SCATTERING OF LIGHT

 AROUND US GIVES RISE TO VARIOUS SCATTERING OF LIGHT - 

                                         THE INTERPLAY OF LIGHT WITH OBJECT PRESENT SPECTACULAR PHENOMENA IN NATURE . THE COLOUR IN DEEP SEA, BLUE COLOUR OF THE SKY, THE REDDENING  OF THE SUNSET AND SUNRISE ARE SOME OF THE WONDERFUL PHENOMENA.

 

1)   TYNDALL EFFECT -

                  THE EARTH ATMOSPHERE IS A HETEROGENEOUS MIXTURE OF SMALL PARTICLES. THESE PARTICLES INCLUDE TINY WATER DROPLETS , SMOKE , SUSPENDED PARTICLE OF DUST . WHEN RAYS OF FALLS ON THESE PARTICLE ,  THE PATH OF THE BEAM BECOMES VISIBLE. THE LIGHT REACHES US, AFTER BEING DIFFUSELY REFLECTED BY THESE TINY PARTICLE . THE PHENOMENA OF SCATTERING OF LIGHT BY THE COLLOIDAL PARTICLE OF LEADS TO TYNDALL EFFECT . WHICH PHENOMENA IS OBSERVED WHEN A FINE BEAM OF SUNLIGHT ENTERS A ROOM FILLED WITH SMOKE THROUGH A SMALL HOLE . THESE PHENOMENA OF SCATTERING OF LIGHT MAKES THE PARTICLE VISIBLE .TYNDALL EFFECT CAN ALSO BE SEEN WHEN SUNLIGHT PASSES THROUGH A CANOPY OF A DENSE FOREST . TINY WATER DROPLETS PRESENT IN THE MIST SCATTER LIGHT.

 

 2)  WHY IS THE COLOUR OF THE CLEAR SKY BLUE ?

                                                                          THE MOLECULES OF AIR AND OTHER FINE PARTICLES IN THE ATMOSPHERE HAVE SIZE SMALLER IN COMPARISON IN WAVELENGTH OF VISIBLE LIGHT . THESE ARE MORE EFFECTIVE IN SCATTERING THE LIGHT HAVING SHORTER WAVELENGTH AT THE BLUE END THAN LIGHT HAVING LONGER WAVELENGTH AT THE RED END . THE RED LIGHT CONTAIN A WAVELENGTH OF ABOUT 1.8 TIMES GREATER  THAN BLUE LIGHT . WHEN SUNLIGHT PASSES THROUGH THE EARTH ATMOSPHERE , THE FINE PARTICLE PRESENT IN AIR SCATTER THE BLUE COLOUR MORE STRONGLY IN COMPARISON TO THE RED . THE SCATTERED BLUE LIGHT FALLS ON OUR EYE . IF THE EARTH HAD NO ATMOSPHERE , THERE WOULD NOT TAKEN PLACE ANY SCATTERING . THAN, THE SKY WOULD HAVE APPEAR DARK. THE SKY LOOKS DARK TO PASSENGERS FLYING AT VERY HIGH ALTITUDES , AS SCATTERING IS NOT PROMINENT AT THESE HEIGHTS . 

3)  COLOUR OF THE SUN AT SUNRISE AND SUNSET -

                                                                             THE SCATTERING OF LIGHT THAT HELP YOU UNDERSTAND SEE THE BLUISH COLOUR OF THE SKY AND THE REDDISH APPEARANCE OF THE SUN AT THE SUNRISE OR THE SUNSET.  LIGHT COMING FOR THE SUN NEAR THE HORIZON PASSES ALONG THE THICKER LAYERS OF AIR AND LARGER VARIOUS DISTANCE IN THE EARTH ATMOSPHERE BEFORE REACHING OUR EYES 

 LIGHT FROM THE SUN OVERHEAD WOULD COMPARATIVELY SHORTER DISTANCE . AT  NOON , THE SUN LOOKS WHITE AS ONLY A LITTLE OF THE VIOLET AND BLUE COLOUR ARE SCATTERED . NEAR THE HORIZON,MOST OF THE BLUE LIGHT AND SHORTER WAVELENGTH ARE SCATTERED AWAY BY THE PARTICLE . THE LIGHT THAT FALLS ON OUR EYE IS LONGER WAVELENGTH . THESE PRODUCES TO THE REDDISH APPEARANCE OF THE SUN .