Quantum physics is a branch of physics that studies the behavior of matter and energy at the molecular, atomic, nuclear, and even smaller microscopic levels. It aims to uncover the properties and behaviors of the very building blocks of nature, such as electrons, photons, and atoms. Quantum physics is a fundamental theory in physics that describes the behavior of nature at and below the scale of atoms. It is the foundation of all quantum physics including quantum chemistry, quantum field theory, quantum technology, and quantum information science .
The field of quantum physics arose in the late 1800s and early 1900s from a series of experimental observations of atoms that didn’t make intuitive sense in the context of classical physics. Among the basic discoveries was the realization that matter and energy can be thought of as discrete packets, or quanta, that have a minimum value associated with them. For example, light of a fixed frequency will deliver energy in quanta called “photons.” Each photon at this frequency will have the same amount of energy, and this energy can’t be broken down into smaller units. In fact, the word “quantum” has Latin roots and means “how much” .
Quantum physics is often described as “weird” or “spooky” because it defies our everyday experiences and expectations. For example, quantum mechanics describes the outcomes of experiments that showed that light and matter had the properties of particles or waves, depending on how they were measured. This is known as wave-particle duality . Another example is the concept of superposition, which states that a quantum system can exist in multiple states simultaneously until it is observed or measured. This means that a particle can be in two places at once, or that a cat in a box can be both alive and dead at the same time .
Quantum physics has many practical applications in our everyday lives. For example, quantum discoveries have been incorporated into our foundational understanding of materials, chemistry, biology, and astronomy. These discoveries are a valuable resource for innovation, giving rise to devices such as lasers and transistors, and