{Download PDF} Physics from Symmetry

Total Page:16

File Type:pdf, Size:1020Kb

{Download PDF} Physics from Symmetry PHYSICS FROM SYMMETRY PDF, EPUB, EBOOK Jakob Schwichtenberg | 287 pages | 01 Jan 2018 | Springer International Publishing AG | 9783319666303 | English | Cham, Switzerland Physics from Symmetry PDF Book Figure 1: Coherent states of light are launched into disordered waveguide arrays. Speaking of Science. Soon afterwards C. Principles Of Physics 0. Cooper and J. A concrete example is the use of symmetries to predict the existence of new particles. The book concludes with first applications of the previously derived equations. Pooley, O. Veltman and G. This issue continues to be discussed in the context of the substantivalist- relationalist debate. Belot, G. Landsman, N. Bekijk de hele lijst. Second, we may derive specific consequences with regard to particular physical situations or phenomena on the basis of their symmetry properties symmetry arguments. Halzen Wisconsin U. Ismael, J. By comparing measurements made under opposite electric fields, experimenters can mitigate systematic uncertainties [ 10 ]. But now, writing in Nature Physics , Hasan Esat Kondakci and co-workers 3 report the discovery of an entirely different behaviour of quantum light in an artificial type of medium: disordered arrays of evanescently coupled waveguides. Get New Updates Email Alerts Enter your email address to subscribe this blog and receive notifications of new posts by email. This is a textbook that derives the fundamental theories of physics from symmetry. May 9. This implied, in virtue of the CPT theorem, the violation of T -symmetry as well; since then, there have been direct observations of T -symmetry violation, as reported by e. Quantum Field Theory 2nd edition, 5. Share this Article. It may then happen that the coarse-grained description thus obtained possesses more symmetries than the deeper theory. For an intuitive characterization of gauge symmetry, one that is more general than the Lagrangian and Hamiltonian formulations of theories using which gauge symmetry is usually expressed, see Belot Such terms can have different origins:. Kondakci et al. It may violate a symmetry of the theory, and traces of this symmetry breaking may remain even after the regulator is removed at the end of the calculations. French and Rickles offer an overview of the above and related issues, and a new twist in the tale can be found in Saunders Drude, P. Historically, the first relevant dualities to be used in physics were electric-magnetic duality, momentum-position duality via Fourier transform — wave-particle duality in the QM context — and the Kramers-Wannier duality of the two-dimensional Ising model in statistical physics. Rights and permissions Reprints and Permissions. Rollo May. Materials Phys. C Phys. Weyl, H. Symmetry considerations dominate modern fundamental physics, both in quantum theory and in relativity. Understanding when and why time T symmetry breaks down could provide answers to some of the biggest open questions in physics, such as why the universe is full of matter and lacks antimatter. And one possible answer to that is this redundancy of description that gauge symmetries give you. Guay, A. One reason that this question is pressing is that as we mentioned in Section 2. Bindwijze: Hardcover. From these different roles we can draw some preliminary conclusions about the status of symmetries. Physics from Symmetry Writer The man would be floating as happily as an astronaut in space, until the ground got in his way. Noether and symmetry have both occupied center stage in physics ever since. Ruetsche discusses symmetry breaking and ferromagnetism from the algebraic perspective. Uitgever: Springer International Publishing Ag. Symmetry Arguments 4. The way in which the regularity of the whole emerges is dictated by the nature of the specified transformation group. Note that this mechanism for the mass generation for the gauge fields is also what ensures the renormalizability of theories involving massive gauge fields such as the Glashow-Weinberg-Salam electroweak theory developed in the second half of the s , as first generally demonstrated by M. In , Philip Anderson realized that to describe the conductivity of