The series is dedicated to the contributions of the pioneer in reversible computing, Edward Fredkin whom we lost on 13 June 2023. Our focus for this series is on the theme of Reversibility across various scientific disciplines.
Speaker: Susmita Sur-Kolay, Indian Statistical Institute (ISI), Kolkata, India
Abstract: Many decades after quantum mechanics including Heisenberg’s matrix mechanics was accepted as a more accurate model of the physical world, Richard Feynman proposed the brilliant vision of building computers based on quantum mechanical systems in 1981. Rolf Landauer had established the importance of reversibility with respect to energy dissipation of a computational process in 1961. Thus the two major drivers for the development of quantum computing have been the need to overcome the time complexity limitations of classical deterministic digital computing models and the soaring energy dissipation levels of IC technology for realising them.
Note: With a brief introduction to reversible and quantum circuits, we will focus on efficient synthesis methodologies for logic synthesis of these circuits including the effects of the existing technologies.
Brief Bio of the Speaker: Susmita Sur-Koley has been a faculty member in the Advanced Computing and Microelectronics Unit of the Indian Statistical Institute, Kolkata, India since 1999 and is presently a Professor. She received the B.Tech. (Hons.) degree in Electronics and Electrical Communications Engineering from Indian Institute of Technology Kharagpur and the Ph.D. degree in Computer Science and Engineering from Jadavpur University India. During the period 1993-99, she was a Reader in the Department of Computer Science and Engineering of Jadavpur University. Prior to that, she was a post-doctoral fellow at University of Nebraska-Lincoln, and a Research Assistant at the Laboratory for Computer Science in Massachusetts Institute of Technology. She was also on sabbatical at Princeton University and Intel Corp., USA. Her research contributions are in the areas of algorithmic design automation for VLSI physical design, fault modeling and testing, synthesis of quantum computers, and graph algorithms. She has co-authored several technical papers in leading international journals and refereed conference proceedings, and a chapter in the Handbook on Algorithms for VLSI Physical Design Automation.
- April 27, 2024
Labels: Understanding Reversibility: Edward Fredkin Memorial Lectures
Location: West Bengal, India
Speaker: Kenichi Morita, Hiroshima University, Japan
Abstract: A reversible cellular automaton (RCA) is said to be "time-reversal symmetric" (T-symmetric, for short) if its forward and backward evolution processes are both governed by the same local transition function. We show that the framework of partitioned cellular automata (PCAs) is useful for studying this property. Here, we consider elementary triangular partitioned CAs (ETPCAs), and elementary square partitioned CAs (ESPCAs). It is shown that all reversible ETPCAs, and about 58 percent of reversible ESPCAs are T-symmetric under simple transformations on configurations. The transformations used here are
They are somewhat similar to the CPT-symmetry in physics. The obtained results on T-symmetries are used to find and analyze backward evolution processes in reversible PCAs. In particular, for a given functional module implemented in a reversible PCA, we can obtain its inverse module very easily using its T-symmetry. For example, from a Switch Gate configuration, an inverse Switch Gate configuration is automatically obtained, and thus a Fredkin gate is implemented easily.
It is also possible to have an inverse reversible Turing machine from a forward one. By this method, designing larger functional objects and reversible machines in RCAs can be simplified.
Brief Bio of the Speaker: Kenichi Morita is a professor emeritus of Hiroshima University. He received his B. Eng., M. Eng., and Dr. Eng. degrees from Osaka University in 1971, 1973, and 1978, respectively. From 1974 to 1987, he was a research associate of the Faculty of Engineering Science, Osaka University. From 1987 to 1990, he was an associate professor, and from 1990 to 1993 a professor of the Faculty of Engineering, Yamagata University. From 1993 to 2013, he was a professor of the Graduate School of Engineering, Hiroshima University. He has been engaged in the research of automata theory, reversible computing, and formal language theory. Related to unconventional computing, he studied many kinds of reversible computing models. They are universal reversible Turing machines, reversible counter machines, reversible cellular automata, reversible logic circuits composed of 2-state reversible logic elements, and some others.
- April 27, 2024
Labels: Understanding Reversibility: Edward Fredkin Memorial Lectures
Location: West Bengal, India
Speaker: Sukanta Das, IIEST, Shibpur, India
Abstract: A system is synonymous if its components agree to act following some value of a common variable. The most usual way to reach such an agreement is by using time, for which the existence of a global clock is needed. The synchronous systems are “disciplined”, but it takes away the independence of the elements of a system. On the contrary, the elements of an asynchronous system can act independently. Question is, can asynchronous systems achieve the goals of synchronous systems? We shall inquire this question through reversibility, which refers to a phenomenon that allows a system to go back without losing any information. We shall introspect this issue through the eyes of cellular automata.
Brief Bio of the Speaker: Sukanta Das, one of the founding members of Cellular Automata India, is an Associate Professor in the Department of Information Technology of Indian Institute of Engineering Science and Technology, Shibpur. He has been leading cellular automata research in India and exploring different aspects of cellular automata and non-uniform cellular automata for more than twenty years. Apart from the research, Sukanta Das is also an active member of the All India Science and Rationalist Organisation (AISRO), a rationalist organization dedicated to advocate against pseudoscience, astrology and mysticism.
