German Physicist Research Articles

120 YEARS SINCE THE DISCOVERY OF X-RAYS.

This paper is intended to celebrate the 120th anniversary of the discovery of X-rays. X-rays (Roentgen-rays) were discovered on the 8th ofNovember, 1895 by the German physicist Wilhelm Conrad Roentgen. Fifty days after the discovery of X-ray, on December 28, 1895. Wilhelm Conrad Roentgen published a paper about the discovery of X-rays - "On a new kind of rays" (Wilhelm Conrad Roentgen: Ober eine neue Art von Strahlen. In: Sitzungsberichte der Wurzburger Physik.-Medic.- Gesellschaft. 1895.). Therefore, the date of 28th ofDecember, 1895 was taken as the date of X-rays discovery. This paper describes the work of Wilhelm Conrad Roentgen, Nikola Tesla, Mihajlo Pupin and Maria Sklodowska-Curie about the nature of X-rays . The fantastic four - Wilhelm Conrad Roentgen, NikolaTesla, Mihajlo ldvorski Pupin and Maria Sklodowska-Curie set the foundation of radiology with their discovery and study of X-rays. Five years after the discovery of X-rays, in 1900, Dr Avram Vinaver had the first X-ray machine installed in abac, in Serbia at the time when many developed countries did not have an X-ray machine and thus set the foundation of radiology in Serbia.

Li-Fi (Light Fidelity)-The Future Technology In Wireless Communication

Li-Fi remains for Light-Fidelity. Li-Fi innovation, proposed by the German physicist—Harald Haas, gives transmission of information through enlightenment by sending information through a LED light that fluctuates in force speedier than the human eye can take after. This paper concentrates on building up a Li-Fi based framework and dissects its execution regarding existing innovation. At the season of utilizing remote web at wherever whether it is own or taking from others, one has presumably gotten disappointed due to the moderate velocity of web when more gadgets are associated with a solitary switch. Because of expanding of web clients exponentially, Radio Spectrum is congested however the interest for remote information twofold every year. LI-FI is presently part of the VLC as is actualized utilizing white LED lights. Information transmission happens from this LED globule by shifting the current at to a great degree high speeds which imperceptible by the human eye. Keywords:-LI-IF , WI-FI , Visible light Communication , Radio Spectrum, High-brightness LED, photodiode, wireless Communication.

Imaging the Ancients

Mummified remains and artefacts, since their discovery, have attracted the interest of scientific investigators. Consequently virtually every paleoimaging modality has been applied to bioarchaeology soon after its technological development. Indeed, the first use of X-rays in mummy investigation was only one year after William Rontgen discovered X-rays in 1895 when, in March 1896, Carl Koenig, a German physicist, published the first X-rays involving mummies, that of an Egyptian mummified cat and the knees of an Egyptian child mummy. The first systematic analysis of a major mummy collection was undertaken at the Field Museum in Chicago in 1931. CT scans of mummies were first carried out in 1977. Not surprisingly, over the years, several problems have been identified in interpreting the images on CT. The presence of many layers of mummy wrapping, organ removal, diagenetic changes, particularly desiccation, may all result in confusion. Special problems in X-ray and CT scanning arise when the diagenetic changes are so massive that the remaining tissues, including bone, are severely degraded - a feature best shown by bog bodies, all of which date to the Northern European Iron Age (approximately 500 BC to 500 AD). Recent technological advances have made MDCT an especially useful means for presentation of findings of anthropological inquiry as exemplified in a brilliant recent exhibition at the British Museum. However, this short lecture will show an almost unique personal experience of imaging of mummies performed over almost a decade in the mid-80s and early 90s. Investigations were undertaken of a bog body discovered in Lindow near Manchester, Muisca bodies discovered in the Andes, and Egyptian mummies from Fayum. All three projects revealed fascinating insights into the lifestyle of these ancients and answered several lines of anthropological inquiry. This presentation will illustrate examples from each of these projects.

DATA COMMUNICATION USING VISIBLE LIGHT

Visible Light Communication (VLC) using a Light Fidelity system, as proposed by a German physicist—Harald Haas, provides transmission of data through illumination by sending data through an LED light source that varies in intensity that can be controlled and adjusted such that it appears as normal light to the naked human eye. Here the property of persistence of vision of the human eye is exploited for additional application of a free, sustainable and green source that can be used for wireless communication at very fast data rates. This paper focuses on developing a low cost Li-Fi based system and analyses its performance with respect to existing wireless technology. Wi-Fi is great for general wireless coverage within buildings, whereas Li-Fi is ideal for high density wireless data coverage in confined area and for relieving radio interference issues. Li-Fi based system provides better bandwidth, efficiency, availability and security than Wi-Fi and has already achieved higher data rates. By leveraging the low-cost nature of LEDs and lighting units there are many opportunities to exploit this medium, from public internet access through day-to-day light sources which have their primary purpose of only emitting light. This project envisions a future where data for communication devices will be transmitted through the visible spectrum thus de-clogging the currently overused RF spectrum.

