As a meme, it wasn’t particularly viral. But for a few hours on the morning of Nov. 6, the words “darkest timeline” were trending on Google searches, and several physicists posted musings on social media about whether we are actually in one. did. All the probabilities presented in opinion polls and prediction markets collapsed into a single, clear outcome, and history moved from “what could have happened” to “what just happened.” Both sides of this hyper-polarized US presidential election agreed on virtually nothing except a shared belief that the outcome would be a fateful choice between two diverging trajectories of the world.
This raises a fairly obvious (but perhaps pointless) question. Could the “darkest timeline” (or any other “timeline” for that matter) actually exist? Could there be a parallel world somewhere far, far away where Kamala Harris won the election instead?
Besides fostering escapist sociopolitical fantasies and lending a scientific gloss to the genre of counterfactual history, the concept of alternate timelines has actually been shown to be taken very seriously by physicists. It turns out. This concept is best expressed in quantum mechanics, where it predicts different outcomes, such as whether the cat is alive or dead. When a particle of light (a photon) hits a mirror that is only partially silvery, the particle can, in a sense, both pass through and be reflected by its surface. These two mutually exclusive outcomes are known in physics terminology as superposition. When an observation is made, only one of these possibilities appears, but until then the particle is dealing with both possibilities simultaneously. This is proven by mathematics and confirmed by experiments. For example, after creating a superposition, you can undo the superposition by directing the light to a second, partially silvered mirror. It is not possible unless both possibilities remain. Although this feature is usually framed in terms of subatomic particles, it is thought to be ubiquitous across all scales in the universe.
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Supporting the idea that these timelines are real and not just fanciful fictions are the following: “have a finger in the pie” each other, It either increases or decreases the probability of their occurrence. I mean, something may have happened, but I don’t Have a measurable impact on what? I will, The former, as if reaching the real world from a shadowy realm of possibility.
Consider the bomb detector proposed by physicists Avshalom Eritzl and Lev Weidman in 1993 and proven since then (fortunately not an actual bomb). Perform an experiment using a partially silvered mirror, but place a photosensitive bomb in one of the two paths. Photons can be captured. This failure makes it impossible to desuperpose and return the migrating photons to their original state. Even if the bomb never exploded, it shows that the photon never exploded. just possibility The fact that photons can hit the bomb affects what happens. In theory, this principle, known as counterfactual clarity, could be used to take X-ray images of cells without exposing them to harmful radiation. In an emerging theme known as counterfactual quantum computing, computers output values without you having to press the “run” button.
One way to think about the clarity of counterfactuals is known as the many-worlds interpretation. When a photon hits a mirror, the time axis of the universe diverges, forming a world in which particles pass through the mirror and a world in which they are reflected by its surface. Each of us is confined within our own world, so we only see one outcome at a time, but the other is still there and visible to the inhabitants of another world. All these worlds together make up the “multiverse”.
Whether you agree with the many-worlds interpretation or not, physicists and philosophers certainly love to discuss it. Some admire its elegance. Some people sulk about conceptual difficulties, such as what exactly constitutes “the world.” Quantum theory not only allows for multiple worlds, but also offers infinite ways to define them.
But in the midst of global debate, the important insights of the idea’s originator, physicist Hugh Everett, are often forgotten. Everett agreed with other physicists that because a particle can only see one of the superposition possibilities when it enters that state, something must cause all other possibilities to be discarded. He developed his views in response to assumptions. In other words, some mechanism must collapse the superposition. Perhaps it is the act of observation itself, or the sporadic randomness inherent in the structure of reality. Everett realized the flaw in this reasoning. everytime It looks as if the superposition has collapsed, even if it remains intact. The reason is that when we make observations, we interact with the particles, and we and the particles become a single coupled system. Particles are in a superposition, so we are also in a superposition. But we don’t know. Everett’s basic points are: Although we are part of the reality we are trying to observe, no part can fully grasp the whole, and therefore our vision is limited. Our embedding in the universe creates multiple timelines within hidden recesses.
In other fields of physics, existence is also thought of as comprising branching timelines. Physicists consider counterfactuals when calculating the path of a particle. According to what they call the principle of least action, even classical particles that exhibit no characteristic quantum effects suggest all possibilities. In statistical physics, researchers study particles in septillions by thinking in terms of “ensembles,” another kind of multiverse that encompasses all the ways in which particles can be arranged and evolve. I will. Over time, the particles explore all the possibilities open to them. We perceive their machinations indirectly as heat flows and the establishment of thermodynamic equilibrium. Beyond physics, evolutionary biologists also regularly talk about multiple timelines. “If we ran species evolution again, would things turn out the same?”
All these scientific questions are rooted in a fundamental puzzle. What does it mean for it to be possible but not real? Why is it one thing and not another? Physicist Paul Davies calls this the “puzzle of existence.” ” he called. It touches on esoteric ideas about timeline bifurcations, as well as aspects of everyday life such as cause and effect. To say that something causes something else, there has to be a possibility that that “something else” never happened in the first place. In a recent book on the physics of life by astrobiologist Sarah Imari Walker, A life that no one knows She believes that the entire observable universe does not contain enough matter to create every conceivable small organic molecule, let alone large organic molecules like the DNA strands we know and love. I pointed out. To her, living things distinguish themselves by creating molecules and other structures that would otherwise have little chance of existing. Life carves a path into a blank space of possibility.
Perhaps some deep rule selects the actual reality from among the possible realities, but efforts to identify that principle have been defeated one after another. It is difficult to claim that our world is the best of all possible worlds. And despite what the 19th century philosopher Arthur Schopenhauer declared, it doesn’t seem to be the worst. Google searches for “darkest timeline” even though things could always get worse. For many, including philosopher David Lewis and cosmologist Max Tegmark, the simplest conclusion is that all possible realities exist.
So the real question is not whether there are other timelines. There certainly is. In fact, that’s why we only see one thing. Perhaps if the bifurcation were too obvious, life and intelligence would be impossible. Physics is full of such preconditions for our existence. For example, without direction in the flow of time, the arrow of time, there would be no lasting change, memory, intelligence, or agency. Hiding other timelines may be equally important. Quantum superposition may serve a special function within our bodies, but if it does not, it disappears through the active exchange of matter and energy with the biological environment, along with traces of alternative timelines. I will. The essence of intelligence is that it is selective. If we had to analyze the limitless infinity, we would become paralyzed. Instead of opening all possibilities, the mind must settle on one possibility, at least tentatively. The effort required to make that choice, and from there acting on it, may be the key to giving us at least a subjective sense of free will.
So be careful what you wish for. In our dark moments, we may imagine alternate timelines and long for escape to them, but we seem inseparable from our own timelines. If it were easier to fly between them, we might only reach oblivion. Whether we like it or not, we are stuck in this situation. If you want to change that, you have to do it the old-fashioned way.
