Monday's Google Doodle celebrates the 126th birthday of Erwin Schrodinger, the man who changed physics with his theories on quantum mechanics.

Born Aug. 12, 1887, the Austrian physicist made several developments in the field of quantum theory, which is based on the principle that matter and energy have properties of both particles and waves. This included the wave equation, also known at the Schrodinger equation that became the basis of wave mechanics. He won the 1933 Nobel Prize in physics for his contributions to wave mechanics.

The doodle, however, illustrates one of Schrodinger’s most famous thought experiments -- Schrodinger’s cat. In the hypothetical experiment, developed in 1935, a cat finds itself inside a box with a small amount of radioactive material, a Geiger counter and a flask of acid. If a chemical chain reaction occurs, releasing the acid, the cat dies; however, if not, the cat lives. The observer is also involved in the experiment: until the box is opened, it isn't known if the cat is dead or alive --theoretically, meaning both states exists at the same time, the scientist explained. 

Schrodinger died in Vienna in 1961 of tuberculosis, a bacterial infection that usually attacks the lungs and other parts of the body. He was 73.

To this day, the issues raised by Schrodinger’s cat thought experiment are still debated in popular science and pop culture.