Transient observers and variable constants or repelling the invasion of the Boltzmann’s brains

2007/03/31 by S. Carlip, S Carlip
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Constant (computer programming) #Flicker #Quantum #Quantum Mechanics and Applications #Relativity and Gravitational Theory #Transient (computer programming) #Universe #Variable (mathematics) #Wonder #astro-ph #hep-th

paper · pdf · doi:10.1088/1475-7516/2007/06/001

published as JCAP 0706:001,2007 · 4 pages, LaTeX; v2: added references; v3: more discussion of setting, alternative approaches, now 5 pages; v4: added discussion of the effect of quantum fluctuations on varying constants, appendix added, now 7 pages; v5: new reference, minor correction

arxiv created 2007/05/26 · openalex publication_date 2007/06/01 · arxiv updated 2010/04/28 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

If the universe expands exponentially without end, 'ordinary observers' like ourselves may be vastly outnumbered by 'Boltzmann's brains,' transient observers who briefly flicker into existence as a result of quantum or thermal fluctuations. One might then wonder why we are so atypical. I show that tiny changes in physics—for instance, extremely slow variations of fundamental constants—can drastically change this result, and argue that one should be wary of conclusions that rely on exact knowledge of the laws of physics in the very distant future.

Citations

• The fundamental constants and their variation: observational and theoretical status
• Search for Time Variation of the Fine Structure Constant
• Can the universe afford inflation?
• Quintessence and the Rest of the World: Suppressing Long-Range Interactions
• Sinks in the landscape, Boltzmann brains and the cosmological constant problem
• A Universe Without Weak Interactions
• Disturbing Implications of a Cosmological Constant
• Limit on the Temporal Variation of the Fine-Structure Constant Using Atomic Dysprosium