A Stab at Time/Time: history of thinking about time, CPT time, matter and anti-matter, mirroring
September 16, 2019
1:30 pm - 3:00 pm
John Harte (UC Berkeley/SFI)
John’s presentation at the “stab at time” workshop began with a review of the history of concepts of time. Shifting perspectives, from the Greek philosophers, to Newton and Leibniz’s mechanics, to Clausius and Boltzmann’s thermodynamics, to Einstein’s relativity, to high energy physics and modern cosmology, were described. The nature of the fundamental symmetries of nature, as reflected in the CPT theorem, were discussed, along with the observed breakdown of P (mirror symmetry) and T (time reversal symmetry) in weak interactions. While the history of physics is generally characterized by the trend toward discovery of the underlying simplicity on the other side of complexity, and of the unity across seemingly distinct domains, the concept of time has arguably resisted this trend. The more we look at time, the more complex it gets.
The probabilistic underpinning of the thermodynamic arrow of time, and the complete compatibility of the second law with the existence of life were discussed, along with speculations and deep puzzles about the connection between microscopic blurring and the awareness of time. The presentation ended with a brief discussion of cultural time, the notion of “time binding” as passage onward to new generations of insights from previous generations, and the inadequacy of this process in the anthropocene where modern global-scale threats to civilization lack historical precedents. John concluded that time is not on humanity’s side.
- Presentation file
- Related files