Teleology without teleology Paul Davies Beyond Center for Fundamental Concepts in Science Arizona State University

1. Teleology without teleologyPaul DaviesBeyond Center for Fundamental Concepts in ScienceArizona State University

5. Origin of the universe

6. c. 2 billion years

7. c. 10 billion years

8. c. 13.7 billion years

9. Law of increasing (accelerating) novelty/variety/diversity/complexity The principle of maximum diversity says that the laws of nature, and the initial conditions at the beginning of time, are such as to make the universe as interesting as possible. Freeman Dyson Biospheres and the universe create novelty and diversity as fast as they can manage to do so without destroying the accumulated propagating organization that is the basis and nexus from which further novelty is discovered and incorporated into the propagating organization. Stuart Kauffman

12. The entropy gap

14. Cosmic expansion itself is the prime mover for the construction of a hierarchy of complex entities throughout the Universe… in an expanding Universe, both the disorder and the order can increase simultaneously--a fundamental duality, strange but true. Eric Chaisson

15. compatibility ≠ explanation

16. Questions • What is a suitable quantification for the entity that increases, and under what physical circumstances does it in fact increase? • Does the putative “law” or principle of incraesing “something” emerge from existing laws of physics or does it augment them? • Is there a universal principle in nature or a patchwork of different principles for different sorts of systems (gravitational, biological, intelligent…)

17. Gravitation: the key! Initial state of matter close to thermodynamic equilibrium Initial state of the gravitational field far from equilibrium

18. Gravitational entropy

19. Growth of clumpiness

20. Perhaps to a black hole… Sbh = 4πkGM2/ћc3

21. Safter ≥ Sbefore ‘Gravitational entropy: beyond the black hole’ P.C.W. Davies, D.N. Page and L.H. Ford, Phys. Rev. D34, 1700 (1986).

22. 'Black hole versus cosmological horizon entropy,’ P.C.W. Davies, T. M. Davis and C. Lineweaver, Classical and Quantum Gravity20, 2753 (2003).

23. Area theorem for cosmological horizons

24. Radiation-filled universe with Λ a(t) a(t) sinh½[2(Λ/3)½t] a(t) Rh ~ t½ t → 0 → (3/Λ)½t → ∞ S~Λ–¾ → Λ–1 Λ–¼ ~ (Rh/Planck length)½ >> 1 t

25. Gravitational entropy –or complexity? CαβγδCαβγδ time

26. Is there a complexity bound on the universe towards which the growth of complexity might tend?

27. The universe has finite computational resources I ≤ 2πkER/ħc 10122 bits

28. A possible experimental test! n particles → 2n possible states 2n~ 10122 → n ~ 400 particles

29. Holographic bound on algorithmic complexity H(X) = – ln P(X) + O(1) algorithmic information H({α}) < Aholo/LP2 Scott Aaronson

30. “No room at the bottom” argument against strong emergence The laws of physics at the micro-level already completely determine the evolution of physical states Additional emergent laws would lead to over-determination

31. Emergent laws of complexity The problem of causal closure Complex system Emergent laws of complexity “Downward causation” Fundamental particles Basic laws of physics

32. Quantum post-selection and the Born rule Pre-selection, no post-selection Born rule Pre-selection, “weird” post-selection “strange” departures from Born rule Three examples: 1. Departures at high energy (“natural” regulation?) 2. Time-symmetric boundary conditions (Gell-Man & Hartle – teleology with teleology) 3. Growth of complexity/diversity

33. Exponential decay law

34. The pattern hidden inside the exponential decay law, revealed by weak measurement w This generalized law is experimentally testable Wheeler’s “turning of the tide” e‒γ(t‒t) i ti tf t

35. Post-selection Pre-selection (e.g. de Sitter vacuum)

36. Biological determinism Life as a ‘cosmic imperative’ Life

37. Christian De Duve “Life is almost bound to arise… wherever physical conditions are similar (to Earth).” “Life is a cosmic imperative!” Multiple origins of life on Earth! Seek evidence from a shadow biosphere

38. Founding tenet of astrobiology Life emerges readily under earthlike conditions Earthlike planets are common, therefore… Life is widespread in the universe

39. 3.5 billion year ago today

40. Search for Extra- Terrestrial Intelligence

42. Stephen Jay Gould N complexity

44. Conclusions • There is no agreed universal measure of what it is “of value” that increases with time. • There is no general theorem proving when complexity increases with time. • An overarching “principle of increasing complexity” or a “cosmic imperative” could be consistent with the existing laws of physics if formulated within the freedom afforded by quantum post-selection.