20.5 Coordinates for Time
I get space coordinates, but in what sense is time really a coordinate?
So, is time the 'fourth dimension'?
Who introduced the idea of time as an additional dimension?
The notion of a grid of clocks spread out through space seems like a fairly elaborate framework. Why do we bother introducing it?
If two observers, however far apart they might be, are not moving relative to one another, should we consider them to be part of the same reference frame?
You mentioned that having clocks spread out through space alleviates the issue of observation vs measurement. How so?