195 relations: Acute radiation syndrome, Allotropes of oxygen, Alternating current, Ancient Greece, Antenna (radio), Astronomy, Astrophysics, Atmosphere of Earth, Atom, Atomic nucleus, Bandplan, Beacon, Black body, Black hole, Cancer, Cavity magnetron, Cell (biology), Centimetre, Chemical bond, Chemical polarity, Chemical reaction, Communications satellite, Compton scattering, Corona, Cosmic microwave background, Cosmic ray, Decimetre, Demodulation, Diathermy, Digital dividend after digital television transition, DNA, DNA repair, Doppler effect, Edward Andrade, Electric current, Electric field, Electroencephalography, Electromagnetic field, Electromagnetic radiation, Electron, Electronvolt, Emission spectrum, Energy, Ernest Rutherford, Exotic atom, Extreme ultraviolet, Extremely high frequency, Extremely low frequency, Far infrared, Faraday effect, ..., Femto-, Fluorescence, Frame of reference, Frequency, Frequency allocation, Gamma ray, Gamma-ray burst, Global Positioning System, Gunn diode, Heinrich Hertz, Hertz, High frequency, Human skin, Hydrogen, Image sensor, IMPATT diode, Infrared, Infrared photography, Infrared window, Innovation, Science and Economic Development Canada, International Telecommunication Union, Ionization, Ionizing radiation, Ionosphere, Irradiation, James Clerk Maxwell, Johann Wilhelm Ritter, Kilo-, Kilometre, Klystron, Lambda, Light, List of international common standards, Low frequency, Luminosity function, Lyman series, Magnetic field, Matter, Maxwell's equations, Medium frequency, Mega-, Metre, Michael Faraday, Micro-, Micrometre, Microwave, Microwave oven, Milli-, Millimetre, Mobile phone, Modulation, Mutagen, Nano-, Nanometre, National Radio Astronomy Observatory, Near and far field, Nebula, Neutron star, Nuclear medicine, Ofcom, Optical fiber, Optical window, Orders of magnitude (length), Oxygen, Ozone layer, Paul Ulrich Villard, Phonon, Photoelectric effect, Photon, Photon energy, Photosynthesis, Pico-, Picometre, Pitch (resin), Planck constant, Planck length, Plasma oscillation, Positron emission tomography, Pyrimidine dimer, Quantum, Radar, Radiant energy, Radiation, Radiation therapy, Radio, Radio broadcasting, Radio receiver, Radio spectrum, Radio wave, Radio window, Radioactive decay, Radiography, Radiolocation, Radionuclide, Radium, Rainbow, Redshift, Reflection (physics), Refraction, Remote control, Resonator, Signal, Skin cancer, Solid-state electronics, Spectroscopy, Spectrum, Speed of light, Submillimetre astronomy, Sun, Sunburn, Super high frequency, Super low frequency, Television, Terahertz radiation, Thorium, Transmission line, Transmission medium, Transmitter, Two-way radio, Ultra high frequency, Ultra low frequency, Ultraviolet, United States Department of Commerce, United States Department of Defense, Universe, University of California, Davis, V band, Very high frequency, Very low frequency, Virtual particle, Visible spectrum, Visual perception, Visual system, Voice frequency, W band, Waveguide, Wavelength, Wi-Fi, Wilhelm Röntgen, William Henry Bragg, William Herschel, Wireless network, Wireless telegraphy, X-ray, X-ray telescope. Expand index (145 more) » « Shrink index
Acute radiation syndrome (ARS) is a collection of health effects that are present within 24 hours of exposure to high doses of ionizing radiation.
There are several known allotropes of oxygen.
Alternating current (AC) is an electric current which periodically reverses direction, in contrast to direct current (DC) which flows only in one direction.
Ancient Greece was a civilization belonging to a period of Greek history from the Greek Dark Ages of the 13th–9th centuries BC to the end of antiquity (AD 600).
In radio, an antenna is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver.
Astronomy (from ἀστρονομία) is a natural science that studies celestial objects and phenomena.
Astrophysics is the branch of astronomy that employs the principles of physics and chemistry "to ascertain the nature of the astronomical objects, rather than their positions or motions in space".
The atmosphere of Earth is the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earth's gravity.
An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element.
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment.
A bandplan or band plan is a plan for using a particular band of radio frequencies, that are a portion of the electromagnetic spectrum.
