Tyndall effect, is firstly observed in 19thcentury by physicist John Tyndall. It is the phenomena of scattering light through a medium contains small particles present in its path by which the beam becomes visible. The amount of light scatter or reflect is depends upon the frequency (or wavelength) of light used. The longer wavelength light is more transmitted whereas the shorter wavelength light is more reflected by scattering. For example – In Tyndall effect, the blue light scattered more than red.
- In fog, the visible beam of headlights is an excellent demonstration of Tyndall effect. The water droplets preset in fog scatter light and making the headlights visible.
- Shining a flashlight beam into the glass of milk – is another example of Tyndall effect.
Important points –
- The blue color of the sky is also due to the scattering of light which is called Rayleigh scattering, or Tyndall effect. Because the particles present in the air are smaller than colloidal particles.
- The scattering of light from dust particles is not due to Tyndall effect because the particles present in dust particles are larger in size than colloidal particles.