40 Years in Research at USC Joseph E. Johnson, PhD Professor Department of Physics and Astronomy, USC March 18, 2009 jjohnson@sc.edu www.nexus.sc.edu www.asg.sc.edu My Personal Premise: Science is the study of information –the measured values of observables. If something cannot be measured, (observed) its existence is meaningless. We should be very cautious when we base our scientific theory on something that cannot be measured. Some Background Math We Need Linear Vector Space (LVS), n dimensions |A> + |B> = |C> and a|A> = B with |A> = ai|i> Metric Space = a LVS with a sym product: <A|B> = a number = AiBi = S<A|i><i|B>= AB cos(q) Lie Algebra = a LVS & an antisym product: Li , Lj ] = Cijk Lk an obeys the Jacobi identity Generates a Lie Group via G(a) = exp (a L) Where L = ai Li and where Li is a basis for the space [ The Classical Physics Classical state of a particle is a vector in 3-space and time in a metric space pointing to the particle along with derivatives of these vectors and functions of them. Space can be measured by the timing of a light pulse. Time is measured by the # on a clock which is A periodic process cycling in the smallest time An aperiodic process that counts the cycles Gravitational and EM fields provide a complementary system with associated fields (and waves). We here assume that no measurement interferes with any other and that there is no limit to information or accuracy (space, time, mass…) as real numbers. The Quantum Theory Observables are operators with known [ , ] (interference properties) and form a LA The state of a system is a vector | > in a metric (Hilbert inf. dim.) space | > must be a representation space of the operators thus Cijk determines reality A many particle system is described by the outer product of these vectors optimally written as creation a+ and annihilation operators a acting on a vacuum |A> = aA+ |0> with aA|0>=0 The state vectors must also support the discrete group T,C,P. Eight Questions that Bother me: 1. What are the fundamental observables and how are they related (in relativistic quantum theory)? 2. What is information & entropy – diffusion, arrow of time,… 3. How can order (information - life) emerge in view of the second law? 4. How can uncertain information be best represented mathematically? 5. What are networks - How can we understand them? 6. Is there a better way to represent data structures? 7. What is the Truth? A possible new game theory Can this ‘game theory’ improve education – knowledge & learning. 8. What is the ‘measurement’ (of an observable)? How is that related to information, entanglement, & classical mechanics. 1. What are the fundamental observables and how are they related (in relativistic quantum theory)? X P I Heisenberg algebra [ X , P ] = I = i h/2p Mun Lorentz Algebra w Rotations (symmetry group) Poincare algebra Pm Mmn (larger symmetry group) I did extensions to X P M I (a 15 parameter algebra) This extends the Poincare algebra with relativistic position operators Results in a nice formal structure with TCP But a proper time dynamics of multiple particles is not easy. But it provided a beautiful group theory basis for particles that is much easier to utilize than the Poincare group. The XPMI Lie Algebra The general state of an elementary particle is given by the simultaneous computing operators for: |h,|k0|,e(k0),k, b0, b1, s, s, +internal…> Heisenberg representation of equations of motion of a free spin ½ particle Heisenberg representation of equations of motion of a spin ½ charged particle I looked for extensions to XPMI to explain internal symmetries (charge, strangeness…) I found an interesting regularity in the hadron mass spectra (possibly a 5th force) But it did not extend to higher dimensional representations as I had thought. We know that internal symmetries are the result of the composite nature of matter – at least the hadrons from quarks. Rethink these problems: My direction then changed to consider what it means to measure an observable & the meaning of information. In particular I was bothered by the exactness of position and momentum measurements (which are impossible i.e. the XP algebra is only approximate) I was also bothered by our number system and our representations of uncertainty – even classically I was also bothered by the concept of measurement and its relationship to information and how it collapses the wave function and provides a link to classical theory. 2. What is information & entropy – diffusion GL(n,R)? Information (which measures order) is the negative of entropy (which measures disorder) Disorder can be studied with the random walk of Einstein, or diffusion via Markov: Markov matrix example: (note columns sum to unity) 0.1 0.8 0.1 0.1 0.8 0.1 0.1 0.8 0.1 0.1 0.8 0.1 0.1 0.8 0.1 0.1 0.8 0.1 The Markov Lie Algebra basis elements form a basis for all off-diagonal elements. Markov Lie Algebra basis Lij = 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 -1 0 0 0 0 0 0 Although diffusion has no inverse, I began studying it from the point of view of group theory and found a new decomposition of the general linear group into a Markov type group and the Abelian scaling group. GL(n,R) = M(n,R) + A(n,R) This gave insight into irreversibility but did not immediately explain ‘information’ What was the result of this work? Lie Algebras & Lie Groups were now connected to Markov theory & thus to diffusion. Two very different branches of mathematics were now connected and we can use the understanding in one area to see further in the other. 