144 relations: Absorbed dose, Acoustics, Acute radiation syndrome, Alpha decay, Alpha particle, Antimatter, Astronomer, Atmosphere of Earth, Atomic nucleus, Australian Radiation Protection and Nuclear Safety Agency, Background radiation, Banana equivalent dose, Beta particle, Billiard ball, Black body, Black-body radiation, Cancer, Cell (biology), Chain reaction, Chemical bond, Cherenkov radiation, Chernobyl disaster, Coronal mass ejection, Cosmic microwave background, Cosmic ray, Depleted uranium, Dispersive prism, Edward Andrade, Effective dose (radiation), Electromagnetic field, Electromagnetic radiation, Electromagnetic spectrum, Electrometer, Electron, Electronvolt, Energy, Equivalent dose, Ernest Rutherford, Food browning, Gamma ray, Gamma-ray burst, Geiger counter, Gravitational wave, Hawking radiation, Heinrich Hertz, Helium-4, Henri Becquerel, Infrared, Infrared sensing in snakes, International Commission on Radiological Protection, ..., International Labour Organization, Inverse-square law, Iodine-131, Ionization, Ionizing radiation, James Clerk Maxwell, Johann Wilhelm Ritter, Kelvin, Light, Linear particle accelerator, Marie Curie, Meson, Microwave, Momentum, Muon, Mutation, Near and far field, Neutrino, Neutron, Neutron activation, Neutron activation analysis, Neutron radiation, Neutron temperature, Non-ionizing radiation, Nuclear fission, Nuclear fusion, Nuclear medicine, Nuclear reactor, Orders of magnitude (length), Ozone layer, Particle, Particle accelerator, Particle radiation, Paul Ulrich Villard, Photon, Physics, Pion, Planck constant, Planck's law, Point source, Polonium, Positron, Proton, Pyrimidine dimer, Quasar, Radiant energy, Radiation damage, Radiation hardening, Radiation hormesis, Radiation properties, Radiation Protection Convention, 1960, Radiation therapy, Radical (chemistry), Radio wave, Radioactive contamination, Radioactive decay, Radioactive tracer, Radiocarbon dating, Radiography, Radiometric dating, Radiometry, Radionuclide, Radium, Radon, Red, Refraction, Relative biological effectiveness, Relativistic speed, Royal Society, Seismic wave, Silver chloride, Sound, Speed of light, Star, Subatomic particle, Sun, Sunburn, Supernova, Thermal energy, Thermometer, Thomas Royds, Thyroid cancer, Transmission medium, Ultrasound, Ultraviolet, Universe, Universiti Tenaga Nasional, Victor Francis Hess, Wave, Wavelength, Wien's displacement law, Wilhelm Röntgen, William Herschel, X-ray. Expand index (94 more) » « Shrink index
Absorbed dose is a measure of the energy deposited in a medium by ionizing radiation.
Acoustics is the branch of physics that deals with the study of all mechanical waves in gases, liquids, and solids including topics such as vibration, sound, ultrasound and infrasound.
Acute radiation syndrome (ARS) is a collection of health effects that are present within 24 hours of exposure to high doses of ionizing radiation.
Alpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or 'decays' into an atom with a mass number that is reduced by four and an atomic number that is reduced by two.
Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus.
In modern physics, antimatter is defined as a material composed of the antiparticle (or "partners") to the corresponding particles of ordinary matter.
An astronomer is a scientist in the field of astronomy who concentrates their studies on a specific question or field outside the scope of Earth.
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.
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.
The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) is an Australian body that monitors and identifies solar radiation and nuclear radiation risks to the population of Australia.
Background radiation is a measure of the ionizing radiation present in the environment at a particular location which is not due to deliberate introduction of radiation sources.
Banana equivalent dose (BED) is an informal measurement of ionizing radiation exposure, intended as a general educational example to compare a dose of radioactivity to the dose one is exposed to by eating one average-sized banana.
A beta particle, also called beta ray or beta radiation, (symbol β) is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus during the process of beta decay.
A billiard ball is a small, hard ball used in cue sports, such as carom billiards, pool, and snooker.
A black body is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence.
Black-body radiation is the thermal electromagnetic radiation within or surrounding a body in thermodynamic equilibrium with its environment, or emitted by a black body (an opaque and non-reflective body).
