Two particles can share a single existence across the universe

Science · Published 24 October 2026 Swipe more like this →

In short: When two subatomic particles become entangled, they cease to be separate entities. Even if separated by vast distances, measuring one instantly determines the state of the other. This isn't just a connection; it is a fundamental shift in how reality is structured at its smallest scale.

To understand entanglement, we must move past classical logic. In our everyday world, if you have a pair of gloves and send one to the moon, the glove on the moon was always 'left-handed.' Its state was determined from the start. Quantum particles do not work this way. Before they are measured, entangled particles exist in a superposition—a state where their properties (like spin) are not yet fixed. They don't have a definite answer until the moment of observation.

This phenomenon was famously derided by Albert Einstein in 1935 as "spooky action at a distance." Alongside Boris Podolsky and Nathan Rosen, he argued that because information cannot travel faster than light (a core tenet of special relativity), there must be some "hidden variables" pre-determining the particles' states. However, in 1964, physicist John Bell devised a mathematical inequality to test this. Experiments in the 1970s by John Clauser and Stuart Freedman confirmed that no hidden variables exist; quantum mechanics predicts stronger correlations than any classical theory allows.

The mechanism lies in the wave function—the mathematical expression describing an object's state. When two particles become entangled, they are described by a single, shared wave function. They effectively become two parts of one single object spread across space. This reveals "nonlocality," where objects aren't just influenced by their immediate neighborhood. While this allows for instantaneous correlation, it doesn't violate relativity because no usable information can be transmitted faster than light; the correlation itself only becomes meaningful once compared via traditional communication.

Today, this "spooky" reality is the backbone of emerging technologies. It enables quantum computing and provides a method for unbreakable encryption, where any attempt to intercept a message would be immediately detected by the collapse of the entangled state.

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