Raised in Depression-era Rockaway Beach, physicist Richard Feynman was irreverent, eccentric, and childishly enthusiastic—a new kind of scientist in a field that was in its infancy. His quick mastery of quantum mechanics earned him a place at Los Alamos working on the Manhattan Project under J. Robert Oppenheimer, where the giddy young man held his own among the nation’s greatest minds. There, Feynman turned theory into practice, culminating in the Trinity test, on July 16, 1945, when the Atomic Age was born. He was only twenty-seven. And he was just getting started. In this sweeping biography, James Gleick captures the forceful personality of a great man, integrating Feynman’s work and life in a way that is accessible to laymen and fascinating for the scientists who follow in his footsteps.
Particle physics as we know it depends on the Higgs boson: It’s the missing link between the birth of our universe—as a sea of tiny, massless particles—and the tangible world we live in today. But for more than 50 years, scientists wondered: Does it exist?
Physicist Jon Butterworth was at the frontlines of the hunt for the Higgs at CERN’s Large Hadron Collider—perhaps the most ambitious experiment in history. In Most Wanted Particle, he gives us the first inside account of that uncertain time, when an entire field hinged on a single particle, and life at the cutting edge of science meant media scrutiny, late-night pub debates, dispiriting false starts in the face of intense pressure, and countless hours at the collider itself. As Butterworth explains, our first glimpse of the elusive Higgs brings us a giant step closer to understanding the universe—and points the way to an entirely new kind of physics.
In Life’s Ratchet, physicist Peter M. Hoffmann locates the answer to this age-old question at the nanoscale. The complex molecules of our cells can rightfully be called “molecular machines,” or “nanobots”; these machines, unlike any other, work autonomously to create order out of chaos. Tiny electrical motors turn electrical voltage into motion, tiny factories custom-build other molecular machines, and mechanical machines twist, untwist, separate and package strands of DNA. The cell is like a city—an unfathomable, complex collection of molecular worker bees working together to create something greater than themselves.
Life, Hoffman argues, emerges from the random motions of atoms filtered through the sophisticated structures of our evolved machinery. We are essentially giant assemblies of interacting nanoscale machines; machines more amazing than can be found in any science fiction novel. Incredibly, the molecular machines in our cells function without a mysterious “life force,” nor do they violate any natural laws. Scientists can now prove that life is not supernatural, and that it can be fully understood in the context of science.
Part history, part cutting-edge science, part philosophy, Life’s Ratchet takes us from ancient Greece to the laboratories of modern nanotechnology to tell the story of our quest for the machinery of life.
You will follow your oxygen atoms through fire and water and from forests to your fingernails. Hydrogen atoms will wriggle into your hair and betray where you live and what you have been drinking. The carbon in your breath will become tree trunks, and the sodium in your tears will link you to long-dead oceans. The nitrogen in your muscles will help to turn the sky blue, the phosphorus in your bones will help to turn the coastal waters of North Carolina green, the calcium in your teeth will crush your food between atoms that were mined by mushrooms, and the iron in your blood will kill microbes as it once killed a star.
You will also discover that much of what death must inevitably do to your body is already happening among many of your atoms at this very moment and that, nonetheless, you and everyone else you know will always exist somewhere in the fabric of the universe.
You are not only made of atoms; you are atoms, and this book, in essence, is an atomic field guide to yourself.
“A modern voyage of discovery.” —Frank Wilczek, Nobel Laureate, author of The Lightness of Being
The Higgs boson is one of our era’s most fascinating scientific frontiers and the key to understanding why mass exists. The most recent book on the subject, The God Particle, was a bestseller. Now, Caltech physicist Sean Carroll documents the doorway that is opening—after billions of dollars and the efforts of thousands of researchers at the Large Hadron Collider in Switzerland—into the mind-boggling world of dark matter. The Particle at the End of the Universe has it all: money and politics, jealousy and self-sacrifice, history and cutting-edge physics—all grippingly told by a rising star of science writing.
Gas-Liquid And Liquid-Liquid Separators is divided into six parts: Part one and two covers fundamentals such as: physical properties, phase behaviour and calculations. Part three through five is dedicated to topics such as: separator construction, factors affecting separation, vessel operation, and separator operation considerations. Part six is devoted to the ASME codes governing wall thickness determination of vessel weight fabrication, inspection, alteration and repair of separators500 illustrationsEasy to understand calculations methodsGuide for protecting downstream equipmentHelps reduce the loss of expensive intermediate endsHelps increase product purity
• It took more than an iceberg to sink the Titanic.
