Quantum suicide
Encyclopedia
In quantum mechanics
, quantum suicide is a thought experiment
. It was originally published independently by Hans Moravec
in 1987 and Bruno Marchal in 1988 and was independently developed further by Max Tegmark
in 1998. It attempts to distinguish between the Copenhagen interpretation
of quantum mechanics and the Everett many-worlds interpretation by means of a variation of the Schrödinger's cat
thought experiment
, from the cat's point of view.
Quantum immortality refers to the subjective experience of surviving quantum suicide regardless of the odds. In their speculative work on the topic of future science and artificial intelligence
, authors Goertzel and Bugaj, describe a very different metaphysical
notion as "quantum immortality", one they claim is applicable in all circumstances, for every "intelligent entity", and that serves as a means of "transfer" to other universes.
Keith Lynch recalls that Everett took great delight in paradoxes such as the unexpected hanging
. Everett didn't mention quantum suicide or quantum immortality in writing, but his work was intended as a solution to the paradoxes of quantum mechanics. Lynch said "Everett firmly believed that his many-worlds theory guaranteed him immortality: His consciousness, he argued, is bound at each branching to follow whatever path does not lead to death", Tegmark explains, however, that life and death situations don't normally hinge upon a sequence of binary quantum events like those in the thought experiment.
thought experiment which used poison gas and a radioactive decay trigger, this version involves a life-terminating device and a device that measures the spin value
of photons. Every 10 seconds, the spin value of a fresh photon is measured. Conditioned upon that quantum bit, the weapon is either deployed, killing the experimenter, or it makes an audible "click" and the experimenter survives.
The theories are distinctive from the point of view of the experimenter only; their predictions are otherwise identical.
The probability of surviving the first iteration of the experiment is 50%, under both interpretations, as given by the squared norm of the wavefunction. At the start of the second iteration, if the Copenhagen interpretation
is true, the wavefunction has already collapsed, so if the experimenter is already dead, there's a 0% chance of survival. However, if the many-worlds interpretation
is true, a superposition of the live experimenter necessarily exists, regardless of how many iterations or how improbable the outcome. Barring life after death
, it is not possible for the experimenter to experience having been killed, thus the only possible experience is one of having survived every iteration.
made some brief comments: He acknowledged the argument that "everyone will be immortal" should follow if a survivor outcome is possible for all life-threatening events. The flaw in that argument, he suggests, is that dying is rarely a binary event; it is a progressive process. The quantum suicide thought experiment attempts to isolate all possible outcomes for the duration of the thought experiment. That isolation delays decoherence in such a way that the subjective experience of the superposition is illustrated. It is only within the confines of such an abstract quantum scenario that an observer finds they defy all odds.
have used themes involving both quantum suicide and quantum immortality. The idea that authors exploit is that a person who dies in one world may survive in another world or parallel universe.
Quantum mechanics
Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...
, quantum suicide is a thought experiment
Thought experiment
A thought experiment or Gedankenexperiment considers some hypothesis, theory, or principle for the purpose of thinking through its consequences...
. It was originally published independently by Hans Moravec
Hans Moravec
Hans Moravec is an adjunct faculty member at the Robotics Institute of Carnegie Mellon University. He is known for his work on robotics, artificial intelligence, and writings on the impact of technology. Moravec also is a futurist with many of his publications and predictions focusing on...
in 1987 and Bruno Marchal in 1988 and was independently developed further by Max Tegmark
Max Tegmark
Max Tegmark is a Swedish-American cosmologist. Tegmark is a professor at the Massachusetts Institute of Technology and belongs to the scientific directorate of the Foundational Questions Institute.-Early life:...
in 1998. It attempts to distinguish between the Copenhagen interpretation
Copenhagen interpretation
The Copenhagen interpretation is one of the earliest and most commonly taught interpretations of quantum mechanics. It holds that quantum mechanics does not yield a description of an objective reality but deals only with probabilities of observing, or measuring, various aspects of energy quanta,...
of quantum mechanics and the Everett many-worlds interpretation by means of a variation of the Schrödinger's cat
Schrödinger's cat
Schrödinger's cat is a thought experiment, usually described as a paradox, devised by Austrian physicist Erwin Schrödinger in 1935. It illustrates what he saw as the problem of the Copenhagen interpretation of quantum mechanics applied to everyday objects. The scenario presents a cat that might be...
thought experiment
Thought experiment
A thought experiment or Gedankenexperiment considers some hypothesis, theory, or principle for the purpose of thinking through its consequences...
, from the cat's point of view.
