THE HABITS OF LIGHT
by Anna Leahy

After Henrietta Leavitt, astronomer

The difference between luminosity and brightness
is the difference between being

and being perceived, between the energy emitted
and the apparent magnitude. O, to be

significant! To have some scope and scale!
Size and heat. Why not make that obvious,

ostensible, stretch it out for all the world to see?
Distance makes a world of difference.

The universe is made of distance and of dust.
More dust than star out there,

more crimson than cobalt from here, looking,
our eyes telling the truth slant

through the almost-nothing
of the universe’s finely grained mattering.

The Universe in Verse — a celebration of science through poetry — returns in April of 2018.