The double-slit experiment

The double-slit experiment is a cornerstone of quantum mechanics, revealing the wave-particle duality of quantum objects. Describe the setup of the experiment, including the role of the double slits and the behavior of particles or waves passing through. Discuss how this experiment challenges classical notions of particle behavior and illustrates the probabilistic nature of quantum mechanics. Furthermore, delve into the implications of the observer effect on the outcome of the experiment and its philosophical implications regarding the nature of reality.