A Basic Introduction to Living Forever
If we’re honest with ourselves, we’re all hoping that the secret to immortality is uncovered
before we kick the bucket. And in fact it seems there might be a chance at eternal life
hidden in the world of physics – as a result of one of the bizarre properties of quantum
particles: superposition.
Quantum mechanics is physics on the smallest possible scale. Over the last century
physicists have discovered a number of rules that apply to quantum particles. One of these
is that we cannot say that a quantum particle is at point x or point y, and the only way to
describe the position of the particle is with a set of probabilities tied to point x and point y,
telling us how likely it is to find the particle at each point. From this comes the idea of
superposition – quantum particles can be said to exist at both point x and point y until we
measure them to be at one or the other, so what happens when the measurement is made?
There is currently no definite answer, but there are several theories. One, the Copenhagen
interpretation, describes the transition from a particle existing in superposition of states to
existing in one definite state as a “collapse” from a set of probabilities to a single known
state. Another interpretation is the Many Worlds theory, which suggests that upon
measurement the universe splits into two: one when the particle is found in one state and
one where it is found in another. It is this second theory that might help us cheat death.
Imagine an experiment where a gun is hooked up to a machine that measures the spin of a
proton. Spin is an intrinsic property of quantum particles with a size and a direction,
clockwise or anticlockwise. If measured one way the system triggers the gun and the
unfortunate experimenter is killed, if measured oppositely the gun does not go off.
Right now it may not seem like the experimenter is going to come off well, but we must first
look at what is happening: because spin is a quantum property the particle exists in
superposition until measured – its spin is both clockwise and anticlockwise. Once measured,
the spin has a definite direction, and, if we follow the Many Worlds interpretation, the
universe splits. In one universe the experimenter dies, in one he lives and the experiment
repeats. This process will repeat, each time the experimenter surviving on in one of the two
worlds. Forever. Of course, there is also an equal number of experimenters being killed but
the trick to this system is that the parallel experimenters are unaware of each other. This
means that although from an outside view we can consider the experimenter both alive and
dead, from the view of the experimenter he has survived every time (the unlucky version of
him not having consciousness to observe his own demise).
Of course this all seems a bit ridiculous and truthfully it is. This amusing thought experiment
(originally devised by Hans Moravec) is not a realistic way to live indefinitely but rather an
idea designed to highlight the oddity of superposition. Sadly, it may be a while longer before
the true mystery of everlasting life is uncovered.
Author: Joseph Edwards, word count: 548