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Current Essay Contest
Previous Contests
Undecidability, Uncomputability, and Unpredictability Essay Contest
December 24, 2019 - April 24, 2020
Contest Partners: Fetzer Franklin Fund, and The Peter and Patricia Gruber Foundation
read/discuss • winners
What Is “Fundamental”
October 28, 2017 to January 22, 2018
Sponsored by the Fetzer Franklin Fund and The Peter & Patricia Gruber Foundation
read/discuss • winners
Wandering Towards a Goal
How can mindless mathematical laws give rise to aims and intention?
December 2, 2016 to March 3, 2017
Contest Partner: The Peter and Patricia Gruber Fund.
read/discuss • winners
Trick or Truth: The Mysterious Connection Between Physics and Mathematics
Contest Partners: Nanotronics Imaging, The Peter and Patricia Gruber Foundation, and The John Templeton Foundation
Media Partner: Scientific American
read/discuss • winners
How Should Humanity Steer the Future?
January 9, 2014 - August 31, 2014
Contest Partners: Jaan Tallinn, The Peter and Patricia Gruber Foundation, The John Templeton Foundation, and Scientific American
read/discuss • winners
It From Bit or Bit From It
March 25 - June 28, 2013
Contest Partners: The Gruber Foundation, J. Templeton Foundation, and Scientific American
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Questioning the Foundations
Which of Our Basic Physical Assumptions Are Wrong?
May 24 - August 31, 2012
Contest Partners: The Peter and Patricia Gruber Foundation, SubMeta, and Scientific American
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Is Reality Digital or Analog?
November 2010 - February 2011
Contest Partners: The Peter and Patricia Gruber Foundation and Scientific American
read/discuss • winners
What's Ultimately Possible in Physics?
May - October 2009
Contest Partners: Astrid and Bruce McWilliams
read/discuss • winners
The Nature of Time
August - December 2008
read/discuss • winners
Current Essay Contest
Previous Contests
Undecidability, Uncomputability, and Unpredictability Essay Contest
December 24, 2019 - April 24, 2020
Contest Partners: Fetzer Franklin Fund, and The Peter and Patricia Gruber Foundation
read/discuss • winners
What Is “Fundamental”
October 28, 2017 to January 22, 2018
Sponsored by the Fetzer Franklin Fund and The Peter & Patricia Gruber Foundation
read/discuss • winners
Wandering Towards a Goal
How can mindless mathematical laws give rise to aims and intention?
December 2, 2016 to March 3, 2017
Contest Partner: The Peter and Patricia Gruber Fund.
read/discuss • winners
Trick or Truth: The Mysterious Connection Between Physics and Mathematics
Contest Partners: Nanotronics Imaging, The Peter and Patricia Gruber Foundation, and The John Templeton Foundation
Media Partner: Scientific American
read/discuss • winners
How Should Humanity Steer the Future?
January 9, 2014 - August 31, 2014
Contest Partners: Jaan Tallinn, The Peter and Patricia Gruber Foundation, The John Templeton Foundation, and Scientific American
read/discuss • winners
It From Bit or Bit From It
March 25 - June 28, 2013
Contest Partners: The Gruber Foundation, J. Templeton Foundation, and Scientific American
read/discuss • winners
Questioning the Foundations
Which of Our Basic Physical Assumptions Are Wrong?
May 24 - August 31, 2012
Contest Partners: The Peter and Patricia Gruber Foundation, SubMeta, and Scientific American
read/discuss • winners
Is Reality Digital or Analog?
November 2010 - February 2011
Contest Partners: The Peter and Patricia Gruber Foundation and Scientific American
read/discuss • winners
What's Ultimately Possible in Physics?
May - October 2009
Contest Partners: Astrid and Bruce McWilliams
read/discuss • winners
The Nature of Time
August - December 2008
read/discuss • winners
FQXi ESSAY CONTEST
May 9, 2021
2012 Questioning the Foundations Winning Essays
First Prize
The paradigm of kinematics and dynamics must yield to causal structure
Robert Spekkens
Robert Spekkens
Essay Abstract
The distinction between a theory's kinematics and its dynamics, that is, between the space of physical states it posits and its law of evolution, is central to the conceptual framework of many physicists. A change to the kinematics of a theory, however, can be compensated by a change to its dynamics without empirical consequence, which strongly suggests that these features of the theory, considered separately, cannot have physical significance. It must therefore be concluded (with apologies to Minkowski) that henceforth kinematics by itself, and dynamics by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality. The notion of causal structure seems to provide a good characterization of this union.
Author Bio
Robert Spekkens is a faculty member at the Perimeter Institute for Theoretical Physics in Waterloo, Canada. His area of research is the foundations of quantum theory.
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The distinction between a theory's kinematics and its dynamics, that is, between the space of physical states it posits and its law of evolution, is central to the conceptual framework of many physicists. A change to the kinematics of a theory, however, can be compensated by a change to its dynamics without empirical consequence, which strongly suggests that these features of the theory, considered separately, cannot have physical significance. It must therefore be concluded (with apologies to Minkowski) that henceforth kinematics by itself, and dynamics by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality. The notion of causal structure seems to provide a good characterization of this union.
Author Bio
Robert Spekkens is a faculty member at the Perimeter Institute for Theoretical Physics in Waterloo, Canada. His area of research is the foundations of quantum theory.
