Category Archives: Business and industry

From bending flames to flying cars

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In January 1800 Thomas Young wrote to the secretary of the Royal Society, Edward Whitaker Gray, to outline his recent “experiments and inquiries respecting sound and light,” as he titled the letter.

Among the findings that Young reported was the generic deflection of fluids near a boundary. Just as a stream of air blowing over water will raise a dimple, he wrote, a candle’s flame will be drawn toward a stream of air. In both cases, and in others, proximity to a surface reduces the local pressure, leading to a net force on the stream.

The effect is not named after Young, however. That honor was bestowed by the aeronautical engineer Theodore von Kármán on his fellow engineer and near contemporary, Henri Coandă. Born in 1886 in Bucharest, Romania, Coandă started off as an artillery officer in the Romanian army. But after six years of military service, during which he was able to pursue his passion for aeronautics, he left Romania for Paris in 1909 to enroll at the École Nationale Supérieure d’Ingenieurs de Construction Aéronautique.

TwoStamps

Coandă’s first job after graduation was with Gianni Caproni’s aircraft factory in Milan, Italy. There, he designed and built an aircraft, the Coandă-1910, that made use of his namesake effect. Depicted on the two stamps above, the Coandă-1910 resembled other aircraft of the time, but with a crucial difference: Instead of spinning a propeller, its four-cylinder piston engine powered a fan that expelled air back along the fuselage. Whether the Coandă-1910 ever flew or was even capable of flight has not been established.

Coandă’s effect has had a more successful life. Its natural manifestations include the diversion of air streams over mountainous terrain and the squirting of blood from the heart’s left ventricle into the left atrium during a disorder known as mitral regurgitation. Among the effect’s practical applications are boundary-layer control systems, which blow engine exhaust over wings to boost lift at low air speeds, and HVAC diffusers, which extend the reach of cooled or heated air.

My favorite application of the Coandă effect is the Avro Canada VZ-9 Avrocar, a flying car developed in the 1950s for the US Air Force and US Army. The VZ-9 looked more like a flying saucer than a car with wings. A central, upward-facing intake drew air into a centrifugal compressor, which directed the flow into three jet engines that were arranged symmetrically around the outside of the compressor like the fireworks in a Catherine wheel. Ducts directed the exhaust down (for lift) and out (for control).

As you can tell from the video, the VZ-9 could actually fly, albeit in somewhat wobbly way. It flew at a maximum speed of 119 mph, but never lifted more than a few feet off the ground. The pitching evident in the video was never eliminated. The project was canceled in December 1961.

By contrast, the Coandă effect remains in good health. Using Google Scholar, I came across several recent papers that evoked it, including

I also found a paper posted last year to the arXiv e-print server by Teresa López-Arias of the University of Trento in Italy. Having discovered Young’s letter to Gray, she posed the question whether the Coandă effect should really be called the Young effect.

Zapping zircons

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Fans of Physics Today's Facebook page occasionally send me messages, most of which are requests for more information about something to do with physics. The one I received on Monday was no exception. A fan from Jordan wanted to know about research in “gemstone treatment.”

Not knowing what he meant, I Googled the phrase, which led me to a website touting the value of untreated gemstones. Some gemstones, I found out, are routinely subjected to heat, chemicals, and even ionizing radiation to change or improve their appearance.

To achieve its so-called super-blue color, this topaz has been bombarded with high-energy electrons from a linear accelerator.

To achieve its so-called super blue color, this topaz has been bombarded with high-energy electrons from a linear accelerator.

Not having heard about the irradiation of gemstones, I investigated further. One of the first documents I came across, thanks to Wikipedia, was Charles Ashbaugh’s “Gemstone irradiation and radioactivity,” which appeared in the winter 1988 issue of Gems & Gemology.

When he wrote the article, Ashbaugh was an engineer at UCLA’s nuclear energy laboratory. His article is worth reading—not only for its review of how both natural and artificial radiation sources alter the optical properties of gemstone minerals, but also for its tutorial on radiation (the sidebar on the various radiation units, with its analogy to sun bathing, is exemplary!).

If you’re like me, you probably knew that amethysts, emeralds, and other gemstones owe their colors to the dilute presence of impurities. Ruby, for example, consists of an aluminum oxide (Al2O3 crystal) doped with chromium atoms. From Ashbaugh I learned that irradiating a gemstone with gamma rays, high-energy electrons, or neutrons transmutes the impurities, thereby changing the wavelengths absorbed by the crystal. Naturally pale blue topaz can be turned a deep “super blue.” Colorless zircon can be turned pink.

