Spacetime Physics (1966) Fig 23 on page 40

[Hacky]

I am self-studying and have followed everything in Taylor and Wheel up to the exploded view of the spacetime diagram on page 40. The diagram in lower right hand corner of Fig 23 on page 40 refers to "Events that an observer at A may yet experience if nothing is shrouded from his gaze."

However, most of this region is outside of the past light cone of point A and thus I do not get how anything in this region could be viewed/experienced by an observer at A. Can anyone explain this to me?

Thanks, Howard

 

[robphy]

Consider an observer that visits event A.
Now consider an event on that observer's worldline after A.

 

[ghwellsjr]

I am self-studying and have followed everything in Taylor and Wheel up to the exploded view of the spacetime diagram on page 40. The diagram in lower right hand corner of Fig 23 on page 40 refers to "Events that an observer at A may yet experience if nothing is shrouded from his gaze."

However, most of this region is outside of the past light cone of point A and thus I do not get how anything in this region could be viewed/experienced by an observer at A. Can anyone explain this to me?

Thanks, Howard

Those diagrams are capturing an instant in Coordinate Time. But at some later Coordinate Time the whole diagram will move up and eventually everything that is in the large upper portion will end up in the bottom cone. When they say "experience" they include what an observer sees and that's why they say "if nothing is shrouded from his gaze".

Does that help?