The Physics of Fine-Tuning

Simon Friederich, Natalja Deng, and Erik Curiel participate in a roundtable discussion addressing questions around probability, fine-tuning, and arguments for a multiverse or deity. Simon Friederich, Natalja Deng, and Erik Curiel participate in a roundtable discussion addressing questions around probability, fine-tuning, and arguments for a multiverse or deity. This discussion was conducted at the Lindeman Lecture Theatre, Clarendon Laboratory, Oxford, on October 6, 2016.

Erik Curiel explains the challenges in making assessments of probability by making assumptions about the space of universes--or cosmological models--that our theories allow. Erik Curiel (Munich Center for Mathematical Philosophy) explains the difficulty of making various concepts of and relating to probability precise, rigorous and physically significant when attempting to apply them in reasoning about objects (e.g., spacetimes) living in infinite-dimensional spaces, working through several examples from cosmology. He concludes that most standard forms of argument used in cosmology to estimate the likelihood of the occurrence of various properties or behaviors of spacetimes have serious mathematical, physical and conceptual problems. This lecture was conducted at the Lindeman Lecture Theatre, Clarendon Laboratory, Oxford, on October 6, 2016.

Natalja Deng discusses whether the apparent fine-tuning of the universe for life can be evidence for a divine creator. Natalja Deng (Yonsei University) comments on two responses to the fine-tuning argument for god, namely one based on dismissive priors , and one based on a ‘God-of-the-gaps' style objection by theistic design theorists. She suggests that the latter response amounts to a practice-based constraint on theistic conceptions, and that often, theistic conceptions that meet this constraint are vulnerable to the former objection. This lecture was conducted at the Lindeman Lecture Theatre, Clarendon Laboratory, Oxford, on October 6, 2016.

Simon Friederich reviews the challenges that arise in using empirical evidence that the universe is tuned for life to evaluate multiverse hypothesis. Simon Friederich (University of Groningen) offers a panoramic view of intricacies and challenges that arise in the assessment of empirical evidence concerning multiverse theories and the relevance of fine-tuning for life. This lecture was conducted at the Lindeman Lecture Theatre, Clarendon Laboratory, Oxford, on October 6, 2016.

Erik Curiel and Simon Friederich hash out the problems we encounter when we look for evidence of a multiverse. How do we gain evidence for a multiverse? In the final part of their discussion, Erik Curiel and Simon Friederich hash out the problems we encounter when we try to use our observations as evidence for the multiverse. This discussion was conducted at the University of Oxford on October 6, 2017.

How similar is the fine-tuning of our universe to probabilistic reasoning we use and understand? Simon Friederich and Erik Curiel go through a series of examples. In the third part of their discussion, Simon Friederich and Erik Curiel go over the connection between a widely recognized fallacy--the Gambler's Fallacy--and the fine-tuning argument. How similar is the fine-tuning argument for the multiverse to common ways of reasoning from observations to likelihoods? This discussion was conducted at the University of Oxford on October 6, 2017.

Erik Curiel and Simon Friederich discuss how reasoning in cosmology sometimes conflates topological stability with probability, and why that might be wrong. In the second part of their discussion, Erik Curiel and Simon Friederich talk about the connection between stability arguments, which are popular in discussions of fine-tuning, and probability. Erik raises a problem for a common form of reasoning in cosmology. This discussion was conducted at the University of Oxford on October 6, 2017.

Simon Friederich and Erik Curiel discuss the problems fine-tuning arguments raise for our understanding of probability. In the first part of their discussion, Simon Friederich and Erik Curiel outline the fine-tuning argument and discuss the problems it raises for our understanding of probability. This discussion was conducted at the University of Oxford on October 6, 2017.

In the fourth part of their discussion, Pedro Ferreira and Jerome Martin conjecture about the future of inflation. They talk about the potential for new evidence for and against the theory, and the variety of new probes into our cosmological environment. This discussion was conducted at the University of Oxford on March 15, 2017.

In the third part of their discussion, Pedro Ferreira and Jerome Martin talk about whether one should look for a deeper physical theory when one's current theory is well-supported by observation. They discuss the rise of inflationary theory, its alternatives, and our expectations for future physics. This discussion was conducted at the University of Oxford on March 15, 2017.

In the second part of their discussion, Pedro Ferreira and Jerome Martin consider ways to build the naturalness of an inflationary model into our expectations for observing it. They debate the feasibility of measuring the degree to which an inflationary model is inspired by considerations from other parts of physics, and describe the applicability of Bayesian methods when we have background knowledge. This discussion was conducted at the University of Oxford on March 15, 2017.

In the first part of their discussion, Pedro Ferreira and Jerome Martin talk about the variety of inflationary models. They discuss methods for distinguishing between them based on evidence and describe the application of Bayesian statistics to inflation. This discussion was conducted at the University of Oxford on March 15, 2017.

