Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. Skip to content. Red sky and sun on the time of Sunset or Sunrise: At the time of sunrise or sunset, the position of the sun is very far away from the earth. Condition for Tyndall effect: When the diameter of the dispersed particles is little smaller than the wavelength of light used.
Sajid Mostaque. Was The Moon Landing Fake? Leave a Reply Cancel reply Your email address will not be published. Click to enlarge; cross-eyed viewing is recommended. The coordinates are obtained from a random number generator. The scattered intensities show strong statistical fluctuations; to reduce these, average values over a larger number of similar systems are taken.
Multiple scattering is ignored. It is seen that the correlations change the colour of the scattered light towards a more sarurated blue, as the longer wavelengths are supressed. Guanophores in front of a dark background layer are seen blue like the blue sky as long as the suspended particles are small compared to the visible wavelengths and thus scatter the shorter waves much more than the longer ones. White light is remitted if the crystals are larger, like the droplets in clouds.
Iridescence is also possible if the crystals form a regular lattice or are platelike and oriented. Structural colours produced by regular nanostructures like stacks of transparent layers beetles, hummingbirds, butterflies or space-lattice like structures peacocks' and pheasants' feathers, butterflies exhibit the whole spectrum of bright colours, while the irregular distribution of small scatterers yields only sky-blue hues.
This is kind of in-between of Tyndall scattering and structural colour. Legal Information Data Privacy. Just before sunset on a hazy day. The sun is about 0. On the right hand side: enlarged detail. More images with sunsets. After sunset on a clear day. In the west the sky is brightest near the horizon left , in the east it is darkest there due to the earth's shadow.
Above the shadow zone there is a slight pink reflection of the setting sun's red light. Left: Feather of an Eurasian jay. Image width 4 cm. Right: enlarged detail. An average has been taken over systems.
The results are in agreement with the experimental findings of Prum et al. Green colour is achieved by adding a transparent top layer of yellow cells. Their pigment mostly a carotenoid acts like a filter and quenches the short waves.
This is modeled in the adjacent figure. The blue line is the scattered light without the yellow layer, the same as in the right image above. The thin yellow line is the transmittance of a yellow filter slightly idealized , and the green line is obtained by applying the filter to the spectral distribution given by the blue line. The colour without and with the yellow layer is also shown. Autumn leaves and blue, cloudless sky.
Automatic white balance. Immediate comparison looking alternatingly out of the window and at the screen attests optimal reproduction of the colours. Selective scattering or Rayleigh scattering occurs when certain particles are more effective at scattering a particular wavelength of light. Air molecules, like oxygen and nitrogen for example, are small in size and thus more effective at scattering shorter wavelengths of light blue and violet.
The selective scattering by air molecules is responsible for producing our blue skies on a clear sunny day. Another type of scattering called Mie Scattering is responsible for the white appearance of clouds.
0コメント