1.3 Spacetime theory of gravitational redshiftWhen Einstein published his first paper on Special Relativity, he introduced the world to a new dimension, the dimension of time. With his theory, he found that space and time are locked together, and cannot be separated. In other words, if space exist, than time is essential for objects to move within it. Since then, the concept of spacetime and the fourth dimension had begun. One of the following papers he published was General Relativity, where he extended his previous paper and the Equivalence Principle to described how gravity can be considered as distortion of space time, which makes a freely falling body to be in its natural state. He imagined a large mass to distort spacetime in the same way a mass placed on top of a rubber sheet distorts the rubber sheet making any other mass in the vicinity to fall towards it as shown in Figure 1.3. He then spent the rest of his life trying to understand how mass and spacetime interact, that is, which force makes spacetime distort. |
Figure 1.3 - Rubber sheet model for space time wrappng around a large mass. |