"Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than those of visible light and shorter than radio waves."
Long-wavelength electromagnetic radiation emitted by warm objects. It has low penetrating ability and is commonly used for heating and imaging applications.
Electromagnetic spectrum: Understanding the various types of electromagnetic waves, their properties, and how they differ from each other.
Infrared radiation: A portion of the electromagnetic spectrum with longer wavelengths than visible light, useful for thermal imaging.
Heat transfer: The different ways that heat can be transferred from one object to another, including conduction, convection, and radiation.
Blackbody radiation: Understanding the theory behind blackbody radiation and how it relates to infrared radiation.
Absorption and emission spectra: The unique patterns of wavelengths that are either absorbed or emitted by various materials.
Planck's law: A mathematical equation that describes the electromagnetic radiation emitted by a black body.
Wien's displacement law: A mathematical relationship between the wavelength of the maximum radiation emitted by a blackbody and its temperature.
Stefan-Boltzmann law: A mathematical equation that describes the relationship between the temperature of a blackbody and the amount of radiation it emits.
Radiation measurement and detection: The different devices used to measure and detect infrared radiation, such as thermographic cameras and infrared sensors.
Applications of infrared radiation: The various ways that infrared radiation is used in industry, science, and medicine, including thermal imaging, remote sensing, and cancer detection.
Radioactivity: Understanding the types of radiation emitted by radioactive materials, their properties, and their potential health effects.
Nuclear reactions: The processes by which atomic nuclei can change, including fission and fusion.
Radioactive decay: The spontaneous breakdown of unstable atomic nuclei, resulting in the emission of radioactive particles.
Half-life: The time required for half of the nuclei in a sample of a radioactive substance to decay.
Radioactive dating: The use of the decay of radioactive isotopes to determine the age of geological and archaeological materials.
Radiation protection: The measures taken to limit exposure to ionizing radiation, including shielding and time, distance, and shielding principles.
Applications of radioactivity: The various ways that radioactivity is used in industry, medicine, and scientific research, including cancer treatment and imaging, nuclear power, and radiocarbon dating.
Near-infrared radiation: This type of infrared radiation has the shortest wavelength and is closest to the visible light spectrum. It is often used in remote controls, fiber optic communications, and thermal imaging cameras.
Mid-infrared radiation: This type of infrared radiation has a longer wavelength than near-infrared radiation, and is used in a variety of applications such as chemical analysis, environmental monitoring, and industrial quality control.
Far-infrared radiation: This type of infrared radiation has the longest wavelength and is used for heating in a variety of applications, including food processing, drying, and curing.
Alpha radiation: Alpha particles are made up of two protons and two neutrons and have a positive charge. They are emitted by certain radioactive elements and can be stopped by a piece of paper or skin.
Beta radiation: Beta particles are high-energy electrons or positrons emitted by some radioactive materials. They can penetrate deeper into matter than alpha particles but can be stopped by a few millimeters of aluminum or plastic.
Gamma radiation: Gamma rays are high-energy electromagnetic radiation emitted by radioactive materials. They can penetrate deep into materials and require thick barriers such as concrete or lead to shield against them.
Neutron radiation: Neutrons can be emitted by certain radioactive isotopes and can cause a variety of effects including ionization, nuclear activation, and damage to materials. They require special shielding and are often used in nuclear reactors and in medical imaging.
"It is therefore invisible to the human eye."
"IR is generally understood to encompass wavelengths from around 1 millimeter (300 GHz) to the nominal red edge of the visible spectrum, around 700 nanometers (430 THz)."
"IR is commonly divided between longer-wavelength thermal infrared that is emitted from terrestrial sources and shorter-wavelength near-infrared that is part of the solar spectrum."
"Almost all black-body radiation from objects near room temperature is at infrared wavelengths."
"In 1800 the astronomer Sir William Herschel discovered that infrared radiation is a type of invisible radiation in the spectrum lower in energy than red light, by means of its effect on a thermometer."
"Slightly more than half of the energy from the Sun was eventually found, through Herschel's studies, to arrive on Earth in the form of infrared."
"Infrared radiation is emitted or absorbed by molecules when changing rotational-vibrational movements. It excites vibrational modes in a molecule through a change in the dipole moment, making it a useful frequency range for the study of these energy states for molecules of the proper symmetry."
"Infrared spectroscopy examines absorption and transmission of photons in the infrared range."
"Infrared radiation is used in industrial, scientific, military, commercial, and medical applications."
"Night-vision devices using active near-infrared illumination allow people or animals to be observed without the observer being detected."
"Infrared astronomy uses sensor-equipped telescopes to penetrate dusty regions of space such as molecular clouds, to detect objects such as planets, and to view highly red-shifted objects from the early days of the universe."
"Infrared thermal-imaging cameras are used to detect heat loss in insulated systems, to observe changing blood flow in the skin, to assist firefighting, and to detect the overheating of electrical components."
"Military and civilian applications include target acquisition, surveillance, night vision, homing, and tracking."
"Humans at normal body temperature radiate chiefly at wavelengths around 10 μm (micrometers)."
"Non-military uses include thermal efficiency analysis, environmental monitoring, industrial facility inspections, detection of grow-ops, remote temperature sensing, short-range wireless communication, spectroscopy, and weather forecasting."
"Detection of grow-ops, remote temperature sensing..."
"Short-range wireless communication..."
"It is electromagnetic radiation (EMR) with wavelengths longer than those of visible light and shorter than radio waves."
"The balance between absorbed and emitted infrared radiation has an important effect on Earth's climate."