April 14 (UPI) -- Monday's Google Doodle marks World Quantum Day, April 14.
The animated artwork shows a thaumatrope or optical illusion with different images on the backs and fronts of discs that spell the word "Google" when they spin on individual red threads.
"The Doodle illustrates the concept of superposition, one of the fundamental principles that makes quantum computing possible," the search engine's homepage said.
"The date, April 14th, represents the first three digits of Planck's constant, which describes the relationship between the energy and frequency of a quantum of energy (such as a photon): 4.14×10−15 eV."
World Quantum Day is an occasion "promoting public awareness and understanding of quantum science and technology around the world," according to the official World Quantum Day website.
