i don't get that joke he says

early saturday morning thomas
lying beside me asks
which way will we fall when gravity's done
i point at the ceiling
oh he says   i thought we'd fall into the world

i wonder about trees in a weightless world
how they'd stay rooted in earth
twigs and leaves pointing into outer space
imagine autumn that year
all the oxygen would go up
sand   placemats   anniversary clocks
everything

i've learned to take nothing for granted
gravity exists for now
my bed on the floor
straight planks
running up and down the rooms
thomas asks   which way will the people in china fall

suddenly i know
hardwood/abyss
mascara/abyss
french doors and wrenches
i whisper abyss
into my son's blind eye
i don't get that joke he says