Tian Cao - Profile on Academia.edu (original) (raw)
Papers by Tian Cao
Key steps toward the creation of QCD — Notes on the logic and history of the genesis of QCD
Modern Physics Letters A
The creation of QCD is one of greatest achievements in the history of science. It has radically c... more The creation of QCD is one of greatest achievements in the history of science. It has radically changed our conception of the fundamental ontology of the physical world and its underlying dynamics. What it has discovered are more than new particles and a new force, but rather a deeper level of physical reality, a new kind of entities. Dynamically, the strong nuclear forces are no longer taken to be fundamental, but are relegated to the status of the un-cancelled residue of far stronger long range force mediated by gluon. From a long term perspective, perhaps more important than these discoveries is that it breaks a new path to explore many novel features of an unknown layer of the physical world, such as instanton, the theta vacuum and effective energy. The notion of effective energy allows us to conceptualize the mysterious quantum number flow and hadronization. Although the metaphysical status of effective energy is not quite clear at this moment, but a window is open for conceptu...
Monism, but not through Reductionism
Why are we philosophers interested in quantum field theory?
Conceptual Foundations of Quantum Field Theory, 1999
ABSTRACT From the text: Generally speaking, philosophers are interested in the metaphysical assum... more ABSTRACT From the text: Generally speaking, philosophers are interested in the metaphysical assumptions adopted by science and the world picture suggested by science. They are also interested in understanding the successes, failures and significant changes that have happened in science, in terms of its ontology and theoretical structure. Thus it is natural for philosophers to be interested in examining various scientific theories from these angles.
Introduction: Conceptual issues in quantum field theory
ABSTRACT From the text: Quantum field theory (QFT) is a powerful language for describing the suba... more ABSTRACT From the text: Quantum field theory (QFT) is a powerful language for describing the subatomic constituents of the physical world (quarks, leptons, gauge bosons, Higgs scalars, and so on) and the laws and principles that govern them. Not only has it provided a framework for understanding the hierarchical structure that can be built from these constituents, it has also profoundly influenced the development of contemporary cosmology and deeply penetrated into the current conception and imagination of the origin and evolution of the universe. For this reason, it has justifiably long been taken to be the foundation of fundamental physics: elementary particle physics and cosmology.
Introduction: Conceptual issues in quantum ?eld theory
Advances in Cognitive Neurodynamics ICCN 2007, 2008
Perception is characterized by the formation of spatiotemporal patterns of neural activity that e... more Perception is characterized by the formation of spatiotemporal patterns of neural activity that embody mental categories of the material events provided by the senses. The patterns are constructed by modifications of the background activity, which is maintained and self-regulated at criticality, such that all frequencies and wavelengths coexist in neural activity, from the atomic level to the whole brain. Pattern formation depends on energy dissipation and occurs by phase transition upon the coincidence of two events, both endogenous. One event is the null spike in the Rayleigh noise, which is generated by mutual excitation and then band pass filtered by feedback inhibition. The frequencyspecific drop in background amplitude enhances the signal-to-noise ratio of sensory-driven activity in each sensory sample taken by an action-perception cycle under limbic control. The other event is the sensory-selected activity from a Hebbian nerve cell assembly constituting reactivation of a memory of experience from past learning that is mobilized by the limbic system. The neural mechanisms of the phase transition that mediates perception may be subject to description in terms of a renormalization group based on systematic segmentation of the temporal spectra of various measures of brain activity.
Renormalization group: an interesting yet puzzling idea
Conceptual foundations of quantum field theory, 1999
ABSTRACT About today’s topic, the meaning of the renormalization group, I have heard in the past ... more ABSTRACT About today’s topic, the meaning of the renormalization group, I have heard in the past any possible disagreement between physicists; in condensed matter and much more in field theory. It is or it is not fundamental. In spite of the empirical success of today’s theories, which lead to Nobel prizes and all that, physicists are confused about the meaning of some aspects of these theories. More often than not, different physicists hold contradictory views on the actual meaning of the renormalization group. I would simply like to correct the impression that might have emerged from yesterday and today’s discussion, that physicists know exactly what is going on in their theories, or that everybody agrees. And I want to tell physicists: if we are interested in knowledge, wouldn’t it be more productive to fully display our confusion and our disagreements?