As you might expect, irradiation could make a gemstone radioactive. In 1988, when Ashbaugh wrote his article, the regulatory status of irradiated gemstones in the US was confusing, inconsistent, and subject to state and federal jurisdiction. It was easier for a US jeweler to legally obtain irradiated gemstones from abroad than from the US. The regulations are clearer now. In fact, now that there are more irradiated gemstones on the market, the Nuclear Regulatory Commission felt the need last year to issue a fact sheet, whose summary succinctly states (in bold font):

  • The NRC believes irradiated gemstones currently on the market are safe.
  • The NRC has not requested that jewelers take these stones off the market.

Does irradiation diminish the allure or value of gemstones? Not for me. For one thing, a perfect diamond crystal consists of identically arranged carbon atoms. If you could make one in the lab, it would be identical and indistinguishable from a perfect natural crystal. Structural perfection, not naturalness of origin, is a crystal’s paramount property.

What’s more, it doesn’t matter to me whether a tourmaline acquired its color through millions of years’ exposure to natural radiation emanating from the surrounding rock or through a few hours’ exposure to 1.17- and 1.33-MeV gamma rays from a cobalt-60 source.

Ashbaugh’s article is illustrated with several photographs of beautiful, gleaming gemstones in a variety of colors—which prompts another question: If you can make, say, a deep red gemstone by irradiating any one of several naturally transparent, colorless crystals, does it matter which crystal you start with?

The answer could be yes—if you care about how much a stone sparkles. Whereas a natural emerald’s refractive index is 1.6, an irradiated green diamond’s is 2.4. Until a crystal’s refractive index can be engineered, I suspect diamonds will remain the most prized gemstones.

As for the Jordanian Facebook fan who wanted to learn about gemstones, it turned out he was really interested in crystal healing. I couldn’t help him.

The death of distance has been exaggerated

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Last April, I went to a meeting at Case Western Reserve University. To get there from Cleveland’s airport, I took a commuter train.

At first, the view from the train was bleakly urban. But as we neared the city center, I expected the industrial outskirts to give way to office and apartment buildings, restaurants, and shops, as in other cities. But no! Through the train windows, right in the center of town, I saw factories, cranes, marshalling yards, piles of gravel, and barges.

I shouldn’t have been surprised—Cleveland is a port. To reduce transport costs, refineries, smelters, and factories are sited as close to rivers and harbors as possible. And in Cleveland, this means the center of town. What’s surprising is that so many other cities have shed their heavy industries and reclaimed their river- and lakefronts.

The Kavli Institute for Theoretical Physics. (Photo by Sarah Vaughan.)

Light industries, including the lightest of all—knowledge-based industries—don’t need to be near harbors. The much-touted death of distance, brought on by the cheapness of telecommunications, means a worker with a modem can be anywhere. Greenwich’s burgeoning hedge-fund industry is based 40 miles from Wall Street, for example, sparing hedge funders a time-consuming commute without disadvantaging their communications.

But is distance really dead? Google, that most 21st-century company, began work earlier this year on a vast data center in Oregon—not in trendy, microbrew-quaffing Portland, but in the modest town of Dalles. At the heart of the center, two buildings the size of football stadiums will house server farms. To cool the servers, the center will draw power from a hydroelectric plant on the nearby Columbia River. Cheap energy brought Google to Dalles.

There’s another sense in which distance remains alive. If you’re a knowledge worker—a computer programmer or an editor, like me—the ability to work anywhere doesn’t mean you’ll set up your broadband wireless computer and work just anywhere. As much as you can, you’ll choose your location. In the 21st century, the best locations might be by rivers and lakes, as they were in the 19th, but this time for recreation rather than transport. You might not set up your laptop in Dalles, Oregon; instead, you might opt for Bend, Oregon, whose pleasant climate and environs have attracted thousands of newcomers in the past decade.

Even theoretical physicists, whose mental abstractions tend to make them indifferent to environment, are succumbing to the pull of place. Twenty-seven years ago, the US National Science Foundation funded a fledgling center for theoretical physics at the University of California’s Santa Barbara campus. At the time, UCSB was hardly at the top of the UC, let alone the US, pecking order. But the campus is on the Pacific Ocean, and the institute is as close to the beach as environmental regulations allow.