- May 05, 2024
Labels: Understanding Reversibility: Edward Fredkin Memorial Lectures
Location: West Bengal, India
Speaker: Norman Margolus, MIT, USA
Abstract: I’d like to talk mainly about my own ideas, but I’ll start the story with Fredkin and how I ended up working with him and caught some of his wonderfully irreverent attitudes about physics, and got to work closely with Toffoli and Bennett and Feynman, and I’ll discuss reversibility and CA machines and the deep connections between reversible CA’s and classical mechanics.
Brief Bio of the Speaker: Norman Margolus is a renowned physicist and computer scientist who is known for his fundamental work on cellular automata and reversible computing. He received his Ph.D. in physics from MIT in 1987, under the supervision of Edward Fredkin. He collaborated closely with Tom Toffoli, Charles Bennett, and Gerard Vichniac within the MIT Information Mechanics Group. He founded and was chief scientist for Permabit, an information storage device company. He co-authored a seminal book "Cellular Automata Machines" with Tom Toffoli on physical modeling using cellular automata. His work includes influential papers on quantum computing, energy metrics in physical dynamics, and reversible cellular automata, accumulating over 10,000 citations across his top ten publications. Norman Margolus is currently focusing on theoretical questions at the interface between physics & computation and exploring the foundations of quantum mechanics at the Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology.
- May 05, 2024
Labels: Understanding Reversibility: Edward Fredkin Memorial Lectures
Location: West Bengal, India
Speaker: Stephen Wolfram, Wolfram Research, USA
Brief Bio of the Speaker: Stephen Wolfram is the creator of Mathematica, Wolfram Alpha and the Wolfram Language; the author of A New Kind of Science; the originator of the Wolfram Physics Project; and the founder and CEO of Wolfram Research. Over the course of more than four decades, he has been a pioneer in the development and application of computational thinking—and has been responsible for many discoveries, inventions and innovations in science, technology and business. Wolfram was educated at Eton, Oxford and Caltech. He published his first scientific paper at the age of 15, and had received his PhD in theoretical physics from Caltech by the age of 20. Wolfram's early scientific work was mainly in high-energy physics, quantum field theory and cosmology, and included several now-classic results. Having started to use computers in 1973, Wolfram rapidly became a leader in the emerging field of scientific computing, and in 1979 he began the construction of SMP—the first modern computer algebra system—which he released commercially in 1981. In recognition of his early work in physics and computing, Wolfram became in 1981 the youngest recipient of a MacArthur Fellowship. Late in 1981 Wolfram then set out on an ambitious new direction in science aimed at understanding the origins of complexity in nature. Wolfram's first key idea was to use computer experiments to study the behavior of simple computer programs known as cellular automata. And starting in 1982, this allowed him to make a series of startling discoveries about the origins of complexity. The papers Wolfram published quickly had a major impact, and laid the groundwork for the emerging field that Wolfram called complex systems research.
- May 11, 2024
Labels: Understanding Reversibility: Edward Fredkin Memorial Lectures
Location: West Bengal, India
Speaker: Tommaso Toffoli, Boston University
Brief Bio of the Speaker: Tommaso Toffoli is a professor of electrical and computer engineering at Boston University where he joined the faculty in 1995. He received his master's degree in physics from the University of Rome La Sapienza in 1967. In 1976 he received a Ph.D. in computer and communication science from the University of Michigan, then in 1978 he joined the faculty of Massachusetts Institute of Technology as a principal research scientist, where he remained until 1995, when he joined the faculty of Boston University. He has worked on Cellular automata and the theory of artificial life (with Edward Fredkin and others), and is known for the invention of the Toffoli gate.
- May 18, 2024
Labels: Understanding Reversibility: Edward Fredkin Memorial Lectures
Location: West Bengal, India
Speaker: Smita Sirker, Jawaharlal Nehru University
Abstract: The talk will focus on some of the possible understanding of reversibility – whether the concept of reversibility is uniform in its applications across different philosophical issues. For instance, the concepts of negation and absence are prevalent in our philosophical discourse. Let us consider a particular case. When we experience an ‘absence of x’ in a certain setup, our perception of that absence (of x) is mediated through the perception of the present (perceptually visible) objects, as we construe mentally what the earlier perceptual configuration (of that scenario) was. In this very act of mental construction (as memory), the contrast between an earlier (temporal) content of perception and the present content of perception (which is our perception of absence of x), we have a reconstruction of the perceived absence. Whether this perceptual construct of absence via the perception of the present (objects) can be treated as reversibility to an earlier temporal (phenomenal) perception? Likewise, we will discuss some other cases and through their analyses try to capture the sense of reversibility. We will try and show how the concept of reversibility (not always in a uniform sense) applies across contexts like moral scenarios, discussions of negation, perception of absence, etc.
Brief Bio of the Speaker: Smita Sirker is a Professor at the Center for Philosophy, School of Social Sciences, Jawaharlal Nehru University, New Delhi. She also taught at the Department of Philosophy, Jadavpur University for a decade and was the Associate Editor of the Jadavpur Journal of Philosophy. She was also appointed as the joint director of School of Cognitive Science, Jadavpur University. Her research interests include philosophy of cognitive science and mind, psychology of moral reasoning, human reasoning and rationality, and philosophy of mathematics. She has co-authored a book entitled Mental Reasoning: Experiment and Theories (2010). She has jointly edited Mind and Cognition: An Interdisciplinary Sharing. She has published in Philosophy East and West, Mind and Language, Journal of Mathematics and Culture and Noûs.
- May 18, 2024
Labels: Understanding Reversibility: Edward Fredkin Memorial Lectures
Location: West Bengal, India