3,357 research outputs found
Farewell to reality: how modern physics has betrayed the search for scientific truth
No full textFrom acclaimed science author Jim Baggott, a pointed critique of modern theoretical physics. In this stunning new volume, Jim Baggott argues that there is no observational or experimental evidence for many of the ideas of modern theoretical physics: super-symmetric particles,super strings, the multiverse, the holographic principle,or the anthropic cosmological principle. These theories are not only untrue, it is not even science. It is fairy-tale physics: fantastical, bizarre and often outrageous, perhaps even confidence-trickery. This book provides a much-needed antidote. Informed,comprehensive, and balanced, it offers lay readers the latest ideas about the nature of physical reality while clearly distinguishing between fact and fantasy. With its engaging portraits of many central figures of modern physics, including Paul Davies, John Barrow, Brian Greene, Stephen Hawking, and Leonard Susskind, it promises to be essential reading for all readers interested in what we know and don’t know about the nature of the universe and reality itself
Quantum space: loop quantum gravity and the search for the structure of space, time, and the universe
No full textToday we are blessed with two extraordinarily successful theories of physics. The first is Albert Einstein's general theory of relativity, which describes the large-scale behaviour of matter in a curved spacetime. This theory is the basis for the standard model of big bang cosmology. The discovery of gravitational waves at the LIGO observatory in the US (and then Virgo, in Italy) is only the most recent of this theory's many triumphs. The second is quantum mechanics. This theory describes the properties and behaviour of matter and radiation at their smallest scales. It is the basis for the standard model of particle physics, which builds up all the visible constituents of the universe out of collections of quarks, electrons and force-carrying particles such as photons. The discovery of the Higgs boson at CERN in Geneva is only the most recent of this theory's many triumphs. But, while they are both highly successful, these two structures leave a lot of important questions unanswered. They are also based on two different interpretations of space and time, and are therefore fundamentally incompatible. We have two descriptions but, as far as we know, we've only ever had one universe. What we need is a quantum theory of gravity. Approaches to formulating such a theory have primarily followed two paths. One leads to String Theory, which has for long been fashionable, and about which much has been written. But String Theory has become mired in problems. In this book, Jim Baggott describes "the road less travelled": an approach which takes relativity as its starting point, and leads to a structure called Loop Quantum Gravity. Baggott tells the story through the careers and pioneering work of two of the theory's most prominent contributors, Lee Smolin and Carlo Rovelli. Combining clear discussions of both quantum theory and general relativity, this book offers one of the first efforts to explain the new quantum theory of space and time.The greatest challenge for physics is to combine its two most successful theories: general relativity and quantum mechanics. The resulting quantum theory of gravity would explain the universe across all scales. Much has been said about the approach based on string theory. Here, Jim Baggott describes its powerful rival: Loop Quantum Gravity
Il bosone di Higgs: l'invenzione e la scoperta della "particella di Dio"
No full textTra i tanti oggetti pervasivi ed elusivi che affollano la dimensione invisibile del mondo subatomico, il "bosone di Higgs" è stato il più pervasivo ed elusivo: quella particella era l'elemento cruciale che mancava a completare il puzzle del Modello Standard, perché conferiva massa a tutte le altre particelle elementari, un enigma rimasto altrimenti insoluto. Quando finalmente il 4 luglio 2012 il CERN ne ha annunciato la verifica sperimentale, la "particella di Dio" (come un fisico l'ha temerariamente denominata) ha attirato su di sé i riflettori dell'attenzione mediatica mondiale. Affrontando l'intera questione con un rigore che ne acuisce la densità intellettuale e la vertigine tecnologica, Jim Baggott segue due percorsi paralleli. Non solo, infatti, ne ricostruisce la genesi teorica, ma ripercorre tutte le stazioni di avvicinamento all'eclatante risultato di Ginevra: il legame tra i primi acceleratori degli anni Venti e le collisioni di particelle nei raggi cosmici; la messa a punto del ciclotrone da parte di Lawrence; il contributo di Van der Meer, il cui metodo di "raffreddamento stocastico" ha permesso al gruppo di Rubbia l'individuazione dei bosoni W e Z, decisivi per arrivare alla scoperta del bosone di Higgs; e le svolte successive del LEP (Large Electron-Positron Collider) e dell'ormai leggendario LHC (Large Hadron Collider), che con i suoi 1600 magneti superconduttori ha permesso di sviluppare energie senza precedenti
Bill Harney on a spear fishing expedition with Eric Jolliffe and Robert Fitzpatrick, off Long Reef, New South Wales, ca. 1940s [picture] /
No full textTitle based on information from acquisition documentation and from caption on verso.; Part of collection: Collection of photographs of author and bushman, Bill Harney, ca. 1940-1962.; Photograph taken by Jim Fitzpatrick, a photographer with the Department of Information in the 1940s in Sydney. Robert Fitzpatrick is the son of the photographer.; Also available in an electronic version via the Internet at: http://nla.gov.au/nla.pic-vn3706122; Purchased from Michael Treloar Antiquarian Booksellers, List 90, Lot 64, 2006