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Second Prizes
Recognising Top-Down Causation
George Ellis
George Ellis
Essay Abstract
One of the basic assumptions implicit in the way physics is usually done is that all causation flows in a bottom up fashion, from micro to macro scales. However this is wrong in many cases in biology, and in particular in the way the brain functions. Here I make the case that it is also wrong in the case of digital computers – the paradigm of mechanistic algorithmic causation - and in many cases in physics, ranging from the origin of the arrow of time to the process of quantum state preparation. I consider some examples from classical physics; from quantum physics; and the case of digital computers, and then explain why it this possible without contradicting the causal powers of the underlying micro physics. Understanding the emergence of genuine complexity out of the underlying physics depends on recognising this kind of causation. It is a missing ingredient in present day theory; and taking it into account may help understand such mysteries as the measurement problem in quantum mechanics:
Author Bio
George Ellis is a relativist and cosmologist residing in Cape Town, South Africa. His books include On the Large Scale Structure of Space-Time co-authored with Stephen Hawking. In addition to contemplating relativistic and philosophical aspects of cosmology, he is now engaged in trying to understand how complex systems such as you and me can arise out of the underlying physics.
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One of the basic assumptions implicit in the way physics is usually done is that all causation flows in a bottom up fashion, from micro to macro scales. However this is wrong in many cases in biology, and in particular in the way the brain functions. Here I make the case that it is also wrong in the case of digital computers – the paradigm of mechanistic algorithmic causation - and in many cases in physics, ranging from the origin of the arrow of time to the process of quantum state preparation. I consider some examples from classical physics; from quantum physics; and the case of digital computers, and then explain why it this possible without contradicting the causal powers of the underlying micro physics. Understanding the emergence of genuine complexity out of the underlying physics depends on recognising this kind of causation. It is a missing ingredient in present day theory; and taking it into account may help understand such mysteries as the measurement problem in quantum mechanics:
Author Bio
George Ellis is a relativist and cosmologist residing in Cape Town, South Africa. His books include On the Large Scale Structure of Space-Time co-authored with Stephen Hawking. In addition to contemplating relativistic and philosophical aspects of cosmology, he is now engaged in trying to understand how complex systems such as you and me can arise out of the underlying physics.
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Patterns in the Fabric of Nature
Steven Weinstein
Steven Weinstein
Essay Abstract
From classical mechanics to quantum field theory, the physical facts at one point in space are held to be independent of those at other points in space. I propose that we can usefully challenge this orthodoxy in order to explain otherwise puzzling correlations at both cosmological and microscopic scales.
Author Bio
Steve Weinstein is an associate professor of philosophy and physics at the University of Waterloo, and an affiliate of the Perimeter Institute for Theoretical Physics. He has written broadly on the foundations of quantum mechanics, on reasoning in cosmology, and on the possibility of extra time dimensions. He is also a musician and songwriter in his copious spare time.
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From classical mechanics to quantum field theory, the physical facts at one point in space are held to be independent of those at other points in space. I propose that we can usefully challenge this orthodoxy in order to explain otherwise puzzling correlations at both cosmological and microscopic scales.
Author Bio
Steve Weinstein is an associate professor of philosophy and physics at the University of Waterloo, and an affiliate of the Perimeter Institute for Theoretical Physics. He has written broadly on the foundations of quantum mechanics, on reasoning in cosmology, and on the possibility of extra time dimensions. He is also a musician and songwriter in his copious spare time.
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Third Prizes
Reductionist Doubts
Julian Barbour
Julian Barbour
Essay Abstract
According to reductionism, every complex phenomenon can and should be explained in terms of the simplest possible entities and mechanisms. The parts determine the whole. This approach has been an outstanding success in science, but this essay will point out ways in which it could nevertheless be giving us wrong ideas and holding back progress. For example, it may be impossible to understand key features of the universe such as its pervasive arrow of time and remarkably high degree of isotropy and homogeneity unless we study it holistically -- as a true whole. A satisfactory interpretation of quantum mechanics is also likely to be profoundly holistic, involving the entire universe. The phenomenon of entanglement already hints at such a possibility.
Author Bio
After completing a PhD in theoretical physics, I became an independent researcher to avoid the publish-or-perish syndrome. For 45 years I have worked on the nature of time, motion, and the quantum theory of the universe. I am the author of two books: The Discovery of Dynamics and The End of Time, in which I argue that time is an illusion. Details of my research work are given at my website platonia.com. Since 2008 I have been a Visiting Professor at the University of Oxford.
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According to reductionism, every complex phenomenon can and should be explained in terms of the simplest possible entities and mechanisms. The parts determine the whole. This approach has been an outstanding success in science, but this essay will point out ways in which it could nevertheless be giving us wrong ideas and holding back progress. For example, it may be impossible to understand key features of the universe such as its pervasive arrow of time and remarkably high degree of isotropy and homogeneity unless we study it holistically -- as a true whole. A satisfactory interpretation of quantum mechanics is also likely to be profoundly holistic, involving the entire universe. The phenomenon of entanglement already hints at such a possibility.
Author Bio
After completing a PhD in theoretical physics, I became an independent researcher to avoid the publish-or-perish syndrome. For 45 years I have worked on the nature of time, motion, and the quantum theory of the universe. I am the author of two books: The Discovery of Dynamics and The End of Time, in which I argue that time is an illusion. Details of my research work are given at my website platonia.com. Since 2008 I have been a Visiting Professor at the University of Oxford.
