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)

Enthusiasts gather for the Model Rail Scotland exhibition on February 24, 2012 in Glasgow, Scotland. (Photo by Jeff J. Mitchell/Getty Images)

These poignant portraits look to shine awareness on the plight of some of the world’s most endangered ecosystems and species of wildlife. The images combine animals, art and celebrity, with Asia's top models posing with the likes of rhinos, giraffes, leopards and marine life. Here: Mikki Yao with an Asian Elephant. (Photo by Sean Lee-Davies/Caters News)

Sun Model students pose for a photo during a training session at the school on March 31, 2014 in Phnom Penh, Cambodia. Having started in August 2010 with only three models, the Sun Model Agency and School is starting to make an impact in the fashion industry in Cambodia. (Photo by Omar Havana/Getty Images)

A replica model of a Lamborghini Aventador LP 700-4 in Dubai, UAE. This is the world's most expensive model car, made from carbon fibre and covered in a thin layer of pure gold. The 1:8 scale replica Lamborghini Aventador LP 700-4, designed by German engineer Robert Gülpen, is available to buy for £200,000. But amazingly this model – currently on display at the Lamborghini showroom in Dubai – is just a prototype for a solid gold model, which will go up for auction in 2014 with a price tag of £4.6 million. (Photo by Robert Gulpen/Barcroft Media)

The X-47B prototype on Tuesday flew off an aircraft carrier and into the history books. Today's achievement, the first-ever catapult launch of an unmanned aircraft from the flight deck of a carrier, promises to open up a new chapter in the annals of naval aviation. Photo: An X-47B pilot-less drone combat aircraft is launched for the first time off an aircraft carrier, the USS George H. W. Bush, in the Atlantic Ocean off the coast of Virginia, May 14, 2013. The U.S. Navy made aviation history on Tuesday by catapulting an unmanned jet off an aircraft carrier for the first time, testing a long-range, stealthy, bat-winged plane that represents a jump forward in drone technology. (Photo by Jason Reed/Reuters)

“Emmy” award-winning cinematographer, Shawn Heinrichs teamed up with model and diver Hannah Fraser to carry out a unique underwater conservation fashion shoot in a remote location in the South Pacific Ocean. The pair are aiming to raise awareness for the plight of the marine mammals at the hands of whalers. During the ten day shoot Fraser swam and glided with pilot and humpback whales. Photo: “In this startling image model Hannah Fraser appears to be “dancing” with the giant whale ”. (Photo by Shawn Heinrichs/Barcroft Media)

Men watch model trains running along the bar at Bar Ginza Panorama Shibuya Branch on June 3, 2009 in Tokyo, Japan. The bar caters to model train enthusists and customers are able to bring their own model trains to run on the tracks. (Photo by Junko Kimura/Getty Images)