List of nuclear and radiation accidents - Criticality accidents. Criticality accidents and power excursions in nuclear reactors, for example the Chernobyl accident was a power excursion. In a smaller scale accident at Sarov a man working with highly enriched uranium was irradiated while attempting a experiment involving a sphere of fissile material. The Sarov accident is interesting because the system remained critical for many days before it could be stopped. This is an example of a limited scope accident where ...

See also:

List of nuclear and radiation accidents, List of nuclear and radiation accidents - Accident types, List of nuclear and radiation accidents - Criticality accidents, List of nuclear and radiation accidents - Decay heat, List of nuclear and radiation accidents - Transport, List of nuclear and radiation accidents - Equipment failure, List of nuclear and radiation accidents - Human error, List of nuclear and radiation accidents - Lost source, List of nuclear and radiation accidents - Others, List of nuclear and radiation accidents - Civilian nuclear accidents, List of nuclear and radiation accidents - Civilian radiation accidents, List of nuclear and radiation accidents - Military nuclear accidents

Read more here: » List of nuclear and radiation accidents: Encyclopedia II - List of nuclear and radiation accidents - Accident types

In Einstein's theory of General Relativity, gravitation is, essentially, identified with spacetime curvature. In the famous slogan promulgated by John Archibald Wheeler, matter tells spacetime how to curve, and spacetime tells matter how to move. For example, humans feel the ground pressing against their feet (or behind, according to stance). From the viewpoint of general relativity, this means that contact with the ground is preventing them from falling freely, thereby accelerating them. Since acceleration is identified with bending ...

See also:

Gravitational radiation, Gravitational radiation - Overview, Gravitational radiation - The Nature of Gravitational Waves, Gravitational radiation - Sources of Gravitational Waves, Gravitational radiation - Detection, Gravitational radiation - Einstein@Home, Gravitational radiation - Prospects, Gravitational radiation - Derivation, Gravitational radiation - Perturbation of Flat Space-time, Gravitational radiation - Perturbation with Sources, Gravitational radiation - Far from Source Approximation, Gravitational radiation - Perturbative versus Exact, Gravitational radiation - Gravitational waves transmit energy

Read more here: » Gravitational radiation: Encyclopedia II - Gravitational radiation - Overview

electromagnetic radiation

Radiation of different wavelengths extending from radio waves to gamma rays and including visible light; often divided between natural (including ki or universal life energy) and artificial such as electrical or microwave

(See also: Electromagnetic radiation, Body Mind and Soul)

The symptoms of radiation sickness become more serious (and the chance of survival decreases) as the dosage of radiation increases. Prolonged exposure to radiation can induce cancer as cell-cycle genes are corrupted. However, since tumors themselves grow by abnormally rapid cell division, the ability of radiation to disturb cell division is also used to treat cancer (see radiotherapy), and low levels of ionizing radiation hav ...

See also:

Radiation poisoning, Radiation poisoning - Measuring radiation dosage, Radiation poisoning - Symptoms and effects, Radiation poisoning - Prevention and treatment, Radiation poisoning - Table of exposure levels and symptoms, Radiation poisoning - 0.05–0.2 Sv 5–20 REM, Radiation poisoning - 0.2–0.5 Sv 20–50 REM, Radiation poisoning - 0.5–1 Sv 50–100 REM, Radiation poisoning - 1–2 Sv 100–200 REM, Radiation poisoning - 2–3 Sv 200–300 REM, Radiation poisoning - 3–4 Sv 300–400 REM, Radiation poisoning - 4–6 Sv 400–600 REM, Radiation poisoning - 6–10 Sv 600–1000 REM, Radiation poisoning - 10–50 Sv 1000–5000 REM, Radiation poisoning - 50–80 Sv 5000–8000 REM, Radiation poisoning - More than 80 Sv >8000 REM, Radiation poisoning - Radiation poisoning in fiction

Read more here: » Radiation poisoning: Encyclopedia II - Radiation poisoning - Symptoms and effects

Definition and meaning of electromagnetic radiation:

electromagnetic radiation - energy that travels through space in the form of waves. The highest frequencies in the spectrum of electromagnetic radiation are gamma-rays; the lowest frequencies are radio waves. All electromagnetic radiation travels at the speed of light. Shorter wavelength radiation (eg, ultraviolet) carries more energy and is likely to be more harmful to living tissue

