Wave-Particle Duality

Average: 2.8 (4 votes)
Your rating: None

Fred had some confusing news for his wife, Barbara. He wasn’t sure how long he had been keeping it from her, exactly, but it seemed like a very long time. Fred was scared to tell her because he didn’t know how she would react, though he knew he couldn’t keep his secret indefinitely. It was making him unhappy and worn out. He felt like he was running on borrowed energy, and you can only do that for so long. So one day, on his commute home from work, he decided he would break the news at last. He doubted Barbara would understand, but he felt he had to take his chances. He would roll the dice.

             Fred pulled into his driveway to find that his wife had arrived home just ahead of him. The front door was open, and she stood smiling in their foyer, waving an outstretched hand in his direction. Fred had spent his ride home composing himself for this encounter, and he was determined to follow his course as planned. But the smiling, waving figure framed by the rectangular aperture of his home’s front doorway somehow unnerved him. As he walked up the footpath, he felt less and less coherent, and when he finally crossed the threshold, he outright scattered.  

            Barbara gasped. Fred’s clothes lay in a heap by the door, his body having transmuted into a semi-material effervescence that spread to fill the volume of the house. All at once he was everywhere at once, a cloudy translucent medium permeating the air. Even more remarkably, he sustained a dynamic pattern of disturbances, which continually moved throughout him, reflecting off the ceilings and walls, self-interfering, superposing, constructing and destructing to generate a network of compressions and rarefactions. These compressions and rarefactions were variations in Fred’s density, and corresponding to this density Fred had varying colour, so that his denser regions were indigo and his least dense regions were red. The regions of intermediate density were accordingly orange, yellow, green, blue, and the rest. In this way a multicoloured concert of spectral pulsations meandered softly through Fred, evolving capriciously with time to immerse Barbara in a giant, three-dimensional standing wave. When she moved, she caused little ripples of colour to emanate from her surface. When she inhaled and exhaled, whirls and eddies of rainbow appeared around her face. It was so queer and so beautiful to see her husband dispersed through the house like this, she thought. It was very quiet.

            “Baby?” Barbara called hesitantly into the aether. She watched the sound waves travel from her mouth and incorporate themselves into the peaceful bustle of colour. The reply was a vague, unintelligible whimpering that rose up around her. “Is something the matter?” she asked, concerned.

            “I have to tell you something.” The anxiety and nervousness in Fred’s disembodied voice were palpable. Barbara now saw the cloud getting fuzzy. After a moment it became apparent that miniscule droplets of water were emerging from the colours, and were falling slowly away onto the floor. She surmised that her husband was crying.

            “Go ahead, baby,” she said, gently.

             “I’ve been doing a lot of talking recently.”

            “With who, babe?”

            “The photons,” Fred was an experimental physicist who worked at a lab, “the ones I’ve been isolating, the ones I’ve been talking about. Remember?” 

            “Of course I do, you told me about them,” she was growing more concerned.

            “Do you remember how I told you about wave-particle duality?” He sounded like he was pleading.

            “Of course. Sometimes photons act like particles, and sometimes they act like waves.”

            “But really they’re neither, right?” He sounded desperate.

            “That’s what you said. A photon is neither particle nor wave.”

            “The only reason people expected light to be ‘particles’ or ‘waves’ was because Isaac Newton thought it would be that way. But really it’s neither, and it’s not a ‘mix’. There is no duality. Light is just light. It is what it is.”

            “That’s right, baby, but who cares what Isaac Newton thought? Particles and waves are just old ideas that don’t properly describe light,” the sound of her steady, compassionate voice reassured Fred. “The universe doesn’t require them to be one way or the other, it just lets light behave like light.”

            “I’m like a photon, Barbara, that’s why I like talking to them.”

            “You mean you’re neither a wave nor a particle? Is that what you’re so upset about?”

            “Not exactly. This is about my identity. As a man. It’s like the photons.”

            “So you’re neither a man nor a wave, is that what you’re saying? Cause right now you look a lot more like a wave than a man.”

            “Erm, sort of...”

            This was all very strange, and Barbara was becoming justifiably exasperated. “Baby, what is going on?”

            “I’m getting gender reassignment surgery.”

            And with that Fred condensed suddenly into his old body, and collapsed naked onto the living room couch. Barbara stood in the foyer processing what she had just heard. She had not expected this. She walked into the living room, slowly, since the hardwood was slick with tears.

            “So you’re a woman?” she asked, surprised but seemingly unperturbed.


            “But you’re not a man.”

            “That’s correct.”

            “But you want to have surgery to become like a woman anatomically.”

            “Yes. It’s hard to explain,” was Fred’s reply. “The photons understood,” he added weakly.

            Barbara was a lepidopterist, by the way, and the walls of the living room were lined with dozens of display cases, all filled with brilliant specimens of butterflies and moths.

            “I still love you,” said Fred.

            “I love you too, baby,” replied Barbara.

            “The operation is expensive,” said Fred.

            “It’ll be worth it,” said Barbara, taking a seat beside him. They sat quietly for a while. Waves oscillated noiselessly somewhere, everywhere.

            “I’ve always liked caterpillars more than butterflies,” said Barbara, “even though they’re less popular.”

            “That’s fair,” replied Fred.

            Isaac Newton rolled in his grave. Neither Fred, nor Barbara, nor the photons seemed to care.

About the Author: 
Dr. Rory Fitzpatrick is an unemployed computer programmer who does not believe in science, much less quantum mechanics. His hobbies are microwave cookery, portraiture, and collecting old calculators. He is unmarried. He is clearly only a pen name and a figment of my imagination.

Newsletter Signup

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

Quantum Theories

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.

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.

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.

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!

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.

U is for ... Universe

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

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!

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.

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.

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.

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.

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.

K is for ... Kaon

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

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.

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.

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.

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 ... 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.

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.

G is for ... Gluon

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

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.

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.

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.

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.

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!

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.

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.

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”.

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.

A is for ... Act of observation

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

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.

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.

R is for ... Randomness

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

I is for ... Information

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

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.

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.

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.

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.

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.

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 ... 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.

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.

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.

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.

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.