• The Challenger disaster was predicted.
• Unbreakable glass dinnerware had its origin in railroad lanterns.
• A football team cannot lose momentum.
• Mercury thermometers are prohibited on airplanes for a crucial reason.
• Kryptonite bicycle locks are easily broken.
“Things fall apart” is more than a poetic insight—it is a fundamental property of the physical world. Why Things Break explores the fascinating question of what holds things together (for a while), what breaks them apart, and why the answers have a direct bearing on our everyday lives.
When Mark Eberhart was growing up in the 1960s, he learned that splitting an atom leads to a terrible explosion—which prompted him to worry that when he cut into a stick of butter, he would inadvertently unleash a nuclear cataclysm. Years later, as a chemistry professor, he remembered this childhood fear when he began to ponder the fact that we know more about how to split an atom than we do about how a pane of glass breaks.
In Why Things Break, Eberhart leads us on a remarkable and entertaining exploration of all the cracks, clefts, fissures, and faults examined in the field of materials science and the many astonishing discoveries that have been made about everything from the explosion of the space shuttle Challenger to the crashing of your hard drive. Understanding why things break is crucial to modern life on every level, from personal safety to macroeconomics, but as Eberhart reveals here, it is also an area of cutting-edge science that is as provocative as it is illuminating.
From the Hardcover edition.
Designed for those new to FTIR, but with enough reference material to appeal to journeyman and expert spectroscopists, this book does not demand any extensive familiarity with chemistry or physics. Specializing in concise and comprehensible explanations of FTIR topics, the author introduces the field of infrared spectroscopy, including the strengths and weaknesses of FTIR as a chemical analysis technique. He then describes the instrument itself and explores topics such as how an interferometer generates a spectrum, optimization of spectral quality, and which tests are used to monitor instrument health.
The book discusses how to properly use spectral processing to increase the information of a spectrum without damaging the data and takes considerable care in instructing on sample preparation, as good sample preparation constitutes half the battle in extracting good data. The final chapters examine single analyte quantitative analysis and conclude with an overview of infrared microscopy.
Drawing on the experience and knowledge of the author as both a professor and practitioner, Fundamentals of Fourier Transform Infrared Spectroscopy offers up-to-date information given in clear, easily understood language to appeal to beginner and expert spectroscopists alike. The author maintains a website and blog with supplemental material. His training course schedule is also available online.
Since the first edition only five years ago, the simulation world has changed significantly -- current techniques have matured and new ones have appeared. This new edition deals with these new developments; in particular, there are sections on:
· Transition path sampling and diffusive barrier crossing to simulaterare events
· Dissipative particle dynamic as a course-grained simulation technique
· Novel schemes to compute the long-ranged forces
· Hamiltonian and non-Hamiltonian dynamics in the context constant-temperature and constant-pressure molecular dynamics simulations
· Multiple-time step algorithms as an alternative for constraints
· Defects in solids
· The pruned-enriched Rosenbluth sampling, recoil-growth, and concerted rotations for complex molecules
· Parallel tempering for glassy Hamiltonians
Examples are included that highlight current applications and the codes of case studies are available on the World Wide Web. Several new examples have been added since the first edition to illustrate recent applications. Questions are included in this new edition. No prior knowledge of computer simulation is assumed.
This book presents an overview of the technological advances that have occurred since the publication of the Editors earlier book High Voltage Vacuum Insulation: The Physical Basis. In this latest book, contributions from internationally recognized professionals and researchers in the field provide expanded treatment of the practical aspects of the subject. High Voltage Vacuum Insulation: Basic Concepts and Technological Practice provides a modern working manual for this specialized technology that is generic to a wide range of applications. The format makes the text suitable for use as a basis for special topic lecture courses at either the undergraduate or graduate level.Provides the fundamental physical concepts of the subjectFocuses on practical applicationsGives a historical survey of the fieldIncludes a detailed account of system design criteriaReviews theoretical models developed to explain the pinhole phenomenaPresents results of a series of experimental investigations on the subject
In order to be able to reflect the development of today's science and to cover all modern aspects of thin films, the series, starting with Volume 20, has moved beyond the basic physics of thin films. It now addresses the most important aspects of both inorganic and organic thin films, in both their theoretical as well as technological aspects. Therefore, in order to reflect the modern technology-oriented problems, the title has been slightly modified from Physics of Thin Films to Thin Films.
