Editing Background independence (section)

==Manifest background independence==
Manifest background independence is primarily an aesthetic rather than a physical requirement. It is analogous and closely related to requiring in [[differential geometry]] that equations be written in a form that is independent of the choice of charts and coordinate embeddings. If a background-independent formalism is present, it can lead to simpler and more elegant equations. However, there is no physical content in requiring that a theory be '''manifestly background-independent''' – for example, the equations of [[general relativity]] can be rewritten in local coordinates without affecting the physical implications.

Although making a property manifest is only aesthetic, it is a useful tool for making sure the theory actually has that property. For example, if a theory is written in a manifestly Lorentz-invariant way, one can check at every step to be sure that Lorentz invariance is preserved. Making a property manifest also makes it clear whether or not the theory actually has that property. The inability to make classical mechanics manifestly Lorentz-invariant does not reflect a lack of imagination on the part of the theorist, but rather a physical feature of the theory. The same goes for making classical mechanics or [[electromagnetism]] background-independent.