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Quantum-informational Principles for Physics
Giacomo D'Ariano
Giacomo D'Ariano
Essay Abstract
It is time to to take a pause of reflection on the general foundations of physics, re-examining the solidity of the most basic principles, as the relativity and the equivalence principles that are currently under dispute for violations at the Planck scale. A constructive criticism engages us in seeking new general principles, which reduce to the old ones as approximations holding in the physical domain already explored. At the very basis of physics are epistemological and operational rules for the same formulability of the physical law and for the computability of its theoretical predictions, rules that give rise to new solid principles. These rules lead us to a quantum-information theoretic formulation, hinging on a logical identification of the experimental protocol with the quantum algorithm.
Author Bio
I am professor at the University of Pavia, where I teach "Physical Theory of Information" and "Foundations of Quantum Mechanics", and enjoy research with a marvelous group of much younger collaborators.
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It is time to to take a pause of reflection on the general foundations of physics, re-examining the solidity of the most basic principles, as the relativity and the equivalence principles that are currently under dispute for violations at the Planck scale. A constructive criticism engages us in seeking new general principles, which reduce to the old ones as approximations holding in the physical domain already explored. At the very basis of physics are epistemological and operational rules for the same formulability of the physical law and for the computability of its theoretical predictions, rules that give rise to new solid principles. These rules lead us to a quantum-information theoretic formulation, hinging on a logical identification of the experimental protocol with the quantum algorithm.
Author Bio
I am professor at the University of Pavia, where I teach "Physical Theory of Information" and "Foundations of Quantum Mechanics", and enjoy research with a marvelous group of much younger collaborators.
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On the Foundational Assumptions of Modern Physics
Benjamin Dribus
Benjamin Dribus
Essay Abstract
General relativity and the standard model of particle physics remain the most fundamental physical theories enjoying robust experimental confirmation. The foundational assumptions of physics changed rapidly during the early development of these theories, but the challenges of their refinement and the exploitation of their explanatory power turned attention away from foundational issues. Deep problems and anomalous observations remain unaddressed. New theories such as string theory attempt to resolve these issues, but are presently untested. In this essay, I evaluate the foundational assumptions of modern physics and propose new physical principles. I reject the manifold structure of spacetime, the existence of an independent time parameter and static background structure, the symmetry interpretation of covariance, the commutativity of spacetime, and a number of related assumptions. The central new principle I propose is called the causal metric hypothesis. The classical version of this hypothesis states that the metric properties of spacetime, up to overall scale, arise from the binary relation generating the causal order. The quantum version states that the phases associated with congruence classes of directed paths in causal configuration space are determined by the causal relations of their constituent universes.
Author Bio
Ben Dribus is a Ph.D. student in mathematics at Louisiana State University, studying algebraic geometry and algebraic K-theory. He has a background in physics and is interested in applying modern algebra, order theory, and graph theory to foundational questions.
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General relativity and the standard model of particle physics remain the most fundamental physical theories enjoying robust experimental confirmation. The foundational assumptions of physics changed rapidly during the early development of these theories, but the challenges of their refinement and the exploitation of their explanatory power turned attention away from foundational issues. Deep problems and anomalous observations remain unaddressed. New theories such as string theory attempt to resolve these issues, but are presently untested. In this essay, I evaluate the foundational assumptions of modern physics and propose new physical principles. I reject the manifold structure of spacetime, the existence of an independent time parameter and static background structure, the symmetry interpretation of covariance, the commutativity of spacetime, and a number of related assumptions. The central new principle I propose is called the causal metric hypothesis. The classical version of this hypothesis states that the metric properties of spacetime, up to overall scale, arise from the binary relation generating the causal order. The quantum version states that the phases associated with congruence classes of directed paths in causal configuration space are determined by the causal relations of their constituent universes.
Author Bio
Ben Dribus is a Ph.D. student in mathematics at Louisiana State University, studying algebraic geometry and algebraic K-theory. He has a background in physics and is interested in applying modern algebra, order theory, and graph theory to foundational questions.
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Gravity can be neither classical nor quantized
Sabine Hossenfelder
Sabine Hossenfelder
Essay Abstract
I argue that it is possible for a theory to be neither quantized nor classical. We should therefore give up the assumption that the fundamental theory which describes gravity at shortest distances must either be quantized, or quantization must emerge from a fundamentally classical theory. To illustrate my point I will discuss an example for a theory that is neither classical nor quantized, and argue that it has the potential to resolve the tensions between the quantum field theories of the standard model and general relativity.
Author Bio
Sabine is an assistant professor at Nordita in Stockholm. Her work is mostly focused on the phenomenology of quantum gravity. In her free time she blogs at backreaction.blogspot.com
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I argue that it is possible for a theory to be neither quantized nor classical. We should therefore give up the assumption that the fundamental theory which describes gravity at shortest distances must either be quantized, or quantization must emerge from a fundamentally classical theory. To illustrate my point I will discuss an example for a theory that is neither classical nor quantized, and argue that it has the potential to resolve the tensions between the quantum field theories of the standard model and general relativity.
