A seemingly abstract image of three perpetually bouncing oil droplets takes home the 2019 overall prize in the Royal Society Publishing Photography Competition, a contest in its fifth year celebrating science and its beauty.
“These silicone oil droplets are bouncing indefinitely above a vibrating pool of silicone oil at 15 Hz,” said winning photographer and physicist Dr Aleks Labuda in a statement sent to IFLScience. “The surface waves generated by the droplets are analogous to quantum mechanical waves that guide the dynamics of quantum particles. While the droplets *move* like quantum particles, they *behave* like quantum waves.”
Labuda set a petri dish filled with oil and placed it atop a loudspeaker in order to depict the pilot-wave theory, a key concept in quantum physics that theorizes quantum particles are simultaneously both waves that influence movement (sound emanating from the speaker) and particles with definable properties (oil droplets).
“Not only is it a remarkable, attention-grabbing image with its black and white moody shades and sharp highlights, but it also has a great scientific back-story in terms of quantum hydrodynamics. In the best tradition of great science photos, the viewer is simultaneously bewildered by the image and then astounded by the story behind it,” said Professor Jon Blundy, a member of the judging panel for this year’s prize from the University of Bristol.

Labuda was also the runner-up in the micro-imaging category for the Magnetostatic Spawn image. This photograph demonstrates the magnetic properties of ferrofluids shifting under a magnetic field set up by using two carefully positioned rare-Earth disc magnets.
Fade to White By Morgan Bennett-Smith, Ecology And Environmental Science Winner

“A juvenile Red Sea clownfish (Amphiprion bicinctus) looks out from between the clear tentacles of a bleaching sea anemone (Entacmea quadricolor) in Thuwal, Saudi Arabia,” said photographer Morgan Bennett-Smith of the Ecology and Environment Science category winning image.
Vigilant Soldier By Abhijeet Bayani, Ecology Runner-Up

Paper wasps build their nests in concealed places, allowing females to alarm other nestmates when their deadliest predator, Vespa tropica, is nearby.
Twister in the Yukon By Lauren Marchant, Earth Science And Climatology Winner

“This photo was taken near to Kluane Lake Research Station in the Yukon, Canada. It depicts a large, cone-shaped, funnel cloud," said photographer Lauren Marchant of her category-winning image. "However, this funnel cloud never made contact with the ground and therefore could not be classified as a tornado.”
Fizzy Sea By Tom Shlesinger, Earth Science Runner-Up

While on a scientific expedition to Papua New Guinea's Ambitle Island, Papua New Guinea, Tom Shlesinger captured this image of volcanic carbon dioxide fizzling from the seafloor in an ecosystem of diverse and healthy coral reefs. Despite acidity levels that are commonly too extreme for corals to survive, reef systems in this area are "surprisingly thriving", allowing the region to serve as a "natural laboratory" that may depict how oceans may change by the end of the century.
Mudskipper Turf War By Daniel Field, Behaviour Winner

"While photographing wading birds in the famous Mai Po wetlands, Hong Kong, I was distracted by the mesmerizing territorial displays of hundreds of blue-spotted mudskippers near the shore. Adjacent individuals would frequently engage in brief skirmishes, allowing me to select the optimal angle for illustrating their aggressive interactions," explained photographer Daniel Field.
Jellyfish By Eduardo Sampaio, Behaviour Runner-Up

A young, blue trevally (Carangoides ferdau) is photographed feeding on a purple jellyfish (Thysanostoma loriferum), and guards its prey from other would-be predators.
Halo By Mikhail Kapychka, Astronomy Winner

"A halo appears in the sky when several factors are combined. Often it is observed in frosty weather in conditions of high humidity. In the air, at the same time, there is a large number of ice crystals," said photographer Mikhail Kapychka. "Passing through them, the lunar or solar light is refracted in a special way, forming an arc around the moon or sun."
Taranaki Stars By James Orr, Astronomy Runner Up

After a "tough hike up to this viewpoint," photographer James Orr says that he spent eight hours watching as the clouds thinned, gradually revealing the Milky Way. The resulting image is made up of four 25-second exposures stitched together.