(Source: US National Oceanic and Atmospheric Administration (NOAA) )

Also see these pages: Oceanography, Oceanography Sitemap, Coral Reef, Environment, Sustainability, Climate Change,

Dose-equivalents are presently stated in sieverts: Radiation poisoning - 0.05–0.2 Sv 5–20 REM. No symptoms. Potential for cancer and mutation of genetic material, according to the LNT model. This is disputed. (Note: see hormesis) Radiation poisoning - 0.2–0.5 Sv 20–50 REM. No noticeable symptoms. Number of red blood cells decreases temporarily. Radiation poisoning - 0.5–1 Sv 50–100 REM. Mild radiation sickness with headache and increased risk of infecti ...

See also:

Radiation poisoning, Radiation poisoning - Measuring radiation dosage, Radiation poisoning - Symptoms and effects, Radiation poisoning - Prevention and treatment, Radiation poisoning - Table of exposure levels and symptoms, Radiation poisoning - 0.05–0.2 Sv 5–20 REM, Radiation poisoning - 0.2–0.5 Sv 20–50 REM, Radiation poisoning - 0.5–1 Sv 50–100 REM, Radiation poisoning - 1–2 Sv 100–200 REM, Radiation poisoning - 2–3 Sv 200–300 REM, Radiation poisoning - 3–4 Sv 300–400 REM, Radiation poisoning - 4–6 Sv 400–600 REM, Radiation poisoning - 6–10 Sv 600–1000 REM, Radiation poisoning - 10–50 Sv 1000–5000 REM, Radiation poisoning - 50–80 Sv 5000–8000 REM, Radiation poisoning - More than 80 Sv >8000 REM, Radiation poisoning - Radiation poisoning in fiction

Read more here: » Radiation poisoning: Encyclopedia II - Radiation poisoning - Table of exposure levels and symptoms

Definition and meaning of solar radiation:

solar radiation - the amount of radiation or energy received from the sun at any given point

(Source: US National Oceanic and Atmospheric Administration (NOAA) )

Also see these pages: Oceanography, Oceanography Sitemap, Coral Reef, Environment, Sustainability, Climate Change,

Definition and meaning of ionizing radiation:

ionizing radiation - high-energy radiation capable of producing ionization in substances through which it passes, i.e., radiation that has enough energy to eject electrons from electrically neutral atoms, leaving behind charged atoms or ions; examples are alpha particles (helium nuclei), beta particles (electrons), neutrons, and gamma rays (high frequency electromagnetic waves, x-rays)

(Source: US National Oceanic and Atmospheric Administration (NOAA) )

Also see these pages: Oceanography, Oceanography Sitemap, Coral Reef, Environment, Sustainability, Climate Change,

Definition and meaning of nonionizing radiation:

nonionizing radiation - radiation that carries enough energy to excite an atom or molecule, but not enough energy to remove an electron from the atom or molecule. This type of radiation does not cause damage to cells and tissues; examples include radio waves, microwaves, infrared light, and ordinary light

(Source: US National Oceanic and Atmospheric Administration (NOAA) )

Also see these pages: Oceanography, Oceanography Sitemap, Coral Reef, Environment, Sustainability, Climate Change,

Definition and meaning of adaptive radiation:

adaptive radiation - the evolution of a single evolutionary stock into a number of different species

(Source: US National Oceanic and Atmospheric Administration (NOAA) )

Also see these pages: Oceanography, Oceanography Sitemap, Coral Reef, Environment, Sustainability, Climate Change,

Definition and meaning of visible radiation:

visible radiation - energy at wavelengths from 400 - 700 nm that is detectable by the human eye

(Source: US National Oceanic and Atmospheric Administration (NOAA) )

Also see these pages: Oceanography, Oceanography Sitemap, Coral Reef, Environment, Sustainability, Climate Change,

Gravitational radiation - Perturbation of Flat Space-time. Consider that the full metric g is nearly the flat metric η plus some small perturbation h. gμν = ημν + hμν The Einstein equation in vacuum is Where R is the Ricci curvature. We will expand R in perturbatively in powers of See also:

