Two events have a spacelike separation.
Show that a frame can be found in which
the two events occur at the same time.

All summer he taught relativity
and knew their first time around
they wouldn’t understand it
—that intuition of the weight of numbers.
Nothing visual helped:
Explosions on trains.
Twins separated and aging differently.
The pole vaulter running through a barn
so fast the pole shrinks by half
to the size of the barn.
He looked always to one student’s squint
and tightened lip, for her form bent
over gas tubes in lab.

At the end they all drove out
to a field to watch the mid-August
meteor shower. He lay next to her
under a college blanket
separate but so close he imagined
the pressure of her knee