# Video Library

Since 2002 Perimeter Institute has been recording seminars, conference talks, and public outreach events using video cameras installed in our lecture theatres.  Perimeter now has 7 formal presentation spaces for its many scientific conferences, seminars, workshops and educational outreach activities, all with advanced audio-visual technical capabilities.  Recordings of events in these areas are all available On-Demand from this Video Library and on Perimeter Institute Recorded Seminar Archive (PIRSA)PIRSA is a permanent, free, searchable, and citable archive of recorded seminars from relevant bodies in physics. This resource has been partially modelled after Cornell University's arXiv.org.

## Being vs. Happening: information from the intrinsic perspective of the system itself

Thursday Apr 12, 2018
Speaker(s):

When applied to a physical system, the two main, established notions of information, Shannon Information and Algorithmic Information, explicitly neglect the mechanistic structure of the system under evaluation. Shannon information treats the system as a channel and quantifies correlations between the system’s inputs and outputs, or between its past and future states. Algorithmic information quantifies the length of the shortest program capable of reproducing the system’s outputs or dynamics.

Scientific Areas:

## Causal inference rules for algorithmic dependences and why they reproduce the arrow of time

Thursday Apr 12, 2018
Speaker(s):

The causal Markov condition relates statistical dependences to causality. Its relevance is meanwhile widely appreciated in machine learning, statistics, and physics. I describe the *algorithmic* causal Markov condition relating algorithmic dependences to causality, which can be used for inferring causal relations among single objects without referring to statistics. The underlying postulate "no algorithmic dependence without causal relation" extends Reichenbach's Principle to a probability-free setting.

Scientific Areas:

## From observers to physics via algorithmic information theory

Thursday Apr 12, 2018
Speaker(s):

Remark to last week's participants: This will be a condensed version of last week's talks. I will drop many details (in particular on the relation to quantum theory) and also drop the introductory slides to algorithmic probability (for this, see Marcus Hutter's introductory talk on Tuesday afternoon, April 10).

Scientific Areas:

## PSI 2017/2018 - Scattering Amplitudes in QFT & String Theory - Lecture 4

Thursday Apr 12, 2018

## PSI 2017/2018 - Cosmology - Lecture 4

Thursday Apr 12, 2018
Speaker(s):
Scientific Areas:

## Observer Localization in Multiverse Theories

Thursday Apr 12, 2018
Speaker(s):

The progression of theories suggested for our world, from ego- to geo- to helio-centric models to universe and multiverse theories and beyond, shows one tendency: The size of the described worlds increases, with humans being expelled from their center to ever more remote and random locations. If pushed too far, a potential theory of everything (TOE) is actually more a theories of nothing (TON). Indeed such theories have already been developed. I show that including observer localization into such theories is necessary and sufficient to avoid this problem.

Scientific Areas:

## PSI 2017/2018 - Machine Learning for Many Body Physics - Lecture 4

Thursday Apr 12, 2018

## Can quantum states be understood as Bayesian states of belief?

Wednesday Apr 11, 2018
Speaker(s):

In accordance with Betteridge's Law of Headlines, the answer to the question in the title is "no." I will argue that the usual norms of Bayesian inference lead the conclusion that quantum states are features of physical reality. The argument will involve both existing $\psi$-ontology results and extension of them that avoids the use of the Cartesian Product Assumption. As the usual norms of Bayesian inference lead to the conclusion of the reality of quantum state, rejecting it requires abandonment of virtually all of Bayesian information theory. This, I will argue, is unwarranted

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## Introduction to Algorithmic Information Theory and Tutorial

Wednesday Apr 11, 2018
Speaker(s):

The progression of theories suggested for our world, from ego- to geo- to helio-centric models to universe and multiverse theories and beyond, shows one tendency: The size of the described worlds increases, with humans being expelled from their center to ever more remote and random locations. If pushed too far, a potential theory of everything (TOE) is actually more a theories of nothing (TON). Indeed such theories have already been developed. I show that including observer localization into such theories is necessary and sufficient to avoid this problem.

Scientific Areas:

## PSI 2017/2018 - Scattering Amplitudes in QFT & String Theory - Lecture 3

Wednesday Apr 11, 2018

## Next Public Lecture

Check back for details on the next lecture in Perimeter's Public Lectures Series

## LECTURES ON-DEMAND

### Roger Melko: Perimeter Institute and University of Waterloo

Speaker: Roger Melko