a solid, electrons have to be considered as waves, which led to the discovery of the effect known today as Anderson localization 5. Download references. They indicate all the ways physicists can shift, rotate, distort and generally mess with their equations without varying anything important. One of the most important roles played by symmetry is that of classification — for example, the classification of crystals using their remarkable and varied symmetry properties. DOI: In group-theoretic terms, this means that the initial symmetry group is broken to one of its subgroups. Thereafter, these tools are put into action and by using symmetry constraints, the fundamental equations of Quantum Mechanics, Quantum Field Theory, Electromagnetism, and Classical Mechanics are derived. Livanios, V. For details see, for example, Teller and Martin Crucially, the parts are interchangeable with respect to the whole — they can be exchanged with one another while preserving the original figure. You can switch places on a teeter-totter and not upset the balance. Well-known examples are laser light for the former, and black-body radiation for the latter. Related Entries quantum mechanics quantum theory: identity and individuality in space and time: inertial frames space and time: the hole argument time: thermodynamic asymmetry in. Lahini, Y. D Phys. Physics from Symmetry Reviews Although the spatial and temporal invariance of mechanical laws was known and used for a long time in physics, and the group of the global spacetime symmetries for electrodynamics was completely derived by H. However, nuclei like radium are short lived and can only be produced in small quantities. Through this difficult time APS and the Physical Review editorial office are fully equipped and actively working to support researchers by continuing to carry out all editorial and peer-review functions and publish research in the journals as well as minimizing disruption to journal access. Below article will solve this puzzle of yours. Dynamical symmetry breaking DSB. It quickly acquired a further, more general, meaning: that of a proportion relation, grounded on integer numbers, and with the function of harmonizing the different elements into a unitary whole. On the other side, what is the theoretical and empirical status of this symmetry principle? This is a textbook that derives the fundamental theories of physics from symmetry. If we speak about a role of this concept of symmetry in the ancient theories of nature, we must be clear that it was not used explicitly in this sense at that time. Lie; and, finally, the connection between the study of physical invariants and the algebraic and geometric theory of invariants that flourished in the second half of the nineteenth century, and which laid the foundation for the geometrical approach to dynamical problems. Researchers design radioactive molecules that might have exceptional sensitivity to the symmetry violations explaining the matter-antimatter imbalance of the Universe. Step-1 : Read the Book Name and author Name thoroughly. You can rotate a snowflake by 60 degrees and it will look the same. Landsman discusses the issue whether SBB in infinite quantum systems can be seen as an example of asymptotic emergence in physics. Source: UC Santa Barbara. Historically, the concept of SSB first emerged in condensed matter physics. Thus far, we have been discussing symmetries which act on the space of states of a physical theory. This error has now been corrected in all versions 7 October For further developments in this debate, including applications to local symmetries and to gauge theories, see Kosso , Brading and Brown , Healey , Healey , Greaves and Wallace , Friederich , Rovelli and Teh , Applied Phys. Since that resistance is inertia, and inertia is a measure of mass, the energy of motion is transformed into mass. Caulton, A. Moreover, the technical apparatus of group theory could then be transferred and used to great advantage within physical theories. Different proposals have been offered for justifying the principle. The second type of disorder is even more intriguing. Symmetry Arguments Consider the following cases. Please enter your name here. Filming for this video by Petr Stepanek. Search for:. The