A beacon is an intentionally conspicuous device designed to attract attention to a specific location.
A black body is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence.
A black hole is a region of spacetime exhibiting such strong gravitational effects that nothing—not even particles and electromagnetic radiation such as light—can escape from inside it.
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body.
The cavity magnetron is a high-powered vacuum tube that generates microwaves using the interaction of a stream of electrons with a magnetic field while moving past a series of open metal cavities (cavity resonators).
The cell (from Latin cella, meaning "small room") is the basic structural, functional, and biological unit of all known living organisms.
A centimetre (international spelling as used by the International Bureau of Weights and Measures; symbol cm) or centimeter (American spelling) is a unit of length in the metric system, equal to one hundredth of a metre, centi being the SI prefix for a factor of.
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds.
In chemistry, polarity is a separation of electric charge leading to a molecule or its chemical groups having an electric dipole or multipole moment.
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.
A communications satellite is an artificial satellite that relays and amplifies radio telecommunications signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth.
Compton scattering, discovered by Arthur Holly Compton, is the scattering of a photon by a charged particle, usually an electron.
A corona (Latin, 'crown') is an aura of plasma that surrounds the Sun and other stars.
The cosmic microwave background (CMB, CMBR) is electromagnetic radiation as a remnant from an early stage of the universe in Big Bang cosmology.
Cosmic rays are high-energy radiation, mainly originating outside the Solar System and even from distant galaxies.
The decimetre (SI symbol dm) is a unit of length in the metric system, equal to one tenth of a metre (the International System of Units base unit of length), ten centimetres or 1/0.254 (approximately 3.93700787) inches.
Demodulation is extracting the original information-bearing signal from a carrier wave.
Diathermy is electrically induced heat or the use of high-frequency electromagnetic currents as a form of physical or occupational therapy and in surgical procedures.
The digital dividend refers to the radio spectrum which is released in the process of digital television transition.
Deoxyribonucleic acid (DNA) is a thread-like chain of nucleotides carrying the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses.
DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome.
The Doppler effect (or the Doppler shift) is the change in frequency or wavelength of a wave in relation to observer who is moving relative to the wave source.
Edward Neville da Costa Andrade FRS (27 December 1887 – 6 June 1971) was an English physicist, writer, and poet.
An electric current is a flow of electric charge.
An electric field is a vector field surrounding an electric charge that exerts force on other charges, attracting or repelling them.
Electroencephalography (EEG) is an electrophysiological monitoring method to record electrical activity of the brain.
An electromagnetic field (also EMF or EM field) is a physical field produced by electrically charged objects.
In physics, electromagnetic radiation (EM radiation or EMR) refers to the waves (or their quanta, photons) of the electromagnetic field, propagating (radiating) through space-time, carrying electromagnetic radiant energy.
The electron is a subatomic particle, symbol or, whose electric charge is negative one elementary charge.
In physics, the electronvolt (symbol eV, also written electron-volt and electron volt) is a unit of energy equal to approximately joules (symbol J).
The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an atom or molecule making a transition from a high energy state to a lower energy state.
In physics, energy is the quantitative property that must be transferred to an object in order to perform work on, or to heat, the object.
Ernest Rutherford, 1st Baron Rutherford of Nelson, HFRSE LLD (30 August 1871 – 19 October 1937) was a New Zealand-born British physicist who came to be known as the father of nuclear physics.
An exotic atom is an otherwise normal atom in which one or more sub-atomic particles have been replaced by other particles of the same charge.
Extreme ultraviolet radiation (EUV or XUV) or high-energy ultraviolet radiation is electromagnetic radiation in the part of the electromagnetic spectrum spanning wavelengths from 124 nm down to 10 nm, and therefore (by the Planck–Einstein equation) having photons with energies from 10 eV up to 124 eV (corresponding to 124 nm to 10 nm respectively).
Extremely high frequency (EHF) is the International Telecommunication Union (ITU) designation for the band of radio frequencies in the electromagnetic spectrum from 30 to 300 gigahertz (GHz).
Extremely low frequency (ELF) is the ITU designation for electromagnetic radiation (radio waves) with frequencies from 3 to 30 Hz, and corresponding wavelengths of 100,000 to 10,000 kilometers, respectively.
