| __CONK! Encyclopedia: Quantum_mechanics__ *(Site not responding. Last check: 2007-10-08)* |

| | During a measurement, the change of the **wavefunction** into another one is not deterministic, but rather unpredictable, i.e., random. |

| | The basic idea is that when a quantum system interacts with a measuring apparatus, their respective **wavefunctions** become entangled, so that the original quantum system ceases to exist as an independent entity. |

| | During a measurement, the probability that a system **collapses** from a given initial state to a particular eigenstate is given by the square of the absolute value of the probability amplitudes between the initial and final states. |

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