Quote: "In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy."
The energy that travels through space in the form of waves, including visible light, radio waves, and X-rays.
Electromagnetic Radiation: The study of the behavior and properties of electromagnetic waves, including the nature of the wave, its generation, and its effects.
Electromagnetic Spectrum: The range of frequencies of electromagnetic radiation, including radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays.
Electromagnetism: The branch of physics that studies the interaction between electrically charged particles and electromagnetic fields.
Maxwell’s Equations: The set of four equations that describe the behavior of electromagnetic waves, including the laws of electric and magnetic fields and their relationship to each other.
Wave Propagation: The movement of waves through a medium, including the physical properties of that medium and the behavior of the wave itself.
Dispersion: The separation of electromagnetic waves into their individual components based on their frequency or wavelength.
Polarization: The orientation of the electric field of an electromagnetic wave, which can be either linear or circular.
Radiometry: The measurement of electromagnetic radiation, including its intensity, direction, and polarization.
Spectrometry: The study of the interaction of electromagnetic radiation with matter, with an emphasis on identifying and measuring the individual components of a complex mixture.
Atmospheric Physics: The study of the behavior of electromagnetic radiation in the Earth’s atmosphere, including its absorption, scattering, and reflection.
Solar Physics: The study of the behavior of electromagnetic radiation emitted by the Sun, including the mechanisms by which it is generated and how it affects Earth.
Plasma Physics: The study of the behavior of ionized gases, including the behavior of electromagnetic radiation in plasma and the interactions between plasma and electromagnetic fields.
Magnetospheric Physics: The study of the behavior of electromagnetic radiation in Earth’s magnetic field, including its interaction with the charged particles in the aurora.
Astrophysics: The study of the behavior of electromagnetic radiation in the universe, including its generation, propagation, and effects on the structure of galaxies and other astronomical objects.
Radiation Protection: The study of the methods and technologies used to protect humans and other organisms from the harmful effects of electromagnetic radiation.
Radio waves: Longest wavelength in the electromagnetic spectrum, have low frequency and are used for communication, as in mobile phones, radios, and television.
Microwaves: Shorter wavelength than radio waves, have higher frequency and are used in microwave ovens, radar, and satellite communication.
Infrared radiation: Also known as heat radiation, has a longer wavelength than visible light and is produced by objects with temperatures above absolute zero.
Visible light: The portion of the electromagnetic spectrum that can be seen by the human eye, consists of seven colors: Red, orange, yellow, green, blue, indigo and violet.
Ultraviolet radiation: Has shorter wavelengths than visible light, is produced by the sun, and can cause skin cancer, eye damage, and other harmful effects.
X-rays: Have shorter wavelengths than ultraviolet radiation, can penetrate soft tissues and are used for medical diagnosis and treatment.
Gamma rays: Shortest wavelength in the electromagnetic spectrum, have the highest frequency and energy, and are produced by nuclear reactions, supernovae, and other astrophysical sources.
Quote: "Types of EMR include radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays."
Quote: "In a vacuum, electromagnetic waves travel at the speed of light, commonly denoted c."
Quote: "In homogeneous, isotropic media, the oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a transverse wave."
Quote: "The position of an electromagnetic wave within the electromagnetic spectrum can be characterized by either its frequency of oscillation or its wavelength."
Quote: "In order of increasing frequency and decreasing wavelength these are: radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays."
Quote: "Electromagnetic waves are emitted by electrically charged particles undergoing acceleration."
Quote: "EM waves carry energy, momentum and angular momentum away from their source particle and can impart those quantities to matter with which they interact."
Quote: "EMR is sometimes referred to as the far field, as it is associated with those EM waves that are free to propagate themselves ('radiate') without the continuing influence of the moving charges that produced them."
Quote: "In this language, the near field refers to EM fields near the charges and current that directly produced them, specifically electromagnetic induction and electrostatic induction phenomena."
Quote: "In quantum mechanics, an alternate way of viewing EMR is that it consists of photons, uncharged elementary particles with zero rest mass which are the quanta of the electromagnetic field, responsible for all electromagnetic interactions."
Quote: "Quantum electrodynamics is the theory of how EMR interacts with matter on an atomic level."
Quote: "Quantum effects provide additional sources of EMR, such as the transition of electrons to lower energy levels in an atom and black-body radiation."
Quote: "The energy of an individual photon is quantized and is greater for photons of higher frequency. This relationship is given by Planck's equation E = hf."
Quote: "A single gamma ray photon, for example, might carry ~100,000 times the energy of a single photon of visible light."
Quote: "The effects of EMR upon chemical compounds and biological organisms depend both upon the radiation's power and its frequency."
Quote: "EMR of visible or lower frequencies (i.e., visible light, infrared, microwaves, and radio waves) is called non-ionizing radiation."
Quote: "The effects of these radiations on chemical systems and living tissue are caused primarily by heating effects from the combined energy transfer of many photons."
Quote: "High frequency ultraviolet, X-rays, and gamma rays are called ionizing radiation since individual photons of such high frequency have enough energy to ionize molecules or break chemical bonds."
Quote: "These radiations have the ability to cause chemical reactions and damage living cells beyond that resulting from simple heating, and can be a health hazard."