The force of gravity does NOT exist

The theory of general relativity is a physical theory developed by Albert Einstein in 1915. Based on its main bases, which we will study in detail:

1. Principle of relativity: The theory of general relativity is based on the principle of relativity, which states that the laws of physics are the same in all inertial systems. This means that the physical laws must be consistent both in a reference frame at rest and in one in uniform rectilinear motion.

2. Equivalence between gravity and acceleration: One of the fundamental concepts of general relativity is that gravity is not a traditional force, but is related to the acceleration of objects. According to Einstein, an observer in free fall in a gravitational field cannot distinguish between gravity and a situation of constant acceleration in the absence of gravity.

3. Curvature of space-time: General relativity proposes that the presence of mass and energy causes the curvature of space-time. Massive objects, such as planets or stars, warp space-time around them, creating a kind of "depression" in the fabric of space-time.

4. Einstein's field equations: Einstein's field equations are the set of equations that describe the relationship between the curvature of space-time and the distribution of mass and energy in the universe. These equations establish how the geometry of space-time is related to the distribution of mass and energy, allowing us to calculate how space-time curves in the presence of masses and how objects move in response to that curvature.

Taken together, the theory of general relativity provides a more complete and accurate description of gravity compared to Newton's law of universal gravitation, by considering the curvature of space-time and how this curvature affects the motion of objects and the propagation of light in the universe.

A. Einstein and his revolutionary conception of space and time

Albert Einstein's theory of general relativity challenges us to rethink our understanding of gravity. As he himself stated, 'Gravity is not a force in itself, but a manifestation of the geometry of warped space-time'. This perspective has led to a new view of gravity, where the curvature of space-time caused by the presence of mass and energy determines the behavior of moving objects. General relativity has been confirmed by strong experimental evidence and observations, and its impact on our understanding of the universe is undeniable. In Einstein's words, 'Gravity explains the motions of the planets, but it cannot explain who sets the planets in motion.' Through his theory, Einstein urges us to explore beyond the traditional conception of gravity as a force, and into the fascinating understanding of how the very fabric of space-time shapes the cosmos around us.

B. The unification of gravity and the geometry of the universe

The unification of gravity and the geometry of the universe is addressed within the framework of Albert Einstein's theory of general relativity. This theory proposes that gravity is not simply a force, but a manifestation of the geometry of space-time.

In general relativity, the curvature of space-time is closely related to the distribution of mass and energy in the universe. Massive objects, such as planets or stars, warp space-time around them, which in turn affects the motion of other nearby objects. This curvature and how it relates to the distribution of mass and energy are described by Einstein's field equations.

The theory of general relativity also makes it possible to address the question of the geometry of the universe on a large scale. According to the theory, the curvature of space-time can be flat, positive (spherical curvature), or negative (hyperbolic curvature), depending on the total amount of mass and energy present in the universe.

The question of the geometry of the universe is related to the idea of ​​cosmic expansion and the concept of the cosmological constant, which Einstein introduced into his field equations. The cosmological constant is associated with dark energy, a hypothetical form of energy that could be causing the acceleration of the expansion of the universe.

In short, the unification of gravity and the geometry of the universe is achieved within the framework of Einstein's theory of general relativity, where gravity is interpreted as the curvature of space-time caused by the distribution of mass and energy. This theory provides us with a deep understanding of the interrelationship between gravity and the geometry of the universe at different scales.