Light bends in space due to the curvature of spacetime caused by massive objects. According to Einstein's theory of general relativity, mass and energy curve the fabric of spacetime, creating what we perceive as gravity. This curvature affects the path of light as it travels near massive objects.
When light passes close to a massive object like a star or a black hole, it follows a curved trajectory instead of traveling in a straight line. This curvature is a result of the warping of spacetime caused by the object's mass. The light follows the curvature of spacetime, which gives the appearance of bending.
To understand this concept, imagine a flat rubber sheet representing the fabric of spacetime. If you place a heavy object like a bowling ball on the sheet, it creates a depression, causing the sheet to curve around it. If you roll a marble (representing light) along the sheet, it will follow a curved path around the bowling ball.
Similarly, in space, when light passes through the curved spacetime around massive objects, its path bends. This effect is known as gravitational lensing. The amount of bending depends on the mass and proximity of the object causing the curvature. Stronger gravitational fields result in more significant bending of light.
Gravitational lensing has been observed and confirmed through various astronomical observations. It has provided valuable insights into the nature of gravity, the properties of massive objects, and the distribution of dark matter in the universe.