快猫短视频

On my train to work there is a dot-matrix sign which has the words 鈥淐alling at鈥� in a Roman font, but the station names below it in italic font. However, if you take a photo of the sign all the words appear Roman (see photo, top).

If the photograph catches the sign at the correct moment, you can see that the italic font is created by the dots on the sign lighting up with some clever on-off timing that fools the eye (see photo, bottom). All the dots are in vertical and horizontal rows. How is this italic effect created and, more intriguingly, why bother?

Craig Mackie, Easton on the Hill, Northamptonshire, UK

This article appeared in print under the headline 鈥淪loping off鈥