presence of these massless bosons, first seen as a serious problem since no particles of the sort had been observed in the context considered, was in fact the basis for the solution — by means of the so-called Higgs mechanism see the next point — of another similar problem, that is the fact that the Yang-Mills theory of non-Abelian gauge fields predicted unobservable massless particles, the gauge bosons. This principle, when combined with the light postulate and certain other assumptions , leads to the Lorentz transformations, these being the transformations between coordinate systems moving uniformly with respect to one another according to STR. In the first type, only the individual refractive indices of the waveguides randomly change but remain constant along the direction of propagation , whereas the inter-site distances remain constant Fig. Physics from Symmetry Read Online Stewart, I. Princeton University Press, 7. Healey discusses the conceptual foundations of gauge theories, arguing in favour of a non-separable holonomy interpretation of classical Yang-Mills gauge theories of fundamental interactions. Symmetry Breaking
Recommended publications
  • Mathematical Languages Shape Our Understanding of Time in Physics Physics Is Formulated in Terms of Timeless, Axiomatic Mathematics
    comment Corrected: Publisher Correction Mathematical languages shape our understanding of time in physics Physics is formulated in terms of timeless, axiomatic mathematics. A formulation on the basis of intuitionist mathematics, built on time-evolving processes, would ofer a perspective that is closer to our experience of physical reality. Nicolas Gisin n 1922 Albert Einstein, the physicist, met in Paris Henri Bergson, the philosopher. IThe two giants debated publicly about time and Einstein concluded with his famous statement: “There is no such thing as the time of the philosopher”. Around the same time, and equally dramatically, mathematicians were debating how to describe the continuum (Fig. 1). The famous German mathematician David Hilbert was promoting formalized mathematics, in which every real number with its infinite series of digits is a completed individual object. On the other side the Dutch mathematician, Luitzen Egbertus Jan Brouwer, was defending the view that each point on the line should be represented as a never-ending process that develops in time, a view known as intuitionistic mathematics (Box 1). Although Brouwer was backed-up by a few well-known figures, like Hermann Weyl 1 and Kurt Gödel2, Hilbert and his supporters clearly won that second debate. Hence, time was expulsed from mathematics and mathematical objects Fig. 1 | Debating mathematicians. David Hilbert (left), supporter of axiomatic mathematics. L. E. J. came to be seen as existing in some Brouwer (right), proposer of intuitionist mathematics. Credit: Left: INTERFOTO / Alamy Stock Photo; idealized Platonistic world. right: reprinted with permission from ref. 18, Springer These two debates had a huge impact on physics.
    [Show full text]
  • HYPOTHESIS: How Defining Nature of Time Might Explain Some of Actual Physics Enigmas P Letizia
    HYPOTHESIS: How Defining Nature of Time Might Explain Some of Actual Physics Enigmas P Letizia To cite this version: P Letizia. HYPOTHESIS: How Defining Nature of Time Might Explain Some of Actual Physics Enigmas: A possible explanation of Dark Energy. 2017. hal-01424099 HAL Id: hal-01424099 https://hal.archives-ouvertes.fr/hal-01424099 Preprint submitted on 3 Jan 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution - NonCommercial - ShareAlike| 4.0 International License SUBMITTED FOR STUDY January 1st, 2017 HYPOTHESIS: How Defining Nature of Time Might Explain Some of Actual Physics Enigmas P. Letizia Abstract Nowadays it seems that understanding the Nature of Time is not more a priority. It seems commonly admitted that Time can not be clearly nor objectively defined. I do not agree with this vision. I am among those who think that Time has an objective reality in Physics. If it has a reality, then it must be understood. My first ambition with this paper was to submit for study a proposition concerning the Nature of Time. However, once defined I understood that this proposition embeds an underlying logic.