What should we expect to learn in the future? In the fourth part of their chat, Dave Sloan and Robert Brandenberger talk about how we expect inflationary theory to develop, and how observations may lead to new physics in this area.

In the third part of their discussion, Dave Sloan and Robert Brandenberger explain the relationship between string theory and inflationary models. Can inflation arise from particle physics, or do we need to look for alternative models? This discussion was conducted at the University of Oxford on March 14, 2017.

In the second part of their discussion, Dave Sloan and Robert Brandenberger tell us what inflation predicts and whether inflation itself seems fine-tuned. This discussion was conducted at the University of Oxford on March 14, 2017.

In the first part of their discussion, Dave Sloan and Robert Brandenberger go over our evidence for inflationary theories and discuss how inflationary models improve on the hot big bang. This discussion was conducted at the University of Oxford on March 14, 2017.

Professor Joe Silk talks with Professor Robert Brandenberger, Professor Jerome Martin, and Dr. Dave Sloan about the current state of research and controversies surrounding inflation. They discuss the possibility of connecting inflation to string theory and the likelihood of the initial conditions required by inflationary models. This lecture was conducted at the Dennis Sciama Theatre at the Denys Wilkinson Building, Oxford, on March 14, 2016.

Professor Robert Brandenberger (McGill) argues that inflationary models still face considerable challenges. He discusses the relationship between inflationary models and particle physics, including string theory and examines alternatives to standard inflationary models. This lecture was conducted at the Dennis Sciama Theatre at the Denys Wilkinson Building, Oxford, on March 14, 2016.

Dr David Sloan (Oxford) discusses the for inflation to occur given typical initial conditions. He argues that, on the right understanding of the background dynamics of the universe, inflationary conditions dominate. This lecture was conducted at the Dennis Sciama Theatre at the Denys Wilkinson Building, Oxford, on March 14, 2016.

Professor Jerome Martin (Institut d'Astrophysique de Paris) explains the current state of evidence for inflationary models. He describes the variety of inflationary models, and discusses how Bayesian statistical methods apply to this space of theories. This lecture was conducted at the Dennis Sciama Theatre at the Denys Wilkinson Building, Oxford, on March 14, 2016.

What is an observer? In the fifth and final part of their discussion, Jim Hartle and Bernard Carr discuss the nature of observers. Should we think of all complex structures as observers, or is there something else--such as consciousness--that makes a system an observer? This discussion was conducted at the Denys Wilkinson Building, Oxford, on October 18, 2016.

Where is the observer in the universe? In the fourth part of their discussion, Jim Hartle and Bernard Carr discuss Jim Hartle's no-boundary proposal. They explain how the proposal accounts for the quantum state of the universe as a whole, and how we find observers like us in a wholly quantum world. This discussion was conducted at the Denys Wilkinson Building, Oxford, on October 18, 2016.

What are the limits of physics? In the third part of their discussion, Bernard Carr and Jim Hartle talk about the point at which physics ends and philosophy begins. Their conversation touches on the connection between physics, mathematics, and evidence. This discussion was conducted in the Denys Wilkinson Building, Oxford, on October 18, 2016.

How do we combine our theory of the very small with our theory of the largest scales of the universe? In the second part of their discussion, Jim Hartle and Bernard Carr hash out the connections between cosmology and quantum mechanics. They also discuss how the probabilities of quantum mechanics can be applied to the universe on its largest scales. This discussion was conducted in the Denys Wilkinson Building, Oxford, on October 18, 2016.

Is the universe fine-tuned for life? In the first part of their discussion, Bernard Carr and Jim Hartle discuss how physical theories might contain unexplained assumptions that are necessary for the existence of life. Their discussion touches on the nature of anthropic reasoning and the possibility of the multiverse. This discussion was conducted in the Denys Wilkinson Building, Oxford, on October 18, 2016.

What surprising features of our theories cry out for explanation? Rocky Kolb and Rafael Alves Batista consider features of our theories that look unlikely or unnatural, and what our chances are for building a unified theory that explains them. This discussion was conducted at the Dennis Sciama Theatre at the Denys Wilkinson Building, Oxford, on September 8, 2016.

We're at a particularly interesting time in the evolution of the universe. Rafael Alves Batista and Rocky Kolb chat about the interesting features of our time, and why we should--or should not--expect to be living now. This discussion was conducted in the Dennis Sciama Theatre at the Denys Wilkinson Building, Oxford, on September 8, 2016.

What sort of things could dark matter be, and how would we tell which it is? Rafael Alves Batista and Rocky Kolb review the main candidate dark matter particles, and consider our chances for telling which one is out there. This discussion took place in the Dennis Sciama Theatre at the Denys Wilkinson Building, Oxford, on September 8, 2016.

In the third part of their discussion, Celine Boehm and Justin Read mull over what we can learn from dark matter. Will understanding dark matter lead us to a small change in the standard model, or a large one? This discussion was conducted at the Denys Wilkinson Building, Oxford, on September 7, 2016.