New Philosophy of Renormalization: From the Renormalization Group Equations to Effective Field Theories
Renormalization, 1993
A Philosopher Looks at Science
Boston Studies in the Philosophy of Science, 1995
Will Einstein Still be the Super-Hero of Physics History in 2050?
Boston Studies in the Philosophy of Science, 2007
From Current Algebra to Quantum Chromodynamics
From Current Algebra to Quantum Chromodynamics, 2010
ABSTRACT 1. Introduction; 2. The rise of current algebra (CA); 3. Sum rules; 4. Saturation and cl... more ABSTRACT 1. Introduction; 2. The rise of current algebra (CA); 3. Sum rules; 4. Saturation and closure; 5. Scaling; 6. Theorizations of scaling; 7. The advent of quantum chromodynamics (QCD); 8. Early justifications and explorations; 9. Structural realism and the construction of QCD; 10. Historiographical issues in the CA-QCD narrative.
Julian Schwinger’s paradoxical legacy
Physics Today, 2003
Synthese, 2000
's lengthy criticism of my book has a philosophically interesting point: while structural continu... more 's lengthy criticism of my book has a philosophically interesting point: while structural continuity in scientific developments, or some version of structural realism, is more or less acceptable, he claims, the idea of ontological synthesis, as a response to Kuhn's antirealist view of science and its development, "misses the point entirely". Of the reasons why he makes such a claim, which will be examined below, one has its roots in his suspicion about the importance, or even the relevance, of the idea of ontology in scientific endeavor and in the philosophical understanding of science. But then, ironically, Saunders also criticizes me of having ignored "altogether the problem of measurement" in quantum mechanics in my discussion of realism, without noticing that in order to appreciate the bearings of the problem of measurement on the realism-antirealism debate, one has to take ontology very seriously, much more seriously than he would take it, even more seriously than I did in my book. However, I will not address this relatively minor point beyond a brief remark in section III, and focus my discussion instead on the notion of ontological synthesis. Let me start with the notion of ontology. 1. ONTOLOGY Usually, the notion of ontology refers to what exists in the world, and the notion of a basic ontology in a scientific theory refers to the irreducible conceptual element in the logical construction of what is assumed to really exist in the domain under investigation. As a representation of deep reality, the basic ontology enjoys a great explanatory power. That is, all appearances should be derivable from it as a result of its behavior. In physical theories, it can be individual objects, such as those in Newtonian mechanics, or non-individual objects, such as those in quantum mechanics, or non-object physical entities, such as fields; it can also be other theoretical entities, such as processes (e.g., currents or transition amplitudes) or
Synthese, 2000
In responding to my criticism of their ontic form of structural realism, Steven French and James ... more In responding to my criticism of their ontic form of structural realism, Steven French and James Ladyman indicate that "there could be more agreement than disagreement between us". In my view, the most important among the agreements are two. First, in defending scientific realism, we have to address the Kuhnian losses at the ontological and explanatory levels. Second, we have to take a structuralist approach to ontology. Disagreements, however, remain substantial. The most important one focuses, at the ontological level, on their attempt to dissolve physical entities into mathematical structures. They argue that this is justly motivated by (i) a structural understanding of unobservable physical entities, (ii) a desire to properly accommodate the metaphysical implications of quantum physics, and (iii) a desire to be in line with the semantic approach to the structure of scientific theories. I reject the move because, as I will argue below, it carries them away from scientific realism and towards Platonic idealism. Essentially, my argument is that, while the third motivation is irrelevant, the first two are wrongly addressed. Let me start with the first motivation.
