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Why does light bend? We know that current always seeks the path with the least resistance to return to the power source to form a closed circuit, and the same goes for electromagnetic waves. The signal transmission tower of a mobile phone emits electromagnetic waves, and the electromagnetic waves will return to the signal tower through the ground to form a closed circuit.
Light is also an electromagnetic wave that returns to the source point to form a closed loop, but the radius of this loop is so large that we consider it a straight line. Einstein said that light only bends when it receives gravity. In fact, light bends even when it is not subjected to any gravity, and it always returns to its source point. Einstein's term for light bending is simply a curve on a closed loop circle. Since it is relatively close to a certain planet, that segment of light has the least resistance, so the light chooses the path with the least resistance to form that segment of bending.
Let's talk about why a rainbow appears when a beam of white light passes through a prism. The light always returns in the path with the least resistance. When passing through a prism, seven different wavelengths of white light with different frequencies or wavelengths choose the path with the least resistance. Therefore, when separated in a prism, no matter how far it travels, as long as it is not absorbed or obstructed, it always returns to the emission point. |