Strange optical effects in water - explained

A rippling halo surrounds your head shadow in shallow water and can extend over a large area as 'radial lines'. The cloudy water can also produce bi-colour shadows as shown here.

Optics expert Les Cowley explains the phenomenon in Spaceweather.com: The light and dark streaks radiating from the head are a water aureole. It is a perspective effect rather like anti-crepuscular rays. Waves on the surface focus the sun into parallel cones of light pointing downwards through the water. The aureole, seen when the water is slightly cloudy, is your view of the cones apparently converging on the point opposite the sun where your shadow is also situated.

The colored shadows are another cloudy water effect. Small particles in water scatter sunlight like the air molecules that make the sky blue. When we see the particles side on to the light against the dark shadow background they look blue. But scattering blue light leaves sunlight reddened. These remaining 'sunset rays' make other shadow edges appear orange-red.

Category:

Science & Technology

Tags:

• water
• ripple
• halo
• shadows
• bi-colour
• strange
• turbid
• cloudy
• optic
• lens
• aureole
• anti
• crepuscular
• rays
• sunlight

[jamiekin]

I just got home from a big Saturday night, and I am drunk as hell, and this video freaked me out.

[r3v3rs3tWiLiT3]

in my video "Sun Sprites Dance on a Woodland Stream" I filmed water bubbles being lit by the sun- causing bright star effect- when I watched the video I shot I noticed magenta points of light like the points of light from a laser pointer or gun sight- I imagine this is some kind of prism effect of light passing through the bubbles? anyone care to look and explain more fully?

[PaNtoKraToRaS]

it is like oposition or something...:)

[carlosepech]

Great video mate!

[Nannaroo17]

Very interesting!

Thanks for sharing it.

:D