The Ultimate Ensemble or mathematical universe hypothesis (MUH) is a speculative theory of everything (TOE), suggested by Max Tegmark[1]. Related to the Anthropic principle and Multiverse theories, the Ultimate Ensemble suggests that not only should worlds corresponding to different sets of initial conditions or different physical constants be considered real, but also worlds ruled by altogether different equations. The only postulate in this theory is that all structures that exist mathematically exist also physically. The Ultimate Ensemble can be considered a physico-mathematical expression of the philosophy known as modal realism.
Tegmark claims that the MUH is a theory with no free parameters, which is not observationally ruled out, and therefore is preferred over all other TOE's by Occam's Razor. He envisages consciousness as occurring in the form of "self-aware substructures" of mathematical structures, which he claims will subjectively perceive themselves as existing in a physically "real" world.
The MUH, like other multiverse theories, has been criticized by some physicists or philosophers on grounds including: that it lacks a properly defined prior distribution over structures [2]; has no predictive power [3]; has problems with Godel's theorem [4] [5]; is self-contradictory because one cannot subsume all possible (partly contradictory) mathematical structures into one structure [6].
Tegmark responds to some of these critiques in [7], where the Ultimate Ensemble is formalized as the "Level IV Multiverse".
Addendum
The Ultimate Ensemble or mathematical universe hypothesis (MUH) is a speculative theory of everything (TOE), suggested by Max Tegmark[1]. Related to the Anthropic principle and Multiverse theories, the Ultimate Ensemble suggests that not only should worlds corresponding to different sets of initial conditions or different physical constants be considered real, but also worlds ruled by altogether different equations. The only postulate in this theory is that all structures that exist mathematically exist also physically. The Ultimate Ensemble can be considered a physico-mathematical expression of the philosophy known as modal realism.
Tegmark claims that the MUH is a theory with no free parameters, which is not observationally ruled out, and therefore is preferred over all other TOE's by Occam's Razor. He envisages consciousness as occurring in the form of "self-aware substructures" of mathematical structures, which he claims will subjectively perceive themselves as existing in a physically "real" world.
The MUH, like other multiverse theories, has been criticized by some physicists or philosophers on grounds including: that it lacks a properly defined prior distribution over structures [2]; has no predictive power [3]; has problems with Godel's theorem [4] [5]; is self-contradictory because one cannot subsume all possible (partly contradictory) mathematical structures into one structure [6].
Tegmark responds to some of these critiques in [7], where the Ultimate Ensemble is formalized as the "Level IV Multiverse".
from wikipedia