Quantum physics

Extracted Attributes

• Field

  Physics

• Key Concepts

  Quantized energy levels, Wave-particle duality, Uncertainty principle, Superposition, Entanglement, Tunneling

• Primary Focus

  Behavior of matter and light at atomic and subatomic scales

• Fundamental Unit

  Quanta (discrete packets of energy/matter, e.g., photons)

• Technological Impact

  Foundation of much modern technology; historically produced major technological spin-offs

• Mathematical Formalism

  Wave function (provides probabilistic information)

• Relationship to Classical Physics

  Explains phenomena classical physics cannot; classical mechanics is an approximation

Timeline

• Arose from experimental observations of atoms that classical physics could not explain. (Source: Web search results)

  Late 1800s - Early 1900s

• Max Planck proposed a solution to the black-body radiation problem, marking an early development in quantum theory. (Source: Wikipedia)

  1900

• Albert Einstein published his paper explaining the photoelectric effect, further contributing to the 'old quantum theory'. (Source: Wikipedia)

  1905

• Full development of modern quantum mechanics by Niels Bohr, Erwin Schrödinger, Werner Heisenberg, Max Born, Paul Dirac, and others. (Source: Wikipedia)

  Mid-1920s

Quantum mechanics

Quantum mechanics is the fundamental physical theory that describes the behavior of matter and of light; its unusual characteristics typically occur at and below the scale of atoms. It is the foundation of all quantum physics, which includes quantum chemistry, quantum biology, quantum field theory, quantum technology, and quantum information science. Quantum mechanics can describe many systems that classical physics cannot. Classical physics can describe many aspects of nature at an ordinary (macroscopic and (optical) microscopic) scale, but is not sufficient for describing them at very small submicroscopic (atomic and subatomic) scales. Classical mechanics can be derived from quantum mechanics as an approximation that is valid at ordinary scales. Quantum systems have bound states that are quantized to discrete values of energy, momentum, angular momentum, and other quantities, in contrast to classical systems where these quantities can be measured continuously. Measurements of quantum systems show characteristics of both particles and waves (wave–particle duality), and there are limits to how accurately the value of a physical quantity can be predicted prior to its measurement, given a complete set of initial conditions (the uncertainty principle). Quantum mechanics arose gradually from theories to explain observations that could not be reconciled with classical physics, such as Max Planck's solution in 1900 to the black-body radiation problem, and the correspondence between energy and frequency in Albert Einstein's 1905 paper, which explained the photoelectric effect. These early attempts to understand microscopic phenomena, now known as the "old quantum theory", led to the full development of quantum mechanics in the mid-1920s by Niels Bohr, Erwin Schrödinger, Werner Heisenberg, Max Born, Paul Dirac and others. The modern theory is formulated in various specially developed mathematical formalisms. In one of them, a mathematical entity called the wave function provides information, in the form of probability amplitudes, about what measurements of a particle's energy, momentum, and other physical properties may yield.

Web Search Results

• Quantum 101: What is Quantum Physics? | QED-C

  Quantum physics is a fascinating branch of science that explores the behavior of matter and energy at the smallest scales of our universe. Imagine a world where objects can exist in multiple places at once, where “entangled” particles separated across vast distances have intertwined fates, and where the very act of observing something can change its nature. This is the strange and captivating realm of quantum physics. [...] Quantum physics is the science of how the universe behaves at the smallest scales—think atoms, electrons, and photons (particles of light) and the coldest temperatures (around what is referred to as “absolute zero”, beyond which there is nothing colder). It’s a branch of science that allows us to understand and predict the behavior of particles that are so tiny, we can’t see them with the naked eye or most microscopes. Unlike the world we see around us, which is referred to as “Classical [...] Quantum physics is the foundation of much of the technology we use today, and its principles shape our understanding of the universe at the smallest scales. This article will break down quantum physics in a way that is simple, approachable, and hopefully, a little fun. ### The Basics of Quantum Physics

• Quantum Physics Explained: From Core Ideas to Real Applications

  Skip to content ## Quantum Physics Quantum Levitation > Quantum Physics Quantum physics is the foundation of our understanding of the smallest building blocks of nature. It governs how particles behave at the atomic and subatomic level and explains phenomena that classical physics simply can’t. In this article, we’ll explore the key ideas behind quantum physics and discover how they impact technologies we use every day. ## What Is Quantum Physics? [...] Also known as quantum mechanics, quantum physics is the scientific framework that describes the behavior of matter and energy at the quantum scale. At this level, particles do not follow deterministic paths but instead behave according to probabilities. From dual behavior as both particles and waves to the phenomenon of entanglement, quantum physics reveals a world full of complexity and potential. ## Core Principles of Quantum Physics ### Wave-Particle Duality [...] It’s the science of how very small particles (like atoms and electrons) behave. At that scale, particles don’t follow exact paths but behave according to probabilities. #### What are the main principles of quantum physics? Some core ideas include wave particle duality, superposition, entanglement, tunneling, and the uncertainty principle. #### What is an example of quantum physics in everyday life?

• What Is Quantum Physics?

  Caltech Science Exchange/Topics/Quantum Science and Technology/ Quantum Physics What Is Quantum Physics? ### Share this TwitterFacebookLinkedInEmailPrintShare This article was reviewed by a member of Caltech's Faculty. Quantum physics is the study of matter and energy at the most fundamental level. It aims to uncover the properties and behaviors of the very building blocks of nature. [...] 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 [...] Knowledge of quantum principles transformed our conceptualization of the atom, which consists of a nucleus surrounded by electrons. Early models depicted electrons as particles that orbited the nucleus, much like the way satellites orbit Earth. Modern quantum physics instead understands electrons as being distributed within orbitals, mathematical descriptions that represent the probability of the electrons' existence in more than one location within a given range at any given time. Electrons

• Quantum mechanics - Wikipedia

  Quantum mechanics is the fundamental physical theory that describes the behavior of matter and of light; its unusual characteristics typically occur at and below the scale of atoms.: 1.1 It is the foundation of all quantum physics, which includes quantum chemistry, quantum biology, quantum field theory, quantum technology, and quantum information science. [...] Quantum mechanics has had enormous success in explaining many of the features of our universe, with regard to small-scale and discrete quantities and interactions which cannot be explained by classical methods. Quantum mechanics is often the only theory that can reveal the individual behaviors of the subatomic particles that make up all forms of matter (electrons, protons, neutrons, photons, and others). Solid-state physics and materials science are dependent upon quantum mechanics. [...] Quantum systems have bound states that are quantized "Quantization (physics)") to discrete values of energy, momentum, angular momentum, and other quantities, in contrast to classical systems where these quantities can be measured continuously. Measurements of quantum systems show characteristics of both particles and waves (wave–particle duality), and there are limits to how accurately the value of a physical quantity can be predicted prior to its measurement, given a complete set of initial

• DOE Explains...Quantum Mechanics

  Quantum mechanics is the field of physics that explains how extremely small objects simultaneously have the characteristics of both particles (tiny pieces of matter) and waves (a disturbance or variation that transfers energy). Physicists call this the “wave-particle duality.”