Relativity by Sarah Howe

Poem first published for UK National Poetry Day in 2015.

For Stephen Hawking

When we wake up brushed by panic in the dark
our pupils grope for the shape of things we know.

Photons loosed from slits like greyhounds at the track
reveal light’s doubleness in their cast shadows

that stripe a dimmed lab’s wall — particles no more — 
and with a wave bid all certainties goodbye.

For what’s sure in a universe that dopplers
away like a siren’s midnight cry? They say

a flash seen from on and off a hurtling train
will explain why time dilates like a perfect

afternoon; predicts black holes where parallel lines
will meet, whose stark horizon even starlight,

bent in its tracks, can’t resist. If we can think
this far, might not our eyes adjust to the dark?