Personalized Quantum Mechanics Building Blac Youth T-Shirt. Quantum Mechanics Building text with you are here arrows pointing to two different locations is a humorous quantum physics design for science geeks at back to school, birthdays, holidays and graduation. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.