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Spectrum
A spectrum (: spectra or spectrums) is a set of related ideas, objects, or properties whose features overlap such that they blend to form a continuum. The word ''spectrum'' was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism. In the optical spectrum, light wavelength is viewed as continuous, and spectral colors are seen to blend into one another smoothly when organized in order of their corresponding wavelengths. As scientific understanding of light advanced, the term came to apply to the entire electromagnetic spectrum, including radiation not visible to the human eye. ''Spectrum'' has since been applied by analogy to topics outside optics. Thus, one might talk about the " spectrum of political opinion", or the "spectrum of activity" of a drug, or the " autism spectrum". In these uses, values within a spectrum may not be associated with precisely quantifiable numbers or definitions. Such uses imply a bro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autism Spectrum
Autism, also known as autism spectrum disorder (ASD), is a neurodevelopmental disorder characterized by differences or difficulties in social communication and interaction, a preference for predictability and routine, sensory processing differences, focused interests, and repetitive behaviors, which may include stimming. Formal diagnosis requires significant challenges in multiple domains of life, with characteristics that are atypical or more pronounced than expected for one's age and sociocultural context.(World Health Organization: International Classification of Diseases version 11 (ICD-11)): https://icd.who.int/browse/2024-01/mms/en#437815624 Motor coordination difficulties are common but not required for diagnosis. Autism is a spectrum disorder, resulting in wide variations in presentation and support needs, such as that between speaking and non-speaking populations. Increased estimates of autism prevalence since the 1990s are primarily attributed to broader cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Spectrum
The electromagnetic spectrum is the full range of electromagnetic radiation, organized by frequency or wavelength. The spectrum is divided into separate bands, with different names for the electromagnetic waves within each band. From low to high frequency these are: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. The electromagnetic waves in each of these bands have different characteristics, such as how they are produced, how they interact with matter, and their practical applications. Radio waves, at the low-frequency end of the spectrum, have the lowest photon energy and the longest wavelengths—thousands of kilometers, or more. They can be emitted and received by antenna (radio), antennas, and pass through the atmosphere, foliage, and most building materials. Gamma rays, at the high-frequency end of the spectrum, have the highest photon energies and the shortest wavelengths—much smaller than an atomic nucleus. Gamma rays, X-rays, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theory Of Colours (book)
''Theory of Colours'' () is a book by Johann Wolfgang von Goethe about the poet's views on the nature of colours and how they are perceived by humans. It was published in German in 1810 and in English in 1840. The book contains detailed descriptions of phenomena such as Complementary colours, coloured shadows, refraction, and chromatic aberration. The book is a successor to two short essays titled "Contributions to Optics" (). The work originated in Goethe's occupation with painting and primarily had its influence in the arts, with painters such as (Philipp Otto Runge, J. M. W. Turner, the Pre-Raphaelites, Hilma af Klint, and Wassily Kandinsky). Although Goethe's work was rejected by some physicists, a number of philosophers and physicists have concerned themselves with it, including Thomas Johann Seebeck, Arthur Schopenhauer (see: ''On Vision and Colors''), Hermann von Helmholtz, Ludwig Wittgenstein, Werner Heisenberg, Kurt Gödel, and Mitchell Feigenbaum. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectroscopy
Spectroscopy is the field of study that measures and interprets electromagnetic spectra. In narrower contexts, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum. Spectroscopy, primarily in the electromagnetic spectrum, is a fundamental exploratory tool in the fields of astronomy, chemistry, materials science, and physics, allowing the composition, physical structure and electronic structure of matter to be investigated at the atomic, molecular and macro scale, and over astronomical distances. Historically, spectroscopy originated as the study of the wavelength dependence of the absorption by gas phase matter of visible light dispersed by a prism. Current applications of spectroscopy include biomedical spectroscopy in the areas of tissue analysis and medical imaging. Matter waves and acoustic waves can also be considered forms of radiative energy, and recently gravitational waves have been associa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visible Light
Light, visible light, or visible radiation is electromagnetic radiation that can be perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 terahertz. The visible band sits adjacent to the infrared (with longer wavelengths and lower frequencies) and the ultraviolet (with shorter wavelengths and higher frequencies), called collectively '' optical radiation''. In physics, the term "light" may refer more broadly to electromagnetic radiation of any wavelength, whether visible or not. In this sense, gamma rays, X-rays, microwaves and radio waves are also light. The primary properties of light are intensity, propagation direction, frequency or wavelength spectrum, and polarization. Its speed in vacuum, , is one of the fundamental constants of nature. All electromagnetic radiation exhibits some properties of both particles and waves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Political Spectrum
A political spectrum is a system to characterize and classify different Politics, political positions in relation to one another. These positions sit upon one or more Geometry, geometric Coordinate axis, axes that represent independent political dimensions. The expressions political compass and political map are used to refer to the political spectrum as well, especially to popular two-dimensional models of it. Most long-standing spectra include the Left–right politics, left–right dimension as a measure of social, political and economic Social hierarchy, hierarchy which originally referred to seating arrangements in the French parliament after the French Revolution, Revolution (1789–1799), with Classical radicalism, radicals on Left-wing politics, the left and Aristocracy, aristocrats on Right-wing politics, the right. While communism and socialism are usually regarded internationally as being on the left, conservatism and Reactionary, reactionism are generally regarded as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Left–right Political Spectrum
