Five Photons

Have you ever wondered what is the most distant source of light we can see, or how a star shines? Did you know that black holes can blaze like cosmic beacons across intergalactic space, and that ancient radio waves might herald the ignition of the very first stars? Have you ever thought about what light really is? Five Photons explains what we know about the universe through five different journeys of light across space and time. They are tales of quantum physics and general relativity, stars and black holes, dark matter and dark energy. Let yourself be swept away on a journey of discovery towards a deeper understanding of the cosmos.

About ten years after the first edition comes this second edition of Monte Carlo Techniques in Radiation Therapy: Introduction, Source Modelling, and Patient Dose Calculations, thoroughly updated and extended with the latest topics, edited by Frank Verhaegen and Joao Seco. This book aims to provide a brief introduction to the history and basics of Monte Carlo simulation, but again has a strong focus on applications in radiotherapy. Since the first edition, Monte Carlo simulation has found many new applications, which are included in detail. The applications sections in this book cover the following: Modelling transport of photons, electrons, protons, and ions Modelling radiation sources for external beam radiotherapy Modelling radiation sources for brachytherapy Design of radiation sources Modelling dynamic beam delivery Patient dose calculations in external beam radiotherapy Patient dose calculations in brachytherapy Use of artificial intelligence in Monte Carlo simulations This book is intended for both students and professionals, both novice and experienced, in medical radiotherapy physics. It combines overviews of development, methods, and references to facilitate Monte Carlo studies.

With clear illustrations throughout and without recourse to quantum mechanics, the reader is invited to revisit unsolved problems lying at the foundations of theoretical physics. Maxwell and his contemporaries abandoned their search for a geometrical representation of the electric and magnetic fields. The wave-particle dilemma and Bose-Einstein statistical counting have resulted in unsatisfactory non-realistic interpretations. Furthermore, a simple structure of the hydrogen atom that includes hyperfine levels is still wanting.Working with the latest experimental data in photonics a proposed solution to the wave-particle dilemma is suggested based on an array of circular-polarized rays. The Bose-Einstein counting procedure is recast in terms of distinguishable elements. Finally, a vortex model of a 'particle' is developed based on a trapped photon. This consists of a single ray revolving around a toroidal surface, and allows a geometrical definition of mass, electric potential, and magnetic momentum. With the adjustment of two parameters, values to 4 dp for the hyperfine frequencies (MHz) of hydrogen can be obtained for which a computer program is available.

Results are presented of an investigation of stability, controllability, and stalling characteristics of five light airplanes. The effect of slots on the flying qualities of one of the airplanes is also shown. These five airplanes are considerd typical of the light airplanes now being manufactured.

James Elkins's How to Use Your Eyes invites us to look at--and maybe to see for the first time--the world around us, with breathtaking results. Here are the common artifacts of life, often misunderstood and largely ignored, brought into striking focus. With the discerning eye of a painter and the zeal of a detective, Elkins explores complicated things like mandalas, the periodic table, or a hieroglyph, remaking the world into a treasure box of observations--eccentric, ordinary, marvelous.

"At long last, a promising dialogue between science and medicine has begun. A focal point of this discussion is healing and how it happens. Jack W. Geis shows how modern physics and spirituality are centrally involved in this debate. No one who is interested in the current interface between science, spirituality and medicine can afford to neglect his ideas."—Larry Dossey, MD, Author: Healing Beyond the Body, and Healing Words: The Power of Prayer and the Practice of Medicine "This book introduces some of the most perplexing and exciting aspects of the revolution going on in physics today as it continues toward an increasingly metaphysical basis for defining reality. This exciting scientific revolution should be shared by everyone and the issues taken up in this book form a basis for that participation. That the math is not in the chalk is becoming increasingly evident, as well as the question as to which is more substantial."—Dr. Laurance R. Doyle, Astrophysics and Planetary Science, Center for the Study of Life in the Universe, SETI Institute

Die Nanotechnologie ist ein relativ junges, stark aufstrebendes Forschungsgebiet. Durch seine ausgeprägte Interdisziplinarität müssen sich Absolventen der einzelnen naturwissenschaftlichen Fachrichtungen (etwa Physik, Chemie, Materialwissenschaften) gezielt weiterbilden, um in die Nanotechnologie einsteigen zu können. Als eines der ersten einschlägigen Bücher bereitet dieses Werk das Gebiet praxisorientiert und anschaulich speziell für diesen Zweck auf.