The conceptual foundations and the philosophical aspects of renormalization theory
Synthese, 1993
Page 1. TIAN YU CAO AND SILVAN S. SCHWEBER THE CONCEPTUAL FOUNDATIONS AND THE PHILOSOPHICAL ASPEC... more Page 1. TIAN YU CAO AND SILVAN S. SCHWEBER THE CONCEPTUAL FOUNDATIONS AND THE PHILOSOPHICAL ASPECTS OF RENORMALIZATION THEORY* 1. INTRODUCTION ... Page 8. 40 TIAN YU CAO AND SILVAN S. SCHWEBER ...
Prerequisites for a Consistent Framework of Quantum Gravity
Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics, 2001
ABSTRACT An ontological approach to the analysis of conceptual frameworks of physical theories is... more ABSTRACT An ontological approach to the analysis of conceptual frameworks of physical theories is introduced and then applied to the case of quantum gravity. The tension between the theoretical constraints posed, respectively, by general relativity and quantum field theory, is analysed. A possible solution to the difficulties created by the tension, based on the notion of ontological synthesis, is suggested.
The Casimir Effect and the Interpretation of the Vacuum
Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics, 1999
ABSTRACT The Casimir force between two neutral metallic plates is often considered conclusive evi... more ABSTRACT The Casimir force between two neutral metallic plates is often considered conclusive evidence for the reality of electromagnetic zero-point fluctuations in ‘empty space’ (i.e. in absence of any boundaries). However, it is not well known that the Casimir force can be derived from many different points of view. The purpose of this note is to supply a conceptually oriented introduction to a representative set of these different interpretations. The different accounts suggest that the Casimir effect reveals nothing conclusive about the nature of the vacuum.
Solid State Communications, 2008
This work investigates the relation between superconductivity and correlations. A simple calculat... more This work investigates the relation between superconductivity and correlations. A simple calculation shows that the appropriate spin-charge correlation is the key role to any superconductivity, and this calculation is consistent with the analyses of unusual properties of superconductors. (Note: the Tc of this model is not given clearly in this work, but we have advanced this mechanism to a t-χ model which includes various superconductivities and magnetisms (please see arXiv:0707.3660 and following works).
Key steps toward the creation of QCD — Notes on the logic and history of the genesis of QCD
Modern Physics Letters A
The creation of QCD is one of greatest achievements in the history of science. It has radically c... more The creation of QCD is one of greatest achievements in the history of science. It has radically changed our conception of the fundamental ontology of the physical world and its underlying dynamics. What it has discovered are more than new particles and a new force, but rather a deeper level of physical reality, a new kind of entities. Dynamically, the strong nuclear forces are no longer taken to be fundamental, but are relegated to the status of the un-cancelled residue of far stronger long range force mediated by gluon. From a long term perspective, perhaps more important than these discoveries is that it breaks a new path to explore many novel features of an unknown layer of the physical world, such as instanton, the theta vacuum and effective energy. The notion of effective energy allows us to conceptualize the mysterious quantum number flow and hadronization. Although the metaphysical status of effective energy is not quite clear at this moment, but a window is open for conceptu...
Monism, but not through Reductionism
Why are we philosophers interested in quantum field theory?
Conceptual Foundations of Quantum Field Theory, 1999
ABSTRACT From the text: Generally speaking, philosophers are interested in the metaphysical assum... more ABSTRACT From the text: Generally speaking, philosophers are interested in the metaphysical assumptions adopted by science and the world picture suggested by science. They are also interested in understanding the successes, failures and significant changes that have happened in science, in terms of its ontology and theoretical structure. Thus it is natural for philosophers to be interested in examining various scientific theories from these angles.
Introduction: Conceptual issues in quantum field theory
ABSTRACT From the text: Quantum field theory (QFT) is a powerful language for describing the suba... more ABSTRACT From the text: Quantum field theory (QFT) is a powerful language for describing the subatomic constituents of the physical world (quarks, leptons, gauge bosons, Higgs scalars, and so on) and the laws and principles that govern them. Not only has it provided a framework for understanding the hierarchical structure that can be built from these constituents, it has also profoundly influenced the development of contemporary cosmology and deeply penetrated into the current conception and imagination of the origin and evolution of the universe. For this reason, it has justifiably long been taken to be the foundation of fundamental physics: elementary particle physics and cosmology.
