Difference Between Tyndall Effect and Brownian Motion

Main difference

The main difference between Tyndall effect and Brownian motion is that Tyndall effect is the phenomenon of light scattering in a colloidal substance while Brownian motion is due to particle collisions by their random motion.

Tyndall Effect vs. Brownian Motion

Tyndall effect was given by the Irish physicist John Tyndall in the 19th century , while Brownian motion was given by the Scottish botanist Robert Brown in 1827. Tyndall effect is the phenomenon of light scattering that is affected by different substances of size, while Brownian motion is the collision of particles of substance with different atoms or molecules of fluids by their random motion. The Tyndall effect is observable in media such as colloidal solutions that are heterogeneous mixtures, on the other side of the coin, Brownian motion is observable in fluids whose atoms or molecules are in the state of continuous motion.

The Tyndall effect is affected by the wavelengths of light, as longer wavelengths are less scattered by colloids, as well as the falloff frequency of the light and the density of the colloidal substance. Brownian motion is affected by factors such as the concentration of molecules, temperature, viscosity, and particle size. The Tyndall effect applied on colloidal solutions has substances with a diameter of 40 to 900 nm, while the Brownian motion applied efficiently on small diameter molecules experience less friction.

The Tyndall effect can be observed with the human eye by passing a beam of light through the colloidal substance, while using a light microscope to observe the Brownian motion of the particles as random motion. Examples of the Tyndall effect are the glass of diluted milk in which when the flashlight is used, scattering is observed and also the blue light from the eye. Examples of Brownian motion are the diffusion of dust particles and gases from industries into the air and the diffusion of calcium from the blood into the bones.

Comparison chart

Tyndall effect Brownian movement
The Tyndall effect is the phenomenon of light scattering by different wavelengths of light in the colloidal solution. Brownian motion is the collision of fluid molecules or atoms by the random motion of fluid particles, which are in a state of continuous motion.
observation medium
by human eye By optical microscope
light scattering phenomenon Movement of particles by collisions
Applicable medium
colloidal solutions Fluids such as liquids, gases.
substance size
From 40 to 900nm smaller diameter
Factors Affecting
Wavelengths of light, density of a colloidal substance, frequency of light Particle size, temperature, viscosity, particle concentration.
Milk solution, Soap solutions, Opalescent glass Diffusion of dust, gases in the air, Diffusion of calcium to the bones

What is the Tyndall effect?

I t works based on the principle that shows the scattering of light by different wavelengths in substances of various sizes.

Tyndall effect, as a light scattering phenomenon, was first observed by an Irish physicist named John Tyndall in the 19th century . This phenomenon applies to colloidal solutions that are not fine and are heterogeneous mixtures that have particles with a diameter of 40 to 900 nm. In this effect, the light is scattered, which can vary by the factors of the frequency of the light and the density of the colloid substance on which the light falls. The Tyndall effect is characteristic of colloidal solutions distinguishing them from true ones.

Longer wavelengths of light, such as red light, are resistant to scattering as it is transmitted through the colloidal solution, but shorter wavelengths of light, such as blue light, show a scattering effect. larger spread. Blue light exhibits the Tyndall effect of being scattered ten times more than red light.


  • The Tyndall effect can be observed in the glass of milk by diluting it with water and then shining the flashlight beam on it. Shows colloidal particles affected by light.
  • For aerosol particle size determination, the Tyndall effect is used in the laboratory.
  • In the fog there are drops of water that are responsible for making the headlights visible by scattering the light.
  • Opalescent glass shows light as orange when it shines through it, while its actual color is blue. Soap solutions, starch, albumin, and blood are also examples of Tyndall effects exhibited by colloids.

What is brownian movement?

Like diffusion, Brownian motion is the collision of particles with atoms or molecules by their random motion in a fluid, which can be liquid or gas.

Brownian motion was first observed in 1827 in pollens from the Clarkia pulchella plant , which were submerged in water (fluid) moving by collisions with water molecules by the Scottish botanist named Robert Brown; therefore, it is called Brownian motion. It also receives the name of pedesis, whose origin is the Greek word, which means to jump. It is also taken into account as the terms Gaussian process and Markov process.

Brownian motion as a macroscopic property is affected by the microscopic effects of random motions of atoms or molecules. Several factors can affect by direct relationship, increasing the rate of Brownian motion.

Some examples are the diffusion of polluting gases and fluids in the air, the diffusion of calcium in the bones from the blood, the movement of holes in semiconductors of electrical charge, the grains of pollen that move in still water by collision with molecules or water atoms that are in a continuous state. movement.

Factors Affecting Brownian Motion

  • In Diffusion , the region of higher particle number allows particles to diffuse to the region of lower particle number.
  • Small size particles without frictional force moving face, therefore they move freely.
  • The low viscosity favors a higher speed of Brownian motion.
  • The high temperature increases the kinetic energy of the molecules, leading them to a higher rate of Brownian motion.

Key differences

  1. The Tyndall effect is the phenomenon of light scattering by colloidal particles as they are large enough to scatter light; on the other hand, Brownian motion is the movement of particles of a substance by collisions with fluid molecules.
  2. The Tyndall effect involves the scattering of light, while Brownian motion involves the collision of particles.
  3. Tyndall effect is named after John Tyndall’s discovery in the 19th century ; by contrast, Brownian motion is named after scientist Robert Brown in 1827.
  4. The Tyndall effect occurs in colloidal solutions whose particle sizes are larger; On the other side of the coin, Brownian motion occurs in fluids such as liquids and gases whose molecules are in a state of motion.
  5. Tyndall effect is a macroscopic property resulting from the microscopic effects of colloid particles, while Brownian motion is also a macroscopic property influenced by microscopic effects of molecules.
  6. The Tyndall effect is affected by the frequency, wavelength of light, and density of colloidal solutions; on the other hand, Brownian motion is affected by particle size, concentration, viscosity, and temperature.
  7. The Tyndall effect can be observed by the human eye as in milk solutions, while Brownian motion can be observed with a light microscope as pollen grains in still water.

Final Thought

The Tyndall effect explains the scattering of light by colloidal solutions of different sizes, while Brownian motion deals with the motion of particles by collision with fluid molecules.

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button