Far infrared (FIR) is a region in the infrared spectrum of electromagnetic radiation.
In physics, the Faraday effect or Faraday rotation is a magneto-optical phenomenon—that is, an interaction between light and a magnetic field in a medium.
Femto- (symbol f) is a unit prefix in the metric system denoting a factor of 10−15 or.
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation.
In physics, a frame of reference (or reference frame) consists of an abstract coordinate system and the set of physical reference points that uniquely fix (locate and orient) the coordinate system and standardize measurements.
Frequency is the number of occurrences of a repeating event per unit of time.
Frequency allocation (or spectrum allocation or spectrum management) is the allocation and regulation of the electromagnetic spectrum into radio frequency bands, which is normally done by governments in most countries.
A gamma ray or gamma radiation (symbol γ or \gamma), is penetrating electromagnetic radiation arising from the radioactive decay of atomic nuclei.
In gamma-ray astronomy, gamma-ray bursts (GRBs) are extremely energetic explosions that have been observed in distant galaxies.
The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Air Force.
A Gunn diode, also known as a transferred electron device (TED), is a form of diode, a two-terminal passive semiconductor electronic component, with negative resistance, used in high-frequency electronics.
Heinrich Rudolf Hertz (22 February 1857 – 1 January 1894) was a German physicist who first conclusively proved the existence of the electromagnetic waves theorized by James Clerk Maxwell's electromagnetic theory of light.
The hertz (symbol: Hz) is the derived unit of frequency in the International System of Units (SI) and is defined as one cycle per second.
High frequency (HF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) between 3 and 30 megahertz (MHz).
The human skin is the outer covering of the body.
Hydrogen is a chemical element with symbol H and atomic number 1.
An image sensor or imaging sensor is a sensor that detects and conveys the information that constitutes an image.
An IMPATT diode (IMPact ionization Avalanche Transit-Time diode) is a form of high-power semiconductor diode used in high-frequency microwave electronics devices.
Infrared radiation (IR) is electromagnetic radiation (EMR) with longer wavelengths than those of visible light, and is therefore generally invisible to the human eye (although IR at wavelengths up to 1050 nm from specially pulsed lasers can be seen by humans under certain conditions). It is sometimes called infrared light.
Top: tree photographed in the near infrared range.
The infrared atmospheric window is the overall dynamic property of the earth's atmosphere, taken as a whole at each place and occasion of interest, that lets some infrared radiation from the cloud tops and land-sea surface pass directly to space without intermediate absorption and re-emission, and thus without heating the atmosphere.
Innovation, Science and Economic Development Canada (Innovation, Sciences et Développement économique Canada), or ISED, formerly Industry Canada, is the department of the Government of Canada with a mandate of fostering a growing, competitive, and knowledge-based Canadian economy.
The International Telecommunication Union (ITU; Union Internationale des Télécommunications (UIT)), originally the International Telegraph Union (Union Télégraphique Internationale), is a specialized agency of the United Nations (UN) that is responsible for issues that concern information and communication technologies.
Ionization or ionisation, is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons to form ions, often in conjunction with other chemical changes.
Ionizing radiation (ionising radiation) is radiation that carries enough energy to liberate electrons from atoms or molecules, thereby ionizing them.
The ionosphere is the ionized part of Earth's upper atmosphere, from about to altitude, a region that includes the thermosphere and parts of the mesosphere and exosphere.
Irradiation is the process by which an object is exposed to radiation.
James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish scientist in the field of mathematical physics.
Johann Wilhelm Ritter (16 December 1776 – 23 January 1810) was a German chemist, physicist and philosopher.
Kilo is a decimal unit prefix in the metric system denoting multiplication by one thousand (103).
The kilometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: km; or) or kilometer (American spelling) is a unit of length in the metric system, equal to one thousand metres (kilo- being the SI prefix for). It is now the measurement unit used officially for expressing distances between geographical places on land in most of the world; notable exceptions are the United States and the road network of the United Kingdom where the statute mile is the official unit used.
A klystron is a specialized linear-beam vacuum tube, invented in 1937 by American electrical engineers Russell and Sigurd Varian,Pond, Norman H. "The Tube Guys".
Lambda, Λ, λ (uppercase Λ, lowercase λ; λάμ(β)δα lám(b)da) is the 11th letter of the Greek alphabet.
Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum.
