You can have a herniated disc in any part of your spine. But most herniated discs affect the lower back (lumbar spine). Some happen in the neck (cervical spine) and, more rarely, in the upper back (thoracic spine). Wear and tear of the disc. As you age, your discs dry out and aren't as flexible.
General relativity is a theory of gravitation that was developed by Albert Einstein between 1907 and 1915. According to general relativity, the observed gravitational effect between masses results from their warping of spacetime. By the beginning of the 20th century, Newton's law of universal gravitation had been accepted for more than two hundred years as a valid description of the gravitational force between masses.
.... This was the fundamental principle for his General Theory of Relativity, which was published in 1916. Its foundation is that the laws of nature in an accelerating frame are equivalent to the laws of a gravitational field. This is known as the Equivalence Principle.In 1915, Einstein proposed a new theory of gravity, which is now called the General Theory of Relativity: In 1666, Sir Isaac Newton had proposed a theory of gravity called Newton's Universal Law of Gravitation.his was the fundamental principle for his General Theory of Relativity, which was published in 1916. Its foundation is that the laws of nature in an accelerating frame are equivalent to the laws of a gravitational field.