This volume, part of the Thin Films Series, has been wholly written by two authors instead of showcasing several edited manuscripts.
assumes only basic mathematical knowledge on the part of the reader and includes more than 100 discussion questions and some 70 problems, with solutions as well as further supplementary material available free to lecturers from the Wiley-VCH website.
Divided into five chapters, the book starts by giving an introduction to the discovery of active nitrogen, the energy content, and the methods by which this may be produced. The succeeding part deals with light emissions from active nitrogen system. This discussion includes molecular spectrum of nitrogen, emission from atomic energy and condensed active nitrogen, emission from molecular species with electronic energy levels below and above 9.76 eV, and light-emitting systems of active nitrogen.
The next part focuses on theories on active nitrogen. The theories discussed are long-lived Lewis-Rayleigh afterglow and short-lived, energetic afterglows. Numerical representations are provided to test the validity of the theories. Lastly, the discussions end with chemical reactions of active nitrogen. Topics contained in this part are text on recombination of N(4S) atoms; rate constants for reactions presumably induced by direct N(4S) attack; reactions caused by excited nitrogen molecular attack; and mechanism for reactions of active nitrogen that seem to influence direct N(4S) attack.
The book is a valuable source of information for readers interested in the research on active nitrogen.
As computer chips continue to shrink in size, scientists anticipate the end of the road: A computer in which each switch is comprised of a single atom. Such a device would operate under a different set of physical laws: The laws of quantum mechanics. Johnson gently leads the curious outsider through the surprisingly simple ideas needed to understand this dream, discussing the current state of the revolution, and ultimately assessing the awesome power these machines could have to change our world.
From the Trade Paperback edition.
Since the publication of the highly successful first edition of Basic Gas Chromatography, the practice of chromatography has undergone several notable developments. Basic Gas Chromatography, Second Edition covers the latest in the field, giving readers the most up-to-date guide available, while maintaining the first edition's practical, applied approach to the subject and its accessibility to a wide range of readers.
The text provides comprehensive coverage of basic topics in the field, such as stationary phases, packed columns and inlets, capillary columns and inlets, detectors, and qualitative and quantitative analysis. At the same time, the coverage also features key additions and updated topics including:Gas chromatography-mass spectrometry (GC-MS) Sampling methods Multidimensional gas chromatography Fast gas chromatography Gas chromatography analysis of nonvolatile compounds Inverse gas chromatography and pyrolysis gas chromatography
Along with these new and updated topics, the references, resources, and Web sites in Basic Gas Chromatography have been revised to reflect the state of the field. Concise and fundamental in its coverage, Basic Gas Chromatography, Second Edition remains the standard handbook for everyone from undergraduates studying analytical chemistry to working industrial chemists.
Mathematical methods are provided as design tools, and are often simplified via curve-fitting techniques that are particularly usable by handheld calculators. Useful equations and numerically solved examples, using situations encountered in practice, are supplied. Above all, this volume is a comprehensive and useful reference where the reader can find design rules and principles of high frequency applicators and probes for material processing and sensing applications. Electronic and electrical R&D engineers, physicists, university professors and students will all find this book a valuable reference.
Mehrdad Mehdizadeh is with the DuPont Company, Engineering Research & Technology Division in Wilmington, Delaware. His areas of expertise include high frequency hardware and electromagnetic methods of processing, sensing, and characterization of materials. His work and innovation in industrial, scientific, and medical applications of radio frequency and microwaves has resulted in 19 US patents and a number of publications. He earned his Ph.D. and M.S. from Marquette University (1983, 1980), and a B.S. from Sharif University of Technology (1977), all in electrical engineering. Dr. Mehdizadeh is a Senior Member of the Institute of Electrical and Electronic Engineers (IEEE ), Sigma Xi (Scientific Research Society), the International Microwave Power Institute (IMPI ), and a voting member of IEEE Standard Association.