Author Bio
Sabine is an assistant professor at Nordita in Stockholm. Her work is mostly focused on the phenomenology of quantum gravity. In her free time she blogs at backreaction.blogspot.com
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The Universe is not a Computer
Ken Wharton
Ken Wharton
Essay Abstract
When we want to predict the future, we compute it from what we know about the present. Specifically, we take a mathematical representation of observed reality, plug it into some dynamical equations, and then map the time-evolved result back to real world predictions. But while this computational process can tell us what we want to know, we have taken this procedure too literally, implicitly assuming that the universe must compute itself in the same manner. Physical theories that do not follow this computational framework are deemed illogical, right from the start. But this anthropocentric assumption has steered our physical models into an impossible corner, primarily because of quantum phenomena. Meanwhile, we have not been exploring other models in which the universe is not so limited. In fact, some of these alternate models already have a well-established importance, but are thought to be mathematical tricks without physical signficance. This essay argues that only by dropping our assumption that the universe is a computer can we fully develop such models, explain quantum phenomena, and understand the workings of our universe.
Author Bio
Ken Wharton is a full professor in the Department of Physics and Astronomy at San Jose State University, and a member of FQXi. His research in the field of Quantum Foundations is focused on realistic models that reside in ordinary spacetime, especially those that feature the same time-symmetry as the phenomena they attempt to explain.
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When we want to predict the future, we compute it from what we know about the present. Specifically, we take a mathematical representation of observed reality, plug it into some dynamical equations, and then map the time-evolved result back to real world predictions. But while this computational process can tell us what we want to know, we have taken this procedure too literally, implicitly assuming that the universe must compute itself in the same manner. Physical theories that do not follow this computational framework are deemed illogical, right from the start. But this anthropocentric assumption has steered our physical models into an impossible corner, primarily because of quantum phenomena. Meanwhile, we have not been exploring other models in which the universe is not so limited. In fact, some of these alternate models already have a well-established importance, but are thought to be mathematical tricks without physical signficance. This essay argues that only by dropping our assumption that the universe is a computer can we fully develop such models, explain quantum phenomena, and understand the workings of our universe.
Author Bio
Ken Wharton is a full professor in the Department of Physics and Astronomy at San Jose State University, and a member of FQXi. His research in the field of Quantum Foundations is focused on realistic models that reside in ordinary spacetime, especially those that feature the same time-symmetry as the phenomena they attempt to explain.
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Fourth Prizes
against spacetime
Giovanni Amelino-Camelia
Giovanni Amelino-Camelia
Essay Abstract
The notion of "location" physics really needs is exclusively the one of "detection at a given detector" and the time for each such detection is most primitively assessed as the readout of some specific material clock. The redundant abstraction of a macroscopic spacetime organizing all our particle detections is unproblematic and extremely useful in the classical-mechanics regime. But I here observe that in some of the contexts where quantum mechanics is most significant, such as quantum tunneling through a barrier, the spacetime abstraction proves to be cumbersome. And I argue that in quantum-gravity research we might limit our opportunities for discovery if we insist on the availability of a spacetime picture.
Author Bio
Researcher in Theoretical Physics as Sapienza University of Rome. Previously worked at CERN, Univ Neuchatel, Oxford Univ, MIT. PhD from Boston University. Was awarded an FQXi Large Grant in 2008
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The notion of "location" physics really needs is exclusively the one of "detection at a given detector" and the time for each such detection is most primitively assessed as the readout of some specific material clock. The redundant abstraction of a macroscopic spacetime organizing all our particle detections is unproblematic and extremely useful in the classical-mechanics regime. But I here observe that in some of the contexts where quantum mechanics is most significant, such as quantum tunneling through a barrier, the spacetime abstraction proves to be cumbersome. And I argue that in quantum-gravity research we might limit our opportunities for discovery if we insist on the availability of a spacetime picture.
Author Bio
Researcher in Theoretical Physics as Sapienza University of Rome. Previously worked at CERN, Univ Neuchatel, Oxford Univ, MIT. PhD from Boston University. Was awarded an FQXi Large Grant in 2008
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Weaving commutators: beyond Fock space
Michele Arzano
Michele Arzano
Essay Abstract
The symmetrization postulate and the associated Bose/Fermi (anti)-commutators for field mode operators are among the pillars on which local quantum field theory lays its foundations. They ultimately determine the structure of Fock space and are closely connected with the local properties of the fields and with the action of symmetry generators on observables and states. We here show that the quantum field theory describing a relativistic particle coupled to three dimensional Einstein gravity as a topological defect must be constructed using a deformed algebra of creation and annihilation operators. This reflects a non-trivial group manifold structure of the classical momentum space and a modification of the Leibniz rule for the action of symmetry generators governed by Newton's constant. We outline various arguments suggesting that, at least at the qualitative level, these three-dimensional results could also apply to real four-dimensional world thus forcing us to re-think the ordinary multiparticle structure of quantum field theory and many of the fundamental aspects connected to it.
Author Bio
Dr. Arzano is a researcher in theoretical physics at the "Sapienza" University of Rome in Italy. He obtained his PhD from the University of North Carolina at Chapel Hill and has worked as a Postdoctoral Researcher at the Perimeter Institute for Theoretical Physics in Canada and as a Marie Curie Fellow at Institute for Theoretical Physics at Utrecht University, The Netherlands. Part of his current research revolves around the question of which of the fundamental pillars of our current description of high energy physics can or must be rethought when (quantum) gravity enters the picture.
