until the divergence takes place. In this case, the divergence is March 18, 2000 event.
You cannot be eradicated during or after the divergence if you existed before the divergence (pre-dated it). Our Barry checks this box. So does the divergent Future Barry-1 present, rescuing the Kid Barry-9 (multiple of 3, like 1.23 Fast Enough Kid Barry – huzzah!). Both Barry-2 and Barry-D1 were around before the Pilot event. The other “safe” party is the doppelganger created during the divergence. This is Kid Barry-9. Since his future is undetermined, it does not matter what happens next: it won’t erase him. If Nora-9 dies, then Kid Barry-9 grows up like Barry-2; if Nora-9 lives, then Kid Barry-9 grows up like Barry-1.
There’s a big, big problem for the post-date doppelganger in the room: Barry-8.
Barry-2 pre-dates the Pilot; so does Barry-D1. Barry-9 is insulated because his future is open at the time of the divergence. Nothing needs to happen for him to exist.
But Nora-9 has to die for Barry-8 to exist.
See, Barry-8 is a Barry-2 descendant. Barry-2 is his direct ancestor. Just like our binary system, major divergences categorize distinct temporal lineages. Nora lives: Barry-1 ancestry, Barry-1 descendants. Nora dies: Barry-2 ancestry, Barry-2 descendants.
1 or 0. Yes or no.
If you flip the switch to yes in a universe that was formerly a no, something catastrophic happens to the doppelgangers that post-date the divergence: they die. The dominoes never fall; they’re erased from existence.
Eobard died because he was in the exact same position as Barry-8 is here: Eobard post-dated the divergence that occurred in 1.23 Fast Enough (he wasn’t even born until 2151, well after 2015). When Eddie shot himself, Eobard’s history died with him: I did the math and Eddie is essentially Eobard’s great-great-great-great grandfather. Without him, Eobard’s great-great-great grandfather is never born, nor is his great-great grandfather, nor his great-grandfather, nor his grandfather, nor his father – nor himself.
Eobard can’t exist if Eddie doesn’t father his great-great-great-grandfather. After that, Eddie could have died – as long as Eobard’s great-great-great-grandfather lived. (One can see how dangerous it is for deep future selves to visit the past; one link in the chain breaks and it all falls apart. Thanks to entropy – the tendency for order to descend into disorder – chains break a lot.)
Eobard, the post-date doppelganger, vanishes. He needed Eddie. Eddie died.
Remember: the pre-date doppelgangers are safe. This is why Team Flash is so disappointed in 2.11 The Reverse-Flash Returns that Eobard seems to be alive and well. Some general hand-waving takes care of the time travel questions. Just like the reveal of Eobard’s true motive is only partial in 1.23 Fast Enough, so too is his “protected by the Speed Force” explanation incomplete. It’s vague. The Flash writers are writing a broad show; they don’t have the time to sort through every potential problem.
I have that leisure. And over the course of eighteen months, I’ve been busy figuring it out.
So, here’s the thing: 2.11 The Reverse-Flash Returns Eobard pre-dates the 1.23 Fast Enough divergence. In fact, he pre-dates everything in the series: he came before the time-traveling event that brought him into contact with April 25, 2024 Barry-1, which is before the Pilot. (How do I know this? Because Eddie more-likely-than-not fathered Eobard’s great-great-great grandfather sometime between 2015 and 2024. Therefore, that link in the chain was unbroken – and nothing interrupted it. Only kill Eddie’s son would have stopped 2.11 The Reverse-Flash Returns Eobard dead in his tracks. Since that didn’t happen, history played out as 2.11 The Reverse-Flash Returns Eobard anticipated.) 2.11 The Reverse-Flash Returns Eobard pretty untouchable, which is good, because if something happened to him, he wouldn’t travel back in time, and Barry-2 would be erased from existence.
It’s my belief that 2.11 The Reverse-Flash Returns Eobard and Barry-1 traveled back in time on April 25, 2024 to the night of March 18, 2000. (For fun, I call this an “equivalency point:” the sync-up times of two divergent universes. In this case, Universe 1 is 2024, Universe 2 is 2000, and Barry-1  is 24 years older than Barry-2 .) There, they fought, Barry-1 saved Barry-2, and history played out according to plan.
