A Sense of Decoherence

Average: 4.5 (2 votes)
Your rating: None

UNPERFORMED MEASUREMENTS HAVE NO OUTCOMES, the sign read. It whizzed past the train window making it hard to tell, if it was some kind of crafty advertising or just random graffiti. Fox checked his wristwatch. ‘Late’ was now definitely an outcome.


The carriage quivered as the train passed over a junction. In the dark, Fox could not tell, whether his part of the train had chosen the left or the right branch of the line. He was already late for his appointment, and now he didn’t even know if he was on the right train. Had he missed a service announcement? No, there had been none.


The two branches of the train line would eventually converge several stations down the line. A quick glance at the almost illegible map over the doors confirmed his hunch. At worst a detour along the longer branch, would make him even later for his appointment.


Then the strange sensation started all over again. The very experience that had put him on this particular train in the first place: First, it was a slight sense of detachment. Like he was watching himself from the outside. Then it grew to a much stronger impression of looking at himself sitting in the train carriage riding down one set of rails, while he was sitting in another carriage following the other branch. If he put an effort to it, he could switch back and forth between the two positions. Eventually the sensation would either fade away or he would wake up with substantial blanks in his memory.


The first time he felt this strange splitting was two months back while teaching a class of high school algebra. He had been unsure of the most sensible sequence of lessons, and suddenly found himself teaching several topics all at once, wiping out equations on the blackboard while writing others on top of them. He had to cut the lesson — or lessons — short and take the rest of the day off, contemplating the strange experience. The following weeks, the sensation had reemerged several times at irregular intervals. It always occurred in situation, where he was unsure of where he was or what would happen next. During that time Fox came to shy away from any ambiguity or doubt.


“It’s nothing to be alarmed about,” his doctor had said, when Fox finally consulted him. “Probably just a mild stress reaction.” At this precise moment Fox simultaneously experienced sitting face to face with his doctor, and being stretched out on the dental chair in the clinic located exactly one floor below the doctors office — a planning mix-up had made him unsure of that afternoon’s schedule. The doctor must have picked up on Fox’ strained expression and added: “Just in case, I’ll have a specialist look at you.” In the same instant the dentist said: “Open up!”


And this was his destination now: A slightly creased card with unostentatious typing


Dr. W. Paul

Psychoengineer, SPR, EAP




Dr. Paul was a friendly, soft-spoken man with a grayish beard and a worn corduroy jacket. After a lengthly conversation about Fox’ symptoms, his work, his general state of health and life situation, followed by some rather trivial exercises involving picture cards, dr. Paul fixated Fox with an expectant look:


“I have a name for you: ODDS, Organic Decoherence Deficiency Syndrome. It’s not even in the catalogue — yet,” he said and padded the thick, blue Diagnostic Manual in front of him on the table. “Of course, we have to make some neurological tests, but you tick all the boxes: The undecisiveness, the split consciousness, the blackouts.” He smiled as if had just successfully completed the Times’ crossword.


“What does it mean?”


“Modern science tell os, that we are not detached observers of the world around us. Rather we constantly create novel situations by some indeterminable effects, hereby forcing the world into a new state. In this way every experience is a singling out of a particular factual result, here and now, from all the theoretical possibilities, the innumerable counterfactuals, thereby making obvious the discontinuous aspect of physical phenomena.”




“You are different. You maintain the counterfactual, the untested possibilities in your mind for a long time indistinguishable from the factual one. You avoid the instant decoherence normally associated with experience. This is why you have these doubling experiences from time to time. We don’t know exactly what causes them. They are associated with physical changes in the frontoparietal attention network, but that could happen for any number of reasons.”


“Can it be suppressed, neutralized, or whatever it is, you do?”


Dr. Paul smiled again: “Well, a cocktail of cognitive therapy, epistemological exercises, and a pinch of psychotropics gets you a long way. But then again, ODDS has been described, but far from defeated. On the other hand, you should consider yourself lucky. Very few people get to experience this astounding aspect of reality first hand. You personally bear witness to something, it took most of the twentieth century to fully grasp: That reality isn’t objective. It is a personal game of conditional probabilities!”


“I don’t feel particularly lucky.”


“No, of course. I will make arrangement for the tests, and then we will see.” The doctor stood up and his chair made a screeching sound.