3. How can order emerge in view of the second law? I attended a talk in 1991 on ‘Fibonacci numbers I suspected that these numbers represented some kind of natural order in nature but what was their source? Rather than a numerical sequence, I looked at them as (old rabbits, new rabbits) – a vector. Formal Study of Order in Systems I reframed them as motion in GL(n,R) – But there were infinitely many such motions. Then I ‘quantized’ this classical continuous system as a two component linear entropy seeking system. This result led to an understanding of how order can emerge in nonequilibrium systems. I showed that the Fibonacci sequence is the simplest quantized linear system that preserves information. It also suggested a whole family of new types of Fibonacci sequences and how they were related. It also opened a question of “why quantization occurs in a classical system?” 4. . How can uncertain information (& numbers) be best represented? The fundamental bit of information (1 & 0) could be generalized as probabilities but this does not form a ‘closed mathematical structure’. In looking at the fundamental 2 dimensional representations of the Markov algebra, (x1,x0) i.e. the transformations that leave x1+ x0 =1, I realized that this ‘vector’ could be used to generalize a bit (1 or 0) of information. Take x1,= probability to be true and x0 = the probability to be false. Thus I am suggesting that probabilities should always be treated as components of a vector, NOT a scalar. We already do this when we use a probability (or probability amplitude) function as it includes all possible states. I developed a new mathematics based upon these objects (x1,x0) which I called a bit vector or ‘bittor’ (similar to the spinor). I (smoothly) generalized the Boolean truth tables as zi = caijk xj yk (i,j,k = 1,0 and a = 0,1…15 for the 16 types of AND, OR, NOR… logic operations) I generalized numbers as outer products of these objects similar to binary numbers. Renyi’ second order entropy is a natural object in the truth table (EQV) and is extremely close to Shannon entropy numerically. The rebuilding of all arithmetic operations can be done smoothly but with some difficult aspects (probability correlations). One hope is to automatically manage uncertainty in all of math in computers. Numbers are now Markov ‘group’ representations ()()…() Eigenvalues are now Bittors and a quantum state can represent a broad location of any probability (as defined by the bittor product). The fundamental branch operation IF x>y Then aaa Else bbb now evokes a bifurcation generating new threads of computation like particle creation in quantum theory. This is much like our mind reasons using simultaneous multiple threads, and dropping outcomes with low probability (annihilation of threads). 5. What are networks - How can we understand them? In classical physics the state of a system (position, momentum,..) is given by a vector. This is also true in both relativity and in quantum theoryjust a vector in higher dimensions. But a network is a set of relationships that must be expressed by a matrix Networks describe: power grids, transportation networks, neural networks, communications networks (internet & phone), electrical networks, and financial networks. Their topologies are of exceptional difficulty and complexity. The relationship of entity i to entity j is given by a positive value or zero, Cij, a matrix with no diagonal and non-negative off diagonal values. I was able to show that if the diagonals of Cij are set to the negative sum of all other elements in that column, then the result is always a member of the Markov Lie algebra. Thus each network exactly determines a continuous set of Markov transformations analogous to diffusion among the nodes at the rates of connection. We have now connected all possible continuous Markov transformations in a 11 fashion to all possible network topologies. We how have connected three branches of mathematics: Lie algebras to Markov Theory to Network theory uniquely. Results in one area can be used in another. This allowed us to derive an entropy network spectra of the columns and identify network attacks and aberrations. 6. Is there a better way to represent data structures? Relational databases are powerful but very difficult to build Hierarchical type data structures (like XML) are highly flexible but are lacking in speed of search and power of analysis I have designed a new kind of database that is in the middle – part XML, part RDB. This concept uses information ‘structures’ like Lego blocks connected in pairs by relationships thus building a database that is a network of simple tables. Our work resembles new research on the semantic web by Tim Berners-Lee /P fn Joe ln Johnson /L /rl works at /place USC /C // Rl work contact Ph 803-777-6431 Web www.asg.sc.edu // // ss 123-45-6789 This new database has the advantages that (a) one can build a database after an hour of instruction, and (b) fields can be added and removed at will. With an icon click, the system will build an associated relational database and also an XML database. Thus I suggest that our fundamental information databases should be networks of information units. Complex information is thus a network or (Markov Lie algebra) with weighted links among information units. 