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The symmetrization postulate and the associated Bose/Fermi (anti)-commutators for field mode operators are among the pillars on which local quantum field theory lays its foundations. They ultimately determine the structure of Fock space and are closely connected with the local properties of the fields and with the action of symmetry generators on observables and states. We here show that the quantum field theory describing a relativistic particle coupled to three dimensional Einstein gravity as a topological defect must be constructed using a deformed algebra of creation and annihilation operators. This reflects a non-trivial group manifold structure of the classical momentum space and a modification of the Leibniz rule for the action of symmetry generators governed by Newton's constant. We outline various arguments suggesting that, at least at the qualitative level, these three-dimensional results could also apply to real four-dimensional world thus forcing us to re-think the ordinary multiparticle structure of quantum field theory and many of the fundamental aspects connected to it.
Author Bio
Dr. Arzano is a researcher in theoretical physics at the "Sapienza" University of Rome in Italy. He obtained his PhD from the University of North Carolina at Chapel Hill and has worked as a Postdoctoral Researcher at the Perimeter Institute for Theoretical Physics in Canada and as a Marie Curie Fellow at Institute for Theoretical Physics at Utrecht University, The Netherlands. Part of his current research revolves around the question of which of the fundamental pillars of our current description of high energy physics can or must be rethought when (quantum) gravity enters the picture.
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A chicken-and-egg problem: Which came first, the quantum state or spacetime?
Torsten Asselmeyer-Maluga
Torsten Asselmeyer-Maluga
Essay Abstract
In this essay I will discuss the question: Is spacetime quantized, as in quantum geometry, or is it possible to derive the quantization procedure from the structure of spacetime? All proposals of quantum gravity try to quantize spacetime or derive it as an emergent phenomenon. In this essay, all major approaches are analyzed to find an alternative to a discrete structure on spacetime or to the emergence of spacetime. Here I will present the idea that spacetime defines the quantum state by using new developments in the differential topology of 3- and 4-manifolds. In particular the plethora of exotic smoothness structures in dimension 4 could be the corner stone of quantum gravity.
Author Bio
I'm a post-doc worker at the German Aerospace Center. I received my PhD at Humboldt university. My research interests are wide-spreaded from evolutionary algorithms and quantum computing to quantum gravity. Since more than 15 years I try to uncover the role of exotic smoothness in general relativity and quantum gravity.
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In this essay I will discuss the question: Is spacetime quantized, as in quantum geometry, or is it possible to derive the quantization procedure from the structure of spacetime? All proposals of quantum gravity try to quantize spacetime or derive it as an emergent phenomenon. In this essay, all major approaches are analyzed to find an alternative to a discrete structure on spacetime or to the emergence of spacetime. Here I will present the idea that spacetime defines the quantum state by using new developments in the differential topology of 3- and 4-manifolds. In particular the plethora of exotic smoothness structures in dimension 4 could be the corner stone of quantum gravity.
Author Bio
I'm a post-doc worker at the German Aerospace Center. I received my PhD at Humboldt university. My research interests are wide-spreaded from evolutionary algorithms and quantum computing to quantum gravity. Since more than 15 years I try to uncover the role of exotic smoothness in general relativity and quantum gravity.
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Not on but of.
Olaf Dreyer
Olaf Dreyer
Essay Abstract
In physics we encounter particles in one of two ways. Either as fundamental constituents of the theory or as emergent excitations. These two ways differ by how the particle relates to the background. It either sits on the background, or it is an excitation of the background. We argue that by choosing the former to construct our fundamental theories we have made a costly mistake. Instead we should think of particles as excitations of a background. We show that this point of view sheds new light on the cosmological constant problem and even leads to observable consequences by giving a natural explanation for the appearance of MOND-like behavior. In this context it also becomes clear why there are numerical coincidences between the MOND acceleration parameter a_0, the cosmological constant Lambda and the Hubble parameter H_0.
Author Bio
Olaf Dreyer is a theoretical physicist working at the university in Rome. He received a PhD in Quantum Gravity at the Pennsylvania State University and has worked at the Perimeter Institute, Imperial College, and the MIT, where he was supported by an FQXi grant.
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In physics we encounter particles in one of two ways. Either as fundamental constituents of the theory or as emergent excitations. These two ways differ by how the particle relates to the background. It either sits on the background, or it is an excitation of the background. We argue that by choosing the former to construct our fundamental theories we have made a costly mistake. Instead we should think of particles as excitations of a background. We show that this point of view sheds new light on the cosmological constant problem and even leads to observable consequences by giving a natural explanation for the appearance of MOND-like behavior. In this context it also becomes clear why there are numerical coincidences between the MOND acceleration parameter a_0, the cosmological constant Lambda and the Hubble parameter H_0.
Author Bio
Olaf Dreyer is a theoretical physicist working at the university in Rome. He received a PhD in Quantum Gravity at the Pennsylvania State University and has worked at the Perimeter Institute, Imperial College, and the MIT, where he was supported by an FQXi grant.
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Rethinking the scientific enterprise: in defense of reductionism
Ian Durham
Ian Durham
Essay Abstract
In this essay, I argue that modern science is not the dichotomous pairing of theory and experiment that it is typically presented as, and I offer an alternative paradigm defined by its functions as a human endeavor. I also demonstrate how certain sci- entific debates, such as the debate over the nature of the quantum state, can be partially resolved by this new paradigm.
Author Bio
Ian Durham is an Associate Professor of Physics at Saint Anselm College where he has served as Chair of both the Physics and Mathematics Departments and as Director of the Computational Physical Science Program. He is a member of FQXi.