    [Show full text]
  • Terminology of Geological Time: Establishment of a Community Standard
    Terminology of geological time: Establishment of a community standard Marie-Pierre Aubry1, John A. Van Couvering2, Nicholas Christie-Blick3, Ed Landing4, Brian R. Pratt5, Donald E. Owen6 and Ismael Ferrusquía-Villafranca7 1Department of Earth and Planetary Sciences, Rutgers University, Piscataway NJ 08854, USA; email: [email protected] 2Micropaleontology Press, New York, NY 10001, USA email: [email protected] 3Department of Earth and Environmental Sciences and Lamont-Doherty Earth Observatory of Columbia University, Palisades NY 10964, USA email: [email protected] 4New York State Museum, Madison Avenue, Albany NY 12230, USA email: [email protected] 5Department of Geological Sciences, University of Saskatchewan, Saskatoon SK7N 5E2, Canada; email: [email protected] 6Department of Earth and Space Sciences, Lamar University, Beaumont TX 77710 USA email: [email protected] 7Universidad Nacional Autónomo de México, Instituto de Geologia, México DF email: [email protected] ABSTRACT: It has been recommended that geological time be described in a single set of terms and according to metric or SI (“Système International d’Unités”) standards, to ensure “worldwide unification of measurement”. While any effort to improve communication in sci- entific research and writing is to be encouraged, we are also concerned that fundamental differences between date and duration, in the way that our profession expresses geological time, would be lost in such an oversimplified terminology. In addition, no precise value for ‘year’ in the SI base unit of second has been accepted by the international bodies. Under any circumstances, however, it remains the fact that geologi- cal dates – as points in time – are not relevant to the SI.
    [Show full text]
  • A Measure of Change Brittany A
    University of South Carolina Scholar Commons Theses and Dissertations Spring 2019 Time: A Measure of Change Brittany A. Gentry Follow this and additional works at: https://scholarcommons.sc.edu/etd Part of the Philosophy Commons Recommended Citation Gentry, B. A.(2019). Time: A Measure of Change. (Doctoral dissertation). Retrieved from https://scholarcommons.sc.edu/etd/5247 This Open Access Dissertation is brought to you by Scholar Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. Time: A Measure of Change By Brittany A. Gentry Bachelor of Arts Houghton College, 2009 ________________________________________________ Submitted in Partial Fulfillment of the Requirements For the Degree of Doctor of Philosophy in Philosophy College of Arts and Sciences University of South Carolina 2019 Accepted by Michael Dickson, Major Professor Leah McClimans, Committee Member Thomas Burke, Committee Member Alexander Pruss, Committee Member Cheryl L. Addy, Vice Provost and Dean of the Graduate School ©Copyright by Brittany A. Gentry, 2019 All Rights Reserved ii Acknowledgements I would like to thank Michael Dickson, my dissertation advisor, for extensive comments on numerous drafts over the last several years and for his patience and encouragement throughout this process. I would also like to thank my other committee members, Leah McClimans, Thomas Burke, and Alexander Pruss, for their comments and recommendations along the way. Finally, I am grateful to fellow students and professors at the University of South Carolina, the audience at the International Society for the Philosophy of Time conference at Wake Forest University, NC, and anonymous reviewers for helpful comments on various drafts of portions of this dissertation.
    [Show full text]
  • Time: a Constructal Viewpoint & Its Consequences
    www.nature.com/scientificreports OPEN Time: a Constructal viewpoint & its consequences Umberto Lucia & Giulia Grisolia In the environment, there exists a continuous interaction between electromagnetic radiation and Received: 11 April 2019 matter. So, atoms continuously interact with the photons of the environmental electromagnetic felds. Accepted: 8 July 2019 This electromagnetic interaction is the consequence of the continuous and universal thermal non- Published: xx xx xxxx equilibrium, that introduces an element of randomness to atomic and molecular motion. Consequently, a decreasing of path probability required for microscopic reversibility of evolution occurs. Recently, an energy footprint has been theoretically proven in the atomic electron-photon interaction, related to the well known spectroscopic phase shift efect, and the results on the irreversibility of the electromagnetic interaction with atoms and molecules, experimentally obtained in the late sixties. Here, we want to show how this quantum footprint is the “origin of time”. Last, the result obtained represents also a response to the question introduced by Einstein on the analysis of the interaction between radiation and molecules when thermal radiation is considered; he highlighted that in general one restricts oneself to a discussion of the energy exchange, without taking the momentum exchange into account. Our result has been obtained just introducing the momentum into the quantum analysis. In the last decades, Rovelli1–3 introduced new considerations on time in physical sciences. In his Philosophiae Naturalis Principia Mathematica4, Newton introduced two defnitions of time: • Time is the quantity one introduce when he needs to locate events; • Time is the quantity which fows uniformly even in absence of events, and it presents a proper topological structure, with a well defned metric.
