from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The property of being identical, or having the same physical properties, in all directions.
from the GNU version of the Collaborative International Dictionary of English
- n. Uniformity of physical properties in all directions in a body; absence of all kinds of polarity; specifically, equal elasticity in all directions.
from The Century Dictionary and Cyclopedia
- n. The state or property of being isotropic.
- n. In embryology, the property whereby all the parts of the unsegmented egg are alike capable of giving rise to any portion of the embryonic body: opposed to anisotropy.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. (physics) the property of being isotropic; having the same value when measured in different directions
(Anisotropy is the opposite of isotropy, which is the condition of having the same value when measured from different directions.)
Put in slightly different terms: isotropic and Quinean processes are global rather than local, and since globality rules out encapsulation, isotropy and Quineanness rule out encapsulation.
Both isotropy and Quineanness are features that preclude encapsulation, since their possession by a system would require potentially unlimited access to the contents of central memory, and hence cognitive penetrability to the max.
It is possible that statistical isotropy/homogeneity is violated at very high significance in some specific fashion that does not correspond precisely to any of the particular observational effects that have been searched for, but that would stand out dramatically in a better-targeted analysis.
There is another important motivation for studying deviations from pure statistical isotropy of cosmological perturbations: a number of analyses have found evidence that such deviations might exist in the real world.
Nevertheless, there is a subtle way for the universe to break isotropy and have a preferred direction: if the tiny observed perturbations somehow have a different character in one direction than in others.
One of the important features of the universe around us is that, on sufficiently large scales, it looks pretty much the same in every direction — “isotropy,” in cosmology lingo.
The most compelling evidence for large-scale isotropy comes from the Cosmic Microwave Background (CMB), the leftover radiation from the Big Bang.
They just decided it would be cool to explore, and will shed no tears if inflation turns out to be a nice creamy vanilla of isotropy.
Personally, I think that the looming flaw in all of these ideas is that they take the homogeneity and isotropy of our universe too seriously.
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