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In this essay, I argue that modern science is not the dichotomous pairing of theory and experiment that it is typically presented as, and I offer an alternative paradigm defined by its functions as a human endeavor. I also demonstrate how certain sci- entific debates, such as the debate over the nature of the quantum state, can be partially resolved by this new paradigm.
Author Bio
Ian Durham is an Associate Professor of Physics at Saint Anselm College where he has served as Chair of both the Physics and Mathematics Departments and as Director of the Computational Physical Science Program. He is a member of FQXi.
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Right about time?
Sean Gryb & Flavio Mercati
Sean Gryb & Flavio Mercati
Essay Abstract
Have our fundamental theories got time right? Does size really matter? Or is physics all in the eyes of the beholder? In this essay, we question the origin of time and scale by reevaluating the nature of measurement. We then argue for a radical scenario, supported by a suggestive calculation, where the flow of time is inseparable from the measurement process. Our scenario breaks the bond of time and space and builds a new one: the marriage of time and scale.
Author Bios
Sean Gryb worked on his PhD at the Perimeter Institute and is now enjoying a postdoc at Utrecht University. Flavio Mercati received his PhD from the University of Rome "Sapienza" and is currently starting a postdoc at the Perimeter Institute. Both are working on developing Shape Dynamics and are generally interested in the foundations and experimental tests of quantum gravity.
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Have our fundamental theories got time right? Does size really matter? Or is physics all in the eyes of the beholder? In this essay, we question the origin of time and scale by reevaluating the nature of measurement. We then argue for a radical scenario, supported by a suggestive calculation, where the flow of time is inseparable from the measurement process. Our scenario breaks the bond of time and space and builds a new one: the marriage of time and scale.
Author Bios
Sean Gryb worked on his PhD at the Perimeter Institute and is now enjoying a postdoc at Utrecht University. Flavio Mercati received his PhD from the University of Rome "Sapienza" and is currently starting a postdoc at the Perimeter Institute. Both are working on developing Shape Dynamics and are generally interested in the foundations and experimental tests of quantum gravity.
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A Critical Look at the Standard Cosmological Picture
Daryl Janzen
Daryl Janzen
Essay Abstract
The discovery that the Universe is accelerating in its expansion has brought the basic concept of cosmic expansion into question. An analysis of the evolution of this concept suggests that the paradigm that was finally settled into prior to that discovery was not the best option, as the observed acceleration lends empirical support to an alternative which could incidentally explain expansion in general. I suggest, then, that incomplete reasoning regarding the nature of cosmic time in the derivation of the standard model is the reason why the theory cannot coincide with this alternative concept. Therefore, through an investigation of the theoretical and empirical facts surrounding the nature of cosmic time, I argue that an enduring three-dimensional cosmic present must necessarily be assumed in relativistic cosmology—and in a stricter sense than it has been. Finally, I point to a related result which could offer a better explanation of the empirically constrained expansion rate.
Author Bio
I recently completed my PhD in physics at the University of Saskatchewan in Saskatoon, Canada, where I live with my wife and two kids, and have been criticising standard cosmology for its shortcomings and inconsistencies for the past few years. This essay presents the main line of argument from my dissertation, which was defended in March.
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The discovery that the Universe is accelerating in its expansion has brought the basic concept of cosmic expansion into question. An analysis of the evolution of this concept suggests that the paradigm that was finally settled into prior to that discovery was not the best option, as the observed acceleration lends empirical support to an alternative which could incidentally explain expansion in general. I suggest, then, that incomplete reasoning regarding the nature of cosmic time in the derivation of the standard model is the reason why the theory cannot coincide with this alternative concept. Therefore, through an investigation of the theoretical and empirical facts surrounding the nature of cosmic time, I argue that an enduring three-dimensional cosmic present must necessarily be assumed in relativistic cosmology—and in a stricter sense than it has been. Finally, I point to a related result which could offer a better explanation of the empirically constrained expansion rate.
Author Bio
I recently completed my PhD in physics at the University of Saskatchewan in Saskatoon, Canada, where I live with my wife and two kids, and have been criticising standard cosmology for its shortcomings and inconsistencies for the past few years. This essay presents the main line of argument from my dissertation, which was defended in March.
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THE PREFERRED SYSTEM OF REFERENCE RELOADED
Israel Perez
Israel Perez
Essay Abstract
According to Karl Popper assumptions are statements used to construct theories. During the construction of a theory whether the statements are either true or false turn out to be irrelevant in view of the fact that, actually, they gain their scientific value when the deductions derived from them suffice to explain experimental evidence. Science is enriched with assumptions of all kinds and physics is not exempted. Beyond doubt, some assumptions have been greatly beneficial for physics. They are usually embraced based on the kind of problems expected to be solved in a given moment of a science. Some have been quite useful, some have not. Some others are discarded in a given moment and reconsidered in a later one. An illustrative example of this is the conception of light, first, according to Newton, as particle; then, according to Huygens, as wave; and then, again, according to Einstein, as particle. Likewise, once, according to Newton, a preferred system of reference (PSR) was assumed; then, according to Einstein, rejected; and then, here the assumption is reconsidered. It is claimed that the assumption that there is no PSR can be fundamentally wrong.
Author Bio
Holding a Ph.D in physics since 2010, Dr. Israel Perez is an active researcher currently performing at the University of Saskatchewan in Canada. His main field of research is experimental condensed matter, particularly, he is focusing his efforts in the study of the electronic properties of High-Tc and iron-based superconductors. During his spare time he also does research in the philosophy of physics and mathematics. Recently, Zeno's paradoxes have become his prey. He is the author of several articles and essays in both fields. As before, this essay should not be taken superficially.
