Samson Abramsky, University of Oxford
Causality and Information Flow in Quantum Protocols
In recent work with Bob Coecke and others, we have developed a categorical axiomatization of quantum mechanics. This analyzes the main structural features of quantum mechanics into simple and general elements, which admit an elegant diagrammatic representation. This enables an illuminating and effective analysis of quantum information protocols and computational structures.One aspect which is brought to light in this analysis is that protocols such as teleportation use entanglement to achieve a logical information flow which has an apparent retro-causal (or even`backward-in-time') component. However, there is also a physical or operational description of the same systems, based on an abstract structural characterization of quantum measurements, which is entirely causally consistent. The systematic relationship between these two descriptions suggests a novel perspective on the flow of time and information in the quantum realm.

Julian Barbour, College Farm
The Theory of Duration and Clocks
In 1898, Poincaré identified two fundamental issues in the theory of time: 1)What is the basis for saying that a second today is the same as a second tomorrow? 2) How can one define simultaneity at spatially separated points? Poincaré outlined the solution to the first problem { which amounts to a theory of duration { in his 1898 paper, and in 1905 he and Einstein simultaneously solved the second problem. Einstein's daring and elegant approach so gripped the imagination of theoreticians, especially after Minkowski's introduction of spacetime,that the definition of duration, and with it the theory of clocks, has received virtually no attentionfor over a century. This is a remarkable state of affairs and is a major cause of the conceptual confusion surrounding the problem of time in the canonical approach to the creation of a quantum theory of gravity. In my talk I shall develop Poincaré's outline into a potentially definitive theory of duration and clocks.

Harvey Brown, Unversity of Oxford
Clocks and time in quantum theory
I will examine a number of time-related issues arising in quantum theory, and in particular attempt to address the following basic questions from a quantum perspective: 1. What is a clock? 2. Why do uniformly moving clocks dilate? 3. What is the behaviour of accelerating clocks?

Phil Dowe, University of Queensland
Philosophical Theories of Time meet Quantum Gravity
A number of startling claims about the nature of time have made on the basis of certain theories of quantum gravity. I canvas the landscape of philosophical theories of time in order to place these claims in a rather different context of argument and counterargument. My aim is to clarify from a philosophical perspective what is at stake in accepting each of these claims.

Adrian Kent
Theory Confirmation in One World and its Failure in Many
I discuss how we can give a satisfactory account of theory confirmation for theories with random data, such as Copenhagen quantum theory, despite the lack of a completely satisfactory definition of probabilistic theories of nature. 
I also explain why neither this nor any other proposed account of scientific confirmation works for many-worlds theories

Wayne C. Myrvold, University of Western Ontario  
Relativistic Quantum State Evolution: Narratability and Relativity
In this talk I will discuss a feature of quantum state evolution in a relativistic spacetime, the feature that David Albert has recently dubbed "non-narratability."  This is: a complete state history given along one foliation does not always, by itself (that is, without specification of the dynamics of the system), determine the history along another foliation.  The question arises: is this a deep distinction between quantum and classical state evolution, that deserves our fuller attention?  I will discuss some results relevant to this question.

John D. Norton, University of Pittsburgh
Why Constructive Relativity Fails
Are time and space independently existing entities? Or is their existence secondary in that they are merely properties of other, more fundamental physical systems? The parameters of this enduring debate have shifted according to the physical theory in which it are set. In the 17th century, Newton's notions of Absolute Time and Space strongly favored the idea of independently existing times and spaces. Yet Leibniz famously plagued Newton by pointing to changes that Newton must suppose real even though they issued in no observable differences. Most recently, with the advent of general relativity and quantum theories of gravity that seek to incorporate it, the balance has shifted once again. Is the independence of space and time now finally revealed by the metric field of space and time absorbing the matter of the gravitational fields? Or has time and space has lost its independence from matter in so far as space and time have been absorbed into the matter of the gravitational field? The focus of my talk will be an intermediate episode of this debate that plays out in the context of special relativity. Lorentz noted that moving electrodynamical systems slow in time and shrink in space. The realist tradition explains this slowing and shrinking through the adaptation of matter fields to a real, independently existing Minkowski spacetime. A dissident constructive tradition has long felt that the reverse is the case. These spatio-temporal effects are best explained by the properties of matter theories, most notably, their Lorentz covariance. Harvey Brown has advocated a form of this latter constructivism in his <i>Physical Relativity: Space- time Structure from a Dynamical Perspective.</i> This debate between these two views has proven hard to resolve. That is largely because the notion of explanation is not sufficiently understood for us to adjudicate cleanly between competing claims of what explains what better. In my talk, I will review a new approach to the debate. Constructivists have tacitly assumed a technical result, that it is indeed possible to construct a Minkowski spacetime from Lorentz covariant matter theories. I will show that this is incorrect. This construction project can succeed only in so far as constructivists presume antecedently the basic tenets of the realist view of spacetime. Hence constructivism fails as an alternative to realism about spacetime.

