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wolram
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Occams razor and logic implies that there has never been nothing, so why back ground independance ?
Of course there's NEVER been nothing. For time itself is something. If there is time then there is something.wolram said:Occams razor and logic implies that there has never been nothing, so why back ground independance ?
loop quantum gravity said:space is independent of the matter which it contains in it
marcus said:https://www.physicsforums.com/showthread.php?t=120755"
[...] Please check for yourself, I don't want to mislead you. But I want to be sure that you understand that the GROUP IS NOT SPACETIME. (because in a sense there isn't any)
the cartesian product of copies of the group is used to define stuff on and integrate on, but it is NOT A SUBSTITUTE FOR SPACETIME. (because in a sense the theory doesn't have any)
AFAICS a mathematical object representing ready-made spacetime does not exist in the theory. But what does get constructed is Feynman diagrams. And averages of Feynman diagrams. I guess you can say that it is THESE things---these diagrams--- that ultimately represent spacetime, to the extent that there is something with that role in the theory.
this mother is background independent as all get-out because it does not even have a ready-made spacetime manifold in the picture. It doesn't even have a BARE one, without a metric on it.
spacetime and matter are both handled by the diagrams and the diagrams emerge or get built somehow. Space time is not something you give yourself at the beginning (as in some older theories) so that you can then build things on it and run model trains and stuff. It is something the point of the theory is to erect. Diagrams are an OBSERVABLE of the theory. Space/matter relations are observables that must be constructed. One of these frustrating "do-it-yourself" kits. Nature playing hard to get [...]
wolram said:I am sure you guys are double glazing salesmen only they could convince some one that a back ground is independant of some thing that has all way existed.
marcus said:I am glad you mentioned that wolram, it just happens that we have a special price on storm windows this month. We can do your whole house and the cost will be recovered in the savings on your first heating bill!*
*if you live in Antarctica.
Background independence is a concept in physics that refers to the idea that the laws of nature should not depend on a specific background structure or reference frame. In other words, the laws of physics should be the same regardless of the specific context in which they are observed.
Occam's Razor is a philosophical principle that states that, when given multiple explanations for a phenomenon, the simplest one is usually the most accurate. Background independence is often seen as a way to apply Occam's Razor to the laws of physics, as it suggests that the most fundamental and simple laws should be independent of any specific background structure.
Background independence is an important concept in physics because it allows for a more elegant and unified description of the laws of nature. It also helps to avoid the problem of having to constantly adjust or modify the laws of physics to fit within a specific background structure, which can become overly complicated and ad hoc.
Background independence is a topic of ongoing research and debate in modern physics, particularly in the field of quantum gravity. Some theories, such as loop quantum gravity and causal dynamical triangulation, incorporate background independence as a key principle. Other approaches, such as string theory, are still grappling with how to incorporate background independence into their frameworks.
If background independence is confirmed as a fundamental principle of nature, it could have significant implications for our understanding of the universe. It could lead to a more unified description of the laws of physics and potentially help reconcile the discrepancies between general relativity and quantum mechanics. It could also have implications for our understanding of the nature of space and time, and potentially lead to new insights and discoveries in cosmology and astrophysics.