The institute is thriving. Its director, David Gross, was lured there from Princeton, and in the institute’s 25th anniversary year, he shared the 2004 Nobel physics prize for his work on quark confinement.

Today, the distance that matters isn’t to a harbor, but to a power plant—or the beach.

This essay by Charles Day first appeared on page 104 of the January/February 2007 issue of Computing in Science & Engineering, a bimonthly magazine published jointly by the American Institute of Physics and IEEE Computer Society.

Buy neutrinos!

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One Sunday morning in spring I took my Airedale terrier puppy, Echo, on a walk from the Capitol Hill neighborhood of Washington, DC, where we live, to the city’s downtown district. As we strolled along that infamous haunt of lawyers and lobbyists, K Street, I noticed a plaque commemorating “the first wireless telephone message in the history of the world.”

This plaque appears on the K-Street side of the Franklin School at 925 13th St NW in Washington, DC.

The plaque intrigued me. I had written about Charles Kao’s share of the 2009 Nobel Prize in Physics for developing and promoting fiber-optic telecommunication, so I knew about attempts in the 1960s to use lasers to transmit information long distances through air and down pipes. But Alexander Graham Bell’s precursor was unfamiliar to me.

My ignorance of what Bell called the photophone is hardly widespread. In fact, besides the inevitable Wikipedia entry, I also found this YouTube video in which Dean Segovis of Hack A Week explains how you can make your own photophone.

Nowadays, the word “wireless” usually connotes Wi-Fi, a technology and associated standards for short-range telecommunication. The range limit isn’t intrinsic. Radio waves in the same few-gigahertz waveband as Wi-Fi are also used to communicate with Earth-orbiting spacecraft. Now, thanks to a fascinating article by Jerry Adler in this month’s Wired magazine, I know of another use for that waveband: transmitting financial information to gain an edge in high-frequency trading (HFT).

Raging bulls

As Adler explains, HFT exploits tiny, fleeting differences in share prices that are identified by computer algorithms and acted on by automatic trading programs. The practice is possible and profitable, thanks to fast, high-capacity fiber-optic cables to transmit the information, fast computers to make the calculations, and quantitative analysts or “quants” to devise the algorithms.

Milliseconds matter in HFT, which is why the trading company McKay Brothers (to be followed soon by its rival Tradeworx) has built strings of radio towers to ferry financial information between the stock exchanges of New York City and the futures markets of Chicago. As you might expect, fiber-optic cables already connect the two cities, but those cables follow a path whose twists and turns, like those of I-80, add distance and time. By contrast, the radio towers transmit information along a path that’s close to an ideal great circle. The time saved for the round trip: about 5 milliseconds.

Physics features quite a bit in Adler’s article—and not just in the context of current technology. It turns out that some HFT quants were disappointed that neutrinos don’t in fact travel faster than light, a shortcoming that deprived them of a means to perform even faster trades. On the other hand, neutrinos’ established ability to travel right through Earth could conceivably be exploited for faster transcontinental communication. “Buy neutrinos” is Adler’s not-quite-serious conclusion.

Not enough peasants, not enough economics

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Many years ago I read an essay in which the author—I think it might have been Frederik Pohl—complained about historical inaccuracies in sword-and-sorcery novels. Of course, it’s hardly “wrong” in such works to have fire-breathing dragons, power-bestowing rings, or shape-shifting ravens. Rather, what so irked Pohl were errors in depicting a plausible world based on medieval technology.

In particular, he lambasted authors for getting the economics wrong. The lack of labor-saving devices in the Middle Ages meant that growing and raising food—the main economic activity—occupied most of the people most of the time. A tale of warring princes may have talking bears and magic cloaks but it must have plenty of peasants!

Pohl’s polemic came back to mind when I encountered an essay in the latest issue of Isis, one of the journals carried by the Niels Bohr Library and Archives. Under the title “Time, money, and history,” David Edgerton of Imperial College London urges his fellow historians of science to include economic factors more fully in how they regard and study science.

Edgerton presents several pieces of historical evidence to make his case. For example, in his view the R&D component of the Manhattan project is routinely overestimated and overemphasized by historians (or “oversized,” to use Edgerton’s word). Of the project’s $2 billion budget, only $70 million—3.5%—was spent on R&D. The lion’s share went to DuPont and other large corporations for building two nuclear factories at Oak Ridge in Tennessee and Hanford in Washington State (shown here under construction).

