The Mapparium
Stand inside a three-storey glass globe in Boston and your own voice seems to come from inside your head.
What was reported
The Mapparium is a three-storey stained-glass globe, about 9 metres across, built in 1935 for the Christian Science Publishing Society. Visitors walk through it on a glass bridge and see the world's countries, as they were in 1935, from the inside.
Its hard, round glass surface plays tricks with sound. A whisper at one end of the bridge can be heard clearly at the other, and a person speaking at the centre hears their own voice loud and close, as if it were all around them.
Explanations offered
A sphere focuses reflected sound back to points inside it, and the glass, which absorbs almost no sound, acts like a near-perfect acoustic mirror. It's the same effect as a whispering gallery.
- When
- Built in 1935
- Where
- Mary Baker Eddy Library, Boston, Massachusetts, USA
- Witnesses
- Visitors
- Status
- Explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.