A list of common and basic information standards, that are related by their frequent and widespread use, and which are conventionally used internationally by industry and organizations.
Low frequency (low freq) or LF is the ITU designation for radio frequencies (RF) in the range of 30 kilohertz (kHz)–300 kHz.
A luminosity function or luminous efficiency function describes the average spectral sensitivity of human visual perception of brightness.
In physics and chemistry, the Lyman series is a hydrogen spectral series of transitions and resulting ultraviolet emission lines of the hydrogen atom as an electron goes from n ≥ 2 to n.
A magnetic field is a vector field that describes the magnetic influence of electrical currents and magnetized materials.
In the classical physics observed in everyday life, matter is any substance that has mass and takes up space by having volume.
Maxwell's equations are a set of partial differential equations that, together with the Lorentz force law, form the foundation of classical electromagnetism, classical optics, and electric circuits.
Medium frequency (MF) is the ITU designation for radio frequencies (RF) in the range of 300 kilohertz (kHz) to 3 megahertz (MHz).
Mega is a unit prefix in metric systems of units denoting a factor of one million (106 or 000).
The metre (British spelling and BIPM spelling) or meter (American spelling) (from the French unit mètre, from the Greek noun μέτρον, "measure") is the base unit of length in some metric systems, including the International System of Units (SI).
Michael Faraday FRS (22 September 1791 – 25 August 1867) was an English scientist who contributed to the study of electromagnetism and electrochemistry.
Micro- (symbol µ) is a unit prefix in the metric system denoting a factor of 10−6 (one millionth).
The micrometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is an SI derived unit of length equaling (SI standard prefix "micro-".
Microwaves are a form of electromagnetic radiation with wavelengths ranging from one meter to one millimeter; with frequencies between and.
A microwave oven (also commonly referred to as a microwave) is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range.
Milli- (symbol m) is a unit prefix in the metric system denoting a factor of one thousandth (10−3).
The millimetre (International spelling as used by the International Bureau of Weights and Measures; SI unit symbol mm) or millimeter (American spelling) is a unit of length in the metric system, equal to one thousandth of a metre, which is the SI base unit of length.
A mobile phone, known as a cell phone in North America, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area.
In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted.
In genetics, a mutagen is a physical or chemical agent that changes the genetic material, usually DNA, of an organism and thus increases the frequency of mutations above the natural background level.
Nano- (symbol n) is a unit prefix meaning "one billionth".
The nanometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American spelling) is a unit of length in the metric system, equal to one billionth (short scale) of a metre (m).
The National Radio Astronomy Observatory (NRAO) is a Federally Funded Research and Development Center of the United States National Science Foundation operated under cooperative agreement by Associated Universities, Inc for the purpose of radio astronomy.
The near field and far field are regions of the electromagnetic field (EM) around an object, such as a transmitting antenna, or the result of radiation scattering off an object.
A nebula (Latin for "cloud" or "fog"; pl. nebulae, nebulæ, or nebulas) is an interstellar cloud of dust, hydrogen, helium and other ionized gases.
A neutron star is the collapsed core of a large star which before collapse had a total of between 10 and 29 solar masses.
Nuclear medicine is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease.
The Office of Communications (Y Swyddfa Gyfathrebiadau), commonly known as Ofcom, is the UK government-approved regulatory and competition authority for the broadcasting, telecommunications and postal industries of the United Kingdom.
An optical fiber or optical fibre is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair.
The meaning of this term depends on the context.
The following are examples of orders of magnitude for different lengths.
Oxygen is a chemical element with symbol O and atomic number 8.
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation.
Paul Ulrich Villard (28 September 1860 – 13 January 1934) was a French chemist and physicist.
In physics, a phonon is a collective excitation in a periodic, elastic arrangement of atoms or molecules in condensed matter, like solids and some liquids.
The photoelectric effect is the emission of electrons or other free carriers when light shines on a material.
The photon is a type of elementary particle, the quantum of the electromagnetic field including electromagnetic radiation such as light, and the force carrier for the electromagnetic force (even when static via virtual particles).
Photon energy is the energy carried by a single photon.
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms' activities (energy transformation).
Pico- (symbol p) is a unit prefix in the metric system denoting one trillionth, a factor of 10−12.
The picometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: pm) or picometer (American spelling) is a unit of length in the metric system, equal to, or one trillionth of a metre, which is the SI base unit of length.
