## Einstein’s Crazy Idea

23 May 2014, 11:00 UTCGeneral relativity is just plain weird. The basic idea of gravity we are taught in school comes from Isaac Newton’s “Principia” in 1687. Gravity is a force exerted by objects with mass. The greater the mass, the greater the gravitational force. The larger the distance between objects, the lesser the force ( it decreases with […]

One of the original plates from the 1919 solar eclipse used to measure the effects of general relativity. Click the image for a larger version, and note the horizontal lines that mark stars that were used for the measurements.

General relativity is just plain weird.

The basic idea of gravity we are taught in school comes from Isaac Newton’s “Principia” in 1687. Gravity is a force exerted by objects with mass. The greater the mass, the greater the gravitational force. The larger the distance between objects, the lesser the force ( it decreases with the square of the distance). The gravity of the Sun pulls on Earth and holds it, along with the other planets, asteroids, comets, etc., in orbit.

Not so, according to Albert Einstein in 1916. He came up with a completely new, and quite radical, alternative explanation.

Einstein’s crazy idea is ...