The first part of a series by Scientific Vorcha, on the science behind Life is Strange. Learn about the theories and laws behind the game and see that maybe Science Is Not So Strange after all.
“Oh, I’m gonna play Life is Strange. It’s just a simple story about a teenage girl who can rewind time…”
How naïve I was, saying that to myself when I downloaded the first episode of Life is Strange. When I first began playing the game, it presented itself as little more than a teenager simulator. By episode five, however, I found that my brain had been well and truly fucked.
I was playing, wondering if I should focus on the gameplay, or thinking, “Who’s the psycho killer?” or even “Which of Chloe’s brilliant ideas will
ultimately kill her next?”, but was that enough? Hell no! I had to look for Easter eggs. I had to look for science.
I finished the game but I couldn’t forget about it. I began sketching out the timeline of parallel universes which Max created with every change of event (Everett theory – more about it later). Drawing on paper wasn’t enough for such a complex process tree so I used MS Excel (which you’re probably using for numbers and spreadsheets, but they are well-suited to drawing branched trees of choices).
When it was done, it looked like some nightmarish monster when it was done, so I decided that the game developers must have done something simpler. But, before I present my conclusions, let’s start with the theory.
I promise it won’t hurt very much.
Fig 1 – My nightmarish timeline of Life is Strange
ONE: Newtonian Determinism and Max Caulfield as a Demon
In classical mechanics, everything is simple. If you have an approximate knowledge of the initial conditions, and you know the laws of nature, you can roughly calculate the behaviour of the system. That is to say that you can predict the course of events for any point in time in the future or you can determine which course of events in the past led to the present state of the system. Every moment of the past and the future is determined by the present. A little scary, because what about free will, right?
In 1814, Pierre-Simon Laplace theorized about creature which could make such calculations, and simulate the future. This wise creature was called later Laplace’s demon:
We may regard the present state of the universe as the effect of its past and the cause of its future. An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough to submit these data to analysis, it would embrace in a single formula the movements of the greatest bodies of the universe and those of the tiniest atom; for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes.
Pierre Simon Laplace, A Philosophical Essay on Probabilities
Newtonian mechanics is invariant under time reversal
For example, a a video showing a ball being kicked and rolling in a stadium, zoomed in on the ball could be played the forward or backwards. It still looks the same. We are not able to tell which direction of rolling was the real one. In classical mechanics, reversing time is indistinguishable from reversing the direction of velocity vectors.
Laplace’s Demon exists in the deterministic universe so it works reversible and is able to reproduce the past from the present.
Fig 2 – Guess if this video is forward or backward in time?
the Demon Max play a bit with our universe. The state of our universe is described as a microstate (microstate refers to the precise state of the system, actual states of individual particles). She doesn’t know the microstate, but she knows something about the macrostate to which it belongs. Now if she reverses the momentum of every single particle in the universe and does some more transformations like changing particles to antiparticles etc. (we need that to maintain integrity of time reversal), what she will see later is evolution toward the “future” in which the universe will collapse, stars and planets will be unformed and entropy will decrease. We will see the history of our universe played backward in time.
Fig 3 – Example of time reversal and evolution toward future which is past.
Max’s ability to know the future is tantamount to being able to rewind time to change the course of events. But keep in mind that time reversal involves not just reversing the evolution of a system (playing each state in the opposite order in time) but also transformations on the states at each time, reversing momentum, changing particles to antiparticles.
Is it always possible to find transformation on the states so that the time reversed evolution obeys the laws of physics? Nope.
the demon Max to be able to predict the future, she would have to have the access to all of the information about the state of the world during the passage of time, all possible positions and velocities of each object in the system: the state of a physical system. In the real world, there is a constant loss of information.
TWO: Surprise, the universe is not entirely deterministic!
But the universe is not fully deterministic; it contains random, stochastic elements, and future events are based on probability, not certainty – yes, you have a free will!
The microscopic world of particles, ruled by quantum mechanics, is governed by its own laws. One of these laws, the Heisenberg uncertainty principle, states that we can’t know both the position and momentum of a particle exactly (more about it later). Measuring the exact location of a particle causes the momentum to become uncertain and vice versa.
Whereas, in classical mechanics, the state of a particle is determined by its position and momentum (a set of six figures: position relative to the three spatial directions and momentum vectors along three orthogonal directions), the quantum mechanical state of a particle’s wave function determines the probability of the particle’s possible states.
Although quantum mechanics seems like mumbo jumbo (What? A particle may be in several places at the same time??), the principle of reverse time is then the same as in the case of classical mechanics: it’s possible to transform states in a way that time reversion after transformation gives full compliance with the initial theory. Quantum physics, however, is not invariant under time reversal; there are of course exceptions, such as particles, which can oscillate, but that’s beyond the scope of this article.
