How is the special theory of relativity connected with spacetime?

Special Theory of Relativity / Beginners Tour Part Conclusion

The brief foray into the special theory of relativity shows how much this theory contradicts our everyday conceptions of space and time. Moving clocks run differently, the speed of light is the same for all (inertial) observers, the result of length measurements depends on who is doing them - all of this is very unusual for us. That this is the case, and that we do not encounter the relativistic effects in everyday life, is essentially due to the fact that the speed of light is very high compared to the speeds that we know from everyday life. The deviation of the relativistic effects from our everyday experience depends directly on the ratio of the relevant relative speed to the speed of light; for the speeds at which we fly in airplanes, for example, the time dilation is so small that it can only be detected with highly precise atomic clocks.

The special theory of relativity represents a framework in which other physical laws can be embedded. It is almost tailor-made for embedding the natural laws of electrical charges, electrical and magnetic forces, for example, the so-called Maxwell's electrodynamics. The combination of special relativity and quantum theories has also proven to be extremely successful; it is addressed in the chapter Relativity and Quanta.

There was only one force that did not want to be absorbed by the special theory of relativity: gravity. This fact led Einstein to formulate an even more far-reaching description of nature: his General theory of relativity.

In the context of Einstein for Beginners, it consequently continues with Chapter 2: The General Theory of Relativity.

If you want to go even deeper into the special theory of relativity, you have the opportunity to first look at the advanced topics on special relativity.