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body.
The cell (from Latin cella, meaning "small room") is the basic structural, functional, and biological unit of all known living organisms.
A chain reaction is a sequence of reactions where a reactive product or by-product causes additional reactions to take place.
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds.
Cherenkov radiation (sometimes spelled "Cerenkov") is electromagnetic radiation emitted when a charged particle (such as an electron) passes through a dielectric medium at a speed greater than the phase velocity of light in that medium.
The Chernobyl disaster, also referred to as the Chernobyl accident, was a catastrophic nuclear accident.
A coronal mass ejection (CME) is a significant release of plasma and magnetic field from the solar corona.
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.
Depleted uranium (DU; also referred to in the past as Q-metal, depletalloy or D-38) is uranium with a lower content of the fissile isotope U-235 than natural uranium.
In optics, a dispersive prism is an optical prism, usually having the shape of a geometrical triangular prism, used as a spectroscopic component.
Edward Neville da Costa Andrade FRS (27 December 1887 – 6 June 1971) was an English physicist, writer, and poet.
Effective dose is a dose quantity in the International Commission on Radiological Protection (ICRP) system of radiological protection.
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 electromagnetic spectrum is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and photon energies.
An electrometer is an electrical instrument for measuring electric charge or electrical potential difference.
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).
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.
Equivalent dose is a dose quantity H representing the stochastic health effects of low levels of ionizing radiation on the human body.
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.
Browning is the process of food turning brown due to the chemical reactions that take place within.
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 Geiger counter is an instrument used for detecting and measuring ionizing radiation used widely in applications such as radiation dosimetry, radiological protection, experimental physics and the nuclear industry.
Gravitational waves are the disturbance in the fabric ("curvature") of spacetime generated by accelerated masses and propagate as waves outward from their source at the speed of light.
Hawking radiation is blackbody radiation that is predicted to be released by black holes, due to quantum effects near the event horizon.
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.
Helium-4 is a non-radioactive isotope of the element helium.
Antoine Henri Becquerel (15 December 1852 – 25 August 1908) was a French physicist, Nobel laureate, and the first person to discover evidence of radioactivity.
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.
The ability to sense infrared thermal radiation evolved independently in several different families of snakes.
The International Commission on Radiological Protection (ICRP) is an independent, international, non-governmental organization, with the mission to provide recommendations and guidance on radiation protection.
The International Labour Organization (ILO) is a United Nations agency dealing with labour problems, particularly international labour standards, social protection, and work opportunities for all.
The inverse-square law, in physics, is any physical law stating that a specified physical quantity or intensity is inversely proportional to the square of the distance from the source of that physical quantity.
Iodine-131 (131I) is an important radioisotope of iodine discovered by Glenn Seaborg and John Livingood in 1938 at the University of California, Berkeley.
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.
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.
The Kelvin scale is an absolute thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics.
Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum.
A linear particle accelerator (often shortened to linac) is a type of particle accelerator that accelerates charged subatomic particles or ions to a high speed by subjecting them to a series of oscillating electric potentials along a linear beamline.
Marie Skłodowska Curie (born Maria Salomea Skłodowska; 7 November 18674 July 1934) was a Polish and naturalized-French physicist and chemist who conducted pioneering research on radioactivity.
In particle physics, mesons are hadronic subatomic particles composed of one quark and one antiquark, bound together by strong interactions.
Microwaves are a form of electromagnetic radiation with wavelengths ranging from one meter to one millimeter; with frequencies between and.
In Newtonian mechanics, linear momentum, translational momentum, or simply momentum (pl. momenta) is the product of the mass and velocity of an object.
The muon (from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 e and a spin of 1/2, but with a much greater mass.
In biology, a mutation is the permanent alteration of the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA or other genetic elements.
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 neutrino (denoted by the Greek letter ν) is a fermion (an elementary particle with half-integer spin) that interacts only via the weak subatomic force and gravity.
Neutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when atomic nuclei capture free neutrons, becoming heavier and entering excited states.
Neutron activation analysis (NAA) is a nuclear process used for determining the concentrations of elements in a vast amount of materials.
Neutron radiation is a form of ionizing radiation that presents as free neutrons.