Pitch is a name for any of a number of viscoelastic polymers.
The Planck constant (denoted, also called Planck's constant) is a physical constant that is the quantum of action, central in quantum mechanics.
In physics, the Planck length, denoted, is a unit of length, equal to metres.
Plasma oscillations, also known as Langmuir waves (after Irving Langmuir), are rapid oscillations of the electron density in conducting media such as plasmas or metals in the ultraviolet region.
Positron-emission tomography (PET) is a nuclear medicine functional imaging technique that is used to observe metabolic processes in the body as an aid to the diagnosis of disease.
Pyrimidine dimers are molecular lesions formed from thymine or cytosine bases in DNA via photochemical reactions.
In physics, a quantum (plural: quanta) is the minimum amount of any physical entity (physical property) involved in an interaction.
Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects.
In physics, and in particular as measured by radiometry, radiant energy is the energy of electromagnetic and gravitational radiation.
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium.
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is therapy using ionizing radiation, generally as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator.
Radio is the technology of using radio waves to carry information, such as sound, by systematically modulating properties of electromagnetic energy waves transmitted through space, such as their amplitude, frequency, phase, or pulse width.
Radio broadcasting is transmission by radio waves intended to reach a wide audience.
In radio communications, a radio receiver (receiver or simply radio) is an electronic device that receives radio waves and converts the information carried by them to a usable form.
The radio spectrum is the part of the electromagnetic spectrum with frequencies from 3 Hz to 3 000 GHz (3 THz).
Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light.
The radio window is the range of frequencies of electromagnetic radiation that the earth's atmosphere lets through.
Radioactive decay (also known as nuclear decay or radioactivity) is the process by which an unstable atomic nucleus loses energy (in terms of mass in its rest frame) by emitting radiation, such as an alpha particle, beta particle with neutrino or only a neutrino in the case of electron capture, gamma ray, or electron in the case of internal conversion.
Radiography is an imaging technique using X-rays to view the internal form of an object.
Radiolocating is the process of finding the location of something through the use of radio waves.
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is an atom that has excess nuclear energy, making it unstable.
Radium is a chemical element with symbol Ra and atomic number 88.
A rainbow is a meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky.
In physics, redshift happens when light or other electromagnetic radiation from an object is increased in wavelength, or shifted to the red end of the spectrum.
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated.
Refraction is the change in direction of wave propagation due to a change in its transmission medium.
In electronics, a remote control or clicker is a component of an electronic device used to operate the device from a distance, usually wirelessly.
A resonator is a device or system that exhibits resonance or resonant behavior, that is, it naturally oscillates at some frequencies, called its resonant frequencies, with greater amplitude than at others.
A signal as referred to in communication systems, signal processing, and electrical engineering is a function that "conveys information about the behavior or attributes of some phenomenon".
Skin cancers are cancers that arise from the skin.
Solid-state electronics means semiconductor electronics; electronic equipment using semiconductor devices such as semiconductor diodes, transistors, and integrated circuits (ICs).
Spectroscopy is the study of the interaction between matter and electromagnetic radiation.
A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary, without steps, across a continuum.
The speed of light in vacuum, commonly denoted, is a universal physical constant important in many areas of physics.
Submillimetre astronomy or submillimeter astronomy (see spelling differences) is the branch of observational astronomy that is conducted at submillimetre wavelengths (i.e., terahertz radiation) of the electromagnetic spectrum.
The Sun is the star at the center of the Solar System.
Sunburn is a form of radiation burn that affects living tissue, such as skin, that results from an overexposure to ultraviolet (UV) radiation, commonly from the sun.
Super high frequency (SHF) is the ITU designation for radio frequencies (RF) in the range between 3 and 30 gigahertz (GHz).
Super low frequency (SLF) is electromagnetic waves (radio waves) in the frequency range between 30 hertz and 300 hertz.
Television (TV) is a telecommunication medium used for transmitting moving images in monochrome (black and white), or in colour, and in two or three dimensions and sound.
Terahertz radiation – also known as submillimeter radiation, terahertz waves, tremendously high frequency (THF), T-rays, T-waves, T-light, T-lux or THz – consists of electromagnetic waves within the ITU-designated band of frequencies from 0.3 to 3 terahertz (THz; 1012 Hz).