• Books in this area are usually theoretical; this book provides practical information for those who actually intend to design a system
• Features real world and numerically solved examples, and curve-fitted simple equations to replace complex equations provided in typical texts
• Author is a voting member of IEEE Standards Association
Part one provides an introduction to quantum information processing using diamond, as well as its principles and fabrication techniques. Part two outlines experimental demonstrations of quantum information processing using diamond, and the emerging applications of diamond for quantum information science. It contains chapters on quantum key distribution, quantum microscopy, the hybridization of quantum systems, and building quantum optical devices. Part three outlines promising directions and future trends in diamond technologies for quantum information processing and sensing.
Quantum Information Processing with Diamond is a key reference for R&D managers in industrial sectors such as conventional electronics, communication engineering, computer science, biotechnology, quantum optics, quantum mechanics, quantum computing, quantum cryptology, and nanotechnology, as well as academics in physics, chemistry, biology, and engineering.Brings together the topics of diamond and quantum information processingLooks at applications such as quantum computing, neural circuits, and in vivo monitoring of processes at the molecular scale
* The first reference work on named reactions to present colored schemes for easier understanding
* 250 frequently used named reactions are presented in a convenient two-page layout with numerous examples
* An opening list of abbreviations includes both structures and chemical names
* Contains more than 10,000 references grouped by seminal papers, reviews, modifications, and theoretical works
* Appendices list reactions in order of discovery, group by contemporary usage, and provide additional study tools
* Extensive index quickly locates information using words found in text and drawings
* Includes a solid introduction to the simulation of equilibrium processes and the simulation of complex kinetic processes.
* Provides examples of routines that are easily adapted to the processes investigated by the reader
* 'Model-based' analysis (linear and non-linear regression) and 'model-free' analysis are covered
This book will be mandatory reading for anyone working on the foundations of modern devices such as free electron lasers, plasma accelerators, synchroton sources and other modern sources of bright, coherent radiation with high spectral density.
The text discusses the practical aspects of building a confocal scanning optical microscope or optical interference microscope, and the applications of these microscopes to phase imaging, biological imaging, and semiconductor inspection and metrology.A comprehensive theoretical discussion of the depth and transverse resolution is given with emphasis placed on the practical results of the theoretical calculations and how these can be used to help understand the operation of these microscopes.Provides a comprehensive introduction to the field of scanning optical microscopy for scientists and engineersExplains many practical applications of scanning optical and interference microscopy in such diverse fields as biology and semiconductor metrologyDiscusses in theoretical terms the origin of the improved depth and transverse resolution of scanning optical and interference microscopes with emphasis on the practical results of the theoretical calculationsConsiders the practical aspects of building a confocal scanning or interference microscope and explores some of the design tradeoffs made for microscopes used in various applicationsDiscusses the theory and design of near-field optical microscopesExplains phase imaging in the scanning optical and interference microscopes
The overall layout of the book is similar to that of the previous two editions however, there are considerable changes in emphasis and several key additions including:
•up-to-date presentation of modern theories of liquid-vapour coexistence and criticality
•areas of considerable present and future interest such as super-cooled liquids and the glass transition
•the area of liquid metals, which has grown into a mature subject area, now presented as part of the chapter ionic liquids
•Provides cutting-edge research in the principles of liquid-state theory
•Includes frequent comparisons of theoretical predictions with experimental and simulation data
•Suitable for researchers and post-graduates in the field of condensed matter science (Physics, Chemistry, Material Science), biophysics as well as those in the oil industry
The selection and organization of the material is in a form to prepare the reader to reason independently and to deal just as independently with available theoretical results and experimental data. The subjects dealt with include:
- electronic transport theory based on the test-particle and correlation-function concepts;
- scattering by phonons, impurities, surfaces, magnons, dislocations, electron-electron scattering and electron temperature;
- two-phonon scattering, spin-flip scattering, scattering in degenerate and many-band models.
This book is an easy-to-use compendium of problems encountered when using various commonly used analytical techniques. Emphasis is on impurities, by-products, contaminants and other artifacts. A separate entry is provided for each artifact. For specific chemicals, this entry provides the common name, mass spectrum, gas chromatographic data, CAS name and registry number, synonyms and a narrative discussion. More than 1100 entries are included. Mass spectral data are indexed in a 6-peak index (molecular ion, base peak, second peak, third peak) and there are also formula, author and subject indexes. An extensive bibliography contains complete literature citations.