The neutron detection temperature, also called the neutron energy, indicates a free neutron's kinetic energy, usually given in electron volts.
Non-ionizing (or non-ionising) radiation refers to any type of electromagnetic radiation that does not carry enough energy per quantum (photon energy) to ionize atoms or molecules—that is, to completely remove an electron from an atom or molecule.
In nuclear physics and nuclear chemistry, nuclear fission is either a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into smaller parts (lighter nuclei).
In nuclear physics, nuclear fusion is a reaction in which two or more atomic nuclei come close enough to form one or more different atomic nuclei and subatomic particles (neutrons or protons).
Nuclear medicine is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease.
A nuclear reactor, formerly known as an atomic pile, is a device used to initiate and control a self-sustained nuclear chain reaction.
The following are examples of orders of magnitude for different lengths.
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation.
In the physical sciences, a particle (or corpuscule in older texts) is a small localized object to which can be ascribed several physical or chemical properties such as volume, density or mass.
A particle accelerator is a machine that uses electromagnetic fields to propel charged particles to nearly light speed and to contain them in well-defined beams.
Particle radiation is the radiation of energy by means of fast-moving subatomic particles.
Paul Ulrich Villard (28 September 1860 – 13 January 1934) was a French chemist and physicist.
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).
Physics (from knowledge of nature, from φύσις phýsis "nature") is the natural science that studies matterAt the start of The Feynman Lectures on Physics, Richard Feynman offers the atomic hypothesis as the single most prolific scientific concept: "If, in some cataclysm, all scientific knowledge were to be destroyed one sentence what statement would contain the most information in the fewest words? I believe it is that all things are made up of atoms – little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another..." and its motion and behavior through space and time and that studies the related entities of energy and force."Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events." Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves."Physics is one of the most fundamental of the sciences. Scientists of all disciplines use the ideas of physics, including chemists who study the structure of molecules, paleontologists who try to reconstruct how dinosaurs walked, and climatologists who study how human activities affect the atmosphere and oceans. Physics is also the foundation of all engineering and technology. No engineer could design a flat-screen TV, an interplanetary spacecraft, or even a better mousetrap without first understanding the basic laws of physics. (...) You will come to see physics as a towering achievement of the human intellect in its quest to understand our world and ourselves."Physics is an experimental science. Physicists observe the phenomena of nature and try to find patterns that relate these phenomena.""Physics is the study of your world and the world and universe around you." Physics is one of the oldest academic disciplines and, through its inclusion of astronomy, perhaps the oldest. Over the last two millennia, physics, chemistry, biology, and certain branches of mathematics were a part of natural philosophy, but during the scientific revolution in the 17th century, these natural sciences emerged as unique research endeavors in their own right. Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms studied by other sciences and suggest new avenues of research in academic disciplines such as mathematics and philosophy. Advances in physics often enable advances in new technologies. For example, advances in the understanding of electromagnetism and nuclear physics led directly to the development of new products that have dramatically transformed modern-day society, such as television, computers, domestic appliances, and nuclear weapons; advances in thermodynamics led to the development of industrialization; and advances in mechanics inspired the development of calculus.
In particle physics, a pion (or a pi meson, denoted with the Greek letter pi) is any of three subatomic particles:,, and.
The Planck constant (denoted, also called Planck's constant) is a physical constant that is the quantum of action, central in quantum mechanics.
Planck's law describes the spectral density of electromagnetic radiation emitted by a black body in thermal equilibrium at a given temperature T. The law is named after Max Planck, who proposed it in 1900.
A point source is a single identifiable localised source of something.
Polonium is a chemical element with symbol Po and atomic number 84.
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron.
Pyrimidine dimers are molecular lesions formed from thymine or cytosine bases in DNA via photochemical reactions.
A quasar (also known as a QSO or quasi-stellar object) is an extremely luminous active galactic nucleus (AGN).
In physics, and in particular as measured by radiometry, radiant energy is the energy of electromagnetic and gravitational radiation.
This article deals with Radiation damage due to the effects of ionizing radiation on physical objects.
Radiation hardening is the act of making electronic components and systems resistant to damage or malfunctions caused by ionizing radiation (particle radiation and high-energy electromagnetic radiation), such as those encountered in outer space and high-altitude flight, around nuclear reactors and particle accelerators, or during nuclear accidents or nuclear warfare.