    [Show full text]
  • Change Without Time Relationalism and Field Quantization
    Change Without Time Relationalism and Field Quantization Dissertation zur Erlangung des Doktorgrades der Naturwissenschaften (Dr. rer. nat.) der naturwissenschaftlichen Fakult¨at II – Physik der Universit¨at Regensburg vorgelegt von Johannes Simon aus Schwandorf 2004 Promotionsgesuch eingereicht am: 19.04.2004 Die Arbeit wurde angeleitet von Prof. Dr. Gustav M. Obermair. Prufungsausschuss:¨ Vorsitzender Prof. Dr. W. Prettl 1. Gutachter Prof. Dr. G. M. Obermair 2. Gutachter Prof. Dr. E. Werner weiterer Prufer¨ Prof. Dr. A. Sch¨afer Tag der mundlichen¨ Prufung:¨ 23.07.2004 Tempus item per se non est [...] Titus Lucretius Carus [Car, 459 ff] Preface This thesis studies the foundations of time in physics. Its origin lies in the urge to understand the quantum measurement problem. While the emergence of classical- ity can be well described within algebraic quantum mechanics of infinite systems, this can be achieved only in infinite time. This led me to a study of quantum dy- namics of infinite systems, which turned out to be far less unique than in the case of finitely many degrees of freedom. In deciding on the correct time evolution the question appears how time – or rather duration – is being measured. Traditional quantum mechanics lacks a time observable, and for closed systems in an energy eigenstate duration is indeed meaningless. A similar phenomenon shows up in general relativity, where absolute duration (as well as spatial distance) becomes meaningless due to diffeomorphism invariance. However, by relating different parts of a closed system through simultaneity (in quantum mechanics as well as in general relativity), an internal notion of time becomes meaningful. This similarity between quantum mechanics and general relativity was recognized in the context of quantum gravity by Carlo Rovelli, who proposed a relational concept of quantum time in 1990.
    [Show full text]
  • A Critical Analysis of the Concept of Time in Physics
    A critical analysis of the concept of time in physics Claudio Borghi Liceo Scientifico Belfiore, via Tione 2, Mantova, Italy Abstract. This paper puts forward a broad critical analysis of the con- cept of physical time. Clock effect is conceived as a consequence of the variation of the gravitational or pseudo gravitational potential, and it is remarked that only some real clocks measure durations in agreement with the predictions of general relativity. A probable disagreement is ex- pected between radioactive and atomic clocks, in the light of Rovelli’s thermal time hypothesis. According to the recent contributions by Rugh and Zinkernagel, the relationship between time and clocks is investigated in order to found on a physical basis the concept of cosmic time. In the conclusive section is argued the impossibility of reducing thermal time to relativistic time. Key words: Time, Relativity, Thermodynamics, Cosmology 1 Introduction The following points resume the main concepts: 1) analysis of the operational definition of time in Newton and Einstein; 2) distinction between time dilation effect and clock effect in Einstein’s theory; 3) considerations about the nonequivalence between atomic clocks and radioac- tive clocks in the light of the clock hypothesis; 4) remarks about the existence, in nature, of thermal clocks that do not behave as relativistic clocks, and about the consequent nonequivalence between ther- mal and relativistic time, in the light of the thermal time hypothesis; 5) reflections about the operational definition of cosmic time in relation to the physical processes, then to the clocks that can be used for measuring it; arXiv:1808.09980v2 [physics.gen-ph] 2 Sep 2018 6) conclusive remarks about the need of a revision and a consequent refounda- tion of the concept of time in physics.