Mass: the quest to understand matter from Greek atoms to quantum fields
No full textEverything around us is made of 'stuff', from planets, to books, to our own bodies. Whatever it is, we call it matter or material substance. It is solid; it has mass. But what is matter, exactly? We are taught in school that matter is not continuous, but discrete. As a few of the philosophers of ancient Greece once speculated, nearly two and a half thousand years ago, matter comes in 'lumps', and science has relentlessly peeled away successive layers of matter to reveal its ultimate constituents. Surely, we can't keep doing this indefinitely. We imagine that we should eventually run up against some kind of ultimately fundamental, indivisible type of stuff, the building blocks from which everything in the Universe is made. The English physicist Paul Dirac called this 'the dream of philosophers'. But science has discovered that the foundations of our Universe are not as solid or as certain and dependable as we might have once imagined. They are instead built from ghosts and phantoms, of a peculiar quantum kind. And, at some point on this exciting journey of scientific discovery, we lost our grip on the reassuringly familiar concept of mass. How did this happen? How did the answers to our questions become so complicated and so difficult to comprehend? In Mass Jim Baggott explains how we come to find ourselves here, confronted by a very different understanding of the nature of matter, the origin of mass, and its implications for our understanding of the material world. Ranging from the Greek philosophers Leucippus and Democritus, and their theories of atoms and void, to the development of quantum field theory and the discovery of a Higgs boson-like particle, he explores our changing understanding of the nature of matter, and the fundamental related concept of mass.Jim Baggott explores how our understanding of the nature of matter, and its fundamental property of mass, has developed, from the ancient Greek view of indivisible atoms to quantum mechanics, dark matter, the Higgs field, and beyond. He shows how the stuff of the universe is proving more elusive and uncertain than we ever imagined
Origins: the scientific story of creation
No full textWhat is the nature of the material world? How does it work? What is the universe and how was it formed? What is life? Where do we come from and how did we evolve? How and why do we think? What does it mean to be human? How do we know? There are many different versions of our creation story. This book tells the version according to modern science. It is a unique account, starting at the Big Bang and travelling right up to the emergence of humans as conscious intelligent beings, 13.8 billion years later. Chapter by chapter, it sets out the current state of scientific knowledge: the origins of space and time; energy, mass, and light; galaxies, stars, and our sun; the habitable earth, and complex life itself. Drawing together the physical and biological sciences, Baggott recounts what we currently know of our history, highlighting the questions science has yet to answer.What is the nature of the material world? How does it work? What is the universe and how was it formed? What is life? Where do we come from and how did we evolve? How and why do we think? What does it mean to be human? How do we know?There are many different versions of our creation story. This book tells the version according to modern science. It is a unique account, starting at the Big Bang and travelling right up to the emergence of humans as conscious intelligent beings, 13.8 billion years later. Chapter by chapter, it sets out the current state of scientific knowledge: the origins of spaJim Baggott sets out the scientific story of creation - 13.8 billion years from the Big Bang to human consciousness, via the origins of space and time, mass and light, stars, the habitable earth, and life itself. From astrophysics to biology, the whole inspiring picture is here.Jim Baggott sets out the scientific story of creation - 13.8 billion years from the Big Bang to human consciousness, via the origins of space and time, mass and light, stars, the habitable earth, and life itself. From astrophysics to biology, the whole inspiring picture is here
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[Portrait of Jim Marrs]
No full textPortrait of Jim Marrs smiling at the camera while sitting on a wooden bench. He wears a plaid button-up shirt, black hat, and sunglasses. Marrs was an American journalist and author of publications such as his book, "Crossfire." Marrs is known for his conspiracy theories, specifically in relation to the assassination of John F. Kennedy
Episode 5: Jim Bowyer
No full textRuntime 57:43In Episode 5, Eli interviews Jim Bowyer, professor emeritus at the University of Minnesota, senior contributor at Dovetail Partners, and author of The Irresponsible Pursuit of Paradise. Jim is well known for life cycle assessment research, designed to assess the environmental impact of a product or action by analyzing all of the component parts and processes. Jim offers insights about wood as a natural resource, the results of an environmental quiz that he has run for decades, and a critique of one of the most prominent environmental analyses ever conducted
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