Updated: Aug 5
Author: Elizabeth Field
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Quantum Immortality seems almost oxymoronic in terminology. Quantum physics is scientific, mathematical, (dis)provable. Immortality, on the other hand, is an inconceivable idea, implausible in any realm of physical, chemical, or biological science. However, the two words fused together illustrate a mind-blowing concept.
Quantum immortality, also known as the quantum suicide experiment, is a theory formulated by Hans Morevic and Bruno Marchal, two scientists from the robotics and health care fields, respectively. The thought experiment has also been proposed by many other scientists like Max Tegmark. The thought experiment is a direct consequence of Hug Everett’s many-worlds interpretation, which states that the possibilities that do not take place in this universe must take place in some parallel universe. Despite their lack of background in quantum mechanics, the basic principles that they developed the theory upon hold and still remain consistent with further studies into quantum physics. The quantum immortality theory mirrors what is probably the most well known quantum physics principle: Schrodinger's cat. Schrodinger’s cat is a thought experiment which demonstrates phenomena occurring at the sub-particle level as perceptible events that at least some people who do not possess doctorates in quantum physics can understand. Basically, you place a cat, a flask of poison, and an acute radioactive source in a steel box. The theory says that the magnitude of the radioactivity would create a 50% chance of a single atom decaying, therefore killing the cat by breaking the glass and releasing the poison. However, the equivalent chances of the cat dying and remaining biologically intact creates what’s called a superposition, in which case both possibilities are happening simultaneously. In quantum physics, particles are suspended in a state of superposition before settling into one option or another, and it is impossible to definitely tell, as of current understanding, which circumstance will result. Hence, the superposition of both dead and alive states emerges within Schrodinger’s cat.
While Schrodinger was simply using this as a paradoxical thought experiment and not as a real possibility, Morevic and Marchal took his work a step farther, birthing quantum immortality. If a cat could theoretically be both dead and alive, why couldn’t humans or any other being for that matter? Hypothetically, they could.
Imagine a gun. However, it is not your average gun; rather, it is driven by an electron spin. If the electron spins clockwise, the gun will fire, and you are dead. If the electron spins counterclockwise, the gun will not fire, and you are not dead. According to quantum physics, it is impossible to know which way the electron is spinning, so the two options cause a 50/50 chance at life and a 50/50 shot at death. The moment comes. You are about to be either lucky and alive or unlucky and dead. Just kidding! You are now both alive and dead. However, the mind cannot fathom death, an unfamiliar realm, so even if you existed in both life and death, you would not know. Consequently, you, or rather your mind, ends up alive, settling into the counterclockwise spin option. You conduct a second trial; 50% probability again at either outcome. The gun goes off, and you are once again suspended in a superposition, settling mentally into consciousness and life. This happens a third time. Then, a fourth time. Then, a fifth time, and so on and so forth until you decide to stop pointing a quantum-mechanically charged gun at yourself (although, the theory technically says 50 times). In essence, you are creating a branch in the multiverse, another out there and highly contested theory. In one universe, you have died. Everyone around you sees that you have died. However, in another, you’re alive and thriving, probably buzzing to tell someone that you’ve just proved quantum immortality by surpassing the odds and surviving 50 gun shots, well sort of. But what’s to say it’s not just dumb luck, literally just beating the odds. Just like quantum immortality, it COULD happen, and it is significantly more feasible to the immortality non-believers frequenting society.
So, you decide to prove them wrong. You will conduct the experiment again, and then show them your survival through another round of incredibly minute odds. Except there are two problems. One, there are still odds, and, in a psychologically-based generalization, people are inherently against revising their beliefs without concrete proof to the contrary, which no one but you has. Two, the universes supposedly split with each trial, so those who denied your admittedly outlandish theory see you parish, as opposed to your self-predicted continuation life. They are unaware that your consciousness is actually in another version of yourself in an alternate branch of the multiverse. Theoretically, you could do this a million times, and because the universe splits each time to settle the superposition, it would remain impossible to prove.
The quantum immortality theory is not limited to electron spins inside of quantum guns, though. It takes the shape of any life or death matter, or even every decision in an extreme version. If a vital organ is failing, you have a superposition in which the organ failed and the organ did not fail. Your consciousness flows through the living option. If you die of old age, even, there is a chance that you did not die of old age. Hence, you remain intact. Everything has its 50/50, direct opposite, and consequently, you are forced into a superposition with everything.
There is no concrete proof that quantum immortality is real or even possible. Some have pointed out that your self in a parallel world is different from your self in this universe. However, the ability to follow scientific thought backing the idea, a theoretical proof of sorts, is incredible. In any case, we can resolve the issue for ourselves when we all become the oldest people on Earth in our respective branches of the multiverse.