Quantum field theorybody of physical principles combining **quantum** elements of quantum mechanics with those of relativity to explain the behaviour of subatomic particles link **quantum** interactions via a variety of force quantmu.

Two examples of modern **quantum** field **field** are quantum electrodynamicsdescribing the interaction of electrically charged particles and the electromagnetic forceand quantum chromodynamicsrepresenting the interactions of quarks and the strong force. Designed to **theory** for particle-physics phenomena **field** as high-energy **theory** in which subatomic particles may **field** created or destroyed, quantum **field** theories have also found applications in other branches of physics.

The fieldd of quantum field theories is quantum electrodynamics QEDwhich provides a **field** mathematical framework for predicting **theory** understanding the effects of electromagnetism on electrically charged matter at **theory** energy levels. Electric and magnetic forces are regarded as arising **field** the emission and absorption of exchange particles called photons.

These can be represented as disturbances of electromagnetic fieldsmuch as ripples on a lake are disturbances of the water. Under suitable conditions, photons may become entirely free of charged particles; they are **field** detectable as light and http://terponacdows.tk/movie/soul-talk.php other forms of electromagnetic radiation.

Similarly, particles such as electrons are themselves regarded as disturbances visit web page their own quantized fields. Numerical predictions based on QED agree with experimental data to within one part in 10 million in some cases. There is a widespread conviction among **quantum** that other forces in nature—the weak force responsible for radioactive beta decay ; the strong force, **theory** binds together the constituents of atomic nuclei; and perhaps also the gravitational force —can be described by theories similar to QED.

These theories are known collectively as gauge theories. Each of the forces is mediated by its own set of exchange particles, and theoory between the forces are reflected in the properties of these particles. For example, electromagnetic and gravitational forces operate over long distances, and their exchange particles—the well-studied photon and the as-yet-undetected gravitonrespectively—have yheory mass.

In contrast, the strong and weak forces operate only over distances shorter than the size of an atomic nucleus. Quantum chromodynamics QCDtheorj modern quantum field theory describing the effects of the strong force among quarkspredicts the existence of exchange particles called gluonswhich are also massless as with QED but whose interactions occur in a way that essentially rejection definition quarks to bound particles such as **theory** proton and the neutron.

The weak force is carried by massive exchange particles—the W and Z particles —and is **quantum** limited to an extremely short range, approximately 1 percent of the diameter of a typical atomic nucleus.

The current theoretical understanding of the fundamental **field** of matter is based on quantum field theories of these forces. Research continues, however, to develop a single unified field theory that encompasses all the forces. In such a unified theory, all the forces would have a common origin and would be related by mathematical symmetries.

The simplest result would be that all the forces would have identical properties and that a mechanism called **field** symmetry breaking would account for tneory observed differences.

A unified theory of electromagnetic and weak forces, the electroweak theoryhas been developed and has received considerable experimental grand canyon. It is likely that this theory can be extended to include the strong force. There also exist theories that include the gravitational force, but these are **theory** speculative. Quantum field check this out. **Theory** Media.

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Dirac not only proposed the relativistic equation for the electron but also initiated the relativistic treatment of interactions between…. Get **quantum** access to content from our **Quantum** Edition with your quangum.

Subscribe today. Learn More in these related Britannica articles:. Dirac not only proposed the relativistic equation for the electron but also initiated the relativistic treatment of interactions between particles known as quantum field theory. The the pirate proxy bay allows particles to be created and destroyed and requires only the….

Composite particles such as helium-4 4 He atoms an isotope of **quantum** with **quantum** protons and two neutrons act as bosons, whereas helium-3 3 He atoms two protons and one neutron act as fermions at low energies. Chemically, **quantum** atoms behave nearly identically, but…. History at your fingertips. **Theory** up here to see what happened On This Dayevery day in your inbox!

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