elektromagnetlaine

Elektromagnetlaine is a type of wave composed of oscillating electric and magnetic fields that propagates through space and various media. It carries energy and momentum and does not require a material medium for basic propagation.

In a vacuum, elektromagnetlaine travels at the speed of light, about 299,792 kilometers per second. The electric (E) and magnetic (B) components oscillate perpendicular to the direction of propagation and to each other. For a plane wave in free space, the fields are closely related in strength, and the energy flux is described by the Poynting vector, S = E × B / μ0.

The electromagnetic spectrum spans a wide range of wavelengths and frequencies, from radio waves to gamma rays. The relation between wavelength and frequency in vacuum is λ = c/f; in media, light slows to v = c/n and may exhibit dispersion. Electromagnetlaine can interact with matter through reflection, refraction, absorption, scattering, and polarization, and can be partially absorbed or transmitted depending on material properties.

Generation and detection rely on accelerating charges and sensitive sensors. Antennas are used for radio and microwave frequencies, while photodetectors and cameras address visible and near-infrared light. Polarization and interference phenomena are common in many applications. Interactions with matter enable numerous technologies, including wireless communications (radio, television, cellular networks, Wi‑Fi), imaging and sensing (cameras, infrared instruments, lasers), medical diagnostics and therapy (X-ray imaging, MRI utilizes radiofrequency fields), and spectral analysis.

Historically, Maxwell's equations showed that electricity, magnetism, and optics are manifestations of a single electromagnetic phenomenon, predicting light as elektromagnetlaine. The existence and properties of these waves were confirmed experimentally by Hertz in the late 19th century. The wave also exhibits particle-like behavior: photons with energy E = hf, contributing to the wave-particle duality central to modern physics.