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The terms derive from the colours red and blue which form the extremes of the visible light spectrum. The main causes of electromagnetic redshift in astronomy and cosmology are the relative motions of radiation sources, which give rise to the relativistic Doppler effect , and gravitational potentials, which gravitationally redshift escaping ...
A simplified Jablonski diagram illustrating the change of energy levels.. The principle behind fluorescence is that the fluorescent moiety contains electrons which can absorb a photon and briefly enter an excited state before either dispersing the energy non-radiatively or emitting it as a photon, but with a lower energy, i.e., at a longer wavelength (wavelength and energy are inversely ...
Example of normal Stokes emission through fluorescence (left, red) and anti-Stokes emission (right, blue) through sensitized triplet-triplet annihilation based photon upconversion, samples excited with green light. Upconversion fluorescence. Optical fiber that contains infrared light shines with a blue color in the dark
In physics and general relativity, gravitational redshift (known as Einstein shift in older literature) [1] [2] is the phenomenon that electromagnetic waves or photons travelling out of a gravitational well lose energy. This loss of energy corresponds to a decrease in the wave frequency and increase in the wavelength, known more generally as a ...
In spectroscopy, bathochromic shift (from Greek βαθύς (bathys) 'deep' and χρῶμα (chrōma) 'color'; hence less common alternate spelling "bathychromic") is a change of spectral band position in the absorption, reflectance, transmittance, or emission spectrum of a molecule to a longer wavelength (lower frequency). [1]
Because the blue color in the visible spectrum has a shorter wavelength than most other colors, this effect is also commonly called a blue shift. [1] It should not be confused with a bathochromic shift, which is the opposite process – the molecule's spectra are changed to a longer wavelength (lower frequency).
There are many ways in which atoms can be brought to an excited state. Interaction with electromagnetic radiation is used in fluorescence spectroscopy, protons or other heavier particles in particle-induced X-ray emission and electrons or X-ray photons in energy-dispersive X-ray spectroscopy or X-ray fluorescence. The simplest method is to heat ...
An example of this phenomenon is when clean air scatters blue light more than red light, and so the midday sky appears blue (apart from the area around the Sun which appears white because the light is not scattered as much). The optical window is also referred to as the "visible window" because it overlaps the human visible response spectrum.