In the second part of their discussion, Celine Boehm and Justin Read talk about how dark matter acts, both on large scales, at early times, and in small galaxies much nearer to us. This discussion was conducted at the Denys Wilkinson Building, Oxford, on September 7, 2016.

In the first part of their discussion, Justin Read and Celine Boehm go over our evidence for dark matter and consider the possible particles that could make it up. This discussion was conducted in the Denys Wilkinson Building, Oxford, on September 7, 2016.

Celine Boehm, Rocky Kolb, and Justin Read discuss fine-tuning in dark matter models, how we judge astrophysical parameters to be fine-tuned, how we get evidence for dark matter, supersymmetry, and our prospects for finding the dark matter particle. This discussion was conducted at the Dennis Sciama Theatre at the Denys Wilkinson Building, Oxford, on September 8, 2016.

Dr. Celine Boehm (Durham) discusses the possible dark matter particles and the constraints--theoretical and experimental--on their parameter space. This lecture was conducted at the Dennis Sciama Theatre at the Denys Wilkinson Building, Oxford, on September 8, 2016.

Dr. Rocky Kolb (Chicago) discusses the theoretical reasons to expect dark matter to be a Weakly Interacting Massive Particle (WIMP), and the prospects for finding one. This lecture was conducted at the Dennis Sciama Theatre at the Denys Wilkinson Building, Oxford, on September 8, 2016.

Dr. Justin Read (Surrey) explains the astrophysical evidence for dark matter, and our prospects for getting more information about its nature and interaction by looking at nearby dwarf galaxies. This lecture was conducted at the Dennis Sciama Theatre at the Denys Wilkinson Building, Oxford, on September 8, 2016.

In the fourth part of their discussion, Joe Silk and John Peacock conjecture about future developments in cosmology. What part of cosmology is most likely to be fruitful? This discussion was conducted at Trinity College, Oxford, on May 12, 2016.

In the third part of their discussion, Joe Silk and John Peacock consider approaches to dark energy. Should we accept the multiverse, or wait for a theory of quantum gravity? This discussion was conducted at Trinity College, Oxford, on May 12, 2016.

In the second part of their discussion, Joe Silk and John Peacock discuss possible future sources of data and developments in cosmology. They conjecture about the search for dark matter and its impact on astronomy. This discussion was conducted at Trinity College, Oxford, on May 12, 2016.

In the first part of their discussion, Joe Silk and John Peacock compare approaches to statistics and how these bear on predictions in cosmology, including Weinberg's prediction of the cosmological constant. This discussion was conducted at Trinity College, Oxford, on May 12, 2016.

In the fourth part of their discussion, Luke Barnes and David Sloan look for ways the fine-tuning problems can lead to advances in physics. This discussion was conducted at Trinity College, Oxford, on May 13, 2016.

In the third part of their discussion, Luke Barnes and David Sloan puzzle over the way we compare theories, and whether there can be a theory that doesn't have some unexplained posits. This discussion was conducted at Trinity College, Oxford, on May 13, 2016.

In the second part of their discussion, Luke Barnes and David Sloan go over the difference between frequentist and bayesian statistics, and how this difference applies to astrophysics and cosmology. This discussion was conducted at Trinity College, Oxford, on May 13, 2016.

In the first part of their discussion, Luke Barnes and David Sloan come up with a working understanding of fine-tuning. They also discuss various examples of fine-tuning in physics. This discussion was conducted at Trinity College, Oxford, on May 13, 2016

The 3rd Workshop in the Physics of Fine Tuning - Stars, Galaxies, and the Multiverse, audience and panel discussion

The 3rd Workshop in the Physics of Fine Tuning - Stars, Galaxies, and the Multiverse, Adrianne Slyz (Oxford) talks about How do Galaxies know when, where and how quickly to form stars?

The 3rd Workshop in the Physics of Fine Tuning - Stars, Galaxies, and the Multiverse, Joe Silk (Oxford, IAP; John Hopkins) talks about The Limits of Cosmology

The 3rd Workshop in the Physics of Fine Tuning - Stars, Galaxies, and the Multiverse, John Peacock (Edinburgh) talks about Observer Selection and Fine-Tuning Puzzles in Cosmology

Astrophysicist and bestselling author Mario Livio delivers a speculative talk about humans place in the cosmos.

Michael R. Meyer, Institute for Astronomy, Department of Physics, ETH Zurich, delivers a talk about planet formation and conditions for life to exist.

Professor Suzanne Aigrain is an expert exoplanet researcher. In this talk she will outline the methods for detection and characterisation of exoplanets in the context of finding planets that might harbor life.

In the fourth part of their discussion, Suzanne Aigrain and Michael Meyer discuss how we move from observations of exoplanets to conclusions about their types and formation. This discussion was conducted at Trinity College, Oxford, on February 12, 2016.