One way or another, 2.11 The Reverse-Flash Returns Eobard has to be born and has to try to kill Barry-2, or Our Barry’s universe falls apart and he and all of his descendants are erased.
This is the fate that awaited 1.23 Fast Enough Eobard: he post-dates the Pilot, since he’s actually the “divergent” Eobard (every time-traveling event brings Barry into contact with a different Eobard, so the 1.15 Out of Time Eobard is not the same Eobard as 1.16 Rogue Time Eobard, nor is 1.23 Out of Time Eobard the same as 1.01 Pilot Eobard, even though Pilot Eobard and 2.11 The Reverse-Flash Returns Eobard shared this history).
It’s a little mind-spinning, but remember this: 2.11 The Reverse-Flash Returns Eobard pre-dates the Pilot, whereas 1.23 Fast Enough Eobard post-dates the Pilot. If anything stops 2.11 The Reverse-Flash Returns Eobard, then everything including the Pilot (which is every Barry except Barry-1 and preceding Barrys) gets erased. If anything stops 1.23 Fast Enough Eobard, then all preceding doppelgangers (Barry-2 and Barry-5, as well as Barry-1) and the concurrent doppelganger (Barry-3) are safe, but future doppelgangers are at risk.
On a smaller scale, this is what happened in 2.23 The Race of His Life, except now it’s anyone after the Pilot at risk. 2.23 The Race of His Life requires the Pilot to have played out like it did in Barry-2′s original universe to preserve post-date doppelgangers.
There’s only one-post date doppelganger in the room.
Only one direct descendant of Barry-2 in enormous danger: Barry-8. Because Barry-8 is the product of the future 1.23 Fast Enough event, he post-dates the 1.01 Pilot event that Our Barry tampers with in 2.23 The Race of His Life. Just as 1.23 Fast Enough Eobard was vulnerable (post-date Pilot) to extinction while 2.11 The Reverse-Flash Returns Eobard was safe (pre-date Pilot), so too is Barry-8, a post-date Pilot doppelganger, in deep trouble.)
He needed the following chain to happen: Barry-9 loses his mother, tips all the dominoes between 1.01 Pilot and 1.23 Fast Enough, to the point where Barry-8 shows up and watches this scene unfold. But that’s not what happens to Barry-9.
Barry-8 can only watch, aghast, as realization sinks in. If Mom doesn’t die …
He never even finishes the thought. He came after this divergence.
And now he’s gone.
Barry-7, Magnetar Barry, pre-dated this erasure: he was safe, too. Which is why Barry-D7 exists, and why Barry-D7 can follow the long spiraling road to becoming Savitar. However, there are no Barry-D8s. There never will be. You can’t undo it.
Entropy can only be added, not reduced.
Entropy, as mentioned above, is the tendency for ordered systems to becomre more disorderly over time. Lighting a fire is adding entropy to the system. So is creating a work of art. Even breathing is adding entropy to the surroundings. Anything that stirs up an otherwise pristine object is creating entropy. Knowledge is entropy: your mind is a “blank slate,” if you will, that acquires more and more entropy over time. (It’s not actually a blank slate, a state of almost zero entropy, but for the explanatory purposes here, it’s sufficient to analogize it as such.)
All of this is to say: Jay Garrick’s, the real Jay Garrick’s, teacup metaphor is all about entropy.
Photo: the answer, as always, is entropy. Featuring Jay (left) and Barry (right).
Every time traveling event adds it. You can’t ever truly “put it back” to its original state, either. From the moment of the conceptualization of the multiverse, entropy has only been added. We penalize speedsters pretty harshly for time traveling, but there is no way to avoid entropy. It’s going to happen. To actualize tragedies – and good universes, the ones where the tsunami doesn’t happen and Cisco lives, among others – is part of the game. Life happens.
Living with it is the end-of-the-day challenge.
We’ve arrived at the end of the road, my dearest friends. I hope you’ve enjoyed this journey so far. There are little elements we didn’t touch upon – among others, alternate universe color theory, lightning color theory, Cisco’s Vibes, lightning rods, Black Flash, and speedster extinction – but the most pertinent material is all here. I hope this helps clarify some of the more complicated Flash phenomenon for you.
Above all else I hope it primes you to ask more questions. Stay curious. Enjoy this magical show.