Google doodle celebrates World Quantum Day

Today’s Doodle honors World Quantum Day, an annual observance aimed at promoting public awareness and appreciation of quantum science and technology. Celebrated on April 14, the date reflects a symbolic reference to Planck’s constant (4.14 x 10⁻¹⁵ eV)—a fundamental value in quantum physics that connects the energy of a particle with its frequency.

The Doodle artwork features a thaumatrope, a classic 19th-century optical toy made up of a disk with two distinct images on either side. When spun quickly, the two pictures appear to merge into one—an effect that cleverly mirrors the principle of quantum superposition, where a quantum particle can exist in multiple states at the same time.

World Quantum Day highlights the importance of quantum research in shaping the future—from secure communication and powerful computing to advanced medical imaging and beyond.