The book is designed to be used. It will not only allow experienced analysts to profit from the mistakes of others, but it will also be invaluable to other scientists who use analytical instruments in their work.
Divided into five parts, the book begins with discussions on group and field theories. The second part summarizes the standard model of particle physics and includes some extensions to the model, such as neutrino masses and CP violation. The next section focuses on grand unified theories and supersymmetry. The book then discusses the general theory of relativity, higher dimensional theories of gravity, and superstring theory. It also introduces various novel ideas and models with extra dimensions and low-scale gravity. The last part of the book deals with astroparticle physics. After an introduction to cosmology, it covers several specialized topics, including baryogenesis, dark matter, dark energy, and brane cosmology.
With numerous equations and detailed references, this lucid book explores the new physics beyond the standard model, showing that particle and astroparticle physics will together reveal unique insights in the next era of physics.
Searching for the best laboratory instruments and systems can be a daunting and expensive task. A poorly selected instrument can dramatically affect results produced and indirectly affect research papers, the quality of student training, and an investigator's chances for advancement. Buying and Selling Laboratory Instruments offers the valuable insights of an analytical chemist and consultant with over four decades of experience in locating instruments based upon both need and price. It helps all decision makers find the best equipment, service, and support while avoiding the brand-loyalty bias of sales representatives so you can fully meet your laboratory's requirements.
The first section of the book guides buyers through the hurdles of funding, purchasing, and acquiring best-fit instruments at the least-expensive price. It explains how to find vendors that support their customers with both knowledgeable service and application support. Also offered is guidance on adapting your existing instruments to new applications, integrating new equipment, and what to do with instruments that can no longer serve in research mode.
The second section explains the sales process in detail. This is provided both as a warning against manipulative sales reps and as a guide to making the sale a win-win process for you and your vendor. It also shows you how to select a knowledgeable technical guru to help determine the exact system configuration you need and where to find the best price for it. Added bonuses are summary figures of buying sequence and sales tools and an appendix containing frequently asked questions and memory aids.
Buying and Selling Laboratory Instruments is for people directly involved in selecting and buying instruments for operational laboratories, from the principle investigator to the person actually delegated with investigating and selecting the system to be acquired. Sales representatives; laboratory managers; universities; pharmaceutical, biotech, and forensic research firms; corporate laboratories; graduate and postdoctoral students; and principle investigators will not want to be without this indispensible guide.
Designed to be completed in one semester, this text enables students to fully grasp and apply the core concepts of analytical chemistry and aqueous chemical equilibria. Moreover, the text enables readers to master common instrumental methods to perform a broad range of quantitative analyses. Author Brian Tissue has written and structured the text so that readers progressively build their knowledge, beginning with the most fundamental concepts and then continually applying these concepts as they advance to more sophisticated theories and applications.
Basics of Analytical Chemistry and Chemical Equilibria is clearly written and easy to follow, with plenty of examples to help readers better understand both concepts and applications. In addition, there are several pedagogical features that enhance the learning experience, including:Emphasis on correct IUPAC terminology "You-Try-It" spreadsheets throughout the text, challenging readers to apply their newfound knowledge and skills Online tutorials to build readers' skills and assist them in working with the text's spreadsheets Links to analytical methods and instrument suppliers Figures illustrating principles of analytical chemistry and chemical equilibria End-of-chapter exercises
Basics of Analytical Chemistry and Chemical Equilibria is written for undergraduate students who have completed a basic course in general chemistry. In addition to chemistry students, this text provides an essential foundation in analytical chemistry needed by students and practitioners in biochemistry, environmental science, chemical engineering, materials science, nutrition, agriculture, and the life sciences.
This book guides the reader through the mathematics, physics and practical techniques needed to use telescopes (from small amateur models to the larger instruments installed in many colleges) and to observe objects in the sky. Mathematics to around Advanced Placement standard (US) or A level (UK) is assumed, although High School Diploma (US) or GCSE-level (UK) mathematics plus some basic trigonometry will suffice most of the time. Most of the physics and engineering involved is described fully and requires no prior knowledge or experience.
This is a ‘how to’ book that provides the knowledge and background required to understand how and why telescopes work. Equipped with the techniques discussed in this book, the observer will be able to operate with confidence his or her telescope and to optimize its performance for a particular purpose. In principle the observer could calculate his or her own predictions of planetary positions (ephemerides), but more realistically the observer will be able to understand the published data lists properly instead of just treating them as ‘recipes.’ When the observer has obtained measurements, he/she will be able to analyze them in a scientific manner and to understand the significance and meaning of the results.
