2 Slit and Wave Particle

Wave Nature of Light

  • In 1803, Thomas Young demonstrated light's wave nature through interference effects.

  • The two-slit experiment contradicted Newton's corpuscular theory of light.

Two-Slit Experiment Overview

  • Richard Feynman highlights the experiment as central to understanding quantum mechanics' mysteries.

  • This phenomenon cannot be explained classically; it reveals quantum characteristics.

Interference Pattern

  • Wave crests from two slits act like semicircles of radius <br><br>, 2<br>2<br>, 3<br>3<br>, etc.

  • Maxima on the detector occur where the path difference <br>2−<br>1=n<br><br>_2 - <br>_1 = n<br> (where n=1,2,3,…n = 1, 2, 3, …).

  • Intensity on the screen I(x)I(x) is due to interference, not just a sum of intensities from individual slits.

Single Photon Experiments

  • Experiment 1: A single photon passes through slits; could show spot or dim interference pattern.

  • Experiment 2: Repeated trials; possible wave-like pattern or particle-like pattern confirmed.

  • Experiment 3: One slit open at a time; particle-like pattern observed.

  • Experiment 4: Both slits open with measurement on which slit; still shows particle-like pattern.

Photon Behavior

  • Quantum mechanics shows that photons behave both as particles and waves.

  • Single photons can exhibit wavelike behavior despite being detected at specific locations.

Notable Quotes

  • "The plurality that we perceive is only an appearance; it is not real." - Erwin Schrödinger

  • David Bohm emphasizes the need for a non-fragmentary world view in modern physics, suggesting a holistic approach to reality.