How Einstein Reinvented Reality

The article overviews the history of the German physicist Albert Einstein's discovery of the equivalence principle of general relativity. Topics addressed include accounts of the thought experiment first used by Einstein to explore the concepts of gravity and acceleration, the events surrounding Einstein's personal life during the 1910s when this theory developed, and the implications of his theory on the scientific conception of reality.

Description and clinical application of the Pulfrich effect.

In 1922, German physicist Carl Pulfrich described an illusory binocular perceptual disturbance in which an object moving across an observer's field of vision is perceived as traveling along a curved trajectory. To review the discovery of the Pulfrich effect, and subsequent clinical applications. We translated Pulfrich's description and searched for subsequent publications using electronic databases and review of reference lists in identified publications. In 1901, Pulfrich developed an optical device to accurately compare stereoscopic photographs, but brightness difference between plates caused distance misperceptions that interfered with precise measurements. Pulfrich proposed that this Stereo-Effekt resulted from interocular differences in perceptual latency. He induced the effect by placing a smoked glass in front of one eye. The resulting perceptual disparity creates an apparently curved trajectory of an object moving sideways across the field of vision. Pulfrich also recognized that visual pathway disorders can produce a pathologic Stereo-Effekt. In 1925, Grimsdale demonstrated this in a man with unilateral retrobulbar optic neuritis and suggested treatment with a neutral density filter (NDF) over the good eye. Not until the 1970s, however, was the Pulfrich effect evaluated as a diagnostic test for retrobulbar optic neuritis and the therapeutic efficacy of an NDF confirmed. Although the clinical importance of the Pulfrich effect was suggested by Pulfrich and quickly confirmed, it took decades before its diagnostic utility and the efficacy of an NDF were assessed. Recognition remains clinically important to minimize safety risks and mislabeling, and because resulting misperceptions can be easily treated.

LI-FI (LIGHT FIDELITY) – THE CHANGING SCENARIO OF WIRELESS COMMUNICATION

As per the growing demands of wireless communication there is enormous new technologies participating to make sophisticated environment for an end user. In a recent survey of International Telecommunication Union (ITU) it was found that the number of mobile phone subscribers has exceeds seven billion subscriptions at the end of 2014 using more than 10 to 15 internet utility apps which is more than the entire population of planet. To serve this increasing number and size of wireless communication system the German physicist – Harald Haas proposed a “Li–Fi technology” which he calls “Data through illumination” or “D-Light”. LiFi is a new approach of VLC which has much more similar working of a OFC communication system providing data rates of ten’s of Gbps. In this technology data is interpreted by the LED’s ON/OFF concepts. This paper gives a brief focus on Li-Fi technology, it’s working principal, some misconceptions about Li-Fi and related researches like Nobel Prize winning Blue Light emitting diode, Optoelectronic integrated circuit (OEIC) receiver, etc.

Heisenberg e a doutrina das cores de Goethe e Newton

Este artigo destina-se a introduzir a conferencia de Heisenberg A doutrina goethiana e newtoniana das cores a luz da moderna, proferida em 1941, cuja traducao e aqui publicada. Analisa-se primeiramente o projeto filosofico de uma ordenacao da realidade, desenvolvido pelo fisico no inicio da decada de 1940, o qual subjaz a discussao sobre as doutrinas das cores em Goethe e Newton. No segundo momento, faz-se uma exposicao de algumas das implicacoes filosoficas da teoria quântica, com enfase na interpretacao da assim denominada escola de Copenhague. Por fim, procura-se mostrar como a querela entre Goethe e Newton e utilizada para defender as abstracoes da teorica dos ataques da assim denominada fisica ariana e, ao mesmo tempo, preservar o valor das consideracoes intuitivas de Goethe.

Erich Regener and the ionisation maximum of the atmosphere

Abstract. In the 1930s the German physicist Erich Regener (1881–1955) did important work on the measurement of the rate of production of ionisation deep under water and in the atmosphere. Along with one of his students, Georg Pfotzer, he discovered the altitude at which the production of ionisation in the atmosphere reaches a maximum, often, but misleadingly, called the Pfotzer maximum. Regener was one of the first to estimate the energy density of cosmic rays, an estimate that was used by Baade and Zwicky to bolster their postulate that supernovae might be their source. Yet Regener's name is less recognised by present-day cosmic ray physicists than it should be, largely because in 1937 he was forced to take early retirement by the National Socialists as his wife had Jewish ancestors. In this paper we briefly review his work on cosmic rays and recommend an alternative naming of the ionisation maximum. The influence that Regener had on the field through his son, his son-in-law, his grandsons and his students, and through his links with Rutherford's group in Cambridge, is discussed in an appendix. Regener was nominated for the Nobel Prize in Physics by Schrödinger in 1938. He died in 1955 at the age of 73.

