Search results
Results from the WOW.Com Content Network
When infrared light of these frequencies strikes an object, the energy is reflected or transmitted. If the object is transparent, then the light waves are passed on to neighboring atoms through the bulk of the material and re-emitted on the opposite side of the object. Such frequencies of light waves are said to be transmitted. [10] [11]
An opaque object is neither transparent (allowing all light to pass through) nor translucent (allowing some light to pass through). When light strikes an interface between two substances, in general, some may be reflected, some absorbed, some scattered, and the rest transmitted (also see refraction ).
Due to the magnitude of c, the effect of light pressure is negligible for everyday objects. For example, a one-milliwatt laser pointer exerts a force of about 3.3 piconewtons on the object being illuminated; thus, one could lift a U.S. penny with laser pointers, but doing so would require about 30 billion 1-mW laser pointers. [22]
For example, since visible light has a wavelength scale on the order of hundreds of nanometers, scattering centers will have dimensions on a similar spatial scale. Most ceramic materials, such as alumina and its compounds, are formed from fine powders, yielding a fine grained polycrystalline microstructure that is filled with scattering centers ...
Lithophane of Frederick the Great, lit from front.After a well known painting by Julius Schrader (1849). [1] The same lithophane, backlit. A lithophane is a thin plaque of translucent material, normally porcelain, which has been moulded to varying thickness, such that when lit from behind the different thicknesses show as different shades, forming an image.
For example, on typical radiographs, bones look white or light gray (radiopaque), whereas muscle and skin look black or dark gray, being mostly invisible (radiolucent). Though the term radiodensity is more commonly used in the context of qualitative comparison, radiodensity can also be quantified according to the Hounsfield scale , a principle ...
Iridescence is also found in plants, animals and many other items. The range of colours of natural iridescent objects can be narrow, for example shifting between two or three colours as the viewing angle changes, [5] [6] An iridescent biofilm on the surface of a fish tank diffracts the reflected light, displaying the entire spectrum of colours ...
The opaque projector, or episcope is a device which displays opaque materials by shining a bright lamp onto the object from above. The episcope must be distinguished from the diascope , which is a projector used for projecting images of transparent objects (such as films), and from the epidiascope , which is capable of projecting images of both ...