7. A New Type of Game Theory What is True? Recall the two person game as a payoff matrix. Dr. John Nash (Nobel Prize for Nash equilibrium in von Neumann game theory) gave the invited talk at dinner at an MIT conference on complex systems and spoke of the difficulties of solving even a three person game when alliances are allowed. We already know that there are extreme difficulties with N-person games, non-zero sum games, and even worse, how to assign the payoff matrix in any real situation. Standard von Neumann game theory has payoff elements as the matrix elements: A Two Person Game 1 2 3 A -4 12 5 B 7 -3 2 Proposal: Based upon my work with automatic grading of questions to a class it occurred to me that a different kind of game theory could be designed that solved all four of the problems with the von Neumann formulation. Questions are posed that have one word or one number unique unambiguous answers. One gets ‘paid’ for the right answer. The probability that each person is right (eq 1) and the probability that each response is right (eq 2) are coupled nonlinear equations that can be solved iteratively for self consistent solutions. The payoff is automatically determined with information theory of the weight of a vote (log (P/(1-P)), the logit function. I presented this framework at the last MIT Complexity Conference and have applied for a patent on the design and algorithm. I also gave a seminar at the University of Utah last summer on this new game theory design. We intend to apply this for expert consensus voting for investments, petroleum mining, medical & pharmaceutical judgments and related problems. 7’. Can this ‘game theory’ improve education – knowledge & learning I am working on first applying this system to education by having students with pocket web devices log on upon entering a class and enter simple responses to questions from the instructor. The instructor has a laptop showing all responses which are automatically graded. Building on this system, with demographic data collection, one can monitor the learning rates of all students, keep them engaged, and send them their grades after each class (as well as the parents, and the school, district, and state administrators. I envision this system that also estimates the value, validity, and other metrics of the questions and extensive correlates. One aspect of the system is to monitor keystroke rates to flag and track the well being of participants. Error and misspelling rates are also tracked for the respondents. Instructor’s question’s quality, validity, difficulty and correlates with other indicators are monitored automatically Peer, subordinate, and supervisory evaluations are periodically performed, anonymous and are in themselves self correcting and graded. 8. What is measurement of an observable? How is that related to information and entanglement? If regular numbers are special cases of Bittor numbers then the eigenvalues in quantum theory become the representations of the Markov type Lie group (monoid) – a kind of ‘third quantization’ These Bittor eigenvalues provide a ‘fuzzy quantization’ to continuum eigenvalues such as space-time and energy-momentum. Space-time becomes ‘pixilated’ automatically. The localization of particles is thus limited by bittor values whose uncertainty is at least bounded by their Compton wavelength. The determination of any momentum is also limited by bittor values whose uncertainty is bounded by the values in a box the size of the universe. Consider an eigenvector |x….; p......> but where the uncertainty in each does not violate the Heisenberg principle. There are an infinite number of degrees of freedom for the uncertain bittor string but each bittor is only half as important as the preceding bittor. Thus we get 1+ ½ + ¼ degrees of new freedom or dimensions in each of 4 space time directions thus a 12 dimensional space-time A consequence of the numerical uncertainty for space time is that one adds sequentially (with decreasing importance) new dimensions (4*(2n1)) to space-time (giving it an extra 4, 12…dimensions) with some topological constraints that are complicated. These are analogous to the ground state energies (e.g. as with the harmonic oscillator) due to the uncertainty principle that manifests itself here in a similar way. The manifolds that join the extra ‘degrees of freedom of uncertainty’ is a joining of a set of 4 positive quadrant sections of two dimensional complex spaces – we get a nine dimensional space and a three dimensional time. These eight additional tiny curled up dimensions that emerge are twice as many as in string theory but turn out to have the feature of being ‘quantized’ (points are designated by integers). Thank You I deeply appreciate the years of support in all of the forms which you, my colleagues, have given me. It has been wonderful to be a part of this University and this faculty. I intend to continue working on grants, contracts, and these research directions.