Replication, the independent confirmation of experimental results and conclusions, is regarded as the "gold standard" in science. This book examines the question of successful or failed replications and demonstrates that that question is not always easy to answer. It presents clear examples of successful replications, the discoveries of the Higgs boson and of gravity waves. Failed replications include early experiments on the Fifth Force, a proposed modification of Newton's Law of universal gravitation, and the measurements of "G," the constant in that law. Other case studies illustrate some of the difficulties and complexities in deciding whether a replication is successful or failed. It also discusses how that question has been answered. These studies include the "discovery" of the pentaquark in the early 2000s and the continuing search for neutrinoless double beta decay. It argues that although successful replication is the goal of scientific experimentation, it is not always easily achieved.

For many years, evidence suggested that all solid materials either possessed a periodic crystal structure as proposed by the Braggs or they were amorphous glasses with no long-range order. In the 1970s, Roger Penrose hypothesized structures (Penrose tilings) with long-range order which were not periodic. The existence of a solid phase, known as a quasicrystal, that possessed the structure of a three dimensional Penrose tiling, was demonstrated experimentally in 1984 by Dan Shechtman and colleagues. Shechtman received the 2011 Nobel Prize in Chemistry for his discovery. The discovery and description of quasicrystalline materials provided the first concrete evidence that traditional crystals could be viewed as a subset of a more general category of ordered materials. This book introduces the diversity of structures that are now known to exist in solids through a consideration of quasicrystals (Part I) and the various structures of elemental carbon (Part II) and through an analysis of their relationship to conventional crystal structures. Both quasicrystals and the various allotropes of carbon are excellent examples of how our understanding of the microstructure of solids has progressed over the years beyond the concepts of traditional crystallography.

Light and Video Microscopy, Third Edition provides a step-by-step journey through philosophy, psychology and the geometrical and physical optics involved in interpreting images formed by light microscopes. The book addresses the intricacies necessary to set up light microscopes that allow one to visualize transparent specimens and, in the process, quantitatively determine various physico-chemical properties of specimens. This updated edition includes the most recent developments in microscopy, ensuring that it continues to be the most comprehensive, easy-to-use, and informative guide on light microscopy. With its presentation of geometrical optics, it assists the reader in understanding image formation and light movement within the microscope.

This book is both an introduction and a demonstration of how Visual Basic for Applications (VBA) can greatly enhance Microsoft Excel (R) by giving users the ability to create their own functions within a worksheet and to create subroutines to perform repetitive actions. The book is written so readers are encouraged to experiment with VBA programming with examples using fairly simple physics or non-complicated mathematics such as root finding and numerical integration. Tested Excel (R) workbooks are available for each chapter and there is nothing to buy or install.