Why is your reflection upside-down in a spoon?

Even if you’re doing a headstand, your picture in a spoon will still be upside-down, but why is that?

4th May 2016
Why is your reflection upside-down in a spoon? (© Alamy)

Asked by: Ella Scott, Leeds

Unlike a flat mirror, the curved surface of the spoon’s bowl bounces incoming rays back towards a central focus point lying between your face and the centre of the spoon’s. In passing through this point, rays from the upper part of your face are reflected downward, while those from the lower part are reflected upward. The result is an upside-down image of your face.