X-rays are a form of electromagnetic radiation, as are radio waves, infrared radiation, visible light, ultraviolet radiation and microwaves. One of the most common and beneficial uses of X-rays is for medical imaging. X-rays are also used in treating cancer and in exploring the cosmos. Electromagnetic radiation is transmitted in waves or particles at different wavelengths and frequencies. This broad range of wavelengths is known as the electromagnetic spectrum. The EM spectrum is generally divided into seven regions in order of decreasing wavelength and increasing energy and frequency. The common designations are: radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV), X-rays and gamma-rays. X-rays are roughly classified into two types: soft X-rays and hard X-rays. Soft X-rays fall in the range of the EM spectrum between (UV) light and gamma-rays. Soft X-rays have comparatively high frequencies — about 3 × 1016 cycles per second, or hertz, … [Read more...] about What Are X-Rays?
Photonic devices pdf
Advertisement Editor’s Picks Oh, Intel, Not #YouToo? Age Discrimination Investigation Underway Who’s Firing? (Qualcomm, GoPro, and IBM—Again) Who’s Hiring? (Facebook, Apple, Amazon) What's the Best City for Software Engineers? Employers in the United States plan to hire 4 percent more new graduates from the class of 2018 than they did from the class of 2017, according to the National Association of Colleges and Employers. And when it comes to competing for jobs, newly minted engineers have the power to punch well above their weight. The engineering industry is responding to a wider “device-driven economy, in which we’re pushing to make everything as mobile as possible,” says Anthony Del Preto, manager of engineering division operations at the recruitment firm Aerotek. He pegs the top opportunities for class of 2018 EEs to medical devices and robotics, autonomous and other vehicles, wearables, … [Read more...] about Where the Jobs Are: 2018
Advertisement Editor’s Picks The Unhackable Envelope Intel's New Path to Quantum Computing Quantum Blockchains Could Act Like Time Machines In 1882, a banker in Sacramento, Calif., named Frank Miller developed an absolutely unbreakable encryption method. Nearly 140 years later, cryptographers have yet to come up with something better. Miller had learned about cryptography while serving as a military investigator during the U.S. Civil War. Sometime later, he grew interested in telegraphy and especially the challenge of preventing fraud by wire—a problem that was frustrating many bankers at the time. As a contemporary, Robert Slater, the secretary of the French Atlantic Telegraph Co., wrote in his 1870 book Telegraphic Code, to Ensure Secresy [sic] in the Transmission of Telegrams, “Nothing then is easier for a dishonest cable operator than the commission of a fraud of gigantic extent.” In his own book on telegraphic code, published in … [Read more...] about The Future of Cybersecurity Is the Quantum Random Number Generator
Advertisement Editor’s Picks How RCA Lost the LCD New Life For Nixies Build a Clock With Lixies, the Nixie-Tube Lookalike On a cold December morning in the Czech village of Březolupy, a man stops his truck in front of a 17th-century castle. He puts on some heavy gloves, steps out of the truck, and opens the back hatch. Carefully, almost lovingly, he unloads crate after crate of heavy equipment and supplies—an industrial glass lathe, a turbomolecular vacuum pump, and glass. Lots and lots of glass. The man is Dalibor Farny. In 2012, Farny began working to revive the manufacture of a display technology called the Nixie tube, the last commercial examples of which were produced when he was still a child. These neon-filled glow lamps were ubiquitous in the late 1950s and 1960s, illuminating numbers, letters, and symbols in scientific and industrial instrumentation. Born in the basement of a German-American tinkerer in the 1930s and later … [Read more...] about The Nixie Tube Story: The Neon Display Tech That Engineers Can’t Quit