# Why does particle measurement cause quantum wavefunctions to collapse

When we attempt to measure a certain property of a particle, how and why does its wave function collapse? I've tried to find answers on my own, but they've been far too complicated for me to comprehend. Would appreciate any answer with limited complex jargon, and more simplistic explanation, if possible.

If the particle is in a state $$|\psi\rangle$$, measurement of the variable (corresponding to ) $$\Omega$$ will yield one of the eigenvalues $$\omega$$ with probability $$P(\omega)\propto |\langle\omega|\psi\rangle|^2$$. The state of the system will change from $$|\psi\rangle$$ to $$|\omega\rangle$$ as a result of the measurement.
Another aspect of this postulate says the measurement of the variable $$\Omega$$ changes the state vector, which is, in general, some superposition of the form $$|\psi\rangle=\sum_{\omega}|\omega\rangle \langle\omega|\psi\rangle$$ into the eigenstate $$|\omega\rangle$$ corresponding to the eigenvalue $$\omega$$ obtained in the measurement. Which is called the collapse or reduction of the state vector.