A series of playing cards was inspired by one of the most famous thought experiments "Schrodinger's Cat " by physicist Erwin Schrödinger in 1935. Come in 3 colors. Black, grey, and green. The Gray - Dead and Alive Edition - The color grey is an emotionless, moody color that is typically associated with meanings of complexity-everything that falls inbetween absolutes. Its the perfect color for Dead and Alive in the Schrodinger's Cat experiment just like it lives between the extremes of black and white.