**Craig Callender**, Institute for Practical Ethics, University of California, San Diego

La Jolla, CA 92093

Article (about Callender): Can Time Be Saved From Physics?, John Farrell, 2019

ArXiv (2): What becomes of a causal set?, 2015**Books**: What Makes Time Special?, Oxford University Press, 2017; Physics meets philosophy at the Planck scale (PDF), 2001**Homepage**(s): FQXi, **Publications**

Twitter (tweet by Bokulich)**Wikipedia****YouTube**: On time (w/Ashar Khan, Aug 16, 2022)**•** The philosophy and ethics of science, 2021**•** Is Time real?, 2015 (Closer to the Truth)

Wed, Jul 10, 2019, 10:34 PM

Dear Prof. Dr. Craig Callender:

I tried posting the note below within your article FQXi , “Can Time Be Saved From Physics?” (which I would add, “and Mathematics” to Physics; and then answer, “No.” And, it shouldn’t. We adopted our commonsense view of time from within the absolutes of Newton’s 1687 work. We know that he did not have all the answers!

Why can’t we use the Planck base units as a starting point? Here is a copy of my post:

**Planck Time (t _{P}) opens basic questions**. First,

**t**is a direct correlation and necessary relation with a length and light in much the same way Einstein’s well-known equation, e=mc

_{P}^{2 }necessarily and dynamically relates mass, energy and light. These four Planck base units are each natural units using only the most fundamental universal constants to define them. Could it is the very first moment in time? Could the universe start cold? If so, then what might be the first expression of these five facets of our reality first manifest? Could it be a sphere? John Archibald Wheeler imagined quantum foam. Others are suggesting that we call these spheres planckspheres. What if there is an application of cubic close packing of equal spheres (ccp) at this scale and the stacking amounts to a doubling? Within 202 doublings of base-2 notations these Planck base units have become the age of the universe, the size of the universe, the total mass of the universe, and the total energy of the universe, and yes, it is still happening right now. The universe is expanding! Exploring such a simple model has been our effort since December 2011: https://81018.com To see a chart of the numbers and to get a sense of the emergence and natural inflation: https://81018.com/chart/

I would be very pleased to hear from you.

Thank you.

-Bruce

**Physics Meets Philosophy at the Planck Scale**:

*Contemporary Theories in Quantum Gravity*, **Callender, Craig; Huggett, Nick** (Editors). Cambridge University Press, 2001. ISBN#:052166280x

**Introduction** Craig Callendar and Nick Huggett**Part I**. Theories of Quantum Gravity and their Philosophical Dimensions:

2. Spacetime and the philosophical challenge of quantum gravity, Jeremy Butterfield and Christopher Isham

3. Naive quantum gravity (PDF), Steven Weinstein

4. Quantum spacetime: what do we know? Carlo Rovelli

**Part II. Strings**:

1. Reflections on the fate of spacetime, Edward Witten

2. A philosopher looks at string theory, Robert Weingard

3. Black holes, dumb holes, and entropy, William G. Unruh

**Part III. Topological Quantum Field Theory**:

1. Higher-dimensional algebra and Planck scale physics John C. Baez

**Part IV. Quantum Gravity and the Interpretation of General Relativity**:

1. On general covariance and best matching Julian B. Barbour

2. Pre-Socratic quantum gravity, Gordon Belot and John Earman

3. The origin of the spacetime metric: Bell’s ‘Lorentzian Pedagogy’ and its significance in general relativity, Harvey R. Brown and Oliver Pooley, 17 Aug 1999

4. Quantum spacetime without observers: ontological clarity and the conceptual foundations of quantum gravity, Sheldon Goldstein and Stefan Teufel

5. On gravity’s role in quantum state reduction, Roger Penrose

6. Why the quantum must yield to gravity, Joy Christian

Time to Think, *John Farrell*, September 17, 2020