What is Einstein's Elevator? скачать в хорошем качестве

What is Einstein's Elevator?

Einstein's Elevator is a thought experiment devised by Albert Einstein to illustrate the principles of his theory of general relativity. The experiment involves a hypothetical scenario of an elevator in free-fall, which allows us to understand how gravity and acceleration are inherently linked in the context of curved spacetime. Imagine an elevator in deep space, far away from any external gravitational influence. In this scenario, the elevator is unaccelerated, and its occupants experience a state of weightlessness as if they were floating in microgravity. According to the equivalence principle of general relativity, the effects of gravity experienced inside the elevator are indistinguishable from the effects of the elevator's upward acceleration in a gravitational field. Now, let's introduce an external gravitational field, such as the Earth's gravitational field. As the elevator falls freely under the influence of gravity, its occupants would experience weightlessness inside the elevator, similar to the scenario in deep space. This is because the acceleration due to gravity is indistinguishable from the acceleration caused by an upward motion in flat spacetime. Einstein's insight was that gravity is not a force acting at a distance, as described by Newtonian physics, but rather a curvature of spacetime caused by mass and energy. In the elevator scenario, the free-fall motion of the elevator and its occupants is equivalent to the motion in the absence of gravity because the curvature of spacetime near the Earth (or any massive body) causes the elevator to follow a geodesic path. The concept of Einstein's Elevator helps us understand that the effects of gravity can be accounted for by considering the curvature of spacetime due to massive objects, and that the distinction between gravitational forces and inertial forces becomes blurred in the context of general relativity. This equivalence principle forms a fundamental cornerstone of Einstein's theory, leading to a deeper understanding of gravity and its effects on the fabric of the universe.