Viewpoint: Yes, hidden variables are necessary to explain the contradictions and paradoxes inherent in quantum theory.

Viewpoint: No, experimental evidence, including the work of John Bell, Alain Aspect, and Nicolas Gisin, has continually shown that hidden variables do not exist.

Quantum physics is a daunting subject that often seems to be beyond comprehension. Nobel prize-winning quantum physicist Richard Feynman once said, "I think I can safely say that nobody understands quantum mechanics," and there would be few, if any, who would disagree with him.

Quantum theory contains many ideas that defy common sense. The popular concept of the atom is that of a tiny planetary system, with a nucleus "sun," and electron "planets" orbiting. However, quantum theory describes atoms and particles as having wavelike properties and avoids talking about specific positions and energies for particles, using...