Quantum physics is the branch of physics that deals with the behavior of matter and energy at the smallest scales, often at the level of atoms and subatomic particles.
This field diverges significantly from classical physics, where the laws governing larger scale objects don't apply.
Matter and light exhibit both wave-like and particle-like properties.
Example: Light can behave as both a wave (interference and diffraction) and as particles called photons.
Particles exist in multiple states simultaneously until measured.
This principle leads to phenomena like quantum entanglement and the famous thought experiment, Schrödinger's cat.
Two or more particles can become entangled, meaning the state of one particle instantaneously affects the state of another, regardless of distance.
This challenges classical notions of locality and causality.
Formulated by Werner Heisenberg, it states that certain pairs of physical properties, like position and momentum, cannot be simultaneously measured with arbitrary precision.
The more accurately one property is measured, the less accurately the other can be controlled.
Quantum states are described by wave functions, which provide the probabilities of finding a particle in a given state.
The wave function evolves according to the Schrödinger equation.
Quantum physics underpins many modern technologies:
Transistors in computers.
Lasers in telecommunications.
MRI in medical imaging.
Utilizes superposition and entanglement to perform computations at speeds unattainable by classical computers.
Quantum bits or qubits can exist in multiple states simultaneously, allowing for complex calculations.
Challenges our understanding of reality and determinism.
Raises philosophical questions about the nature of existence and observation.
Quantum physics has led to advancements in theoretical physics, leading to greater insights into the universe.