Four Australian inventions that transformed how we see the world around us, and what we know about it. William and Lawrence Bragg invented X-ray crystallography to reveal the atomic structure of crystals. Milutin Stoilovic and colleagues at the Australian National University worked with Federal Police to create a forensic lamp, the Polilight, which could detect latent finger prints. Charles Tait created the world's first feature film with the help of his family, and William Beech invented the periscope rifle in the trenches of Gallipoli.