Introduction: Conceptual issues in quantum ?eld theory
Advances in Cognitive Neurodynamics ICCN 2007, 2008
Perception is characterized by the formation of spatiotemporal patterns of neural activity that e... more Perception is characterized by the formation of spatiotemporal patterns of neural activity that embody mental categories of the material events provided by the senses. The patterns are constructed by modifications of the background activity, which is maintained and self-regulated at criticality, such that all frequencies and wavelengths coexist in neural activity, from the atomic level to the whole brain. Pattern formation depends on energy dissipation and occurs by phase transition upon the coincidence of two events, both endogenous. One event is the null spike in the Rayleigh noise, which is generated by mutual excitation and then band pass filtered by feedback inhibition. The frequencyspecific drop in background amplitude enhances the signal-to-noise ratio of sensory-driven activity in each sensory sample taken by an action-perception cycle under limbic control. The other event is the sensory-selected activity from a Hebbian nerve cell assembly constituting reactivation of a memory of experience from past learning that is mobilized by the limbic system. The neural mechanisms of the phase transition that mediates perception may be subject to description in terms of a renormalization group based on systematic segmentation of the temporal spectra of various measures of brain activity.
Renormalization group: an interesting yet puzzling idea
Conceptual foundations of quantum field theory, 1999
ABSTRACT About today’s topic, the meaning of the renormalization group, I have heard in the past ... more ABSTRACT About today’s topic, the meaning of the renormalization group, I have heard in the past any possible disagreement between physicists; in condensed matter and much more in field theory. It is or it is not fundamental. In spite of the empirical success of today’s theories, which lead to Nobel prizes and all that, physicists are confused about the meaning of some aspects of these theories. More often than not, different physicists hold contradictory views on the actual meaning of the renormalization group. I would simply like to correct the impression that might have emerged from yesterday and today’s discussion, that physicists know exactly what is going on in their theories, or that everybody agrees. And I want to tell physicists: if we are interested in knowledge, wouldn’t it be more productive to fully display our confusion and our disagreements?
New Philosophy of Renormalization: From the Renormalization Group Equations to Effective Field Theories
Renormalization, 1993
A Philosopher Looks at Science
Boston Studies in the Philosophy of Science, 1995
Will Einstein Still be the Super-Hero of Physics History in 2050?
Boston Studies in the Philosophy of Science, 2007
From Current Algebra to Quantum Chromodynamics
From Current Algebra to Quantum Chromodynamics, 2010
ABSTRACT 1. Introduction; 2. The rise of current algebra (CA); 3. Sum rules; 4. Saturation and cl... more ABSTRACT 1. Introduction; 2. The rise of current algebra (CA); 3. Sum rules; 4. Saturation and closure; 5. Scaling; 6. Theorizations of scaling; 7. The advent of quantum chromodynamics (QCD); 8. Early justifications and explorations; 9. Structural realism and the construction of QCD; 10. Historiographical issues in the CA-QCD narrative.
