RAYLEIGH-scattering in a very simple experiment

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RAYLEIGH-scattering is the cause of the blue sky and the orange sunset.

If p is the scattering-probability and l is the wavelength of radiation, than is


The probability for scattering is very high for a short wavelength.

That’s why the blue part of the white sunlight is scattered all over the sky and sometimes –it depends on the way through the atmosphere and some meteorological facts- it is so strong that the sunlight is visible in white minus blue: orange.

When it is useful?

It is possible to show the effect every time to show little children why the sky is blue.

And it is possible too, if you want to explain it by using the word RAYLEIGH-scattering.

Then it sounds very professional.


Which material you need?

-one small aquarium


-one very normal lamp with focus, maybe a torch

-a little bit of coffee-whitener (no milk, and really only a very little bit)




The rest is shown here


The view from the left side shows the orange light.

Show before, that the light is white!

The view from the top shows a light-blue cone from the right to the left.



RAYLEIGH-scattering is also visible if you watch tobacco smoke.

The smoke direct from the tobacco is blue! …

After inhaling in a humid body and exhaling, the size of particles gets bigger.

RAYLEIGH-scattering never happens. The smoke is gray or brown.