# Albert Einstein’s Special Theory of Relativity, What is the Theory of Relativity?

June 26, 2021 Off By Felso

The Special Theory of Relativity was explained by Albert Einstein in his 2nd article “On the electrodynamics of moving bodies” in 1905 in the journal Annalen der Physik, and then in his 5th article “Can the inertness of a body be related to its energy content?” Reinforced by the article titled.

The Special Theorem of Relativity was put forward by Albert Einstein in 1905 in his publication “On the Electrodynamics of Moving Bodies”. More than three hundred years ago, Galileo’s Principle of Relativity stated that time-invariant motion is relative; He proposed that there could be no absolute and fully defined state of rest. According to the idea put forward by Galileo; Someone on board a ship that is said to be moving by an outside observer can say that the ship is stationary. Einstein’s theory combines Galileo’s Principle of Relativity with the proposition that all observers will always measure the speed of light at the same magnitude, whatever the state of its linear and invariant motion.

This theorem allows us to arrive at many interesting conclusions that cannot be perceived intuitively, but have been proven experimentally. The special relativity theorem makes Newton’s concept of absolute space-time meaningless by stating that distance and time can change depending on the observer. Space and time can be perceived differently depending on the observer. This theorem also shows that matter and energy are linked by the famous formula E=mc2 (c is the speed of light). The special relativity theorem gives the same results as Newtonian mechanics in application areas where all velocities are very small compared to the speed of light.

The reason why the theorem is called with a special expression is because the principle of relativity is applied only to the inertial observation frame. Einstein developed the General Theorem of Relativity, which applies to all observation frames and takes into account the effect of the gravitational force. Special Relativity does not take into account the gravitational force, but also examines the case of accelerated observers.

Special Relativity states that concepts such as time, which we perceive as absolute in our daily life, are relative, while concepts that we intuitively think are relative are absolute. He says that the speed of light is the same for all observers, no matter how they move relative to each other. Special Relativity has revealed that the coefficient c is not only the speed of light of a certain natural event, but also the basic feature of the relationship between space and time. Special Relativity also says that no matter can be accelerated to reach the speed of light.

Overview of Theory

Relativity as a theory first emerged in Galileo Galilei’s thought about velocities. According to Galileo, an observer traveling at a constant speed or a stationary observer must use the same physical laws. For example, if you throw a stone upwards on a ship traveling at a constant speed, it will fall in the same place – as if you were standing still. This understanding was put into formulation in Newtonian physics. The form of Newton’s equations is the same for an object moving at a constant speed or a stationary object. It is worth noting here. An object traveling with constant velocity is described with respect to the observer. If you are traveling with an object at the same constant speed, the object will appear motionless to you. But for an outside observer, the object is considered moving. The word relativity arises here. The velocities we observe are not absolute. However, it is defined by the observer. But the form of the laws that apply to the observed event is the same.

A reference system that moves at a constant speed (non-accelerated) is called an inertial reference system. This concept has a very important place in the special theory of relativity. According to the special theory of relativity, no inertial reference system is superior to another, and the observations made in all of them are equally valid.

In the electrodynamics of uniformly-linear moving bodies, Einstein discovered:

– We live in a 4-dimensional space-time universe formed by 3 space and 1 time dimensions.

– Time dimension and flow depend on the velocity of moving objects.

– Mass depends on the speed of moving objects.

– The length of the object in the direction of motion depends on the velocity of the object.

– The concept of “simultaneousness” in the 4-dimensional universe is also not absolute, it is relative, that is, it changes from one observer to the instantaneous observer.

– Space-time references of objects moving at different speeds are different from each other.

– The speed of light is the upper speed limit in the universe.

– The most important reason for the strength and soundness of the special theory of relativity is that it is built on only two postulates.