The Double Slit, Turned to Face You
Theory Painting
About this work
The double slit experiment is the demonstration that light will not behave like an ordinary object. Thomas Young ran the first version in 1801: light sent through two narrow openings arrives on the far side not as two bright bars but as a row of them, because the two paths interfere the way ripples on water do. The strange part came later. Send the light through one particle at a time and the same striped pattern still builds up, one dot at a time, as though each particle had gone through both openings. Put a detector at the slits to record which one it actually took, and the stripes disappear.
The most reproduced diagram in physics, rotated to face the observer. Drawn from the side, the experiment is a diagram about light. Turned to face you, it becomes a description of looking: the beam travels toward your eye, and you stand where the detector stands. You are the measurement.