Let's unpack your questions in detail.

1. Is the Effect Instantaneous?

The effect observed in quantum entanglement is non-local and appears instantaneous when one particle's state is measured and affects the state of the other, even if they are far apart. However, the instantaneity of the effect is not quite as straightforward as it might seem.

• Quantum Entanglement: When two particles are entangled, their properties become linked in such a way that the state of one particle cannot be fully described without considering the state of the other, even when they are separated by vast distances. For example, if one particle's spin is measured as "up," the spin of the other particle, when measured, will immediately be found to be "down," and vice versa.

• Non-locality: The interaction appears to occur instantaneously in the sense that the measurement of one particle’s state affects the state of the other particle in real-time. This seems to defy the usual concept of locality (the idea that information cannot travel faster than the speed of light).

• Relativity and Information Transfer: However, while the outcome of the measurements may appear instantaneous, no information is actually transmitted faster than light. This is a critical distinction. The measurement of one particle's state doesn't send information to the other particle; rather, the system as a whole is described by a shared quantum state, and once one particle's state is measured, the overall state of the system is determined. There is no signal traveling between the two particles at faster-than-light speeds, which preserves the causality of relativity.

So, while the effect might look instantaneous, it doesn’t violate relativity because no usable information is transferred faster than light, and no "communication" occurs between the particles. The phenomenon is understood in terms of quantum correlations rather than classical communication or causal influence.

2. Are All Particles of the Same Type Affected, or Are There Twinned Particles?

The concept of entanglement typically involves particles of the same type (e.g., two photons, two electrons), but particles do not need to be "twinned" in a strict sense. Entanglement occurs as a result of the quantum state of the system as a whole, rather than the individual particles themselves being intrinsically linked in a particular way. Here's what that means:

• Entangled Particles: The particles involved in quantum entanglement are not "twinned" in the sense of being identical or having an inherent connection. They are simply in a shared quantum state where their properties (like spin, position, or polarization) are correlated. This correlation persists regardless of the distance between them.

• No Need for "Twinned" Particles: While entanglement often involves pairs of particles of the same type (e.g., two electrons or two photons), it is not a requirement for entanglement. Particles of different types can also become entangled. For example, an electron and a photon can become entangled under certain conditions, although they might exhibit different types of correlations based on their respective properties.

• Entanglement Across Different Types of Particles: The correlation between entangled particles depends on the quantum state of the system as a whole. If two particles, regardless of their type, share a quantum state (e.g., through interaction), they can exhibit entanglement. The key is that the total state of the system is described by a wavefunction that encapsulates the entire system, not just individual particles.

3. Why Does This Happen?

The reason particles in entangled pairs exhibit these correlations has to do with the quantum nature of particles:

• Superposition: In quantum mechanics, particles can exist in a superposition of states, meaning they can simultaneously be in multiple states at once. When two particles interact and become entangled, they form a single quantum system described by a shared wavefunction. This wavefunction encompasses the possible states of both particles.

• Measurement: When a measurement is made on one of the entangled particles (for example, determining its spin), the measurement affects the entire system because the particles are described by the same wavefunction. This collapse of the wavefunction leads to a definite outcome for both particles, even if they are far apart.

• Quantum Non-locality: This "spooky" effect arises because the quantum state is not localized in space. The system of entangled particles is described by a global wavefunction that exists in a kind of abstract mathematical space. This means that information about one particle is, in a sense, inherently linked to information about the other, regardless of distance.

In essence, the particles are not "communicating" in the classical sense, but the measurement of one particle’s state defines the state of the other, creating the appearance of instantaneous action.

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Summary

• The effect of quantum entanglement can appear instantaneous, but it doesn’t violate relativity because no information is being transmitted faster than light.

• The particles involved in entanglement are not necessarily "twinned" or inherently linked, but are instead in a shared quantum state.

• Entanglement occurs due to the quantum superposition of particles, where the system as a whole is described by a single wavefunction, and the measurement of one particle leads to an immediate definition of the state of the other.

The non-locality and apparent instantaneity of quantum entanglement challenge our classical intuitions about space, time, and causality, but they do not necessarily imply "action at a distance" in the traditional sense of sending information or signals across space. Instead, they highlight the deeply interconnected nature of quantum systems.

You said:

There is no action at a distance because this would imply two or more things acting upon one another but there is, on one level, one thing?

ChatGPT said:

Yes, you've touched on a profound insight related to quantum entanglement and its paradoxical nature. The idea that there is no "action at a distance" because there isn't a clear separation of things acting on each other is indeed closely tied to the conceptual shift that quantum mechanics offers.

One Unified Thing, Not Two Acting on Each Other

In classical physics, the idea of "action at a distance" suggests that one object exerts a force or influence on another, across space. This interaction typically involves two distinct entities that are separate but connected by a force or signal. However, in the quantum realm, the situation is radically different:

• Quantum Entanglement: When two particles become entangled, they are described by a single quantum state, not as separate, independent objects. The properties of the two particles are not determined individually but instead are linked by the wavefunction that governs the whole system. In this view, the system of entangled particles is not composed of two independent entities interacting across space but of a single unified quantum entity.

• Non-separation of Particles: This unified system does not adhere to the classical concept of particles being distinct "things" that influence each other. Instead, the particles are part of a larger quantum state, and their properties are intrinsically interconnected within this state. When one particle’s property is measured, the global state of the system "collapses," determining the properties of both particles at once. The particles do not "act on each other" in the traditional sense but are co-dependent within a single quantum description.

• No Need for Communication: The key point here is that no communication or classical "action" is taking place between the particles. There is no signal or force traveling between the particles at faster-than-light speeds, which would be required for "action at a distance." Instead, the state of the system, including both particles, is described by a single wavefunction, and the measurement of one part of the system affects the entire state.

The Collapse of the Wavefunction

The wavefunction is a mathematical description of the quantum state of a system. For entangled particles, the wavefunction encompasses both particles and their relationship to one another, meaning their properties are not independent but intertwined.

• When a measurement is made on one particle, the wavefunction collapses, and the properties of the other particle are immediately determined as well. This collapse appears instantaneous, but it's not because information has been transmitted across space. It's because the entire system is one entity described by a global wavefunction, and the measurement of one part of the system reveals information about the whole.

Philosophical Implications

The absence of "action at a distance" leads us to reconsider the very notion of what it means for two things to be "separate" or "distinct." In quantum mechanics, especially in entanglement, the boundary between two particles blurs, and they are better understood as parts of a whole rather than independent entities that interact with one another.

• Holistic View: This suggests that on some level, there is no true separation between the particles. Instead of thinking of them as distinct "things" influencing each other, we might think of them as aspects of a single, undivided reality.

• Non-locality: Quantum entanglement challenges our classical understanding of locality and separation, pointing toward a more holistic, non-local view of the universe.