The screeching sound was followed by a slowing down of the train. Fox opened his eyes. Where was he? On his way to see the specialist? No, he had already been there. Or had he? He remembered the bearded doctor Paul and his strange syndrome, but maybe that was merely another counterfactual fantasy.


He so wished that someone would peer down his confined box and update his state; let him decohere into something definite and stable, whatever that might be. But the ODDS seemed to be against him, he thought. Fox gazed into the darkness through the grimy train window. There it was again: UNPERFORMED MEASUREMENTS HAVE NO OUTCOMES.

About the Author: 
A quantum ghost possessed both a PhD in physics and partiality for ambiguous storytelling.

Newsletter Signup

Submit your email address so we can send you occasional competition updates and tell you who wins!

Quantum Theories

T is for ... Tunnelling

This happens when quantum objects “borrow” energy in order to bypass an obstacle such as a gap in an electrical circuit. It is possible thanks to the uncertainty principle, and enables quantum particles to do things other particles can’t.

M is for ... Multiverse

Our most successful theories of cosmology suggest that our universe is one of many universes that bubble off from one another. It’s not clear whether it will ever be possible to detect these other universes.

E is for ... Entanglement

When two quantum objects interact, the information they contain becomes shared. This can result in a kind of link between them, where an action performed on one will affect the outcome of an action performed on the other. This “entanglement” applies even if the two particles are half a universe apart.

B is for ... Bell's Theorem

In 1964, John Bell came up with a way of testing whether quantum theory was a true reflection of reality. In 1982, the results came in – and the world has never been the same since!

T is for ... Teleportation

Quantum tricks allow a particle to be transported from one location to another without passing through the intervening space – or that’s how it appears. The reality is that the process is more like faxing, where the information held by one particle is written onto a distant particle.

C is for ... Cryptography

People have been hiding information in messages for millennia, but the quantum world provides a whole new way to do it.

X is for ... X-ray

In 1923 Arthur Compton shone X-rays onto a block of graphite and found that they bounced off with their energy reduced exactly as would be expected if they were composed of particles colliding with electrons in the graphite. This was the first indication of radiation’s particle-like nature.

S is for ... Superposition

Quantum objects can exist in two or more states at once: an electron in superposition, for example, can simultaneously move clockwise and anticlockwise around a ring-shaped conductor.

N is for ... Nonlocality

When two quantum particles are entangled, it can also be said they are “nonlocal”: their physical proximity does not affect the way their quantum states are linked.

G is for ... Gluon

These elementary particles hold together the quarks that lie at the heart of matter.

B is for ... Bose-Einstein Condensate (BEC)

At extremely low temperatures, quantum rules mean that atoms can come together and behave as if they are one giant super-atom.

D is for ... Dice

Albert Einstein decided quantum theory couldn’t be right because its reliance on probability means everything is a result of chance. “God doesn’t play dice with the world,” he said.

I is for ... Information

Many researchers working in quantum theory believe that information is the most fundamental building block of reality.

Z is for ... Zero-point energy

Even at absolute zero, the lowest temperature possible, nothing has zero energy. In these conditions, particles and fields are in their lowest energy state, with an energy proportional to Planck’s constant.

Y is for ... Young's Double Slit Experiment

In 1801, Thomas Young proved light was a wave, and overthrew Newton’s idea that light was a “corpuscle”.

P is for ... Probability

Quantum mechanics is a probabilistic theory: it does not give definite answers, but only the probability that an experiment will come up with a particular answer. This was the source of Einstein’s objection that God “does not play dice” with the universe.

W is for ... Wave-particle duality

It is possible to describe an atom, an electron, or a photon as either a wave or a particle. In reality, they are both: a wave and a particle.

J is for ... Josephson Junction

This is a narrow constriction in a ring of superconductor. Current can only move around the ring because of quantum laws; the apparatus provides a neat way to investigate the properties of quantum mechanics.

R is for ... Reality

Since the predictions of quantum theory have been right in every experiment ever done, many researchers think it is the best guide we have to the nature of reality. Unfortunately, that still leaves room for plenty of ideas about what reality really is!

A is for ... Act of observation

Some people believe this changes everything in the quantum world, even bringing things into existence.

