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Emergence and Phenomenology in Quantum Gravity
Emergence and Phenomenology in Quantum Gravity by Isabeau Premont-Schwarz´ A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Doctor of Philosophy in Physics Waterloo, Ontario, Canada, 2010 © Isabeau Premont-Schwarz´ 2010 AUTHOR’S DECLARATION I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii AUTHORSHIP STATEMENT This thesis is based on the following five articles: • A. Hamma, F. Markopoulou, I. Pr´emont-Schwarz and S. Severini, “Lieb-Robinson bounds and the speed of light from topological order,” Phys. Rev. Lett. 102 (2009) 017204 [arXiv:0808.2495 [quant-ph]]. • I. Pr´emont-Schwarz ,A. Hamma, I. Klich and F. Markopoulou, “Lieb-Robinson bounds for commutator-bounded operators ,” Phys. Rev. A 81, 040102(R) (2010) .[arXiv:0912.4544 [quant-ph]]. • I. Pr´emont-Schwarz and J. Hnybida, “Lieb-Robinson bounds with dependence on interaction strengths, ” [arXiv:1002.4190 [math-ph]]. • L. Modesto and I. Pr´emont-Schwarz, “Self-dual Black Holes in LQG: Theory and Phenomenology,” Phys. Rev. D 80, 064041 (2009) [arXiv:0905.3170 [hep-th]]. • S. Hossenfelder, L. Modesto and I. Pr´emont-Schwarz, “A model for non-singular black hole collapse and evaporation ,” Phys. Rev. D 81, 044036 (2010) [arXiv:0912.1823 [gr-qc]]. I did the majority of the work in the first article, but the project was initiated by Fotini Markopoulou-Kalamara and Alioscia Hamma and the manuscript was mostly written by Alioscia Hamma. -
In This Issue NIOSH Not Issuing New Recommended Exposure Limit For
Volume 11, No. 2 • Summer 2016 Environmental Protection Agency (US EPA) and the Food and In This Issue Drug Administration (FDA) to require companies to submit data on worker exposures to nanosilver before products con- • Recent Government Briefs taining nanosilver are allowed into the marketplace. These • Reports, Reviews, White Papers, and Books groups also supported implementing controls to mitigate ex- • Hot-off-the-Presses: Peer-reviewed Research posures (e.g., eliminating exposure to nanosilver or using less- Articles of Note hazardous substances) and recommended that companies be • Upcoming Meetings and Conferences required to submit safety data on potential risks to workers • New Product Review (e.g., liver and lung effects). Specifically, these groups noted the need to address women's exposures to nanosilver (e.g., for reproductive endpoints), because most occupational studies Recent Government Briefs of this substance have focused on men. Link to the Risk Policy Report, by Reynolds: http://insideepa.com/risk-policy-report/niosh-for- goes-novel-limit-nanosilver-citing-insufficient-risk-da- NIOSH Not Issuing New Recommended ta Exposure Limit for Nanosilver The docket, including comments and supporting documenta- tion, can be accessed here: Based on the comments it received on the draft document https://www.regulations.gov/#!docketDetail;D=C "Health Effects of Occupational Exposure to Silver Nanomate- DC-2016-0001 rials," the National Institute for Occupational Safety and Health (NIOSH) has decided it will not issue a specific -
The State of the Multiverse: the String Landscape, the Cosmological Constant, and the Arrow of Time
The State of the Multiverse: The String Landscape, the Cosmological Constant, and the Arrow of Time Raphael Bousso Center for Theoretical Physics University of California, Berkeley Stephen Hawking: 70th Birthday Conference Cambridge, 6 January 2011 RB & Polchinski, hep-th/0004134; RB, arXiv:1112.3341 The Cosmological Constant Problem The Landscape of String Theory Cosmology: Eternal inflation and the Multiverse The Observed Arrow of Time The Arrow of Time in Monovacuous Theories A Landscape with Two Vacua A Landscape with Four Vacua The String Landscape Magnitude of contributions to the vacuum energy graviton (a) (b) I Vacuum fluctuations: SUSY cutoff: ! 10−64; Planck scale cutoff: ! 1 I Effective potentials for scalars: Electroweak symmetry breaking lowers Λ by approximately (200 GeV)4 ≈ 10−67. The cosmological constant problem −121 I Each known contribution is much larger than 10 (the observational upper bound on jΛj known for decades) I Different contributions can cancel against each other or against ΛEinstein. I But why would they do so to a precision better than 10−121? Why is the vacuum energy so small? 6= 0 Why is the energy of the vacuum so small, and why is it comparable to the matter density in the present era? Recent observations Supernovae/CMB/ Large Scale Structure: Λ ≈ 0:4 × 10−121 Recent observations Supernovae/CMB/ Large Scale Structure: Λ ≈ 0:4 × 10−121 6= 0 Why is the energy of the vacuum so small, and why is it comparable to the matter density in the present era? The Cosmological Constant Problem The Landscape of String Theory Cosmology: Eternal inflation and the Multiverse The Observed Arrow of Time The Arrow of Time in Monovacuous Theories A Landscape with Two Vacua A Landscape with Four Vacua The String Landscape Many ways to make empty space Topology and combinatorics RB & Polchinski (2000) I A six-dimensional manifold contains hundreds of topological cycles. -
Introduction to Copyright and Licensing in an Open Access Environment
