Title: A compact stress recording

Aongus McCarthy

School of EPS

Viewing transparent moulded plastic items between crossed polarisers can reveal colourful stress patterns because of the induced birefringence. This was first described by the Scottish physicist Sir David Brewster in the early 19th century. These photographs shown a CD jewel case insert tray back illuminated with polarised light and photographed through a polarising filter attached to the camera.