H is for ... Hidden Variables

One school of thought says that the strangeness of quantum theory can be put down to a lack of information; if we could find the “hidden variables” the mysteries would all go away.

F is for ... Free Will

Ideas at the heart of quantum theory, to do with randomness and the character of the molecules that make up the physical matter of our brains, lead some researchers to suggest humans can’t have free will.

W is for ... Wavefunction

The mathematics of quantum theory associates each quantum object with a wavefunction that appears in the Schrödinger equation and gives the probability of finding it in any given state.

P is for ... Planck's Constant

This is one of the universal constants of nature, and relates the energy of a single quantum of radiation to its frequency. It is central to quantum theory and appears in many important formulae, including the Schrödinger Equation.

S is for ... Schrödinger’s Cat

A hypothetical experiment in which a cat kept in a closed box can be alive and dead at the same time – as long as nobody lifts the lid to take a look.

S is for ... Schrödinger Equation

This is the central equation of quantum theory, and describes how any quantum system will behave, and how its observable qualities are likely to manifest in an experiment.

K is for ... Kaon

These are particles that carry a quantum property called strangeness. Some fundamental particles have the property known as charm!

U is for ... Universe

To many researchers, the universe behaves like a gigantic quantum computer that is busy processing all the information it contains.

R is for ... Radioactivity

The atoms of a radioactive substance break apart, emitting particles. It is impossible to predict when the next particle will be emitted as it happens at random. All we can do is give the probability that any particular atom will have decayed by a given time.

M is for ... Many Worlds Theory

Some researchers think the best way to explain the strange characteristics of the quantum world is to allow that each quantum event creates a new universe.

G is for ... Gravity

Our best theory of gravity no longer belongs to Isaac Newton. It’s Einstein’s General Theory of Relativity. There’s just one problem: it is incompatible with quantum theory. The effort to tie the two together provides the greatest challenge to physics in the 21st century.

Q is for ... Quantum biology

A new and growing field that explores whether many biological processes depend on uniquely quantum processes to work. Under particular scrutiny at the moment are photosynthesis, smell and the navigation of migratory birds.

H is for ... Hawking Radiation

In 1975, Stephen Hawking showed that the principles of quantum mechanics would mean that a black hole emits a slow stream of particles and would eventually evaporate.

A is for ... Atom

This is the basic building block of matter that creates the world of chemical elements – although it is made up of more fundamental particles.

L is for ... Large Hadron Collider (LHC)

At CERN in Geneva, Switzerland, this machine is smashing apart particles in order to discover their constituent parts and the quantum laws that govern their behaviour.

D is for ... Decoherence

Unless it is carefully isolated, a quantum system will “leak” information into its surroundings. This can destroy delicate states such as superposition and entanglement.

U is for ... Uncertainty Principle

One of the most famous ideas in science, this declares that it is impossible to know all the physical attributes of a quantum particle or system simultaneously.

Q is for ... Qubit

One quantum bit of information is known as a qubit (pronounced Q-bit). The ability of quantum particles to exist in many different states at once means a single quantum object can represent multiple qubits at once, opening up the possibility of extremely fast information processing.

L is for ... Light

We used to believe light was a wave, then we discovered it had the properties of a particle that we call a photon. Now we know it, like all elementary quantum objects, is both a wave and a particle!

O is for ... Objective reality

Niels Bohr, one of the founding fathers of quantum physics, said there is no such thing as objective reality. All we can talk about, he said, is the results of measurements we make.

A is for ... Alice and Bob

In quantum experiments, these are the names traditionally given to the people transmitting and receiving information. In quantum cryptography, an eavesdropper called Eve tries to intercept the information.

I is for ... Interferometer

Some of the strangest characteristics of quantum theory can be demonstrated by firing a photon into an interferometer: the device’s output is a pattern that can only be explained by the photon passing simultaneously through two widely-separated slits.

V is for ... Virtual particles

Quantum theory’s uncertainty principle says that since not even empty space can have zero energy, the universe is fizzing with particle-antiparticle pairs that pop in and out of existence. These “virtual” particles are the source of Hawking radiation.

R is for ... Randomness

Unpredictability lies at the heart of quantum mechanics. It bothered Einstein, but it also bothers the Dalai Lama.

C is for ... Computing

The rules of the quantum world mean that we can process information much faster than is possible using the computers we use now.