Topics / Quantum entanglement
How does quantum entanglement work?
What is quantum entanglement really?
Entanglement happens when two particles interact so closely that afterwards they can no longer be described separately. In physical terms they no longer have their own independent state — there is only one shared state for both together. Measure something like the spin of one particle, and in the same instant it is fixed what you would measure on the other, even if it is kilometres or light-years away.
What matters just as much is what does not happen: no signal is sent, nothing travels faster than light, and you cannot transmit a message through entanglement. The outcome of the single measurement stays random. The only thing that is fixed is the link between the two outcomes — their correlation.
This is exactly where the relations model earns its keep. With any subject it asks first: what is connected to what here? For entanglement the answer is unusually clear. The real thing is not two particles each with their own properties, but the connection they share.
Why does the relation matter more than the individual particles?
In everyday life we think of things first and their relationships second: a particle here, a particle there, and maybe some connection in between. Entanglement reverses that order. Taken on their own the two particles no longer carry a fixed property; only their shared relation holds the full information.
In the model's language: when the particles interacted, a relation between them became active. And a relation that has once become active does not simply vanish again — it stays, even as the entities move far apart. The connection is not the sum of two things, it is a quantity of its own.
That sounds abstract, but it is the heart of the matter. The model already claims that no entity exists on its own, only within the web of its relations. Entanglement is in a sense the extreme case of that idea: a state in which the relation can no longer be reduced to the individual parts at all.
How can distance play no role?
The most unsettling thing about entanglement is that distance changes nothing. Whether the particles are a metre or a galaxy apart, the correlation stays exactly as strong. To our everyday intuition that feels backwards, because we are used to influence fading with distance.
The model offers an image for this without replacing the physics: spatial distance is itself only a relation — the spatial relationship between two places. Entanglement, however, lives on a different network level than space does. On the level of space the particles are far apart; on the level of their shared state they are one thing. Two relations on different levels need not translate into each other.
So it is no contradiction that something can be spatially distant and, in terms of state, one. Distance belongs to one level of description, entanglement to another. This is a way of seeing, not a derivation of quantum mechanics — but it makes vivid why farness loses its usual meaning here.
What happens to the state when you measure?
Before the measurement the single particle has no fixed value — it sits in an open, undecided state. Only the measurement settles an outcome. And because both particles share the same common state, measuring one instantly co-determines what comes out of the other.
In the model this reads through states: the entangled relation is active but undecided. The measurement is the stimulus that settles it — it tips the open state into a definite result, and that transition touches both ends of the relation at once. It is not that the particle passes something along; the shared relation takes on a fixed value.
That dissolves the impression that something must secretly rush from A to B. Nothing travels. A shared, until-now open state is decided for the whole by a stimulus at one point.
Entanglement in the larger network: from quantum computers to decoherence
Zoom out from the two-particle view and the entangled pair itself becomes a single entity — a system better described as a whole than through its parts. This is exactly the property quantum computers use: they entangle many particles into one shared state and compute with the web of relations instead of with individual bits.
The more particles are entangled, though, the more sensitive this network becomes to its surroundings. Every unwanted interaction with the outside world ties new relations and disturbs the delicate shared order. This decay is called decoherence — the entanglement is not lost, it spreads out into the environment until it can no longer be used amid the noise.
Here too the way of thinking holds: a state stays pure only as long as the network is small and shielded. Open it to many new relations and the original connection loses its sharpness. Progress in quantum computing through 2025 and 2026 is largely about keeping those disturbing relations away.
What the model explains — and what it doesn't
The relations model is a lens here, not a physical proof. It helps sort entanglement differently — putting the relation before the things, seeing space and state as separate levels — but it does not derive quantum mechanics and does not replace its mathematics.
The lower boundary matters: entanglement is not a channel for thoughts, not action at a distance in an esoteric sense, and not evidence that ‘everything is magically connected to everything’. You cannot transmit anything through it, control anything, or feel anything across distance. Anyone claiming otherwise has left physics behind.
What remains is a sober but beautiful statement: in entanglement the connection is the real thing, not the individual parts. That is precisely the thought the model brings to every subject — here nature shows it with unusual clarity.
Seen through the model
Picture two photons born from the same source and entangled in the process. Call them A and B. At the moment they arise, a relation becomes active between them — a connection that holds their shared state. Then we send A to the left and B to the right, further and further apart.
As long as no one measures, the shared state stays open. Neither photon has a fixed polarisation of its own; only their relation is determined. Now someone measures A and gets a result. In the same moment it is settled what a measurement on B would give — not because A calls out to B, but because both share the same relation and it has now taken on a value.
This is one way of seeing it — a lens, not a finished truth. But it reframes the puzzle: the question ‘how does B find out about A so fast?’ dissolves as soon as you stop looking for two separate things and look instead for a relation that was the real thing all along.
Frequently asked
Can you communicate faster than light using quantum entanglement?
No. The individual measurement results stay random, and you cannot control what comes out at the other end. Only when both sides compare their results over a classical channel does the correlation show up. That is why no information can be transmitted through entanglement and the speed of light is not violated.
Does entanglement last forever?
In principle yes, as long as the pair stays undisturbed — a connection once formed does not vanish on its own. In practice the environment almost always interferes: through interaction with air, heat or measuring devices the shared state spreads outward. This is called decoherence, and it makes entanglement fragile in the lab.
What does quantum entanglement have to do with quantum computers?
Quantum computers entangle many particles into one shared state and compute with that web instead of with independent bits. This lets them work through certain tasks at once that classical machines would have to handle step by step. The big engineering hurdle is keeping the entanglement stable for long enough.
Does entanglement mean everything in the universe is connected?
Not in a magical sense. Entanglement only arises through concrete interaction and is extremely delicate. It is no proof of some all-encompassing telepathic bond. The only accurate statement is the sober one: where entanglement exists, the relation between the particles is more real than their individual states.
Why did Einstein call it ‘spooky action at a distance’?
Einstein was uneasy with the idea that two distant particles could be correlated without any mediating signal, and called it ‘spooky action at a distance’. Later experiments on Bell's theorem showed that nature really does behave this way. Nothing travels between the particles — the shared state was one from the start.
Keep thinking
Related terms: Entity, Relation, The three states: empty, active, passive, Network level, Zoom in / zoom out