Albert Einstein was only 26 years old when he published these theories that will be explained.They alone are a real revolution, however, go beyond, because it changed our perspective of looking at the Universe. "Brownian" Motion
It is the year 1921, when Einstein devoted himself to the study of atoms and molecules.He explained the effect they have on the tiny pollen grains suspended in water.
But first it is better to understand where this effect came from.
In 1827, Robert Brown, a biologist, observed, under the microscope, the oscillatory motions that were made by pollen grains immersed in water. This movement compared to a dance, he has given the name of "Brownian" motion. Despite having observed this movement, he could not explain it.
Then, Albert Einstein, in his study of May 1905, suggested how the vibration of water caused this movement. He calculated the size of water molecules, and furthermore, predicted specific properties of their atoms.
This theory dissipated, even more, any trace of doubt about the existence of the atom and was used by other scientists as a basis for further research. The Special Theory of Relativity
This theory was published in June 1905. Currently, it is widely accepted, but may have some unknown contours.
It was an affront to the basic belief that the measure of time is a constant throughout the universe.
A belief that came from scientists like Isaac Newton.
To understand this theory, I cite an example: imagine that two people synchronize the clock with accuracy. One person goes around the world by plane. The other stays home. When the person who traveled the plane has returned, his watch will be late in relation to the person who stayed at home. From the standpoint of the person who was in the house, time passed slowly for the person who was on the plane. Of course, this difference is not visible on a common clock, it is infinitesimal in terms of human standard speed. However, if this speed approaching the speed of light, the time will pass significantly more slowly, objects will be smaller and it''s mass increases.
This theory says that the constant in the whole Universe is the speed and not time.
An example of the usefulness of this theory is the clocks on the satellites of the Global Positioning System (better known as GPS). These watches do not work as fast as the clocks on Earth. If this effect of relativity was not corrected, the GPS signal would be completely useless.