Back to Scientific Theories

Table of Contents

• Introduction
  • Quantum Mechanics, the theory of the interactions among atoms, subatomic particles, and electromagnetic radiation, has proved remarkably successful at predicting the outcome of experiments. Yet, “in spite of the overwhelming practical success of quantum mechanics, the foundations of the subject contain unresolved problems—in particular, problems concerning the nature of measurement.” (Britannica)
• Failure of Classical Physics
  • Around the beginning of the 20th century Classical Physics was confronted with phenomena for which its predictions were false. Nonclassical, ad hoc hypotheses were set forth. But it took a score of physicists ten years to build a new theory that successfully addressed the problems.
  • View Failure of Classical Physics
• Postulates and Prediction
  • Classical Physics predicts the behavior of a physical system. But Quantum Mechanics predicts only the outcome of a measurement.
  • View Postulates and Prediction
• The Double Path Experiment
  • At the core of Quantum Mechanics is a mystery, which in Richard Feynman’s words, “we cannot make go away by ‘explaining’ how it works.”
  • View Double Path Experiment
• Entanglement
  • Entanglement seems to imply what Einstein called “spooky action at a distance.”
  • View Quantum Entanglement