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Everything you’ve heard about quantum entanglement is wrong
Quantum entanglement. What the hell is it? Perhaps you’ve read that,
Quantum entanglement is a bizarre, counterintuitive phenomenon that explains how two subatomic particles can be intimately linked to each other even if separated by billions of light-years of space. Despite their vast separation, a change induced in one will affect the other.
Not true. Maybe you’ve read that,
When two or more particles link up in a certain way, no matter how far apart they are in space, their states remain linked.
Nope. Even Wikipedia is wrong, stating:
Quantum entanglement is the physical phenomenon that occurs when a group of particles are generated, interact, or share spatial proximity in a way such that the quantum state of each particle of the group cannot be described independently of the state of the others, including when the particles are separated by a large distance.
The official YouTube account of Fermilab, which is hosted by an award-winning physicist and celebrated science communicator, states that quantum information can travel faster than light, which is certainly false.
The Royal Institution recently hosted one of my favourite and most lucid communicators of theoretical physics who said entanglement has to happen when two particles interact. Ok, that is kind of true. But, the whole point of the video is to shock you with some explanation of how entanglement is some spooky connection between distant objects.
The picture is like this.
The moral of any quantum entanglement story is that it arises when particles interact and create a “link,” which we call entanglement. Importantly, entanglement remains no matter how far apart they might be. The “state” of each individual particle is not well defined, but their joint (entangled) state is. Thus, the two particles must be considered as a single entity, spread across a potentially vast distance. If you believe that story, I agree it’s mystical, just as the internet told you.
