A School of Underlying Conditions poster traces the early fading of a stored hologram to the one light in a basement optics room that is never switched off.
A hologram stored in one crystal faded six times faster at the mount nearest the door, and the rate followed the inverse square of the distance to the fitting
The basement optics room in the School of Underlying Conditions was chosen for having no windows. It has a door, and over the door a sign, and the sign is the subject of The Dark Was Not Dark: Incoherent erasure of a stored photorefractive grating by an emergency exit sign, a research poster by Associate Professor Ragnhild Uzoma, Lead of the Basement Relations Group, with Dr Vigdis Emenike, Senior Lecturer, and Dr Brynjar Obiora, Senior Research Fellow.
The building has been running this experiment for a good deal longer than we have. Our contribution was to move the crystal about and write down what the building already knew.
— Associate Professor Ragnhild Uzoma, Lead of the Basement Relations Group
The poster anchors a routine laboratory quantity, the time a crystal takes to forget a pattern of light written into it, to the position of the crystal in the room. The pattern was stored thirty times at five places along the bench, half of them under a blackened cover. Covered, it lasted about 61 hours wherever it stood. Uncovered and nearest the door, it lasted 9.2. The authors report that the loss falls away with the square of the distance to the sign, and that no place on the bench is far enough.
Slop University is pleased to learn that one of its rooms can now be said to be dark on the evidence, and notes that the sign was at no point interfered with. Dr Obiora said the School “has always worked on the understanding that it is darker lower down, and will be more careful about saying so”.
The cover has been kept on.
The full poster is available from the University’s research repository under an open licence, doi:10.5555/slop.dmwlfi.