Quantum immortality refers to the subjective experience of surviving quantum suicide regardless of the odds. In their speculative work on the topic of future science and artificial intelligence
Artificial intelligence
Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...
, authors Goertzel and Bugaj, describe a very different metaphysical
Metaphysics
Metaphysics is a branch of philosophy concerned with explaining the fundamental nature of being and the world, although the term is not easily defined. Traditionally, metaphysics attempts to answer two basic questions in the broadest possible terms:...
notion as "quantum immortality", one they claim is applicable in all circumstances, for every "intelligent entity", and that serves as a means of "transfer" to other universes.
Keith Lynch recalls that Everett took great delight in paradoxes such as the unexpected hanging
Unexpected hanging paradox
The unexpected hanging paradox, hangman paradox, unexpected exam paradox, surprise test paradox or prediction paradox is a paradox about a person's expectations about the timing of a future event The unexpected hanging paradox, hangman paradox, unexpected exam paradox, surprise test paradox or...
. Everett didn't mention quantum suicide or quantum immortality in writing, but his work was intended as a solution to the paradoxes of quantum mechanics. Lynch said "Everett firmly believed that his many-worlds theory guaranteed him immortality: His consciousness, he argued, is bound at each branching to follow whatever path does not lead to death", Tegmark explains, however, that life and death situations don't normally hinge upon a sequence of binary quantum events like those in the thought experiment.
Quantum suicide thought experiment
Unlike the Schrödinger's catSchrödinger's cat
Schrödinger's cat is a thought experiment, usually described as a paradox, devised by Austrian physicist Erwin Schrödinger in 1935. It illustrates what he saw as the problem of the Copenhagen interpretation of quantum mechanics applied to everyday objects. The scenario presents a cat that might be...
thought experiment which used poison gas and a radioactive decay trigger, this version involves a life-terminating device and a device that measures the spin value
Spin (physics)
In quantum mechanics and particle physics, spin is a fundamental characteristic property of elementary particles, composite particles , and atomic nuclei.It is worth noting that the intrinsic property of subatomic particles called spin and discussed in this article, is related in some small ways,...
of photons. Every 10 seconds, the spin value of a fresh photon is measured. Conditioned upon that quantum bit, the weapon is either deployed, killing the experimenter, or it makes an audible "click" and the experimenter survives.
The theories are distinctive from the point of view of the experimenter only; their predictions are otherwise identical.
The probability of surviving the first iteration of the experiment is 50%, under both interpretations, as given by the squared norm of the wavefunction. At the start of the second iteration, if the Copenhagen interpretation
Copenhagen interpretation
The Copenhagen interpretation is one of the earliest and most commonly taught interpretations of quantum mechanics. It holds that quantum mechanics does not yield a description of an objective reality but deals only with probabilities of observing, or measuring, various aspects of energy quanta,...
is true, the wavefunction has already collapsed, so if the experimenter is already dead, there's a 0% chance of survival. However, if the many-worlds interpretation
Many-worlds interpretation
The many-worlds interpretation is an interpretation of quantum mechanics that asserts the objective reality of the universal wavefunction, but denies the actuality of wavefunction collapse. Many-worlds implies that all possible alternative histories and futures are real, each representing an...
is true, a superposition of the live experimenter necessarily exists, regardless of how many iterations or how improbable the outcome. Barring life after death
Life After Death
Life After Death is the second and final studio album by American rapper The Notorious B.I.G., released March 25, 1997 on Bad Boy Records. A double album, it was released posthumously following his death on March 9, 1997 and serves as his final studio album...
, it is not possible for the experimenter to experience having been killed, thus the only possible experience is one of having survived every iteration.
Max Tegmark's work
In response to questions about "subjective immortality", Max TegmarkMax Tegmark
Max Tegmark is a Swedish-American cosmologist. Tegmark is a professor at the Massachusetts Institute of Technology and belongs to the scientific directorate of the Foundational Questions Institute.-Early life:...
made some brief comments: He acknowledged the argument that "everyone will be immortal" should follow if a survivor outcome is possible for all life-threatening events. The flaw in that argument, he suggests, is that dying is rarely a binary event; it is a progressive process. The quantum suicide thought experiment attempts to isolate all possible outcomes for the duration of the thought experiment. That isolation delays decoherence in such a way that the subjective experience of the superposition is illustrated. It is only within the confines of such an abstract quantum scenario that an observer finds they defy all odds.
In fiction
Authors of science fictionScience fiction
Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...
have used themes involving both quantum suicide and quantum immortality. The idea that authors exploit is that a person who dies in one world may survive in another world or parallel universe.