An Efficient Feature Extraction Method Based on Entropy for Power Quality Disturbance

This study explores the applicability of entropy defined as thermodynamic state variable introduced by German Physicists Rudolf clausius and also presents the concepts and application of said state variable as a measure of system disorganization. Later an entropy-based feature Analysis method for power quality disturbance analysis has been proposed. Feature extraction of a disturbed power signal provides information that helps to detect the responsible fault for power quality disturbance. A precise and faster feature extraction tool helps power engineers to monitor and maintain power disturbances more efficiently. Firstly, the decomposition coefficients are obtained by applying 10-level wavelet multi resolution analysis to the signals (normal, sag, swell, outage, harmonic and sag with harmonic and swell with harmonic) generated by using the parametric equations. Secondly, a combined feature vector is obtained from standard deviation of these features after distinctive features for each signal are extracted by applying the energy, the Shannon entropy and the log-energy entropy methods to decomposition coefficients. Finally the entropy methods detect the different types of power quality disturbance.

Plutonium Worlds. Fast Breeders, Systems Analysis and Computer Simulation in the Age of Hypotheticality

This article examines the media history of one of the hallmark civil nuclear energy programs in Western Germany – the development of Liquid Metal Fast Reactor (LMFBR) technology. Promoted as a kind of perpetuum mobile of the Atomic Age, the Manhattan Project not only imported big science thinking. In its context, nuclear technology was also put forth as an avantgarde of scientific inquiry, dealing with the most complex and 'critical' technological endeavors. In the face of the risks of nuclear technology, German physicist Wolf Hafele thus announced a novel epistemology of hypotheticality. In a context where traditional experimental engineering strategies became inappropiate, he called for the application of advanced media technologies: Computer Simulations (CS) and Systems Analysis (SA) generated computerized spaces for the production of knowledge. In the course of the German Fast program, such methods had a twofold impact. One the one hand, Hafele emphazised – as the father of the German Fast Breeder – the utilization of CS for the actual planning and construction of the novel reactor type. On the other, namely as the director of the department of Energy Systems at the International Institute for Applied Systems Analysis (IIASA), Hafele advised SA-based projections of energy consumption. These computerized scenarios provided the rationale for the conception of Fast programs as viable and necessary 'alternative energy sources' in the first place. By focusing on the role of the involved CS techniques, the paper thus investigates the intertwined systems thinking of nuclear facilities’s planning and construction and the design of large-scale energy consumption and production scenarios in the 1970s and 1980s, as well as their conceptual afterlives in our contemporary era of computer simulation.

Effortful text production in translation

This article analyzes data generated by the combined use of keylogging and eye tracking to examine grammatical (de)metaphorization as a case of explicitation/implicitation (Steiner 2001). It also aims at investigating effortful text production from the perspective of automaticity and monitoring in the translation process (Tirkkonen-Condit 2005). Brazilian and German physicists and professional translators were recruited to translate one of two versions of an English (L2) source text into Brazilian Portuguese or German, respectively (L1). The versions differed in the level of grammatical metaphoricity of the sentences. Quantitative and qualitative data was analyzed to determine the impact of metaphoricity level on target text renditions as evidence of effort in the translation process. Results showed that regardless of which of the two versions was translated, most subjects opted for a particular wording from the start of their text production process; subsequent changes had to do with attempting more delicate choices in lexis rather than in grammar, evidence in favor of Tirkkonen-Condit’s claims about automatism in the translation process. Variables used to measure effort (i.e., number of renditions in microunits, pause duration, and drafting time) indicated that (de)metaphorization is an effortful procedure. Eye tracking, eliciting more fine-grained data, was instrumental in mapping instances of grammatical (de)metaphorization. The results have implications for issues related to the development of professional competence in translation, suggesting that instances of grammatical (de)metaphorization relate to higher levels of monitoring.

Going from Strength to Strength

[Crystallography at 100 Special Issue][1] In 1912, the German physicist Max von Laue published the first paper demonstrating x-ray diffraction from a crystal. This discovery, for which he was awarded the Nobel Prize in 1914, provided a window into the regular atomic arrangements within crystals.

The International Year of Crystallography (2014): A Philatelic Celebration

The International Year of Crystallography (IYCr) is a year-round celebration of the science of crystallography, its enthralling history, and its multifarious contributions to society. Sponsored by UNESCO and the International Union of Crystallography (IUCr), a sister organization of IUPAC, the year 2014 marks, among other milestones, the centennial of the Nobel Prize in Physics awarded to the German physicist Max von Laue (1879-1960) for his seminal discovery of the diffraction of X‑rays by crystals. According to the IUCr, close to 50 scientists have now been awarded Nobel Prizes for scientific achievements directly related to, or relying heavily on the use of, crystallographic methods! Hence, it is not surprising that X‑ray crystallography has experienced an explosive growth since its inception and is now considered to be the most powerful technique for the determination of the structure of matter. As such, it is a key driving force in the development of modern chemistry, physics, molecular biology, nanotechnology, medicine, materials science, and many other fields of science and technology.

