As light moves through a medium, it will become dimmer as it is being 'extinguished'. Illustration is labeled Transmission: Light can pass through. The arrow does not change as it moves into, through, and out of the box. The belief in aether as an element was held by medieval. It was the name given to the material that was believed to fill the universe beyond the terrestrial sphere. (1) Aether was the fifth element in alchemical chemistry and early physics. The roots of the term absorbance are in the Beer–Lambert law. A red arrow representing a light ray points straight down from the top and passes straight through the light purple box, exiting below it. There are two related science definitions for the term 'aether', as well as other non-scientific meanings. History and uses of the term absorbance Beer-Lambert law Sometimes the term 'attenuance' or 'experimental absorbance' is used to emphasize that radiation is lost from the beam by processes other than absorption, with the term 'internal absorbance' used to emphasize that the necessary corrections have been made to eliminate the effects of phenomena other than absorption. The term absorption refers to the physical process of absorbing light, while absorbance does not always measure only absorption it may measure attenuation (of transmitted radiant power) caused by absorption, as well as reflection, scattering, and other physical processes. What these uses of the term tend to have in common is that they refer to a logarithm of the ratio of a quantity of light incident on a sample or material to that which is detected after the light has interacted with the sample.

While the term has its origin in quantifying the absorption of light, it is often entangled with quantification of light which is “lost” to a detector system through other mechanisms. The term is used in many technical areas to quantify the results of an experimental measurement. However, the blanket only reflects the yellow light waves, and it absorbs all the others. Alternatively, for samples which scatter light, absorbance may be defined as 'the negative logarithm of one minus absorptance, as measured on a uniform sample'. The light bulb emits the entire light spectrum of all the colors. For other uses, see Refractive index, Nucleic acid quantitation, and Neutral-density filter.Ībsorbance is defined as 'the logarithm of the ratio of incident to transmitted radiant power through a sample (excluding the effects on cell walls)'.

Transmission light science definition