Gravitational Lensing
Our eyes crave baths of light—
flickering playgrounds of shivering stars
an image of a blue arc on the rim
coiling around clusters of galaxies
the vivid shimmer behind you in the garden
as the torch frames your silhouette in the dark
we long for a glimpse of planets in slow motion
counting them long into the balcony of the night—
So, after we see quasars in the distance distorted
we want to understand how mass bends the light
how dark matter halos—assemble over time by gravity
their complex webs cushioning around baryonic matter
or black holes infer their presence
from distant stars or flowing accretion discs
Gravity flexes the structure of spacetime
(warping light from traveling in its straight line)
as if a universal river pools at the sides
of invisible stone—the brightness lit from behind
When a large galaxy becomes the front-view focal lens
far off galaxies are magnified and curved, arching
at the frames. Strong and weak lensing
enhance surrounding or further set stellar hives
some nurseries billions of years in our past
If the foreground mass, background and observer
are perfectly aligned, this Einstein ring resembles
the imprint of a cereal bowl abandoned
for morning play, a seemingly concentric stain
We try to see beyond what is immediately visible
and illuminate what is known but concealed
Our bare eyes, in the coldness of night, peering
through a telescope, unable to locate most
of the weight of the universe—missing out
on all the things we cannot see
What happens to light when passes near a black hole? A cluster of galaxies? Any giant mass? The gravitational pull from these objects can distort or bend the light as it travels towards an observer. This effect is called gravitational lensing. Light follows the curvature of spacetime.
Gravitational lensing was predicted in Einstein’s general theory of relativity and is being used to detect the presence of dark matter and help discover what dark matter could be.
This short film is based around the science of gravitational lensing and poetically looks at light’s resilience to anything in its path and how light offers up cues to the very nature of the universe.
Alicia Sometimes is an Australian poet, writer and broadcaster. She has performed her spoken word and poetry at many venues, festivals and events around the world. Her poems have been in Best Australian Science Writing, Best Australian Poems, Overland, Southerly, Meanjin, Griffith Review, ABC TV’s Sunday Arts, SBS’s Nomad and more. She is director and co-writer of the art/science planetarium shows, Elemental and Particle/Wave. Alicia was previous Fellow at the State Library of Victoria and has had residencies at Katharine Susannah Prichard Writers’ Centre, Varuna and Melbourne Aquarium. She is currently a Science Gallery Melbourne ‘Leonardo’ (creative advisor). Her TedxUQ talk in 2019 was about the passion of combining art with science. In 2020 Alicia won the Bruce Dawe Poetry Prize. In 2021 she is completing a Boyd Garret residency for the City of Melbourne and the Virtual Writer in Residency for Manchester City of Literature and Manchester Literature Festival.