Gravitational radiation, Gravitational radiation - Overview, Gravitational radiation - The Nature of Gravitational Waves, Gravitational radiation - Sources of Gravitational Waves, Gravitational radiation - Detection, Gravitational radiation - Einstein@Home, Gravitational radiation - Prospects, Gravitational radiation - Derivation, Gravitational radiation - Perturbation of Flat Space-time, Gravitational radiation - Perturbation with Sources, Gravitational radiation - Far from Source Approximation, Gravitational radiation - Perturbative versus Exact, Gravitational radiation - Gravitational waves transmit energy

Read more here: » Gravitational radiation: Encyclopedia II - Gravitational radiation - Derivation

While relativity holds that the speed of light in a vacuum is a universal constant (c), the speed of light in a material may be significantly less than c. For example, the speed of light in water is only 0.75c. Matter can be accelerated beyond this speed during nuclear reactions and in particle accelerators. Cherenkov radiation results when a charged particle, most commonly an electron, exceeds the speed o ...

See also:

Cherenkov radiation, Cherenkov radiation - Physical origin, Cherenkov radiation - Characteristics, Cherenkov radiation - Uses, Cherenkov radiation - Notes

Read more here: » Cherenkov radiation: Encyclopedia II - Cherenkov radiation - Physical origin

Radiotherapy is in itself painless. Many low-dose palliative treatments (e.g. radiotherapy to bony metastases) cause minimal or no side effects. Treatment to higher doses causes variable side effects during treatment (acute side effects) or in the months to years following treatment (long term side effects.) The nature of the side effects depends on the site which receives the radiation, and the treatment schedule (type of radiation, dose, fractionation, concurrent chemotherapy.) Individuals differ somewhat in their radiation reaction. Retre ...

See also:

Radiation therapy, Radiation therapy - Application, Radiation therapy - Side Effects, Radiation therapy - Acute Side Effects, Radiation therapy - Medium and Long-Term Side Effects, Radiation therapy - Dosage, Radiation therapy - Fractionation Schedules, Radiation therapy - How It Works, Radiation therapy - Kinds of Radiation Therapy, Radiation therapy - Conventional External Beam Radiotherapy, Radiation therapy - Virtual Simulation 3-Dimensional Conformal Radiotherapy and Intensity-Modulated Radiotherapy

Read more here: » Radiation therapy: Encyclopedia II - Radiation therapy - Side Effects

Radiation therapy works by damaging the DNA of cells. The damage is caused by an electromagnetic, electron or proton beam directly or indirectly ionizing the atoms which make up DNA chain. Indirect ionization happens as a result of the ionization of water, forming free radicals, notably hydroxyl radicals, which then damage the DNA. In the most common forms of radiation therapy, most of the radiation effect is through free radicals. Because cells have mechanisms for repairing DNA breakage, where the DNA is broken on both strands of the DNA ar ...

See also:

Radiation therapy, Radiation therapy - Application, Radiation therapy - Side Effects, Radiation therapy - Acute Side Effects, Radiation therapy - Medium and Long-Term Side Effects, Radiation therapy - Dosage, Radiation therapy - Fractionation Schedules, Radiation therapy - How It Works, Radiation therapy - Kinds of Radiation Therapy, Radiation therapy - Conventional External Beam Radiotherapy, Radiation therapy - Virtual Simulation 3-Dimensional Conformal Radiotherapy and Intensity-Modulated Radiotherapy

Read more here: » Radiation therapy: Encyclopedia II - Radiation therapy - How It Works

Generally, EM radiation is classified by wavelength into electrical energy, radio, microwave, infrared, the visible region we perceive as light, ultraviolet, X-rays and gamma rays. The behavior of EM radiation depends on its wavelength. Higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths. When EM radiation interacts with single atoms and molecules, its behavior depends on the amount of energy per quantum it carries. Spectroscopy can detect a much wider region of the EM spectrum than the vi ...

