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)
“Words are finite organs of the infinite mind. They cannot cover the dimensions of what is in truth. They break, chop, and impoverish it.”
—Ralph Waldo Emerson (1803–1882)