Abdo, A. A.; Allen, B.; Berley, D.; Blaufuss, E.; Casanova, S.; Chen, C.; Coyne, D. G.; Delay, R. S.; Dingus, B. L.; Ellsworth, R. W.; Fleysher, L.; Fleysher, R.; Gebauer, I.; Gonzalez, M. M.; Goodman, J. A.; Hays, E.; Hoffman, C. M.; Kolterman, B. E.; Kelley, L. A.; Lansdell, C. P.; Linnemann, J. T.; McEnery, J. E.; Mincer, A. I.; Moskalenko, I. V.; Nemethy, P.; Noyes, D.; Ryan, J. M.; Samuelson, F. W.; Saz Parkinson, P. M.; etal. (2007). "Discovery of TeV Gamma-Ray Emission from the Cygnus Region of the Galaxy". The Astrophysical Journal. 658 (1): L33–L36. arXiv: astro-ph/0611691. Bibcode: 2007ApJ...658L..33A. doi: 10.1086/513696. S2CID 17886934. Look for evidence of the company engaging with reputable, third-party organisations such as B Corp, the EU Ecolabel or the GSTC. They set global standards and are less likely to be biased. Herschel Discovers Infrared Light". Cool Cosmos Classroom activities. Archived from the original on 2012-02-25 . Retrieved 4 March 2013. He directed sunlight through a glass prism to create a spectrum […] and then measured the temperature of each colour. […] He found that the temperatures of the colours increased from the violet to the red part of the spectrum. […] Herschel decided to measure the temperature just beyond the red of the spectrum in a region where no sunlight was visible. To his surprise, he found that this region had the highest temperature of all. The electromagnetic spectrum is the spectrum of electromagnetic radiation, ranging over a domain of frequencies and their respective wavelengths and photon energies. f = c λ , or f = E h , or E = h c λ , {\displaystyle f={\frac {c}{\lambda }},\quad {\text{or}}\quad f={\frac {E}{h}},\quad {\text{or}}\quad E={\frac {hc}{\lambda }},}

Generally, electromagnetic radiation is classified by wavelength into radio wave, microwave, infrared, visible light, ultraviolet, X-rays and gamma rays. The behavior of EM radiation depends on its wavelength. When EM radiation interacts with single atoms and molecules, its behavior also depends on the amount of energy per quantum (photon) it carries. She moans so much about having to edit, surely there can’t be that much involved? I saw someone’s comment the other day thanking Emma for daily vlogging because she knows how much work is involved in it! Trust me, Emma is doing this for her own benefit, she’s not doing anyone a favour!Near-infrared, from 120 THz to 400 THz (2,500–750nm). Physical processes that are relevant for this range are similar to those for visible light. The highest frequencies in this region can be detected directly by some types of photographic film, and by many types of solid state image sensors for infrared photography and videography. Maxwell's predicted waves included waves at very low frequencies compared to infrared, which in theory might be created by oscillating charges in an ordinary electrical circuit of a certain type. Attempting to prove Maxwell's equations and detect such low frequency electromagnetic radiation, in 1886, the physicist Heinrich Hertz built an apparatus to generate and detect what are now called radio waves. Hertz found the waves and was able to infer (by measuring their wavelength and multiplying it by their frequency) that they traveled at the speed of light. Hertz also demonstrated that the new radiation could be both reflected and refracted by various dielectric media, in the same manner as light. For example, Hertz was able to focus the waves using a lens made of tree resin. In a later experiment, Hertz similarly produced and measured the properties of microwaves. These new types of waves paved the way for inventions such as the wireless telegraph and the radio.

Collective oscillation of charge carriers in bulk material ( plasma oscillation). An example would be the oscillatory travels of the electrons in an antenna. If radiation having a frequency in the visible region of the EM spectrum reflects off an object, say, a bowl of fruit, and then strikes the eyes, this results in visual perception of the scene. The brain's visual system processes the multitude of reflected frequencies into different shades and hues, and through this insufficiently-understood psychophysical phenomenon, most people perceive a bowl of fruit.Stimac, Tomislav. "Definition of frequency bands (VLF, ELF... etc.)". vlf.it . Retrieved 2022-01-21. A cult film or cult movie, also commonly referred to as a cult classic, is a film that has acquired a cult following. Cult films are known for their dedicated, passionate fanbase which forms an elaborate subculture that engage in repeated viewings, quoting dialogue, and audience participation. Inclusive definitions allow for major studio productions, especially box office bombs, while exclusive definitions focus more on obscure, transgressive films shunned by the mainstream. The difficulty in defining the term and subjectivity of what qualifies as a cult film mirror classificatory disputes about art. The term cult film itself was first used in the 1970s to describe the culture that surrounded underground films and midnight movies, though cult was in common use in film analysis for decades prior to that. Feynman, Richard; Leighton, Robert; Sands, Matthew (1963). The Feynman Lectures on Physics, Vol.1. US: Addison-Wesley. pp. 2–5. ISBN 978-0-201-02116-5. Davidson, Michael W. "Johann Wilhelm Ritter (1776–1810)". The Florida State University . Retrieved 5 March 2013. Ritter […] hypothesized that there must also be invisible radiation beyond the violet end of the spectrum and commenced experiments to confirm his speculation. He began working with silver chloride, a substance decomposed by light, measuring the speed at which different colours of light broke it down. […] Ritter […] demonstrated that the fastest rate of decomposition occurred with radiation that could not be seen, but that existed in a region beyond the violet. Ritter initially referred to the new type of radiation as chemical rays, but the title of ultraviolet radiation eventually became the preferred term.

Main article: Microwaves Plot of Earth's atmospheric opacity to various wavelengths of electromagnetic radiation. This is the surface-to-space opacity, the atmosphere is transparent to longwave radio transmissions within the troposphere but opaque to space due to the ionosphere. Plot of atmospheric opacity for terrestrial to terrestrial transmission showing the molecules responsible for some of the resonances Uses of Electromagnetic Waves | gcse-revision, physics, waves, uses-electromagnetic-waves | Revision World Energetic ejection of core electrons in heavy elements, Compton scattering (for all atomic numbers), excitation of atomic nuclei, including dissociation of nucleiThe last portion of the electromagnetic spectrum was filled in with the discovery of gamma rays. In 1900, Paul Villard was studying the radioactive emissions of radium when he identified a new type of radiation that he at first thought consisted of particles similar to known alpha and beta particles, but with the power of being far more penetrating than either. However, in 1910, British physicist William Henry Bragg demonstrated that gamma rays are electromagnetic radiation, not particles, and in 1914, Ernest Rutherford (who had named them gamma rays in 1903 when he realized that they were fundamentally different from charged alpha and beta particles) and Edward Andrade measured their wavelengths, and found that gamma rays were similar to X-rays, but with shorter wavelengths. The distinction between X-rays and gamma rays is partly based on sources: the photons generated from nuclear decay or other nuclear and subnuclear/particle process are always termed gamma rays, whereas X-rays are generated by electronic transitions involving highly energetic inner atomic electrons. [7] [8] [9] In general, nuclear transitions are much more energetic than electronic transitions, so gamma rays are more energetic than X-rays, but exceptions exist. By analogy to electronic transitions, muonic atom transitions are also said to produce X-rays, even though their energy may exceed 6 megaelectronvolts (0.96pJ), [10] whereas there are many (77 known to be less than 10keV (1.6fJ)) low-energy nuclear transitions ( e.g., the 7.6eV (1.22aJ) nuclear transition of thorium-229m), and, despite being one million-fold less energetic than some muonic X-rays, the emitted photons are still called gamma rays due to their nuclear origin. [11]