Difference Between Quantum Mechanics and General Relativity

The two most significant discoveries of the 20th century, Quantum Mechanics and the General Theory of Relativity, serve as the cornerstones of modern physics. Both of these hypotheses are crucial to our present knowledge of physics, yet they don't appear to mesh well. For many years, physicists have labored to find a middle ground between these two schools of thought. The main problems of Newtonian physics were addressed by both views. These two theories have drastically affected our sense of what objects ought to be and how they ought to act.

The General Theory of Relativity, written by Albert Einstein and published in 1915, is the cornerstone of contemporary physics and synthesizes special relativity and gravity. This is essential to our knowledge of many areas of astrophysics and cosmology. Quantum Mechanics, on the other hand, describes the fundamental properties of matter and energy at the subatomic and atomic levels. It examines the actions of the many particles that make up our cosmos, including photons, electrons, and positrons. Both theories have quite distinct formulations and are essentially very different.

What is Quantum Mechanics?

The strange actions of photons, electrons, and all the other particles that make up the cosmos are described by quantum mechanics, the theoretical foundation of modern physics. The inability of classical physics to account for a variety of microphysical phenomena seen around the turn of the nineteenth and early twentieth century led to the development of quantum mechanics.

Quantum mechanics is the subfield of physics concerned with the behaviour of subatomic particles. It is a crucial branch of contemporary physics that tries to explain the nature of molecules, atoms, and the elements that make them up. In a nutshell, physics is the study of how things operate.

What is General Relativity?

The General Theory of Relativity, often known as General Relativity, is a fundamental concept in classical physics since it unifies the concepts of special relativity and gravity. Several aspects of astrophysics and cosmology depend on the theory of relativity. Our concepts of space and time were substantially altered by general relativity.

According to relativity, objects cannot be in two different states at the same time. Yet the term "at the same time" is the issue here. Now, the idea of time is just a relative one, based on the perspective of the observer. According to relativity, your observations and measurements of an event are conditional on both your own viewpoint and the event itself. In 1915, Albert Einstein released his geometric theory of gravitation, which is known as the theory of relativity.

Differences: Quantum Mechanics and General Relativity

The following table highlights the major differences between Quantum Mechanics and General Relativity −


Quantum Mechanics

General Relativity


The study of quantum mechanics, which attempts to characterize the behavior of molecules and atoms and their constituents, is one of the most significant branches of modern physics.

Einstein's theory of relativity rests on the notion that the speed of light and all electromagnetic radiation are constants, independent of the observer's position with respect to the source.


In quantum mechanics, events are the sudden, localized manifestations of the basic interaction between subatomic particles.

What you witness and measure about an event relies on your own point of view and the event itself, according to Einstein's Theory of Relativity, which states that events are continuous and deterministic.

All observations must be understood in the context of the observer making them. An event is something that takes place at a given time and location.

The fundamental building blocks of the space-time cosmological description are events.


Quantum mechanics and general relativity are two important theories in physics that describe the behavior of matter and energy on different scales.

Despite their success, these theories have fundamental differences that have yet to be fully reconciled, including their probabilistic and deterministic nature and the underlying principles they are based on. The problem of quantum gravity is a result of these differences and remains one of the biggest unsolved problems in physics today.

Updated on: 26-Apr-2023


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