See also:

Electromagnetic radiation, Electromagnetic radiation - Physics, Electromagnetic radiation - Theory, Electromagnetic radiation - Properties, Electromagnetic radiation - Wave model, Electromagnetic radiation - Particle model, Electromagnetic radiation - Speed of propagation, Electromagnetic radiation - Electromagnetic spectrum, Electromagnetic radiation - Light, Electromagnetic radiation - Radio waves, Electromagnetic radiation - Derivation

Read more here: » Electromagnetic radiation: Encyclopedia II - Electromagnetic radiation - Electromagnetic spectrum

The average energy density of solar radiation just above the Earth's atmosphere, in a plane perpendicular to the rays, is about 1367 W/m², a value called the solar constant (although it fluctuates by a few parts per thousand from day to day). The Earth receives a total amount of radiation determined by its cross section (π R2), but as the planet rotates this energy is distributed across the entire surface area (4 π R2). Hence, the average incoming solar radiation (known as "insolation") is 1/4th the solar constant or ~342 W/m². At any given location and time, the amount received at ...

See also:

Solar radiation, Solar radiation - Climate effect of solar radiation

Read more here: » Solar radiation: Encyclopedia II - Solar radiation - Climate effect of solar radiation

A black hole emits thermal radiation at a temperature , in natural units with G, c, and k equal to 1, and where κ is the surface gravity of the horizon. In particular, the radiation from a Schwarzschild black hole is black-body radiation with temperature: where is the reduced Planck constant, c is the speed of light, k is the Boltzmann constant, G is the gravitational ...

See also:

Hawking radiation, Hawking radiation - Overview, Hawking radiation - Example, Hawking radiation - Problems with the theory, Hawking radiation - Emission process, Hawking radiation - Black hole evaporation

Read more here: » Hawking radiation: Encyclopedia II - Hawking radiation - Emission process

Definition and meaning of IR, infrared radiation:

IR (infrared) radiation - earth-emitted radiation over thermal wavelengths: 3-15 micrometers. Used for satellite remote sensing because it can be used to monitor weather and oceanographic conditions 24 hours a day

(Source: US National Oceanic and Atmospheric Administration (NOAA) )

Also see these pages: Oceanography, Oceanography Sitemap, Coral Reef, Environment, Sustainability, Climate Change,

Definition and meaning of UV, ultraviolet radiation:

UV (ultraviolet) radiation - the region of the electromagnetic spectrum consisting of wavelengths from 1 to 400 nm

(Source: US National Oceanic and Atmospheric Administration (NOAA) )

Also see these pages: Oceanography, Oceanography Sitemap, Coral Reef, Environment, Sustainability, Climate Change,

Gravitational waves are caused by certain motions of mass or energy. The type of motion required is different from electromagnetism in one very important respect however: the strongest type of electromagnetic radiation is dipole radiation, while the strongest type of gravitational radiation is quadrupole radiation. [1] According to general relativity, the quadrupole moment (or some higher moment) of an isolated system must be time-varying in order for it to emit gravitational radiation. Here are some examples which illus ...

See also:

Gravitational radiation, Gravitational radiation - Overview, Gravitational radiation - The Nature of Gravitational Waves, Gravitational radiation - Sources of Gravitational Waves, Gravitational radiation - Detection, Gravitational radiation - Einstein@Home, Gravitational radiation - Prospects, Gravitational radiation - Derivation, Gravitational radiation - Perturbation of Flat Space-time, Gravitational radiation - Perturbation with Sources, Gravitational radiation - Far from Source Approximation, Gravitational radiation - Perturbative versus Exact, Gravitational radiation - Gravitational waves transmit energy

Read more here: » Gravitational radiation: Encyclopedia II - Gravitational radiation - Sources of Gravitational Waves

When particles escape, the black hole loses a small amount of its energy and therefore of its mass (recall that mass and energy are related by Einstein's famous equation E = mc²). The power emitted by a black hole in the form of Hawking radiation can easily be estimated for the simplest case of a nonrotating, non-charged Schwarzschild black hole of mass M. Combining the formulae for the Schwarzschild radius of the black hole, the Stefan-Boltzmann law of black-body radiation, the above formula for the temperature of the radiation, and the formula for the surface area of a sphere ( ...

See also:

Hawking radiation, Hawking radiation - Overview, Hawking radiation - Example, Hawking radiation - Problems with the theory, Hawking radiation - Emission process, Hawking radiation - Black hole evaporation

Read more here: » Hawking radiation: Encyclopedia II - Hawking radiation - Black hole evaporation