Classical field theory is a research area in theoretical physics that studies continuous fields, such as electromagnetic, gravitational, and scalar fields, within a pre-quantum, typically relativistic or Galilean-invariant framework. It formulates dynamics via Lagrangian and Hamiltonian densities, leading to Euler–Lagrange field equations and conservation laws derived from spacetime and internal symmetries through Noether’s theorem. The discipline underpins general relativity and classical electrodynamics, and provides the mathematical and conceptual foundation for quantum field theory, emphasizing variational principles, gauge invariance, and the structure of classical solutions including waves, solitons, and topological defects.
Poly(N-isopropylacrylamide) (PNIPAM) hydrogel undergoes significant but precise changes in size between 20°C and 40°C, making it an excellent candidate for use in variable-size deterministic lateral displacement (DLD) array ...
Cell & Microbiology
Dec 3, 2025
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When ultraviolet light hits ice—whether in Earth's polar regions or on distant planets—it triggers a cascade of chemical reactions that have puzzled scientists for decades.
General Physics
Nov 20, 2025
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Neutrinos are fundamental particles characterized by no electric charge and very small masses, which are known to interact with other matter via the weak force or gravity. While these particles have been the focus of numerous ...
Classical physics theories suggest that when two or more electromagnetic waves interfere destructively (i.e., with their electric fields canceling each other out), they cannot interact with matter. In contrast, quantum mechanics ...
A team of physicists and engineers at the University of Colorado Boulder has discovered a new way to measure the orientation of magnetic fields using what may be the tiniest compasses around—atoms.
Optics & Photonics
Jan 30, 2025
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Researchers at Tohoku University and the University of California, Santa Barbara, have developed new computing hardware that utilizes a Gaussian probabilistic bit made from a stochastic spintronics device. This innovation ...
Condensed Matter
Dec 11, 2024
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Deep in outer space, invisible hands mold the universe. One is dark matter, an unseen substance thought to bind distant galaxies. The other is dark energy, a force believed to push stellar structures apart with gravity-defying ...
Quantum Physics
May 15, 2024
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Gravity is one of four fundamental interactions. The most precise description of this force is still provided by Einstein's General Theory of Relativity, published in 1915, an entirely classical theory. This description sets ...
General Physics
May 7, 2024
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Glycerol, a major by-product of biomass refining accounting for approximately 10% of the yield, presents a significant challenge due to its global surplus. The presence of multiple active hydroxyl groups in glycerol unveils ...
Nanomaterials
Mar 25, 2024
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In a surprising new study, researchers at the University of Minnesota Twin Cities have found that the electron beam radiation that they previously thought degraded crystals can actually repair cracks in these nanostructures.
Nanophysics
Oct 12, 2023
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