An easy-to-understand explanation for 'General Relativity'

You may have come across the phrase "theory of relativity" or "theory of general relativity" in physics. So what is the theory of general relativity? Let's find the easiest way to understand this concept.

General relativity (or relativity for short) is a 'building block,' a fundamental element that makes up modern physics. This theory explains gravity (or gravitational force) based on the way space can bend, or more precisely, it links gravity to the changing shape of space-time.

Illustration of an object with mass that can bend space-time. (Photo: PashaIgnatov/iStock).

History of general relativity

The scientist Albert Einstein proposed this "general" theory in 1915, a decade after he proposed a "special" theory of relativity that applied the cosmic speed of light to the assumption that the laws of physics do not change in any frame of reference.

When he applied accelerated mass to that particular theory, he realized that objects with mass affect the dimensions around it (space-time) in such a way that the object acts in such a way that it can attract other objects with mass.

We can think of it as matter within a space-time fabric that presses down on that fabric, creating a "curve" that causes other matter near it to slide toward it.

The importance of general relativity

The mathematical equations of Einstein's general theory of relativity have been tested many times by scientists and remain the most accurate way to predict gravitational interactions, replacing the equations proposed by Isaac Newton several centuries earlier.

So far, we do not have such equivalent quantum field theories due to huge incompatibilities, for example: quantum mechanics has many ways to consider concepts like infinity, but if we also consider the concept of infinity in general relativity, the mathematics will give completely meaningless predictions.

Today, modern physicists are still trying to build a quantum physics "version" of general relativity.