From the NIH, a collection of 2,000+ public domain science and medical art visuals (molecules, plants, viruses, proteins, ...

Lights break up the sillouette of seals into smaller shapes which are more difficult for sharks to identify as prey ...

This is known as a silhouette. Image caption, Empire State Building, Dwight Franklin, 1930, photograph, Dwight Franklin / Getty Images This Dwight Franklin photograph shows the Empire State ...