Radiation hormesis is the hypothesis that low doses of ionizing radiation (within the region of and just above natural background levels) are beneficial, stimulating the activation of repair mechanisms that protect against disease, that are not activated in absence of ionizing radiation.
Conduction and convection are heat transfer processes that require the presence of a medium.
Radiation Protection Convention, 1960 is an International Labour Organization Convention to restrict workers from exposure of ionising radiation and to prohibit persons under 16 engaging in work that causes such exposure.
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.
In chemistry, a radical (more precisely, a free radical) is an atom, molecule, or ion that has an unpaired valence electron.
Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light.
Radioactive contamination, also called radiological contamination, is the deposition of, or presence of radioactive substances on surfaces or within solids, liquids or gases (including the human body), where their presence is unintended or undesirable (from the International Atomic Energy Agency - IAEA - definition).
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.
A radioactive tracer, or radioactive label, is a chemical compound in which one or more atoms have been replaced by a radionuclide so by virtue of its radioactive decay it can be used to explore the mechanism of chemical reactions by tracing the path that the radioisotope follows from reactants to products.
Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon.
Radiography is an imaging technique using X-rays to view the internal form of an object.
Radiometric dating or radioactive dating is a technique used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed.
Radiometry is a set of techniques for measuring electromagnetic radiation, including visible light.
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.
Radon is a chemical element with symbol Rn and atomic number 86.
Red is the color at the end of the visible spectrum of light, next to orange and opposite violet.
Refraction is the change in direction of wave propagation due to a change in its transmission medium.
In radiobiology, the relative biological effectiveness (often abbreviated as RBE) is the ratio of biological effectiveness of one type of ionizing radiation relative to another, given the same amount of absorbed energy.
Relativistic speed refers to speed at which relativistic effects become significant to the desired accuracy of measurement of the phenomenon being observed.
The President, Council and Fellows of the Royal Society of London for Improving Natural Knowledge, commonly known as the Royal Society, is a learned society.
Seismic waves are waves of energy that travel through the Earth's layers, and are a result of earthquakes, volcanic eruptions, magma movement, large landslides and large man-made explosions that give out low-frequency acoustic energy.
Silver chloride is a chemical compound with the chemical formula AgCl.
In physics, sound is a vibration that typically propagates as an audible wave of pressure, through a transmission medium such as a gas, liquid or solid.
The speed of light in vacuum, commonly denoted, is a universal physical constant important in many areas of physics.
A star is type of astronomical object consisting of a luminous spheroid of plasma held together by its own gravity.
In the physical sciences, subatomic particles are particles much smaller than atoms.
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.
A supernova (plural: supernovae or supernovas, abbreviations: SN and SNe) is a transient astronomical event that occurs during the last stellar evolutionary stages of a star's life, either a massive star or a white dwarf, whose destruction is marked by one final, titanic explosion.
Thermal energy is a term used loosely as a synonym for more rigorously-defined thermodynamic quantities such as the internal energy of a system; heat or sensible heat, which are defined as types of transfer of energy (as is work); or for the characteristic energy of a degree of freedom in a thermal system kT, where T is temperature and k is the Boltzmann constant.
A thermometer is a device that measures temperature or a temperature gradient.
Thomas Royds (April 11, 1884 – May 1, 1955) was a Solar physicist who worked with Ernest Rutherford on the identification of alpha radiation as the nucleus of the helium atom, and who was Director of the Kodaikanal Solar Observatory.
Thyroid cancer is cancer that develops from the tissues of the thyroid gland.
A transmission medium is a material substance (solid, liquid, gas, or plasma) that can propagate energy waves.
Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing.
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 Universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy.
Universiti Tenaga Nasional (UNITEN) is a private university, located in Selangor, Malaysia, with GLC university status.
Victor Franz Hess (24 June 188317 December 1964) was an Austrian-American physicist, and Nobel laureate in physics, who discovered cosmic rays.
In physics, a wave is a disturbance that transfers energy through matter or space, with little or no associated mass transport.
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.
Wien's displacement law states that the black body radiation curve for different temperatures peaks at a wavelength inversely proportional to the temperature.
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.
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.
X-rays make up X-radiation, a form of electromagnetic radiation.