The Uncertainty Principle doesn’t operate in the same way forward and backward in time. Some phenomena care about direction of time flow. The Uncertainty Principle tells us that we cannot know the position and momentum at the same time, so we can’t predict the future. The future is unpredictable and uncertain.
THREE: Arrow of time, entropy and Max as another Demon
What is the arrow of time? It’s a distinction between past and future. All the events are always followed in the correct order, time moves forward and never backwards. In the life of the universe, as in ours, everything is irreversibly changing. Permanent changes are part of our life.
The second law says that the total entropy of a closed system always increases (Die Welt der Entropie strebt einem Maximum zu. – Rudolf Clausius).
The universe tends to decay and disorder always increases, “there is a universal tendency to its dissipation, which produces gradual augmentation and diffusion of heat, cessation of motion, and exhaustion of potential energy through the material universe. The result would inevitably be a state of universal rest and death.” (William Thomson / Lord Kelvin).
The Arrow of Time won’t turn up one day. All matter will fall into stillness and stillness is death. The stars run out of fuel resources at the end, the temperature drops to absolute zero, and life on Earth will not be possible. Each system tends from less probable states to more probable. So it is possible, though unlikely, that the physical system spontaneously adopts a more orderly state. A broken egg could return to its original unbroken state, but it is extremely improbable, like cold coffee becoming hot without interference.
The second law of thermodynamics is the tendency of the universe to move from structured state of low entropy to chaotic macrostates (high entropy).
What if in accordance with the laws of Newtonian mechanics, Max will try to reverse the sense of the speed of molecules in a system where a spontaneous process occurred leading to an increase in entropy? Will entropy decrease? In the nineteenth century Scottish scientist James Clerk Maxwell corresponded with another Scotsman Peter Tait.
He created a thought experiment: a demon who guards two tanks of gas. The demon directs the movement of particles: slow (cold) to the left, and the fast (hot) particles to the right. After some time, one end of the container will be hot and the other cold. Such a demon could violate the second law of thermodynamics, decrease entropy (Remember: the state of maximum entropy is the ultimate annihilation!).
Let us draw an arrow arbitrarily. If as we follow the arrow we find more and more of the random element in the state of the world, then the arrow is pointing towards the future; if the random element decreases the arrow points towards the past. That is the only distinction known to physics. This follows at once if our fundamental contention is admitted that the introduction of randomness is the only thing which cannot be undone. I shall use the phrase ‘time’s arrow’ to express this one-way property of time which has no analogue in space.
Fig 4 – You cannot fix this until you violate Second Law of Thermodynamics!
So can Max be a Maxwell Demon and decrease entropy of the world? Not really. She’s a part of thermodynamic system, and so within her work of managing molecules (or fixing book from being destroyed by a drink) she produces some energy.
With attempts at ordering the world and even with existence and evolution, we don’t reduce entropy. The order in one place causes disorder in the other. The fact is that Earth is an open system. But the solar system is a closed system where second law of thermodynamics works. Long ago., energy from the Sun transformed inanimate molecules inside the Primordial Soup into complex, highly organized, replicating living cells. Then transformed populations of simple organisms in the complex ones.
The complexity of our life is an example of a system in which entropy has decreased under the influence of time, but it is only because that life on our planet “feeds” the power lead from the outside, from the Sun, negative entropy. However the total amount of matter and energy can neither arise out of nothing, or simply disappear. Entropy of the solar system increases for billions of years, from the beginning of evolution.
The slight decrease in entropy associated with the presence of life on Earth, is largely offset by the huge increase associated with the transport of heat, which traverses the cold space and heated on the way to Earth. The existence of our universe started with low entropy, end with high.
Okay so if because of damn physics Max can’t rewind time, can she just freeze it?
Fig 5 – Let’s freeze time
Time inside of Max body must be unchanged and time needs to exist for each molecule of air and water inside Max or she will die immediately (she need to breathe, have a working heartbeat, electrical impulses and rhythm of the central nervous system). As we can see, she’s alive so only time around her stopped, every movement and rhythm of the world around she stopped completely.
If the air molecules on the campus just freeze in time, each of them will remain exactly in a position when Max stopped time. It means Max won’t be able to move, trapped in rigidly located air molecules.
So let’s assume that time function normally inside Max body and in her nearest surrounding, so she can move. Some kind of time bubble around her. But everything else is frozen in time, so neither light nor sound will come to Max – she will be deaf and blind. Max cannot freeze time and just walk.
In the next part of Science is Strange: chaos theory, butterfly effect, parallel universes and why is it possible to travel into past if rewinding is not possible?