Coloured X-ray of a barn owl. A physicist has used X-ray to create an extraordinary collection of artwork. Arie van't Riets pictures reveal birds, fish, monkeys and flowers in an incredible new light. The 66-year-old, from Bathmen in the Netherlands, began X-raying flowers as a means to teach radiographers and physicians how the machine worked. But after adding a bit of colour to the pictures, the retired medical physicist realised the potential for an exciting new collection of art. (Photo by Arie van't Riet/Barcroft Media)

A farmer and his cow “Cilly” wait for results of the “Milchgipfel” (lit. Milk summit) which takes place at the German Ministry of Food and Agriculture in Berlin, Germany on May 30, 2016. Minister of Food and Agriculture Christian Schmidt met with representatives of agriculture and dairy farming to evaluate measures to help dairy farmers in light of plummeting milk prices. (Photo by Maurizio Gambarni/EPA)

In this May 3, 2016 photo provided by the New York State Department of Environmental Conservation, a deer with its head caught in the globe from a lighting fixture over its head stands in the woods in Centereach, N.Y. The deer was able to extricate itself with the help of Environmental Conservation Officer, Jeff Hull. Hull wrestled with the deer for a while and the globe shook free in the process. (Photo by New York State Department of Environmental Conservation via AP Photo)

Men stand at the top of a traffic lights post as they attend a rally to protest against satirical cartoons of prophet Mohammad, in Grozny, Chechnya January 19, 2015. Tens of thousands of people staged the rally on Monday in Chechnya against French magazine Charlie Hebdo's cartoons of the prophet, which the predominantly Muslim region's leader denounced as “vulgar and immoral”. The posters read, “Mohammad”. (Photo by Eduard Korniyenko/Reuters)

A tale of two foxes. Surprising behaviour, witnessed in Wapusk national park, on Hudson Bay, Canada, in early winter. Red foxes don’t actively hunt Arctic foxes, but where the ranges of two predators overlap, there can be conflict. Though the light was poor, the snow-covered tundra provided the backdrop for the moment that the red fox paused with the smaller fox in its mouth in a grim pose. (Photo by Don Gutoski/2015 Wildlife Photographer of the Year)

The Museum of Feelings doesn't really have “exhibits" in the conventional sense; rather, visitors move from one themed alcove to another, five in total, each with its own distinctive aroma. The “Optimistic Room," bathed in vivid pink and purple light, is little more than a lightshow, with patrons using small reflective panels to bounce light around the room. Here: People interact in the “optimistic” room at the Museum of Feelings, a pop-up installation in New York, December 15, 2015. (Photo by Stephanie Keith/Reuters)

Number 10. BELL H-13 SIOUX was a two-bladed, single engine, light helicopter built by Bell Helicopter. Westland Aircraft manufactured the Sioux under license for the British military as the Sioux AH.1 and HT. In 1947, the United States Air Force ordered the improved Bell Model 47A. Most were designated YR-13 and three winterized versions were designated YR-13A. The United States Army first ordered Bell 47s in 1948 under the designation H-13. These would later receive the name Sioux. The Bell-built H-13 B is seen airborne in this April 29, 1951 photo. The helicopter is equipped with a 173 horsepower engine, cruises at 85 miles per hour, climbs 900 feet in a minute and has a service ceiling of 11,500 feet. (Photo by AP Photo)

Divers swim beside millions of silverside fish at Devil's Grotto, Cayman Islands. Swimming in unison, millions of silverside fish dwarf the divers. The fish create waves of silver light as they move around the grottos that lie beneath the surface of the Caribbean Sea. These amazing photographs were captured by Belgian photographer Ellen Cuylaerts, 44, on a diving trip to the Devil's Grotto, Cayman Islands. (Photo by Ellen Cuylaerts/This is Guavo Media)