Question

In School (15 years ago) quantum physics really fascinated me. The implications on reality, what we know, and how the world behaves is amazing. In school it was mainly about how we change stuff just by observering (double slit, waves vs particles and even changing the past).

But as i rediscovered and read about some of these topics in the last couple of days i've also read about quantum entaglement, i don't quite get it, and don't see how it's any different from things we observe in everyday life. As I understood, the main experiment for quantum entaglement is somehow splitting a particle and we end up with two particles that complement each other. Particle A has either property X or Y. Particle B has either property X or Y. But both properties must be present, so if A = X then B = Y. Now if we measure A, and we can see it has X, if we measure B before light could travel from A-> B we see it has Y.
Why is this spooky, or sometimes even intreprted that A has influence over B state? Isn't it just applied logic?

Answer 1

Quantum entanglement involves particles that instantaneously affect each other no matter the distance, which defies classical physics.

It illustrates 'spooky action at a distance', a concept that challenges locality and the speed of light as the ultimate speed limit. Entanglement highlights the unique and non-intuitive nature of quantum mechanics.

Step-by-step explanation:

The phenomenon you're describing is known as quantum entanglement, which is a peculiar aspect of quantum mechanics where two or more particles become linked and instantaneously affect each other, regardless of the distance separating them.

When we measure one entangled particle, the state of the other particle is known immediately, even if they are light-years apart. This defies the classical concept of local realism, where objects are influenced directly only by their immediate surroundings.

Quantum theory describes particles fundamentally as waves through the wave-particle duality. This concept is counterintuitive as it defies our everyday experiences.

What makes entanglement 'spooky', as Einstein referred to it, is that it suggests a form of instantaneous communication between particles, which conflicts with the principle that nothing can travel faster than the speed of light set by the theory of relativity.

Unlike classical correlations, where the outcome could be determined by pre-existing properties, entangled particles behave in a way that is intrinsically connected despite their separation. This phenomenon goes beyond applied logic and suggests that there are features of the quantum world that are fundamentally different from our everyday experiences and expectations.