The Girl

4
Average: 4 (3 votes)
Your rating: None

To this ant, she said, this tree is its world. And perhaps the grass around this tree, the fallen leaves, these stones, comprises its Universe. The ant does not know that it is being watched. It does not know that trees make forests, that oceans exist, that lands lie beyond oceans, that forests and oceans all lie on a sphere suspended in nothingness; that other spheres spin in the nothingness beyond. These things, an ant cannot possibly perceive.  
We think we are the observers, she continued, and know better than ants. But what if we, too, are being observed, ants to eyes who watch us from dimensions far beyond what we can possibly perceive? What if they are always watching? Perhaps that is why we are trapped as a single point in space and time. Perhaps if no one was watching, we could be wavefunctions of possibilities, traversing every crossroad and path in life that we had to pass by because we could only travel down one route at a time. Wouldn’t it be amazing if we could do that, Jun-kun? 
She turned to me, her eyes dark and wide and earnest. We were sitting huddled together between the giant roots of a hundred-year-old tree near a Shinto shrine. Autumn sunlight sieved through the branches and leaves of the old tree, covering us in a quilt of shadow and light.
You think too much, I only said, laughing.  
Her eyes fell. In silence, we watched as leaves of red and gold fluttered up from the ground, and began spinning and twirling and dancing around us.
 
I adored her. This girl, who spoke of universes and dimensions and wavefunctions, who clambered up to rooftops of buildings to write haikus; who knew how to mend the wings of birds, and name all the clouds and constellations in the sky. But no matter how hard I tried I could never quite understand her, never quite catch up with her—she was like a particle hurtling through multiple dimensions at the speed of light; but I, I was just mere man and matter, massive and slow, confined only to chasing the light of faraway stars with my eyes. You are too Newtonian, she once said, with a glimmer of mischief and sadness in her eyes, too predictable. You are the kind of person who travels fixed paths, paths governed by the classical equations of family and society and propriety. You never surprise.   
When we graduated from university, she told me that she would spend the rest of her life travelling around the world like a nomad, taking on odd jobs and earning just enough along the road to get by. She asked me to come with her, though we both knew even before she asked that I would not. At the airport on the day she left, she interlaced her fingers in mine, smiled, and said: Don’t be sad, Jun-kun. We have been together ever since the beginning. Like trees our roots have grown entangled, and even if we are far separated in distance, you and I will always be a part of each other’s hearts.
As lightly as I could, I returned: But there could be decoherence, and then your heart might couple with another.
She laughed. So you finally read the book I gave you, she said only.
She wrote to me. Letters and postcards, some spilling over into several pages, others barely a hastily scribbled sentence. With the letters came photos of her on a wild lonely crag overlooking the ocean, or with zebras and antelopes grazing on yellow fields behind; of mountains capped in clouds and shoed with plains of wild flowers; of cityscapes at night silhouetted only by lights. I never quite knew where she was at any one point in time—and if I did, then how fast and far she would be travelling next. In her letters she spoke about what she saw and did and heard, of the people she met, of her random musings of life and the world; but never where she was heading to, or when.  
On the night before he called, I dreamt of her. She was standing in front of the padi fields of our village, the familiar solitary rust-coloured mountain towering up behind them. She was smiling at me. One day, she said in the dream as she had said as a child, we will climb that mountain. Together.
We never did.
 “Are you Tanaka Jun?” On the phone his voice was scratchy and distant, his English hesitant and weighed down by a heavy accent that I could not quite place. 
“Yes,” I said cautiously in English. 
 He pronounced her name. “Do you know her?”
“Yes,” I said.
A pause. “We found your name and telephone number slotted in the cover of her passport,” he said. “It was written with the instruction that you should be called if anything should happen.”   
“And what has happened?” A lump was forming in my throat.
“I am Dr Gupta from Punarjanma Hospital,” he said, “in India. A villager found her in a gully in the mountains below a path, bleeding from her head. There was a storm just before, and she must have slipped and fell in the rain.”       
Another pause.
“I am sorry,” said Dr. Gupta. “She did not make it.”  
 
Perhaps, if Everett was correct, there are worlds in which the storm would not have tossed her like a rag doll into the gully. Perhaps there are worlds in which she would still be clambering up rooftops of foreign cities, or stalking the calls of birds through the rainforests, or watching auroras singe through the icy night sky. And perhaps there would be some worlds in which she had never left, never left my side, and we would have grown old together, and die one after another with our children and grandchildren by our beds. Perhaps there are some worlds like that out there. I hope Everett was right.

Newsletter Signup

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

Quantum Theories

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.

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.

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.

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.

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.

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.

A is for ... Act of observation

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

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.

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.

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.

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.

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.

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.

I is for ... Information

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

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.

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 ... 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.

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!

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.

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!

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.

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.

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.

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 ... 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.

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.

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.

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.

G is for ... Gluon

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

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.

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.

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.

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.

R is for ... Randomness

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

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.

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.

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”.

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!

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.

K is for ... Kaon

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

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.

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.

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.

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.