Roger Penrose, University of Oxford
Clocks at the Big Bang? Quantum gravity is not what you think!
It has been a common viewpoint that the process of quantization ought to replace the singularities of classical general relativity by some chaotic-looking structure at the scale of the Planck length. In this talk I shall argue that whereas this is to be expected at black-hole singularities, Nature's true picture of what goes on at the Big Bang is very different, where clocks cannot exist and the conformal geometry is completely smooth.

Lee Smolin, Perimeter Institute
On the reality of time and the evolution of laws
There are a number of arguments in the philosophical, physical and cosmological literatures for the thesis that time is not fundamental to the description of nature. According to this view, time should be only an approximate notion which emerges from a more fundamental, timeless description only in certain limiting approximations.  My first task is to review these arguments and explain why they fail. I will then examine the opposite view, which is that time and change are fundamental and, indeed, are perhaps the only aspects of reality that are not emergent from a more fundamental, microscopic description.

The argument involves several aspects of contemporary physics and cosmology including 1) the problem of the landscape of string theory, 2) cosmological inflation and the problem of initial conditions, 3) the interpretation of the “wavefunction of the universe,” and the problem of what is an observable in classical and quantum general  relativity.    It also involves issues in the foundations of mathematics and the issue of the proper understanding of the role of mathematics in physics.  The view that time is real and not emergent is, I will argue,  supported by considerations arising from all these issues  It leads finally to a need for a notion of law in cosmology which replaces the freedom to choose initial conditions with a notion of laws evolving in time.
The arguments presented here have been developed in collaboration with Roberto Mangabeira Unger.

Rafael Sorkin, Perimeter Institute
Solved and unsolved problems of time in quantum gravity
I will identify six "problems of time" that arise in connection with quantum gravity and review the extent to which some of them can be regarded as solved, highlighting the very different aspects that they assume depending on one's starting point: Hamiltonian vs. path-integral, discrete vs continuous.

Aephraim Steinberg, University of Toronto
Thinking Inside the Box: Weakly Measuring Postselected Ensembles
The presumed irreversibility of quantum measurements (whatever they are) leads, in conventional approaches to quantum theory, to an asymmetry between state preparation and post-selection.  Is it possible that a trajectory can be  predicted from the former, yet not inferred from the latter?  Especially in light of the exciting applications of non-unitary operations (i.e., postselection) in quantum information, it becomes timely to reconsider how much one can say about a post-selected subensemble.  I will review the weak-measurement formalism of Aharonov, Vaidman et al., and discuss some applications and extensions.  These will include a proposed experiment to study the duration of the tunneling process (a question controversial since the 1930s) and a recently completed experiment aiming to "resolve" Hardy's retrodiction paradox.

Leonard Susskind, Stanford University, Perimeter Institute
Cosmic Time and Renormalization Group Flow
I will explain two examples of how cosmic time emerges as an RG-flow parameter. The  first example is the global analysis of  an eternally inflating cosmology and the second is the local analysis of a "Cosmic Census Taker." Connecting the two, gives insight into the so-called "measure problem."

Roderich Tumulka, Rutgers University
Time in Bohmian Mechanics
My favorite version of quantum mechanics is Bohmian mechanics, a theory about particle trajectories. What is so great about it is that it removes all the mystery from quantum mechanics. I will provide a Bohmian perspective on some issues about time, including time measurements (Why is there no time operator?), tunnelling times (How long did the particle stay inside the barrier?), and the problem of time in quantum gravity (How can it be that the wave function of the Wheeler-de Witt equation is time-independent?). I will particularly address the arrow of time, including the question whether quantum measurements are examples of fundamental time asymmetry (like PCT violations, as Roger Penrose has suggested) or merely of irreversibility (like thermodynamics), and the problem how to transfer Boltzmann's explanation of the arrow of time from classical to quantum mechanics.

Neil Turok, Perimeter Institute
Time and the big bang
The evidence for the big bang is now overwhelming.However, the basic question of what caused the bang remains open. One possibility is that time somehow "emerged," placing the universe in an inflationary state. Another, perhaps more conservative possibility, is that the big bang was a violent event in a pre-existing universe. I will describe model calculations employing the AdS/CFT correspondence which show how this is possible, and which point to a new explanation for the origin of large scale structure in the universe.

Jos Uffink, Utrecht University
On the time-energy uncertainty relation
In contrast to Heisenberg's position-momentum uncertainty relation, the status of the time-energy uncertainty relation has always remained dubious, For example, it is often said that "time" in quantum theory is not an observable and not represented by a self-adjoint operator. I will review the background of the problem and propose a view on the uncertainty relations in which  the cases of position-momentum and time-energy can be treated in the same way.

William Unruh, University of British Columbia
A voyage in time

Lev Vaidman, Tel Aviv University
The Two State Vector Formalism
A brief review of the Two State Vector Formalism (TSVF) will be presented. It will be argued that we need to consider also backwards evolving quantum state because information given by forwards evolving quantum states is not complete. Both past and future measurements are required for providing complete information about quantum systems. Peculiar properties of pre- and post-selected quantum systems which can be efficiently analyzed in the framework of the TSVF and which can be observed using weak measurements will be described. An example is a particle reaching a certain location without being on the path that leads to and from this location. An extension of the TSVF to multiple space-time points will be discussed.