Julian Schwinger’s paradoxical legacy
Physics Today, 2003
Synthese, 2000
's lengthy criticism of my book has a philosophically interesting point: while structural continu... more 's lengthy criticism of my book has a philosophically interesting point: while structural continuity in scientific developments, or some version of structural realism, is more or less acceptable, he claims, the idea of ontological synthesis, as a response to Kuhn's antirealist view of science and its development, "misses the point entirely". Of the reasons why he makes such a claim, which will be examined below, one has its roots in his suspicion about the importance, or even the relevance, of the idea of ontology in scientific endeavor and in the philosophical understanding of science. But then, ironically, Saunders also criticizes me of having ignored "altogether the problem of measurement" in quantum mechanics in my discussion of realism, without noticing that in order to appreciate the bearings of the problem of measurement on the realism-antirealism debate, one has to take ontology very seriously, much more seriously than he would take it, even more seriously than I did in my book. However, I will not address this relatively minor point beyond a brief remark in section III, and focus my discussion instead on the notion of ontological synthesis. Let me start with the notion of ontology. 1. ONTOLOGY Usually, the notion of ontology refers to what exists in the world, and the notion of a basic ontology in a scientific theory refers to the irreducible conceptual element in the logical construction of what is assumed to really exist in the domain under investigation. As a representation of deep reality, the basic ontology enjoys a great explanatory power. That is, all appearances should be derivable from it as a result of its behavior. In physical theories, it can be individual objects, such as those in Newtonian mechanics, or non-individual objects, such as those in quantum mechanics, or non-object physical entities, such as fields; it can also be other theoretical entities, such as processes (e.g., currents or transition amplitudes) or
Synthese, 2000
In responding to my criticism of their ontic form of structural realism, Steven French and James ... more In responding to my criticism of their ontic form of structural realism, Steven French and James Ladyman indicate that "there could be more agreement than disagreement between us". In my view, the most important among the agreements are two. First, in defending scientific realism, we have to address the Kuhnian losses at the ontological and explanatory levels. Second, we have to take a structuralist approach to ontology. Disagreements, however, remain substantial. The most important one focuses, at the ontological level, on their attempt to dissolve physical entities into mathematical structures. They argue that this is justly motivated by (i) a structural understanding of unobservable physical entities, (ii) a desire to properly accommodate the metaphysical implications of quantum physics, and (iii) a desire to be in line with the semantic approach to the structure of scientific theories. I reject the move because, as I will argue below, it carries them away from scientific realism and towards Platonic idealism. Essentially, my argument is that, while the third motivation is irrelevant, the first two are wrongly addressed. Let me start with the first motivation.
The conceptual foundations and the philosophical aspects of renormalization theory
Synthese, 1993
Page 1. TIAN YU CAO AND SILVAN S. SCHWEBER THE CONCEPTUAL FOUNDATIONS AND THE PHILOSOPHICAL ASPEC... more Page 1. TIAN YU CAO AND SILVAN S. SCHWEBER THE CONCEPTUAL FOUNDATIONS AND THE PHILOSOPHICAL ASPECTS OF RENORMALIZATION THEORY* 1. INTRODUCTION ... Page 8. 40 TIAN YU CAO AND SILVAN S. SCHWEBER ...
Prerequisites for a Consistent Framework of Quantum Gravity
Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics, 2001
ABSTRACT An ontological approach to the analysis of conceptual frameworks of physical theories is... more ABSTRACT An ontological approach to the analysis of conceptual frameworks of physical theories is introduced and then applied to the case of quantum gravity. The tension between the theoretical constraints posed, respectively, by general relativity and quantum field theory, is analysed. A possible solution to the difficulties created by the tension, based on the notion of ontological synthesis, is suggested.
The Casimir Effect and the Interpretation of the Vacuum
Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics, 1999
ABSTRACT The Casimir force between two neutral metallic plates is often considered conclusive evi... more ABSTRACT The Casimir force between two neutral metallic plates is often considered conclusive evidence for the reality of electromagnetic zero-point fluctuations in ‘empty space’ (i.e. in absence of any boundaries). However, it is not well known that the Casimir force can be derived from many different points of view. The purpose of this note is to supply a conceptually oriented introduction to a representative set of these different interpretations. The different accounts suggest that the Casimir effect reveals nothing conclusive about the nature of the vacuum.
Solid State Communications, 2008
This work investigates the relation between superconductivity and correlations. A simple calculat... more This work investigates the relation between superconductivity and correlations. A simple calculation shows that the appropriate spin-charge correlation is the key role to any superconductivity, and this calculation is consistent with the analyses of unusual properties of superconductors. (Note: the Tc of this model is not given clearly in this work, but we have advanced this mechanism to a t-χ model which includes various superconductivities and magnetisms (please see arXiv:0707.3660 and following works).