Promienie x wilhelm roentgen biography

X-RAYS AND ENERGY

X-rays have much higher energy and much shorter wavelengths than ultraviolet light, and scientists usually refer to x-rays in terms of their energy rather than their wavelength. This is partially because x-rays have very small wavelengths, between 0.03 and 3 nanometers, so small that some x-rays are no bigger than a single atom of many elements.

DISCOVERY OF X-RAYS

X-rays were first observed and documented in 1895 by German scientist Wilhelm Conrad Roentgen. He discovered that firing streams of x-rays through arms and hands created detailed images of the bones inside. When you get an x-ray taken, x-ray sensitive film is put on one side of your body, and x-rays are shot through you. Because bones are dense and absorb more x-rays than skin does, shadows of the bones are left on the x-ray film while the skin appears transparent.

An x-ray image of teeth. Can you see the filling?

An X-ray photo of a one year old girl who swallowed a sewing pin. Can you find it?

Our Sun's radiation peaks in the visual range, but the Sun's corona is much hotter and radiates mostly x-rays. To study the corona, scientists use data collected by x-ray detectors on satellites in orbit around the Earth. Japan's Hinode spacecraft produced these x-ray images of the Sun that allow scientists to see and record the energy flows within the corona.

TEMPERATURE AND COMPOSITION

The physical temperature of an object determines the wavelength of the radiation it emits. The hotter the object, the shorter the wavelength of peak emission. X-rays come from objects that are millions of degrees Celsius—such as pulsars, galactic supernovae remnants, and the accretion disk of black holes.

From space, x-ray telescopes collect photons from a given region of the sky. The photons are directed onto the detector where they are absorbed, and the energy, time, and direction of individual photons are recorded. Such measurements can provide clues about the composition, temperature

INTRODUCTION

On January 8, 1896 (three days after the publication of Roentgen's discovery in Vienna's Die Presse) Cracow-based Czas, as the first Polish newspaper, reprinted that spectacular report. In a short note the methods of obtaining the rays, their basic physical properties and hypothetical applications were presented (1). It was also stated that "the problem, although it seems an All Fools' Day joke, is seriously considered in serious circles." Acting on that information a professor of chemistry of the Jagiellonian University Karol Olszewski (the man who was the first one, along with W. Wróblewski, to liquefy air) repeated Roentgen's experiment ( Fig. 1). He constructed a device generating X-rays ( Fig. 2) and successfully took pictures of various objects and one of a human hand. The information about those experiments was published by Czas on January 21, 1896 JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY 2003, 54, S3, 211223 www.jpp.krakow.pl (2). The descriptions of those experiments as well as pictures taken at that time have been retained. The first Polish X-ray picture is assumed to be the picture of a metal a lizard-shaped paper-weight ( Fig. 2).

On the first days of February 1896 professor Olszewski, at the order of a professor of surgery of the Jagiellonian University Alfred Obaliñski, performed an X-ray picture in a patient with the suspicion of a dislocation of the elbow joint. Purposes" by professor Alfred Obaliñski (Fig. 3). It was the first scientific article on the medical application of X-rays (3).

Towards the end of January 1896 radiological investigations were successfully performed also in other Polish medical centres -Warsaw and Poznan. After the clinical usefulness of X-rays was shown the new diagnostic method was introduced into medical practice. Between February and June 1896 radiological laboratories were established in large

Form of electromagnetic radiation

This article is about the type of radiation. For the medical specialty, see Radiology. For other uses, see X-ray (disambiguation).

An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ranging from 10 nanometers to 10 picometers, corresponding to frequencies in the range of 30 petahertz to 30 exahertz (3×10 Hz to 3×10 Hz) and photon energies in the range of 100 eV to 100 keV, respectively.

X-rays were discovered in 1895 by the German scientist Wilhelm Conrad Röntgen, who named it X-radiation to signify an unknown type of radiation.

X-rays can penetrate many solid substances such as construction materials and living tissue, so X-ray radiography is widely used in medical diagnostics (e.g., checking for broken bones) and material science (e.g., identification of some chemical elements and detecting weak points in construction materials). However X-rays are ionizing radiation and exposure can be hazardous to health, causing DNA damage, cancer and, at higher intensities, burns and radiation sickness. Their generation and use is strictly controlled by public health authorities.

History

Pre-Röntgen observations and research

X-rays were originally noticed in science as a type of unidentified radiation emanating from discharge tubes by experimenters investigating cathode rays produced by such tubes, which are energetic electron beams that were first observed in 1869. Early researchers noticed effects that were attributable to them in many of the early Crookes tubes (invented around 1875). Crookes tubes created free electrons by ionization of the residual air in the tube by a high DCvoltage of anywhere between a f