Science Forums 2

[sebbysteiny]

The question you are posing is,by enlarge, still at the cutting edge of science.

However, the basics are still capable of being understood by people like you and me.

Every particle is a wave and thus can be described as a wavefunction. A wavefunction contains all the terms that have been measured. However, due to Hysenburg's uncertainty principal, some measurements cannot be known when others are known, eg momentum and position. So what happens to the position of, say, an electron when you measure it's momentum exactly? It becomes a superposition of numerous position states, with each one having a probability. Thus, the electron efectively acts and behaves as if it's position wer blurred. It does not behave like it has a position, it's just we don't know it yet, it behaves as if it has all possible possitions.

What does this mean? An electron wave with a measured momentum, could go in one of two slits. Each slit is this a position state. When the electron passes through the slits, and you measure the electron position at a screen, you get a diffraction pattern as if every electron went through both slits at the same time and interferred with itself. However, if you try to measure which slit the electron went through, the act of making the measurement changes the wavefunction and thus the properties. The electron now behaves as if it went through one slit only so it doesn't interfear with itself and you get no diffracion pattern.

Young's slits is the most vivid example I can think of where a wavefunction acts not as if the unmeasured state is unknown, but as if the unmeasured state is a combination of all the possible states.

Entanglement is essentially the same. The electrons, before they are measured, have become coupled together. They act as if they are a combination of the two possible states, and not as if they are either one or the other but we don't know which. Thus, when you measure one of the entagled particles, you force it's quantum state and it's properties thus change. At that exact moment, the quantum state of the entangled particle also changes state and therefore it's properties.

Exchanging some quasi-particle between entangled particles simply does not explain why the behavior of one particle actually physically changes suddenly simply because the other particle in a different place has been measured.