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According to Karl Popper assumptions are statements used to construct theories. During the construction of a theory whether the statements are either true or false turn out to be irrelevant in view of the fact that, actually, they gain their scientific value when the deductions derived from them suffice to explain experimental evidence. Science is enriched with assumptions of all kinds and physics is not exempted. Beyond doubt, some assumptions have been greatly beneficial for physics. They are usually embraced based on the kind of problems expected to be solved in a given moment of a science. Some have been quite useful, some have not. Some others are discarded in a given moment and reconsidered in a later one. An illustrative example of this is the conception of light, first, according to Newton, as particle; then, according to Huygens, as wave; and then, again, according to Einstein, as particle. Likewise, once, according to Newton, a preferred system of reference (PSR) was assumed; then, according to Einstein, rejected; and then, here the assumption is reconsidered. It is claimed that the assumption that there is no PSR can be fundamentally wrong.
Author Bio
Holding a Ph.D in physics since 2010, Dr. Israel Perez is an active researcher currently performing at the University of Saskatchewan in Canada. His main field of research is experimental condensed matter, particularly, he is focusing his efforts in the study of the electronic properties of High-Tc and iron-based superconductors. During his spare time he also does research in the philosophy of physics and mathematics. Recently, Zeno's paradoxes have become his prey. He is the author of several articles and essays in both fields. As before, this essay should not be taken superficially.
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Is quantum linear superposition an exact principle of nature?
Angelo Bassi, Tejinder Singh & Hendrik Ulbricht
Angelo Bassi, Tejinder Singh & Hendrik Ulbricht
Essay Abstract
The principle of linear superposition is a hallmark of quantum theory. It has been confirmed experimentally for photons, electrons, neutrons, atoms, for molecules having masses up to ten thousand amu, and also in collective states such as SQUIDs and Bose-Einstein condensates. However, the principle does not seem to hold for positions of large objects! Why for instance, a table is never found to be in two places at the same time? One possible explanation for the absence of macroscopic superpositions is that quantum theory is an approximation to a stochastic nonlinear theory. This hypothesis may have its fundamental origins in gravitational physics, and is being put to test by modern ongoing experiments on matter wave interferometry.
Author Bios
Angelo Bassi works on foundations of quantum mechanics and has a Ph.D. degree in Physics from University of Trieste. After completing post-docs at ICTP and University Ludwig-Maxmillian he joined University of Trieste as faculty. Tejinder Singh is Professor at the Tata Institute of Fundamental Research in Mumbai. His research interests are in quantum gravity and measurement problem. Hendrik Ulbricht received his Ph.D. in the surface science experimental group of Gerhard Ertl, and after completing post-docs at Vanderbilt and Vienna he is now Reader at Southampton University where he leads an experimental effort on Matter-wave Interferometry and quantum-nanophysics.
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The principle of linear superposition is a hallmark of quantum theory. It has been confirmed experimentally for photons, electrons, neutrons, atoms, for molecules having masses up to ten thousand amu, and also in collective states such as SQUIDs and Bose-Einstein condensates. However, the principle does not seem to hold for positions of large objects! Why for instance, a table is never found to be in two places at the same time? One possible explanation for the absence of macroscopic superpositions is that quantum theory is an approximation to a stochastic nonlinear theory. This hypothesis may have its fundamental origins in gravitational physics, and is being put to test by modern ongoing experiments on matter wave interferometry.
Author Bios
Angelo Bassi works on foundations of quantum mechanics and has a Ph.D. degree in Physics from University of Trieste. After completing post-docs at ICTP and University Ludwig-Maxmillian he joined University of Trieste as faculty. Tejinder Singh is Professor at the Tata Institute of Fundamental Research in Mumbai. His research interests are in quantum gravity and measurement problem. Hendrik Ulbricht received his Ph.D. in the surface science experimental group of Gerhard Ertl, and after completing post-docs at Vanderbilt and Vienna he is now Reader at Southampton University where he leads an experimental effort on Matter-wave Interferometry and quantum-nanophysics.
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Is Life Fundamental?
Sara Walker
Sara Walker
Essay Abstract
A central challenge in studies of the origin of life is that we don’t know whether life is 'just' very complex chemistry, or if there is something fundamentally distinct about living matter. What’s at stake here is not merely an issue of complexification; the question of whether life is fully reducible to just the rules chemistry and physics (albeit in a very complicated manner) or is perhaps something different, forces us to assess precisely what it is that we mean by the very nature of the question of the emergence of life. I argue that if we are going to treat the origin of life as a solvable scientific inquiry (which we certainly can and should), we must assume, at least on phenomenological grounds, that life is nontrivially different from nonlife. As such, a fully reductionist picture may be inadequate to address the emergence of life. The essay focuses on how treating the unique informational narrative of living systems as more than just complex chemistry may open up new avenues for research in investigations of the origin of life. I conclude with a discussion of the potential implications of such a phenomenological framework – if successful in elucidating the emergence of life as a well-defined transition – on our interpretation of life as a fundamental natural phenomenon.