“Telescopes and Techniques, 3rd Edition” fills a niche at the start of an undergraduate astronomer’s university studies, as shown by it having been widely adopted as a set textbook. This third edition is now needed to update its material with the many new observing developments and study areas that have come into prominence since it was published. The book concentrates on the knowledge needed to understand how small(ish) optical telescopes function, their main designs and how to set them up, plus introducing the reader to the many ways in which objects in the sky change their positions and how they may be observed. Both visual and electronic imaging techniques are covered, together with an introduction to how data (measurements) should be processed and analyzed. A simple introduction to radio telescopes is also included. Brief coverage of the most advanced topics of photometry and spectroscopy are included, but mainly to enable the reader to see some of the developments possible from the basic observing techniques covered in the main parts of the book.
The text presents meaningful problems by topic — supplemented by ample illustrations, applications, and exercises — that address the most intriguing questions of modern physics. Answers to selected problems appear in the appendix. Geared toward science and engineering majors, this volume is also appropriate for independent study by those who have completed a general physics course.
* Helps readers to understand where models come from, so they don't use them blindly and
* Provides many visual and geometric models for understanding a largely mathematical method
* Allows readers to judge whether recently published models are of sufficiently high quality and detail to be useful in their own work
* Allows readers to study macromolecular structure independently and in an open-ended fashion on their own computers, without being limited to textbook or journals illustrations
* Provides access to web tools in a format that will not go out of date. Links will be updated and added as existing resources change location or are added
CMOS Processors and Memories is divided into two parts: processors and memories. In the first part we start with high performance, low power processor design, followed by a chapter on multi-core processing. They both represent state-of-the-art concepts in current computing industry. The third chapter deals with asynchronous design that still carries lots of promise for future computing needs. At the end we present a “hardware design space exploration” methodology for implementing and analyzing the hardware for the Bayesian inference framework. This particular methodology involves: analyzing the computational cost and exploring candidate hardware components, proposing various custom architectures using both traditional CMOS and hybrid nanotechnology CMOL. The first part concludes with hybrid CMOS-Nano architectures.
The second, memory part covers state-of-the-art SRAM, DRAM, and flash memories as well as emerging device concepts. Semiconductor memory is a good example of the full custom design that applies various analog and logic circuits to utilize the memory cell’s device physics. Critical physical effects that include tunneling, hot electron injection, charge trapping (Flash memory) are discussed in detail. Emerging memories like FRAM, PRAM and ReRAM that depend on magnetization, electron spin alignment, ferroelectric effect, built-in potential well, quantum effects, and thermal melting are also described.
CMOS Processors and Memories is a must for anyone serious about circuit design for future computing technologies. The book is written by top notch international experts in industry and academia. It can be used in graduate course curriculum.
The truth is that Janssen never saw any sign of a new element during his observations in India. His reports and letters do not mention any such claim.
Other sources would have you believe that helium was jointly discovered by Janssen and Norman Lockyer, a British scientist, and that their discovery letters reached Paris the same day, one sent from India, and the other from England.
Again, the truth is completely different. Two letters from Lockyer and Janssen did reach Paris the same day in 1868, but their letters did not mention any new element. What they had discovered was a new way of observing the Sun without a solar eclipse. This would ultimately lead to the discovery of helium, in which Lockyer would play a prominent role, but not Janssen.
At the same time, Norman Robert Pogson, a disgruntled British astronomer stationed in India did notice something peculiar during the eclipse. He was the first one to notice something odd about the spectrum of the Sun that day, and his observations would prove crucial to Lockyer’s own investigations of helium. But Pogson’s report was never published in any peer reviewed journal and it languished on the desk of a local British officer in colonial India.
This book tells the real story behind the discovery of helium, along with biographical sketches of the scientists and descriptions of the milieu in which they worked. It will convey the excitement, confusion, and passion of nineteenth century scientists, using their own words, from their letters and reports.
“The Story of Helium and the Birth of Astrophysics” chronicles one of the most exciting discoveries ever made and explains why it also marked the birth of a new branch of science called ‘astrophysics.’