Sinking: Difference between revisions

Latest revision as of 05:41, 30 March 2024

A mirage in which the image of distant objects is displaced downward.

Because the displacement increases with distance, a horizontal surface, such as that of a body of water, desert, or road, appears to bend downward and one's perception is that of being on top of an inverted bowl or possibly on a planet with a very much smaller radius. Indeed, the downward bending surface results in an (optical) horizon that can be very much closer to the observer than in the absence of a mirage. Sinking is an example of an inferior mirage. The opposite of sinking is looming. Sinking occurs when the concave side of light rays from a distant object is up, and this in turn occurs when the refractive index of the atmosphere increases with height. This only happens near a surface when the heat flux is upward and so the temperature gradient decreases with height. This is common over a warm surface (such as might occur over sun-warmed ground or a lake at night). Sinking is often accompanied by a two-image inferior mirage.
Compare stooping.

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+{{Term
+|Display title=sinking
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+|Meaning=A [[mirage]] in which the [[image]] of distant objects is displaced downward.
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+|Explanation=Because the displacement increases with distance, a horizontal surface, such as that of a body  of water, [[desert]], or road, appears to bend downward and one's perception is that of being on top  of an inverted bowl or possibly on a planet with a very much smaller radius. Indeed, the downward  bending surface results in an (optical) [[horizon]] that can be very much closer to the observer than  in the absence of a mirage. Sinking is an example of an [[inferior mirage]]. The opposite of sinking  is [[looming]]. Sinking occurs when the concave side of [[light]] rays from a distant object is up, and  this in turn occurs when the [[refractive index]] of the [[atmosphere]] increases with height. This only  happens near a surface when the [[heat flux]] is upward and so the [[temperature]] gradient decreases  with height. This is common over a warm surface (such as might occur over sun-warmed ground  or a lake at night). Sinking is often accompanied by a two-image inferior mirage. <br/>''Compare'' [[stooping]].
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-<div class="definition"><div class="short_definition">A [[mirage]] in which the [[image]] of distant objects is displaced downward.</div><br/> <div class="paragraph">Because the displacement increases with distance, a horizontal surface, such as that of a body  of water, [[desert]], or road, appears to bend downward and one's perception is that of being on top  of an inverted bowl or possibly on a planet with a very much smaller radius. Indeed, the downward  bending surface results in an (optical) [[horizon]] that can be very much closer to the observer than  in the absence of a mirage. Sinking is an example of an [[inferior mirage]]. The opposite of sinking  is [[looming]]. Sinking occurs when the concave side of [[light]] rays from a distant object is up, and  this in turn occurs when the [[refractive index]] of the [[atmosphere]] increases with height. This only  happens near a surface when the [[heat flux]] is upward and so the [[temperature]] gradient decreases  with height. This is common over a warm surface (such as might occur over sun-warmed ground  or a lake at night). Sinking is often accompanied by a two-image inferior mirage. <br/>''Compare'' [[stooping]].</div><br/> </div>
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