There are several key differences between Albert Einstein's theory of general relativity and Sir Isaac Newton's laws of motion and gravitation. Here are some of the main distinctions:
Framework: Newtonian physics is based on classical mechanics, which assumes that space and time are absolute and separate entities. Einstein's general relativity, on the other hand, is a theory of gravitation based on the concept of spacetime, where space and time are interconnected and influenced by matter and energy.
Gravity: Newton's law of universal gravitation states that two objects with mass exert an attractive force on each other. This force depends on the masses of the objects and the distance between them. In general relativity, gravity is not seen as a force but as the curvature of spacetime caused by mass and energy. Objects move along curved paths in response to this curvature.
Light and Gravity: According to Newtonian physics, light is not influenced by gravity. However, in general relativity, gravity can bend the path of light. This prediction has been confirmed by observations, such as the bending of starlight around massive objects like the Sun.
Predictions: General relativity makes predictions that differ from those of Newtonian physics in certain situations. For example, general relativity predicts the existence of black holes, the bending of starlight in the presence of massive objects, the expansion of the universe, and the existence of gravitational waves. These predictions have been supported by various observations and experiments.
Einstein introduced his own theory because Newtonian physics had limitations in explaining certain phenomena. Newtonian mechanics worked well for most everyday situations and planetary motion, but it couldn't fully account for the behavior of gravity in extreme conditions or at very high speeds. For example, Newtonian mechanics couldn't explain the observed precession of Mercury's orbit or the bending of starlight during a solar eclipse.
Einstein aimed to develop a more comprehensive theory that would be consistent with both electromagnetism and gravity. His theory of general relativity provided a more accurate and comprehensive description of gravity, successfully explaining the observed phenomena that Newtonian physics couldn't fully account for. By introducing the concept of curved spacetime, Einstein's theory provided a new understanding of gravity that extended the boundaries of classical physics and revolutionized our understanding of the universe on both large and small scales.