The Tyndall effect, which is also known as Tyndall scattering, is the name of the effect that was described for the very first time by 19th century physicist John Tyndall. It is described as the scattering of light as a light ray passes through a colloid. Basically, the individual suspension particles scatter and reflect light and the beam becomes visible.
The frequency of the light and the density of the particles are two things that determine the amount of scattering. Just like Rayleigh scattering, the blue light is scattered more strongly compared to the red one by the Tyndall effect. Aside from that, you can also see that the longer wavelength light is transmitted, while the shorter one is reflected by scattering.
The size of the particles is the thing that differentiate a colloid from a true solution. To make a mixture a colloid, keep in mind that it is a must for the particles to be in the range 1-1000 nanometers in diameter.
There are a lot of examples of the Tyndall effects. Here are some of those examples:
- Blue eye color is born from the Tyndall scattering through the translucent layer over the iris of the eye.
- The blue color of smoke from motorcycles or two stroke engines is the second example of the Tyndall effect that scatters blue light.
- The headlights that are seen in fog are examples of Tyndall effect. The light is scattered by the water droplets and it makes the headlight beams visible.
- The Tyndall effect is apparently used in commercial and lab settings. The aim of it is to determine the particle size of aerosols. The one that is in charge to show the Tyndall effect is the opalescent glass. The glass looks blue but the light that shines through it seems to be orange.
- When you shine a flashlight beam into a glass of milk, you will be able to see the Tyndall effect. Milk is known as a colloid that has globules of fat and protein. If you want to see the effect of the colloid particles on the light beam, you can try to use skim milk. Another way that you can do it is to dilute the milk with a bit of water.
- When you suspend flour or cornstarch in water. Usually, the color of the four is off white or slightly yellow. In the end, the liquid will appear to be a bit blue because the particles scatter blue light more than red.
If you are thinking about the blue color of the sky when talking about the Tyndall effect, then you are wrong because rather than the Tyndall effect, it is called Rayleigh scattering. The reason for it is because the particles that are involved are molecules in the air. All of them are smaller compared to the ones in a colloid. However, when the sky is cloudy, the scattering of light is due to the relatively large cloud droplets. Instead of the Tyndall effect or Rayleigh effect, this one is known as Mie scattering.
Not only the blue color of the sky, light scattering from the dust particles is also not due to the Tyndall effect. While the particles in the blue color of the sky are smaller compared to in a colloid, the particles in the light scattering form dust particles are larger, hence cannot be considered as the Tyndall effect.
These followings will uncover more about the Tyndall effect on blue eye color due to a lot of people who are interested in this topic. If you also find it interesting, you can keep reading the article until the very end.
Basically, what makes the blue, brown, and black colored irises different is the amount of melanin in one of its layers. There is a relatively lower amount of melanin in the layer of the blue iris compared to the black ones. That’s why it is translucent. When there is a light on the translucent layer, it is scattered due to the Tyndall effect.
Due to the fact that the wavelength in the blue light is shorter compared to the red one, it is scattered to a greater extent. Another layer deeper that the iris have is in charge of absorbing the unscattered light. Apparently, the scattered light is mainly blue, which explains why these irises earn their characteristic blue color.
Learning chemistry is always fun. It is like an onion that has many layers. Everyday, we can get to know about something by learning a new thing. If you are interested in the effects such as Tyndall effects, you might also want to check out the other effects, including abscopal effect, accelerator effect, Allee effect, accordion effect, additive genetic effect, Aharonov-Bohm effect, Askaryan effect, Baldwin effect, Baskerville effect, Bauschinger effect, beta-silicon effet, Bezold effect, Bezold-Brucke effect, Biefeld-Brown effect, black drop effect, Blazhko effect, Bridgman effect, cage effect, captodative effect, calendar effect, Casimir effect, catapult effect, ceiling effect, Cherenkov effect, Christiansen effect, Christofilos effect, cis effect, common-ion effect, cotton-mouton effect, crabtree effect, cytopathic effect, dole effect, domino effect, Edison effect, Efimov effect, Einstein-de Hass effect, electroviscous effect, EMC effect, Evershed effect, espresso crema effect, Faraday effect, Fahraeus-Lindquist effect, floating body effect, flux pinning, fractional quantum hall effect, free surface effect, Garshelis effect, Gauche effect, Gibbsons-Hawking effect, Gibbs-Donnan effect, Gibbs-Thomson effect, glasser effect, Goos-Hanchen effect, green-bread effect, Hanbury Brown and Twiss effect, Holtzman effect, hot chocolate effect, hydrophobic effect, hyperchromic effect, inductive effect, inert pair effect, Jupiter effect, Kapitsa effect, Kerr effect, kinetic isotope effect, Kirkendall effect, Klein-Nishina effect, Kohn effect, Kondo effect, lake effect, Lee-Boot effect, Leidenfrost effect, Lenard effect, lense-thirring effect, leveling effect, liquid sky effect, little-parks effect, lockin effect, magnetic isotope effect, magneto-optic effect, magneto-optic Kerr effect, magnetocaloric effect, magnus effect, Malter effect, Marangoni effect, Marchywka effect, McCollough effect, memory effect, mesomeric effect, Mikheyev-Smimov-Wolfenstein effect, milky seas effect, Miller effect, and many more.