IOP publications Frequently asked questions Glossary Frequently asked questions Creative Commons Moral rights Creative Commons Assignment Open access Dealing with copyright works Introduction to copyright copyright.iop.org Introduction to Introduction open access environment access open copyright and licensing in an in licensing and copyright Introduction to copyright to Introduction works copyright with Dealing access Open Assignment Commons Creative Commons Creative questions asked Frequently Glossary questions asked Frequently publications IOP Moral rights rights Moral What is copyright? As soon as an idea is expressed in a physical medium, such as writing a paper, it qualifies for copyright protection. Copyright is a legal right that gives the copyright holder exclusive rights over how others use their work. The level and type of protection offered by copyright varies between countries. A form of intellectual property, copyright can be dealt with like other types of property – it can be acquired, disposed of or licensed. Copyright is time-limited. The period of protection varies, but in most countries a journal article created at the present time will be protected for between 50 and 70 years from the death of the last surviving author. By means of a number of local and international laws and conventions, copyright which arises in one country is recognised and protected in many others. Treatment of copyright in the digital environment is evolving at an unprecedented rate. Copyright exists to protect the rights of an owner of an original piece of work by imposing restrictions on reuse but it does not always fit well with how we use and share information in the digital sphere. -
Women in Engineering Fixing the Talent Pipeline
REPORT WOMEN IN ENGINEERING FIXING THE TALENT PIPELINE Amna Silim and Cait Crosse September 2014 © IPPR 2014 Institute for Public Policy Research ABOUT IPPR IPPR, the Institute for Public Policy Research, is the UK’s leading progressive thinktank. We are an independent charitable organisation with more than 40 staff members, paid interns and visiting fellows. Our main office is in London, with IPPR North, IPPR’s dedicated thinktank for the North of England, operating out of offices in Newcastle and Manchester. The purpose of our work is to conduct and publish the results of research into and promote public education in the economic, social and political sciences, and in science and technology, including the effect of moral, social, political and scientific factors on public policy and on the living standards of all sections of the community. IPPR 4th Floor 14 Buckingham Street London WC2N 6DF T: +44 (0)20 7470 6100 E: [email protected] www.ippr.org Registered charity no. 800065 This paper was first published in September 2014. © 2014 The contents and opinions in this paper are the authors’ only. NEW IDEAS for CHANGE CONTENTS Summary ............................................................................................................1 Introduction: Why should we care about the lack of women in engineering? .....2 1. The scale of the challenge in the UK .............................................................3 2. The choices girls make in education ..............................................................5 2.1 Choices at school ............................................................................................ 5 2.2 Choices in higher education ............................................................................. 6 2.3 Choices in employment.................................................................................... 7 3. Why do girls reject the idea of a career in engineering?..............................10 3.1 Perception of STEM subjects and engineering careers .................................. -
Sabine Hossenfelder on “The Case Against Beauty in Physics” Julia
Rationally Speaking #211: Sabine Hossenfelder on “The case against beauty in physics” Julia: Welcome to Rationally Speaking, the podcast where we explore the borderlands between reason and nonsense. I'm your host, Julia Galef, and I'm here with today's guest, Sabine Hossenfelder. Sabine is a theoretical physicist, focusing on quantum gravity. She's a research fellow at the Frankfurt Institute for Advanced Studies, and blogs at Back Reaction. She just published the book, "Lost in Math: How Beauty Leads Physics Astray." "Lost in Math” argues that physicists, in at least certain sub-fields, evaluate theories based heavily on aesthetics, like is this theory beautiful? Instead of simply, what does the evidence suggest is true? The book is full of interviews Sabine did with top physicists, where she tries to ask them: what's the justification for this? Why should we expect beauty to be a good guide to truth? And, spoiler alert, ultimately, she comes away rather unsatisfied with the answers. So, we're going to talk about "Lost in Math" and the case for and against beauty in physics. Sabine, welcome to the show. Sabine: Hello. Julia: So, probably best to start with: what do you mean by beauty, in this context? And is it closer to a kind of “beauty is in the eye of the beholder” thing, like, every physicist has their own sort of aesthetic sense? Or is more like there's a consensus among physicists about what constitutes a beautiful theory? Sabine: Interestingly enough, there's mostly consensus about it. Let me put ahead that I will not try to tell anyone what beauty means, I am just trying to summarize what physicists seem to mean when they speak of beauty, when they say “that theory is beautiful.” There are several ingredients to this sense of beauty. -
