This physical phenomenon scientifically explains why colloid particles in solution or gas are only visible if the suspension is crossed by an intense ray of light. This Tyndall effect is present in our daily lives when we turn on the car lights in the fog or when sunlight enters through our window and there is suspended dust in our room.
What is light?
To understand this phenomenon, we need to know that light is electromagnetic radiation transmitted through waves that allow us to see, and like any wave, it is subject to reflection and refraction phenomena.
Light reflection happens when a ray of light hits an opaque surface, causing the light to reflect in one or more directions just like mirrors. For its part, refraction is the change in direction and speed of the wave from one medium to another with a different refracted index, such as when sunlight hits the sea, since it has different properties from those of air, making the ray of light passes through it and changes direction.
colloidal state of matter
Another key point for this phenomenon is colloidal particles, this is a condition of mixtures when one of its elements in a solid state is dispersed in another that is in a liquid or gaseous state, such as aerosols, smoke or mist.
The colloidal state occurs when there are two chemical phases inside at the same time, these are known as the dispersed phase and the fluid phase. The dispersed phase corresponds to the solid composed of small particles, and the fluid phase is made up of a liquid or a gas where the solid particles are in a state of dispersion.
What is the Tyndall effect?
This phenomenon was studied by the Irish scientist John Tyndall in 1869, and it happens when a ray of light passes through a colloid, causing the solid particles that make it up to deflect the light and that is when the small flashes of light appear. we observe.
It is known as the phenomenon in which the existence of colloidal particles becomes visible, which are so small for our human eye to observe, due to their ability to reflect or refract light.
This is why the phenomenon makes it possible to explain why the sky is blue. The light comes from the Sun and is white, but once it enters the Earth and comes into contact with the gas molecules that compose it, it undergoes deviations. This deviation through which the light passes is different in each color depending on its wavelength. The colors that suffer the most from this deviation are blue and violet, because they are the ones with the shortest length, since the longer the length, the shorter. It will be your deviation.
This does not happen with true gases or solutions, since they do not have colloid particles and are therefore completely transparent as they do not have any component that can scatter light. Unlike this, when a ray of light passes through a dark room with colloid particles it will be possible to observe its path marked by a correlation of particles that reflect and refract light radiation.
It is for this reason that at concerts, gas chambers are used to successfully disperse the effects of the lights. In this way, an atmosphere full of rays of colored lights is created that invades the venue. Light works in mysterious ways and day by day we can observe its phenomena, although we do not always pay attention.