Brownian movement

Brownian motion deals with the random activity contemplated in the particles that are located in a fluid environment, whether gas or liquid, as a consequence of collisions, against the molecules that are present in said fluids. It receives this name to honor its discoverer, the biologist and botanist Robert Brown.

In 1827, Brown looked through his microscope at particles found within a grain of pollen found in water, indicating that the particles were moving through the liquid. However, he did not have the ability to define the methods that caused these movements.

The hasty movement of these particles occurs because their surface is persistently besieged by the molecules present in the fluid, subjecting them to thermal alteration. However, this bombardment is not entirely uniform, so it is subject to significant statistical variations. In this way, the pressure exerted on the sides can be slightly modified over time and thus the contemplated movement originates.

At first Brown could not find the answer about the cause that generated the movement of the particles. He first thought that the pollen was likely to be alive. To verify this, he placed a little pollen from plants that had been dead for a long time in a container filled with water and was able to observe that the pollen showed the same movements.

The mathematical explanation of this phenomenon was made by Albert Einstein, who edited an article where he explained in detail how the activity that Brown had seen was the product of pollen, which was being moved by the individual molecules present in the water. Einstein’s explanation corroborated the fact that molecules and atoms do exist. Later this theory was verified by Jean Perrin in the year of 1908 and that made him worthy of a Nobel Prize in Physics.