EPIC Members Directory In
clionixumotL88 EPIC Consortium Members Directory: 737 members Questions/Comments, please contact [email protected] This directory is updated every month. Latest revision: 15 September 2021 Table of contents 1. II-VI Incorporated ................................................................................................................ 20 2. III-V Lab ................................................................................................................................ 21 3. 3D AG................................................................................................................................... 21 4. 3photon ............................................................................................................................... 21 5. 3SP Technologies ................................................................................................................. 21 6. 4isp ...................................................................................................................................... 22 7. 4JET Group ........................................................................................................................... 22 8. 603OPTX .............................................................................................................................. 22 9. 8photonics ........................................................................................................................... 23 10. Aarhus University ............................................................................................................... -
The Multiverse: Conjecture, Proof, and Science
The multiverse: conjecture, proof, and science George Ellis Talk at Nicolai Fest Golm 2012 Does the Multiverse Really Exist ? Scientific American: July 2011 1 The idea The idea of a multiverse -- an ensemble of universes or of universe domains – has received increasing attention in cosmology - separate places [Vilenkin, Linde, Guth] - separate times [Smolin, cyclic universes] - the Everett quantum multi-universe: other branches of the wavefunction [Deutsch] - the cosmic landscape of string theory, imbedded in a chaotic cosmology [Susskind] - totally disjoint [Sciama, Tegmark] 2 Our Cosmic Habitat Martin Rees Rees explores the notion that our universe is just a part of a vast ''multiverse,'' or ensemble of universes, in which most of the other universes are lifeless. What we call the laws of nature would then be no more than local bylaws, imposed in the aftermath of our own Big Bang. In this scenario, our cosmic habitat would be a special, possibly unique universe where the prevailing laws of physics allowed life to emerge. 3 Scientific American May 2003 issue COSMOLOGY “Parallel Universes: Not just a staple of science fiction, other universes are a direct implication of cosmological observations” By Max Tegmark 4 Brian Greene: The Hidden Reality Parallel Universes and The Deep Laws of the Cosmos 5 Varieties of Multiverse Brian Greene (The Hidden Reality) advocates nine different types of multiverse: 1. Invisible parts of our universe 2. Chaotic inflation 3. Brane worlds 4. Cyclic universes 5. Landscape of string theory 6. Branches of the Quantum mechanics wave function 7. Holographic projections 8. Computer simulations 9. All that can exist must exist – “grandest of all multiverses” They can’t all be true! – they conflict with each other. -
Inside Science
SPRING 2009 NEWS FROM THE ROYAL SOCIETY INSIDE SCIENCE YOUNG EXPLORERS TOUCHDOWN IN NEW ZEALAND International Expedition Prize is a ‘once in a lifetime experience’ SCIENCE TAKES TO THE STAGE The Royal Shakespeare Company premiers a new play on the emergence of modern science UPDATE FROM THE ROYAL SOCIETY This third issue of Inside Science contains early information DID YOU KNOW? about exciting plans for the Royal Society’s 350th Anniversary in 2010. The Anniversary is a marvellous STEADY FOOTING, opportunity to increase the profile of science, explore its SHAKY BRIDGE benefits and address the challenges it presents for society On its opening day, crowds of but perhaps most important of all to inspire young minds pedestrians experienced unexpected with the excitement of scientific discovery. swaying as they walked across London’s Our policy work continues to address major scientific issues Millennium Bridge. Whilst pedestrians affecting the UK. In December we cautioned the Government on fondly nicknamed it the ‘wobbly bridge’, the levels of separated plutonium stockpiled in the UK – currently physicists were busy exploring the the highest in the world. With support from our Plutonium Working Group, the Society has reasons for the phenomenon. submitted detailed comment to the Nuclear Decommissioning Authority (NDA) for a report to The view was widely held that the Government on management options for the stockpile. ‘wobble’ was due to crowd loading and Late last year we ran an extremely successful MP-Scientist pairing scheme, helping to build pedestrians synchronising their footsteps bridges between parliamentarians and some of the best young scientists in the UK. -
Modified Standard Einstein's Field Equations and the Cosmological
