The Hypothetical Killing of Cats This work is considered exceptional by our editorial staff.

You are sitting in a small locked room, pointing a gun at your temple. With shaking fingers you pull the trigger, waiting for the bullet to rip through flesh and blood and end your life. To your dismay, the gun clicks but does not fire. You squeeze your eyes shut and try again. Again, the mechanism clicks but no bullet is released. A third time, you pull the trigger, only to hear it click once more. The gun isn’t broken; it is a quantum gun, which means it has a 50% chance of firing every time the trigger is pulled. If the odds of dying increase exponentially every time you pull the trigger, why is it that you are still alive? And what would you think if it were proposed that no matter how many times you pull the trigger, you would never die?

The theory behind this is quantum mechanics, or the study of atomic and subatomic particles. At first, the scenario above (referred to henceforth as “quantum suicide”) seems implausible or impossible; surely you would die by around the fourth or fifth time you pulled the trigger, if the odds were so high. However, once you understand the fundamental principles of quantum physics, quantum suicide doesn’t seem so far-fetched; the only problem would be finding a willing volunteer.

The famous slit experiment helps to explain the nature of the electrons that power your quantum gun. In this experiment, electrons are shot at a barrier with only two small slits in it that the electrons can pass through. Directly on the other side of the barrier is a screen that indicates which slit the electron went through. When one slit is covered, the electron goes through the uncovered hole and marks the screen behind it. However, when both are uncovered and only a single electron is fired at the barrier, a mark on the screen is recorded behind both slits. How is it possible that one electron is observed having gone through two slits simultaneously? When originally tested, scientists observed the electron’s path to the screen to figure out why it appeared to have gone though both slits. To their dismay, they found that upon observing it, the electron only went through only one of the slits! They were completely baffled; why would the electron appear to have gone through both slits when unobserved, but only one slit when observed? The results revealed a quality of electrons and other subatomic particles that continues to confound scientists: a dual wave-particle nature. This means that they will have some properties of waves and some properties of particles. Furthermore, this means that they can be in literally more than once place at once.

Scientists have theorized that the electron takes all possible paths when unobserved, acting as a wave, but then when it is observed it “chooses” one path. This phenomenon can be explained by two theories: the Everett many-worlds interpretation, and the Copenhagen interpretation. The latter theory simply states that, due to the probabilistic nature of quantum mechanics, it is impossible to be able to observe all aspects of the particle, and therefore observation causes it to be so.

Obviously a physician who attempts to measure a patient's blood pressure is faced with a problem. What she measures is not simply blood pressure, but the blood pressure of a person having his blood pressure taken by a physician. A physician would be wiser to look for indirect means of determining true blood pressure than to assert that her "observer-created" reality is all the reality that exists—and that the patient has no blood pressure until she tries to measure it.


As explained in the quote above, observing the particle (or blood pressure) can cause it to be different than what it would be when unobserved.

The other theory to explain quantum mechanics is the Everett many-worlds interpretation. According to this interpretation, every time there is more than one option (a probability), the particle will take all of them. In order to do this, the universe bifurcates, or splits apart, and a new universe is created for each outcome of the probability. All the universes occupy the same space, and none are able to come in contact with each other. Obviously, this interpretation of quantum mechanics is unsettling to the casual observer, because the implications of such an existence are mind-boggling.

Quantum mechanics can come across as crazy or confusing at first. Even brilliant quantum physicists who have been studying it for decades admit to not fully understanding it. As Neils Bohr, renowned pioneer of quantum physics, puts it, “Anyone who is not shocked by quantum theory does not understand it.” After becoming familiar with the basis of quantum physics, it is easy to see why: what is observed at a subatomic level seems to defy the laws of physics.

The famous paradox of Schrödinger’s cat helps to explain how such a thing could be possible. In Schrödinger’s experiment, a live cat is placed in a box with a vial of poison. The poison is attached to a reactor with a 50% chance of going off, based on the direction of the spin of the electron inside. If it goes off, the poison is released and the cat dies, but if it doesn’t go off, the cat continues to live. If the box is sealed and the results unknown, Schrödinger theorized that the cat is both alive and dead at the same time, due to the nature of the reactor. According to the Copenhagen interpretation, it would not be until opening the box and observing the results that the cat would cease to be one of the two probabilities. However, it is impossible to tell, because the simple act of opening the box to see if the cat lives would cause one of the probabilities to cease to exist.

The many-worlds interpretation of the Schrödinger’s cat paradox says that the cat is both alive and dead, but in separate universes. The act of sealing the box and setting the reactor with a 50% chance of going off creates a bifurcation. What was one cat and one observer becomes two; with one, the cat lives, and with the other, the cat dies.

Quantum suicide is a thought experiment (purely hypothetical; there is no way of testing it) from the cat’s point of view. With a 50% chance of dying each time the trigger is pulled, your chances of survival dwindle. However, being the only observer to the experiment, you yourself cannot be aware of your death. If the universe splits every time the trigger is pulled, then every time, another universe is created where your colleagues will open the door to find you dead. But, being unable to be aware of your death, you will continue to live on no matter how many times you attempt quantum suicide.

The theory of quantum suicide can be applied to larger scales as well. Often referred to as universal quantum suicide, the theory is that if something were to happen that would end the world, no one would live to experience it. Therefore, only universes in which such a catastrophe has been avoided will continue to exist; were there nobody to experience the theoretical end of the world, such a universe could not be observed. In this case, the whole universe is taking the place of the cat. Without anybody to “open the box” and find out if the universe has survived or not, it is both continuing on and ended at once. However, seeing as there is nobody alive to be aware of the ended universe, the only universes that are observed are the ones that have thus far avoided catastrophe. Such logic can be used to explain bizarre occurrences that have little likelihood of happening, but happen despite; perhaps, were they not to have occurred, something that resulted would have ended the world and created universal quantum suicide.


Quantum physics and the theory of parallel universes have been talked about and written about for decades, even though the science behind them is still in the early stages of discovery. The effects of such knowledge alter people’s perceptions of the world, and the science fiction stories written about them serve as a means of opening people’s minds to the unique approach at thinking of the universe.

The message behind the stories is that every choice has different possibilities and may alter the universe in untold ways. If the theory that a separate universe exists for every probability is true, the number of universes that overlap is unfathomable. Although the science is only beginning to be understood, and is mind-boggling to newcomers due to the mindset required to process it, the implications are clear. If in the future, a technology is developed that could connect two of these universes, how will that alter people’s perception of the world? If it is commonly known that there are untold numbers of each and every person on earth, all living lives of various successes in different universes, how will that knowledge be used?





Post a Comment

Be the first to comment on this article!

bRealTime banner ad on the left side
Site Feedback