• DOI:10.1111/phpr.12834
• Corpus ID: 235642093

Time's arrow and self‐locating probability

@article{Chen2021TimesAA,
  title={Time's arrow and self‐locating probability},
  author={Eddy Keming Chen},
  journal={Philosophy and Phenomenological Research},
  year={2021}
}

• Eddy Keming Chen
• Published 16 January 2020
• Philosophy
• Philosophy and Phenomenological Research

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. Unfortunately, in a universe where there are many copies of us (in the distant “past” or the distant “future”), the Past Hypothesis is not enough; we also need to postulate self-locating (de se) probabilities. However, I show that we can similarly use self-locating probabilities to strengthen its rival—the Fluctuation Hypothesis, leading to in-principle empirical underdetermination and radical epistemological skepticism. The underdetermination is robust in the sense that it is not resolved by the usual appeal to ‘empirical coherence’ or ‘simplicity.’ That is a serious problem for the vision of providing a completely scientific explanation of time’s arrow.