Thorium is a weakly radioactive metallic chemical element with symbol Th and atomic number 90.
In communications and electronic engineering, a transmission line is a specialized cable or other structure designed to conduct alternating current of radio frequency, that is, currents with a frequency high enough that their wave nature must be taken into account.
A transmission medium is a material substance (solid, liquid, gas, or plasma) that can propagate energy waves.
In electronics and telecommunications, a transmitter or radio transmitter is an electronic device which produces radio waves with an antenna.
A two-way radio is a radio that can do both transmit and receive a signal (a transceiver), unlike a broadcast receiver which only receives content.
Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one decimeter.
Ultra low frequency (ULF) is the ITU designation for the frequency range of electromagnetic waves between 300 hertz and 3 kilohertz.
Ultraviolet (UV) is electromagnetic radiation with a wavelength from 10 nm to 400 nm, shorter than that of visible light but longer than X-rays.
The United States Department of Commerce is the Cabinet department of the United States government concerned with promoting economic growth.
The Department of Defense (DoD, USDOD, or DOD) is an executive branch department of the federal government of the United States charged with coordinating and supervising all agencies and functions of the government concerned directly with national security and the United States Armed Forces.
The Universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy.
The University of California, Davis (also referred to as UCD, UC Davis, or Davis), is a public research university and land-grant university as well as one of the 10 campuses of the University of California (UC) system.
The V band ("vee-band") is a standard designation by the Institute of Electrical and Electronic Engineers (IEEE) for a band of frequencies in the microwave portion of the electromagnetic spectrum ranging from 40 to 75 gigahertz (GHz).
Very high frequency (VHF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) from 30 to 300 megahertz (MHz), with corresponding wavelengths of ten to one meter.
Very low frequency or VLF is the ITU designation for radio frequencies (RF) in the range of 3 to 30 kilohertz (kHz), corresponding to wavelengths from 100 to 10 kilometers, respectively.
In physics, a virtual particle is a transient fluctuation that exhibits some of the characteristics of an ordinary particle, but whose existence is limited by the uncertainty principle.
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye.
Visual perception is the ability to interpret the surrounding environment using light in the visible spectrum reflected by the objects in the environment.
The visual system is the part of the central nervous system which gives organisms the ability to process visual detail, as well as enabling the formation of several non-image photo response functions.
A voice frequency (VF) or voice band is one of the frequencies, within part of the audio range, that is being used for the transmission of speech.
The W band of the microwave part of the electromagnetic spectrum ranges from 75 to 110 GHz, wavelength ≈2.7–4 mm.
A waveguide is a structure that guides waves, such as electromagnetic waves or sound, with minimal loss of energy by restricting expansion to one dimension or two.
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.
Wi-Fi or WiFi is technology for radio wireless local area networking of devices based on the IEEE 802.11 standards.
Wilhelm Conrad Röntgen (27 March 1845 – 10 February 1923) was a German mechanical engineer and physicist, who, on 8 November 1895, produced and detected electromagnetic radiation in a wavelength range known as X-rays or Röntgen rays, an achievement that earned him the first Nobel Prize in Physics in 1901.
Sir William Henry Bragg (2 July 1862 – 12 March 1942) was a British physicist, chemist, mathematician and active sportsman who uniquelyThis is still a unique accomplishment, because no other parent-child combination has yet shared a Nobel Prize (in any field).
Frederick William Herschel, (Friedrich Wilhelm Herschel; 15 November 1738 – 25 August 1822) was a German-born British astronomer, composer and brother of fellow astronomer Caroline Herschel, with whom he worked.
A wireless network is a computer network that uses wireless data connections between network nodes.
Wireless telegraphy is the transmission of telegraphy signals from one point to another by means of an electromagnetic, electrostatic or magnetic field, or by electrical current through the earth or water.
X-rays make up X-radiation, a form of electromagnetic radiation.
An X-ray telescope (XRT) is a telescope that is designed to observe remote objects in the X-ray spectrum.
EM Spectrum, EM spectrum, Electomagnetic spectrum, Electro magnetic spectrum, Electro-magnetic spectrum, Electrocmagnetic spectrum, Electromagentic spectra, Electromagnetic Spectrum, Electromagnetic frequency spectrum, Em spectrum, Invisible light (physics), Light spectrum, Radiation spectrum, Solar Light, Spectral range, Spectrum of light.