    [Show full text]
  • Multidimensional Time
    International Journal of Science and Research (IJSR) ISSN: 2319-7064 ResearchGate Impact Factor (2018): 0.28 | SJIF (2018): 7.426 Time: Multidimensional Time Ankit Thapliyal M.Sc. (Physics), HNBGU, Dehradun, Bhauwala, India (248007) Abstract: What is time? It’s a beautiful and mysterious question of all time in physics. Great scientist Newton told us that time is absolute and it’s uniformly ticking throughout whole universe. But Einstein did not agree with Newton at this point and gave us a revolutionary idea in physics, that was “time is relative”. He gave us famous theory of relativity which is the basis of modern physics. But there is some paradox which arose with this theory as a result of time dilation and one of them is twin paradox. However, we have many explanations about these paradoxes. But the question is how time appears faster or slower. Well the answer lies in the fact that universe have more than four dimensions and time which we assume to have single dimension is made up of more than two dimensions and that’s the true reason why we find sometimes it moves faster while sometimes it moves slower. Just as gravity goes through every possible dimension and appears weak in three or four dimensions and that’s exactly the case with time, we can relate its faster and slower speed at different places of universe with time’s multidimensional nature. Keywords: Time, Time dilation, Time multidimension 1. Introduction Now the question arises that, could this be the case with time? Till now we assume it as one dimensional but what if Time is considered as one of the mysterious things in physics time has more than one dimensions? all time.
    [Show full text]
  • Symmetries in Physics: Philosophical Reflections
    SYMMETRIES IN PHYSICS: PHILOSOPHICAL REFLECTIONS EDITED BY K. BRADING1 AND E. CASTELLANI2 CAMBRIDGE UNIVERSITY PRESS, 2003 CONTENTS 1. Introduction Section I: Continuous symmetries 2. Extracts from H. Weyl 3. Extracts from E. P. Wigner 4. Review paper: C. Martin, ‘On continuous symmetries and the foundations of modern physics’ 5. T. Ryckman, ‘The philosophical roots of the gauge principle: Weyl and transcendental phenomenological idealism’ 6. K. A. Brading and H. R. Brown, ‘Symmetries and Noether’s theorems’ 7. J. Norton, ‘General covariance, gauge theories, and the Kretschmann objection’ 8. M. Redhead, ‘The interpretation of gauge symmetry’ 9. J. Earman, ‘Tracking down gauge: an ode to the constrained Hamiltonian formalism’ 10. D. Wallace, ‘Time-dependent symmetries: the link between gauge symmetries and indeterminism’ 11. A. Nounou, ‘A fourth way to the A-B effect’ Section II: Discrete symmetries 12. Extracts from the Leibniz-Clarke correspondence 13. Extracts from I. Kant 14..Extracts from M. Black 15. Review paper: S. French and D. Rickles, ‘Understanding permutation symmetry’ 16. N. Huggett, ‘Quarticles and the identity of indiscernibles’ 17. Review paper: O. Pooley, ‘Handedness, parity violation, and the reality of space’ 18. N. Huggett, ‘Mirror symmetry: what is it for a relational space to be orientable?’ 19. S. Saunders, ‘Physics and Leibniz’s principles’ 1 Wolfson College, Oxford. E-mail: [email protected] 2 University of Florence, Italy. E-mail: [email protected] Section III: Symmetry breaking 20. Extracts from H. Weyl 21. Extracts from P. Curie 22. Extracts from G. Jona-Lasinio 23. Review paper: E. Castellani, ‘On the meaning of symmetry breaking’ 24.
