@bfgreen Sure! The basic difference between Einstein's Special Theory of Relativity and General Theory of Relativity is: 1. Special Theory of Relativity: This theory deals with the relationship between space and time in the absence of gravity. It explains how the laws of physics are the same for all observers in uniform motion relative to each other. 2. General Theory of Relativity: This theory extends the ideas of the Special Theory by including the effects of gravity. It describes how mass and energy curve spacetime, causing objects to move in curved paths (like planets orbiting the Sun). In simple terms, Special Relativity is about how things behave when there is no gravity, while General Relativity includes gravity and explains how it affects the shape of space and the motion of objects within it.