Addressing his fellow historians, Edgerton writes:

We need to follow all the money, not just that going to the university. Rough estimates of the comparative scale of industrial, government, and academic research through the century show that the usual implicit maps of the historians systematically oversize academic research by comparison with government and industrial research. Industry and the military (largely in industry) have been—nearly everywhere and nearly always—the main funders of research and development. Not only research within the academy but, indeed, those aspects of academic research least connected to industry are oversized—physics, particularly particle physics, and biology, particularly molecular biology—while chemistry, mathematics, and engineering are undersized.

Edgerton’s essay triggered another literary recollection—this time, of a paper I’d read in the March issue of the British Journal for the History of Science. In “The limits to ‘spin-off’: UK defence R&D and the development of gallium arsenide technology,” Graham Spinardi of Edinburgh University tells a fascinating story of government-sponsored R&D. And in doing so, he implicitly supports Edgerton’s case.

Gallium arsenide is a semiconductor whose properties make it better than silicon for certain applications. Thanks to its excellent electron mobility, GaAs can operate at the high frequencies used for mobile telephony. And thanks to its direct, as opposed to indirect, bandgap, GaAs beats Si as a material for making lasers, LEDs, and other optoelectronic devices.

But Si has offsetting advantages that continue to give it an edge over GaAs and other semiconductors in computational applications. Si is cheap, stable, and readily doped. It has an insulating phase, thanks to its native oxide. And its hole mobility, while an order of magnitude lower than the electron mobility of GaAs, is still high enough to support gigahertz clock rates.

By the mid 1950s, Si’s predominance in commercial electronics was clear. It was also clear that semiconductors would have military applications. Recognizing that market forces alone would likely propel Si-based technologies, the British defense establishment decided at that time to fund research into GaAs, which was less developed. The goal, to quote one of Spinardi’s sources, was “to leapfrog silicon technology.”

Fateful repercussions

That decision had fateful repercussions for Britain’s electronics industry. In a sense, the British government’s investment in GaAs paid off. By the 1990s, when the commercial applications of GaAs in LEDs and microwave telecommunications were taking off, British labs had already developed devices and manufacturing techniques that could support a consumer-focused GaAs industry.

But, as Spinardi explains, those companies, which included Plessey and Marconi, opted instead to continue developing devices for their original military sponsors. What’s more, their decades-long focus on GaAs had left them little room to develop Si-based technologies. Britain’s electronics industry missed out on booms in Si and GaAs.

To discover why British companies failed to achieve commercial success in GaAs in proportion to their expertise, Spinardi interviewed researchers and managers and studied documents from labs and government departments. Within the economic and industrial conditions of the time, those companies did not act foolishly. In fact, they developed successful products in three areas: defense, equipment for processing GaAs, and radar.

Those areas have one thing in common, notes Spinardi. They’re inhabited by a few big, commercial or government customers, rather than thousands or millions of individual customers. To quote Spinardi: “Unlike consumer products, where buyers are sought after production, made-to-order goods are only produced once a buyer has agreed terms. Investment is therefore far less risky because it can be based on, and costed into, procurement contracts.”

That aversion to risk partly reflected British corporate governance. The big British electronics companies were public and had to answer to their shareholders. In the short term, bidding on large contracts made commercial sense.

It might also have made sense in the long term. As British investment in GaAs was beginning to bear fruit in the 1980s, Sony, Matsushita and other deep-pocketed Japanese companies were moving into the consumer electronics industry. The US had begun investing in military applications of semiconductors. Competing against either the Japanese in the commercial sector or the Americans in their own military sector might have been a futile and costly mistake.

Whether Britain’s investment in GaAs was a success or a failure is a matter of perspective. On the one hand, the expected military applications were realized, to the gain of both Britain’s armed forces and their British suppliers. On the other hand, having made that investment, the final step to mass-market success was surely small enough that at least one company could have, and maybe should have, taken the financial risk and jumped. Spinardi concludes his paper with this observation:

The dominance of defense in the post-war UK innovation system helped provide a technology base with much spin-off potential, but ironically it also engendered industrial conditions that may have limited the capacity of UK industry to make the most of this.