Issue 1 (January) PROGRESS IN PHYSICS Volume 14 (2018) Modified Standard Einstein’s Field Equations and the Cosmological Constant Faisal A. Y. Abdelmohssin IMAM, University of Gezira, P.O. BOX: 526, Wad-Medani, Gezira State, Sudan Sudan Institute for Natural Sciences, P.O. BOX: 3045, Khartoum, Sudan E-mail: [email protected] The standard Einstein’s field equations have been modified by introducing a general function that depends on Ricci’s scalar without a prior assumption of the mathemat- ical form of the function. By demanding that the covariant derivative of the energy- momentum tensor should vanish and with application of Bianchi’s identity a first order ordinary differential equation in the Ricci scalar has emerged. A constant resulting from integrating the differential equation is interpreted as the cosmological constant introduced by Einstein. The form of the function on Ricci’s scalar and the cosmologi- cal constant corresponds to the form of Einstein-Hilbert’s Lagrangian appearing in the gravitational action. On the other hand, when energy-momentum is not conserved, a new modified field equations emerged, one type of these field equations are Rastall’s gravity equations. 1 Introduction term in his standard field equations to represent a kind of “anti ff In the early development of the general theory of relativity, gravity” to balance the e ect of gravitational attractions of Einstein proposed a tensor equation to mathematically de- matter in it. scribe the mutual interaction between matter-energy and Einstein modified his standard equations by introducing spacetime as [13] a term to his standard field equations including a constant which is called the cosmological constant Λ, [7] to become Rab = κTab (1.1) where κ is the Einstein constant, Tab is the energy-momen- 1 Rab − gabR + gabΛ = κTab (1.6) tum, and Rab is the Ricci curvature tensor which represents 2 geometry of the spacetime in presence of energy-momentum. -
Introduction to Refereeing
PUBLISHING GLOSSARY / IOP PUBLICATIONS FREQUENTLY ASKED QUESTIONS ETHICAL ISSUES AFTER YOU SUBMIT YOUR REPORT HOW TO WRITE A REFEREE REPORT AN INTRODUCTION TO THE PEER REVIEW PROCESS CONTENTS g referees.iop.or Introduction to refereeing to Introduction An introductory guide CONTENTS INTRODUCTIONAN PEERTHEREVIEWTOPROCESS REFEREEWRITETOAHOW REPORT AFTERSUBMITYOUYOURREPORT ETHICALISSUES FREQUENTLYASKEDQUESTIONS PUBLISHINGPUBLICATIONSIOP GLOSSARY/ to refereeing IOP Publishing (IOP) is a leading scientific publisher that specializes in physics and related subjects. We are an integral part of the Institute of Physics, an international learned society and professional body, whose mission is to promote the advancement and dissemination of physics worldwide. For more information, visit iopscience.org. Contents Page An introduction to the peer review process 4 How to write a referee report 6 After you submit your report 9 Ethical issues 10 Frequently asked questions 12 Publishing glossary 14 IOP publications 15 Front cover image: An image showing time evolution of magnetic quantum cellular automata (MQCA). The arrows indicate the local magnetization direction in the nanomagnetic elements L Gross et al 2010 Nanotechnology 21 325301. Artistic interpretation by Frédérique Swist. IOP Publishing 3 An introduction to the peer review process What is peer review? of published papers, it also ensures that Peer review is the process used to assess an readers can trust a journal to provide reliable academic paper before deciding whether it information. As members of the scientific should be published or not. The paper is looked community, researchers are expected to referee at by experts in the field, known as referees, papers. The referees also benefit from the whose identities are kept anonymous. -
Royal Society, 1985
The Public Understanding of Science Report of a Royal Society adhoc Group endorsed by the Council of the Royal Society The Royal Society 6 Carlton House Terrace London SWlY 5AG CONTENTS Page Preface 5 Summary 6 1. Introduction 7 2. Why it matters 9 3. The present position 12 4. Formal education 17 5. The mass media 2 1 6. ' The scientific community 24 7. Public lectures, children's activities, museums and libraries 27 8. Industry 29 9. Conclusions and recommendations 31 Annexes A. List of those submitting evidence B. Visits and seminars C. Selected bibliography PREFACE This report was prepared by an ad hoc group under the chairmanship of Dr W.F. Bodmer, F.R.S.; it has been endorsed by the Council of the Royal Society. It deals with an issue that is important not only, or even mainly, for the scientific community but also for the nation as a whole and for each individual within it. More than ever, people need some understanding of science, whether they are involved in decision-making at a national or local level, in managing industrial companies, in skilled or semi-skilled employment, in voting as private citizens or in making a wide range of personal decisions. In publishing this report the Council hopes that it will highlight this need for an overall awareness of the nature of science and, more particularly, of the way that science and technology pervade modern life, and that it will generate both debate and decisions on how best they can be fostered. The report makes a number of recommendations.