Personalized Quantum Mechanics Building Infant Dress. Quantum Mechanics Building text with a floor plan and the you are here arrows pointing to 2 different spots. Particles can be in two different places simultaneously. Can You? A humorous physics design for your favorite student, teacher, engineer or scientist at birthdays and holidays. Your little one will be adorable and comfortable in this 100% combed ringspun cotton 1x1 baby rib dress!