The left–right political spectrum is a system of classifying political positions, ideologies and political parties, parties, with emphasis placed upon issues of social equality and social hierarchy. In addition to positions on the left and on the right, there are centrist and moderate positions, which are not strongly aligned with either end of the spectrum. It originated during the French Revolution based on the seating in the French National Assembly (French Revolution), National Assembly. On this type of political spectrum, left-wing politics and right-wing politics are often presented as opposed, although a particular individual or group may take a left-wing stance on one matter and a right-wing stance on another; and some stances may overlap and be considered either left-wing or right-wing depending on the ideology. In France, where the terms originated, the left has been called "the party of movement" or ''liberal'', and the right "the party of order" or ''conservative''. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rainbow Above Kaviskis Lake, Lithuania
A rainbow is an optical phenomenon caused by refraction, internal reflection and dispersion (optics), dispersion of light in water droplets resulting in a continuous visible spectrum, spectrum of light appearing in the sky. The rainbow takes the form of a multicoloured circular arc (geometry), arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the Sun. Rainbows can be caused by many forms of airborne water. These include not only rain, but also mist, spray, and airborne dew. Rainbows can be full circles. However, the observer normally sees only an arc formed by illuminated droplets above the ground, and centered on a line from the Sun to the observer's eye. In a primary rainbow, the arc shows red on the outer part and violet on the inner side. This rainbow is caused by light being refracted when entering a droplet of water, then reflected inside on the back of the droplet and refracted again when leaving it. In a double rainbow, a second ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rainbow
A rainbow is an optical phenomenon caused by refraction, internal reflection and dispersion of light in water droplets resulting in a continuous spectrum of light appearing in the sky. The rainbow takes the form of a multicoloured circular arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the Sun. Rainbows can be caused by many forms of airborne water. These include not only rain, but also mist, spray, and airborne dew. Rainbows can be full circles. However, the observer normally sees only an arc formed by illuminated droplets above the ground, and centered on a line from the Sun to the observer's eye. In a primary rainbow, the arc shows red on the outer part and violet on the inner side. This rainbow is caused by light being refracted when entering a droplet of water, then reflected inside on the back of the droplet and refracted again when leaving it. In a double rainbow, a second arc is seen outside the primary arc, and has the or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
On Vision And Colors
''On Vision and Colors'' (originally translated as ''On Vision and Colours''; ) is a treatise by Arthur Schopenhauer that was published in May 1816 when the author was 28 years old. Schopenhauer had extensive discussions with Johann Wolfgang von Goethe about the poet's ''Theory of Colours'' of 1810, in the months around the turn of the years 1813 and 1814, and initially shared Goethe's views.Karl Robert Mandelkow, Bodo Morawe: Goethes Briefe (''Goethe's Letters''). 1. edition. Vol. 3: Briefe der Jahre 1805-1821 (''Letters of the years 1805-1821''). ''Christian Wegner'' publishers, Hamburg 1965, p. 639. "Vom November 1813 bis zum Mai 1814 sind sie in Weimar sehr häufig zusammengewesen. (...) In den Mittelpunkt der Diskussionen rückte schließlich die Goethesche ''Farbenlehre''. Schopenhauer teilte prinzipiell die Ansichten des Dichters, wich jedoch in gewissen Einzelheiten von ihnen ab." (''"From November 1813 till May 1814, they were together very often in Weimar. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wavelength
In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats. In other words, it is the distance between consecutive corresponding points of the same ''phase (waves), phase'' on the wave, such as two adjacent crests, troughs, or zero crossings. Wavelength is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. The multiplicative inverse, inverse of the wavelength is called the ''spatial frequency''. Wavelength is commonly designated by the Greek letter lambda (''λ''). For a modulated wave, ''wavelength'' may refer to the carrier wavelength of the signal. The term ''wavelength'' may also apply to the repeating envelope (mathematics), envelope of modulated waves or waves formed by Interference (wave propagation), interference of several sinusoids. Assuming a sinusoidal wave moving at a fixed phase velocity, wave speed, wavelength is inversely proportion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narrow-spectrum Antibiotic
A narrow-spectrum antibiotic is an antibiotic that is only able to kill or inhibit limited species of bacteria. Examples of narrow-spectrum antibiotics include fidaxomicin and sarecycline Sarecycline, sold under the brand name Seysara, is a narrow-spectrum tetracycline-derived antibiotic medication. It is specifically designed for the treatment of acne, and was approved by the FDA in October 2018 for the treatment of inflammat .... Advantages * Narrow-spectrum antibiotic allow to kill or inhibit only those bacteria species that are unwanted (i.e. causing disease). As such, it leaves most of the beneficial bacteria unaffected, hence minimizing the collateral damage on the microbiota. * Low propensity for bacterial resistance development. Disadvantages Often, the exact species of bacteria causing the illness is unknown, in which case narrow-spectrum antibiotics can't be used, and broad-spectrum antibiotics are used instead. To know the exact species of bacteria causing the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
