Chen, Eddy Keming (2020) Time's Arrow and De Se Probabilities. [Preprint]

Preview

Text PH-PI-2020Jan-archive.pdf Download (404kB) | Preview

Abstract

One of the most difficult problems in the foundations of physics is what gives rise to the arrow of time. Since the fundamental dynamical laws of physics are (essentially) symmetric in time, the explanation for time's arrow must come from elsewhere. A promising explanation introduces a special cosmological initial condition, now called the Past Hypothesis: the universe started in a low-entropy state. In this paper, I argue that, in a universe where there are many copies of us (in the distant past or the distant future), the Past Hypothesis needs to be supplemented with de se (self-locating) probabilities. However, letting in de se probabilities also helps its rival---the Fluctuation Hypothesis, leading to a kind of empirical underdetermination and radical epistemological skepticism. The skeptical problem is exacerbated by the possibility of ``Boltzmann bubbles.'' Hence, it seems that explaining time's arrow is more complicated than we have realized, and that its explanation may depend on how we resolve philosophical issues about de se probabilities. Thus, we need to carefully examine the epistemological and probabilistic principles underlying our explanation of time's arrow. The task is especially urgent for theories that invoke the Past Hypothesis. The philosophical analysis offered in the paper aims at preparing the conceptual foundation for such a task.

---

Export/Citation:

EndNote | BibTeX | Dublin Core | ASCII/Text Citation (Chicago) | HTML Citation | OpenURL

Social Networking:

Share |

---

Item Type:	Preprint
Creators:	Creators Email ORCID Chen, Eddy Keming eddykemingchen@ucsd.edu 0000-0001-5144-0952
Keywords:	Past Hypothesis, Principle of Indifference, Principal Principle, de se probabilities, time's arrow, entropy, Bayesian epistemology, confirmation, empirical underdetermination, skepticism
Subjects:	General Issues > Confirmation/Induction General Issues > Evidence General Issues > Laws of Nature Specific Sciences > Physics Specific Sciences > Probability/Statistics Specific Sciences > Physics > Statistical Mechanics/Thermodynamics
Depositing User:	Dr. Eddy Keming Chen
Date Deposited:	17 Jan 2020 00:35
Last Modified:	17 Jan 2020 00:35
Item ID:	16824
Subjects:	General Issues > Confirmation/Induction General Issues > Evidence General Issues > Laws of Nature Specific Sciences > Physics Specific Sciences > Probability/Statistics Specific Sciences > Physics > Statistical Mechanics/Thermodynamics
Date:	January 2020
URI:	https://philsci-archive.pitt.edu/id/eprint/16824

Available Versions of this Item

• Time's Arrow and De Se Probabilities. (deposited 17 Jan 2020 00:35) [Currently Displayed]
  • Time's Arrow and Self-Locating Probability. (deposited 24 Oct 2021 03:41)

Monthly Views for the past 3 years

Monthly Downloads for the past 3 years

Plum Analytics

Actions (login required)

View Item