The Tap

Holograms are made by photographing objects from different angles with the aid of a laser. Holograms are now used on ID cards, for example, to make them more difficult to copy.

When standing in the room in front of the picture and moving your gaze you can see The Tap from the side and from the front. Just as in the real world, you discover parts that may be hidden when viewed from one direction but not from another. We show some examples of a type of hologram that works without needing special illumination. If you block the source of light, the hologram effect immediately disappears.

Computers can be used to create holograms of images from magnet resonance imaging or computer tomography. The hologram may show, for example, the three-dimensional shape of a brain tumour and its location inside the head.