Notes on Contributors

Notes on Contributors

Physics: Overhearing Heisenberg

Ann Finkbeiner ponders a script inspired by the 1945 internment of eminent German physicists in England.

What does a GP need to know about radiotherapy?

In 1895 the German physicist, Wilhelm Rontgen discovered electromagnetic radiation in a previously unknown wavelength. He later named this wavelength ‘X-ray’ (X referring to an unknown quantity). Since this discovery and through the hard work of many others, most prominently Pierre and Marie Curie and Alexander Graham Bell, radiotherapy has developed into an integral part of the treatment of cancer. Approximately 320 500 people were diagnosed with cancer in the UK in 2009, which equates to around 519 cases for every 100 000 people. Roughly one-half of all patients diagnosed with cancer will receive radiotherapy treatment at some point during their journey. The aim of this article is to provide a brief overview of the background of radiotherapy, some of the more frequently occurring side effects that GPs need to be aware of and the role of the GP in patients receiving radiotherapy treatment.

The Case of the Missing German Quantum Chemists

This paper discusses factors limiting the development of a modern, quantum-based chemistry in Nazi Germany. The first part presents a case study of industrial research in Nazi Germany that suggests the delayed introduction of space-filling molecular models into structural analysis and synthesis in industrial organic chemistry, almost a decade after their invention by a German physicist. Was this symptomatic of a broader pattern of neglect of quantum chemistry in Nazi Germany? To answer this question this paper examines the origins of such models, and their appearance (or not) in selected textbooks and monographs dealing with problems in the interdisciplinary borderland between the physical and organic dimensions of chemistry. While it appears that those on the physical side were more comfortable with such models than those on the organic side, it is also clear that even a theoretically unsophisticated organic chemist could learn to use these models effectively, without necessarily understanding the intricacies of the quantum chemistry on which they were based. Why then were they not better integrated into mainstream chemical education? To this end the second part discusses three phases (pre-1933, 1933–38, 1939–43) of the broader scientific, institutional, and political contexts of efforts to reform or “modernize” chemical education among many groups in Germany, particularly through the Association of Laboratory Directors in German Universities and Colleges, the autonomous group that administered the predoctoral qualifying examination (Association Examination) for chemistry students until its dissolution in 1939 by the Education Ministry and the establishment of the first official certifying examination and associated title for chemists, the Diplom-Chemiker (certified chemist). Continuing debates modified the examination in 1942–43, but given the limitations imposed by the political and wartime contexts, and the need to accelerate chemical training for the purposes of industrial and military mobilization, the resulting chemical education could not produce students adequately trained in the modern physical science emerging elsewhere in the world. Quantum chemists remained missing in action in Nazi Germany.

Who discovered the magnetocaloric effect?

A magnetic body changes its thermal state when subjected to a changing magnetic field. In particular, if done under adiabatic conditions, its temperature changes. For the past 15 years the magnetocaloric effect has been the focus of significant research due to its possible application for efficient refrigeration near room temperature. At the same time, it has become common knowledge within the magnetic refrigeration research community that the magnetocaloric effect was discovered by the German physicist E. Warburg in 1881. We re-examine the original literature and show that this is a misleading reading of what Warburg did, and we argue that the discovery of the effect should instead be attributed to P. Weiss and A. Piccard in 1917.

Forman at forty: New perspectives on “Weimar culture and quantum mechanics”

This volume, timed to appear during the fortieth anniversary of the publication of the so-called ‘‘first Forman thesis,’’ is based on contributions delivered at a workshop held in 2007. The book is divided into three sections. The first contains reprints of five of Paul Forman’s papers, including ‘‘Weimar Culture, Causality, and Quantum Theory, 1918–1927: Adaptation by German Physicists and Mathematicians to a Hostile Intellectual Environment’’ (1971). Part Two includes contemporary papers engaging with topics related to the Forman thesis, focusing in particular on the physical sciences from the late nineteenth to the mid-twentieth century. Part Three engages with the thesis at a methodological level. The papers examine the life and human sciences, popular science, and philosophy. As a whole, the book is large and varied, spanning well over 500 pages and containing 15 new and almost uniformly high-quality papers. It is not, however, an easy thing with which to work. It contains neither an index nor a bibliography. (A selected bibliography of Forman’s works is to be found on pp. 21–23.) For a volume of such heft and diversity, the editors’