Author Bio
Sara Imari Walker is a NASA Astrobiology Postdoctoral Fellow working in the Beyond Center for Fundamental Concepts in Science at Arizona State University. She received her Ph.D. in Physics and Astronomy from Dartmouth College. She then worked as postdoctoral fellow in the NSF/NASA Center for Chemical Evolution and the NASA Astrobiology Institute Center for Ribosomal Origins and Evolution based at the Georgia Institute of Technology. She is also member of the leadership council for the space science research and education nonprofit Blue Marble Space and a researcher at the Blue Marble Space Institute of Science.
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A central challenge in studies of the origin of life is that we don’t know whether life is 'just' very complex chemistry, or if there is something fundamentally distinct about living matter. What’s at stake here is not merely an issue of complexification; the question of whether life is fully reducible to just the rules chemistry and physics (albeit in a very complicated manner) or is perhaps something different, forces us to assess precisely what it is that we mean by the very nature of the question of the emergence of life. I argue that if we are going to treat the origin of life as a solvable scientific inquiry (which we certainly can and should), we must assume, at least on phenomenological grounds, that life is nontrivially different from nonlife. As such, a fully reductionist picture may be inadequate to address the emergence of life. The essay focuses on how treating the unique informational narrative of living systems as more than just complex chemistry may open up new avenues for research in investigations of the origin of life. I conclude with a discussion of the potential implications of such a phenomenological framework – if successful in elucidating the emergence of life as a well-defined transition – on our interpretation of life as a fundamental natural phenomenon.
Author Bio
Sara Imari Walker is a NASA Astrobiology Postdoctoral Fellow working in the Beyond Center for Fundamental Concepts in Science at Arizona State University. She received her Ph.D. in Physics and Astronomy from Dartmouth College. She then worked as postdoctoral fellow in the NSF/NASA Center for Chemical Evolution and the NASA Astrobiology Institute Center for Ribosomal Origins and Evolution based at the Georgia Institute of Technology. She is also member of the leadership council for the space science research and education nonprofit Blue Marble Space and a researcher at the Blue Marble Space Institute of Science.
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Special Commendation Prizes
Toward an Informational Mechanics
Karl Coryat
Karl Coryat
Essay Abstract
The assumption that classical information derives from underlying objects or things, with absolute properties, may be impeding progress in physics. Taking Wheeler's "it from bit" seriously requires placing informational systems in relational context to each other. Doing so raises questions about the nature of the early universe, and suggests a possible "simplest-case scenario" for ultimate reality. An informational mechanics could describe the world as a compact, evolutionary system of information, where objects, spacetime, and physical laws emerge in relation to topologically connected complex subsystems ("observers"). Under this program, interpretational concerns may be neglected, while recovering the full predictive power of 20th-century quantum mechanics.
Author Bio
A desire to hobnob with rock stars led me to a career in music journalism out of college, but I've always stayed close to my science roots. I've been making music under the name "Eddie Current" since taking freshman physics at University of California Berkeley (BA Biological Science), and while I lost my top form long ago, I can still recite π to 40 or 50 decimal places. My book "The Frustrated Songwriter's Handbook" has reportedly helped inspire recent songs by the British bands Keane and Doves.
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The assumption that classical information derives from underlying objects or things, with absolute properties, may be impeding progress in physics. Taking Wheeler's "it from bit" seriously requires placing informational systems in relational context to each other. Doing so raises questions about the nature of the early universe, and suggests a possible "simplest-case scenario" for ultimate reality. An informational mechanics could describe the world as a compact, evolutionary system of information, where objects, spacetime, and physical laws emerge in relation to topologically connected complex subsystems ("observers"). Under this program, interpretational concerns may be neglected, while recovering the full predictive power of 20th-century quantum mechanics.
Author Bio
A desire to hobnob with rock stars led me to a career in music journalism out of college, but I've always stayed close to my science roots. I've been making music under the name "Eddie Current" since taking freshman physics at University of California Berkeley (BA Biological Science), and while I lost my top form long ago, I can still recite π to 40 or 50 decimal places. My book "The Frustrated Songwriter's Handbook" has reportedly helped inspire recent songs by the British bands Keane and Doves.
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Cosmic Solipsism
Amanda Gefter
Amanda Gefter
Essay Abstract
Cosmology is the study of the origin and evolution of the universe – the one we all love and inhabit. In this essay, however, I argue that the basic assumption of a single universe shared by multiple observers is wrong. Synthesizing the implications of black hole radiation, horizon complementarity, dark energy, observations of the cosmic microwave background and quantum logic, I argue that moving toward a true theory of quantum gravity will require us to give up the notion that we all share the same universe. Instead, I argue, each observer has their own universe, which constitutes a complete and singular reality.
Author Bio
I am a science writer, consultant for New Scientist magazine and 2012-13 MIT Knight Science Journalism Fellow. I have a master's degree in the philosophy and history of science from the London School of Economics.
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Cosmology is the study of the origin and evolution of the universe – the one we all love and inhabit. In this essay, however, I argue that the basic assumption of a single universe shared by multiple observers is wrong. Synthesizing the implications of black hole radiation, horizon complementarity, dark energy, observations of the cosmic microwave background and quantum logic, I argue that moving toward a true theory of quantum gravity will require us to give up the notion that we all share the same universe. Instead, I argue, each observer has their own universe, which constitutes a complete and singular reality.
Author Bio
I am a science writer, consultant for New Scientist magazine and 2012-13 MIT Knight Science Journalism Fellow. I have a master's degree in the philosophy and history of science from the London School of Economics.
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