    [Show full text]
  • Arxiv:2006.10084V3 [Quant-Ph] 7 Mar 2021
    Quantum time dilation in atomic spectra Piotr T. Grochowski ,1, ∗ Alexander R. H. Smith ,2, 3, y Andrzej Dragan ,4, 5, z and Kacper Dębski 4, x 1Center for Theoretical Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland 2Department of Physics, Saint Anselm College, Manchester, New Hampshire 03102, USA 3Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755, USA 4Institute of Theoretical Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland 5Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore (Dated: March 9, 2021) Quantum time dilation occurs when a clock moves in a superposition of relativistic momentum wave packets. The lifetime of an excited hydrogen-like atom can be used as a clock, which we use to demonstrate how quantum time dilation manifests in a spontaneous emission process. The resulting emission rate differs when compared to the emission rate of an atom prepared in a mixture of momentum wave packets at order v2=c2. This effect is accompanied by a quantum correction to the Doppler shift due to the coherence between momentum wave packets. This quantum Doppler shift affects the spectral line shape at order v=c. However, its effect on the decay rate is suppressed when compared to the effect of quantum time dilation. We argue that spectroscopic experiments offer a technologically feasible platform to explore the effects of quantum time dilation. I. INTRODUCTION The purpose of the present work is to provide evi- dence in support of the conjecture that quantum time The quintessential feature of quantum mechanics is dilation is universal.
    [Show full text]
  • Space, Time and Relativity
    GENERAL I ARTICLE Space, Time and Relativity S Chaturvedi, R Simon and N Mukunda 1. Introduction Special Relativity is now a hundred years old, and Gen­ eral Relativity is just ten years younger. Even the gen­ eral literate public probably knows that these two the­ ories of physics - STR and GTR - profoundly altered previous conceptions and understanding of space and time in physics. We will try to describe these changes ~ginning with earlier ideas which had served physics fer almost 300 years, and seeing how they had to be (left) S Chaturvedi is Professor at the School of modified in the light of accumulating experience. Physics, University of 2. Newtonian Space and Time, Inertial Frames Hyderabad since 1993. His current research interests In his great work titled the 'Principia' published in 1685, are mathematical physics, geometric phases, Newton began by expressing in clear terms the natures coherent states, Wigner of space and time as he understood them. The impor­ distribution, and quantum tance of his enunciation of their properties cannot be entanglement. overestimated, because they provided something tangi­ (right) R Simon is with ble which could be used as a basis for further work, and the Institute of Math­ equally importantly which could be examined and crit­ ematical Sciences, icised in a fruitful manner. Quoting from Einstein: Chennai. His research interests are in quantum "... what we have gained up till now would have been information science and impossible without Newton's clear system" quantum optics. Newton was carrying forward what Galileo had begun. (center) N Mukunda is at the Centre for High Let us start by reminding you of the implicit and explicit Energy Physics, liSe, assumptions underlying Galilean- Newtonian physics, al­ Bangalore.
    [Show full text]
  • Space and Time in Life and Science
    GENERAL ARTICLE Space and Time in Life and Science Vasant Natarajan, V Balakrishnan and N Mukunda Space and tim e are conceptsthatseem to be em - bedded in our very consciousness. A s we grow up, our `intuitive understanding' of these con- cepts seem s to grow as well. A nd yet the fact is that our understanding of space-tim e in the deepest scienti¯c sense is far from com plete, al- though w e have covered a considerable distance along the route. There m ay stillbe m any sur- prises aw aiting us on the road ahead. 1.It Began w ith G eom etry A ll of us have som e intuitive ideas about the natures (left) Vasant Natarajan is at the Department of Physics, of space and tim e in which we are em bedded. Space IISc. His research interests appears to be the stage on which all events, experi- are in high-resolution laser ences and phenom ena take place, w hile tim e is like a spectroscopy, optical background against w hich this happens. A llobjects,in- frequency measurement, and cluding ourselves,exist in space and change w ith tim e. use of laser-cooled atoms to search for time-reversal In this article, w e shalldescribe in sim ple and qualita- violation in the laws of tive term show ourunderstanding ofspace and tim e has physics. developed over the centuries,and w hat we have learnt about their properties. W e w illsee that m any strands (right) V Balakrishnan is at com e togetherin thisstory { notonly from m athem atics the Department of Physics, IIT- Madras, Chennai.
    [Show full text]