Size and age of recently discovered black hole shrinks braneworld
Red alert: Scientists are shrinking branes.
A team of theoretical physicists and astronomers has calculated that any hidden extra dimension beyond our familiar three-dimensional space, a world known in physics parlance as a 3-brane, must be less than 3 micrometers. The researchers base their findings on the recent discovery of one of the smallest and oldest black holes ever found.
The new limit is less than half that of previous limits on the length of an extra