Introduction to Quantum Mechanics
With classical physics, we are certain that we can determine the future by analyzing the data from the past and the present. However, the discovery of quantum mechanics shown that even with all necessary information, the future remains probabilistic rather than deterministic.
Revolutionary Events of Early 1900s
In the early 1900s, four important events revolutionized science and the way we think about the world around us:
- Planck's solution to the blackbody radiation (1900)
- Einstein's explanation of the photoelectric effect (1905)
- The Bohr model of the atom (1913)
- The de Broglie wavelength of material particles (1924)
Wave-Particle Duality
One of the most fascinating aspects of quantum mechanics is wave-particle duality. This principle states that all matter and energy exhibits both wave-like and particle-like properties.
The de Broglie wavelength equation demonstrates this relationship:
where:
- λ (lambda) is the wavelength
- h is Planck's constant
- p is the momentum of the particle
Heisenberg Uncertainty Principle
The uncertainty principle, formulated by Werner Heisenberg in 1927, states that we cannot simultaneously know both the position and momentum of a particle with absolute precision.
The mathematical expression:
where:
- Δx is the uncertainty in position
- Δp is the uncertainty in momentum
- ℏ is the reduced Planck constant (h/2π)
Schrödinger's Wave Equation
In 1926, Erwin Schrödinger proposed an equation that describes how the quantum state of a physical system changes over time. This equation is central to quantum mechanics and provides a way to calculate the wave function of a system.