Several speculative physical theories have introduced extra dimensions of space for various reasons:
- Kaluza–Klein theory introduces extra dimensions to explain the fundamental forces other than gravity (originally only electromagnetism).
- Large extra dimension and the Randall–Sundrum model attempt to explain the weakness of gravity. This is also a feature of brane cosmology.
- The extra dimensions in superstring theory are required for mathematical consistency and are often assumed to have the shape of a Calabi–Yau manifold.
- Universal extra dimension
"Extra dimensions" may also refer to:
- Parallel universe (fiction)
Famous quotes containing the words extra and/or dimensions:
“When a lady of wealth, is seen roaming about in search of cheaper articles, or trying to beat down a shopkeeper, or making a close bargain with those she employs, the impropriety is glaring to all minds. A person of wealth has no occasion to spend time in looking for extra cheap articles; her time could be more profitably employed in distributing to the wants of others. And the practice of beating down tradespeople, is vulgar and degrading, in any one.”
—Catherine E. Beecher (1800–1878)
“It seems to me that we do not know nearly enough about ourselves; that we do not often enough wonder if our lives, or some events and times in our lives, may not be analogues or metaphors or echoes of evolvements and happenings going on in other people?—or animals?—even forests or oceans or rocks?—in this world of ours or, even, in worlds or dimensions elsewhere.”
—Doris Lessing (b. 1919)