Suppose that a = a0 eˆ 0+a1 eˆ 1 is forward timelike, and that b = b0 eˆ 0+b1 eˆ 1 has b · a = 0....

Suppose that a = a0 eˆ 0+a1 eˆ 1 is forward
timelike, and that b = b0 eˆ 0+b1 eˆ 1 has b · a = 0. (a) Show that, when drawn
on a spacetime diagram, a makes an angle φ with the forward light cone
where

(b) Show that b makes the same angle φ with the forward light cone,
but on the opposite side.

(c)
Plot a and b schematically on a spacetime
diagram for the case a1 < 0.="">