Boltzmann babies in the proper time measure

Abstract

After commenting briefly on the role of the typicality assumption in science, we advocate a phenomenological approach to the cosmological measure problem. Like any other theory, a measure should be simple, general, well-defined, and consistent with observation. This allows us to proceed by elimination. As an example, we consider the proper time cutoff on a geodesic congruence. It predicts that typical observers are quantum fluctuations in the early universe, or Boltzmann babies. We sharpen this well-known youngness problem by taking into account the expansion and open spatial geometry of pocket universes. Moreover, we relate the youngness problem directly to the probability distribution for observables, such as the temperature of the cosmic background radiation. We consider a number of modifications of the proper time measure, but find none that would make it compatible with observation.

Tree-like structure of eternal inflation: A solvable model

“…This section is rather technical and readers who are not measure enthusiasts are welcome to skip it. Similar computations have been done for other slicings in [39,38,26,40,37], but we will use geometric tricks to simplify these analyses and obtain some nice "exact" results. We will assume that decay rates are small enough that the bubble nucleates well after its ancestor and thus that the light-cone time is comoving inside of the ancestor.…”

“…We drop the order one factor since we will not keep track of it in other terms. This is called the "square bubble approximation" [38], and it produces a contribution to dV m of the form…”

New local duals in eternal inflation

“…For example, with H max of order the Planck scale, we thus find that events today are less likely than events yesterday by a factor of exp(−10 48 ), and less likely than a billion years ago by a factor of exp(−10 60 ). As a consequence, this measure assigns higher probability to (conventionally unlikely) observers arising from large quantum fluctuations in the early universe (and their bizarre observations) than to our observations [22,[41][42][43][44][45][46][47].…”

“…The proper time measure famously suffers from the youngness problem [22,[41][42][43][44][45][46], or "Boltzmann babies" [47]. Typical observers are predicted to be thermal fluctuations in the early universe, and our own observations have probability of order exp(−10 60 ).…”

A Version of Jung’s Synchronicity in the Event of Correlation of Mental Processes in the Past and the Future: Possible Role of Quantum Entanglement in Quantum Vacuum

“…Perhaps we should also mention the so-called Boltzman brain paradox, which has to do with the quantum vacuum and consciousness (Albrecht and Sorbo, 2004;Linde, 2007;Bousso et al, 2008;Page, 2008;Simone et al, 2010). The phenomenon described by Russian scientist Gariaev may be of interest as well.…”