Introduction
Last time: Birth of Relativity
- Einstein’s two postulates for special relativity (special in the sense that it is restricted to descriptions in inertial reference frames moving at constant velocity).
- Explored consequences of these two postulates within the framework of thought (gedanken) experiments.
- Conclusion: We must give up idea that time is the same at different places.
Today: Time and Space
- Einstein’s postulates let us calculate what different observers will measure for the time interval between the same two events. Note: they won’t get the same answer!!
- Given that time is different for different observers, we will see that space must be different as well!!
- Today we will give explicit formulas for the apparent slowdown of time and change of length of moving objects