The Tyndall effect refers to the:

1. A colloidal solution has particles bigger than molecules but small enough to stay suspended. 2. When light passes through such a colloid, the particles scatter it. 3. The path of the light becomes visible as a bright streak. 4. This visible streak is called the Tyndall effect. 5. Examples include sunlight through forest canopy and a torch beam in misty air. _Source: syllabus Science Ch 11 'Human Eye and the Colourful World'_