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ARE BOSE-EINSTEIN CONDENSATES SUPERFLUID? Previously physicists have demonstrated that Bose Einstein condensates (BEC is created when trapped atoms are chilled so low that they begin to overlap) constitute a single macroscopic quantum state, which implies superfluidity. However, physicists would like to see frictionless flow more directly. Two new experiments pave the way toward this goal. A NIST/Colorado group has observed quantized vortices in a condensate of rubidium atoms, while an MIT group has observed that excitations can move through a condensate of sodium atoms and lose little or no energy if the velocity is below a certain critical value. In the Colorado/NIST work the BEC state consists of atoms residing in two separate spin states (referred to as 1 and 2). Using microwaves and a separate probe laser beam working at the fringe of the condensate, the spins of 1-state atoms are flipped, turning them into 2-state atoms in one sector of the condensate after another. This sets a vortex of 2-state atoms into motion around the outer part of the condensate while 1-state atoms remain at rest at the core of the vortex. Thus the vortex is like a smoke-ring of 2-state atoms (with a filling of 1-state atoms) rotating about every 3 seconds. Furthermore, it has exactly one unit of angular momentum. Meanwhile the MIT group uses a focused laser beam to punch a hole in the BEC blob (the light repels atoms from its focus) and then scans the hole along at various speeds. The moving hole is equivalent to a moving object. Below a scan velocity of about 2 mm/sec, no energy dissipation was observed.

The existence of such a critical velocity for frictionless motion is an attribute of superfluidity. One reason for this kind of BEC research, other than for studying fundamental aspects of a novel form of atomic matter, is that it might afford a new way of learning about superfluidity and superconductivity.

SEPARATING CHEMICAL ISOTOPES WITH A TABLE-TOP TERAWATT LASER has been demonstrated by researchers at the University of Michigan, providing a more compact alternative to the bulky techniques for extracting isotopes, and introducing a new method for making ultrapure thin films, which can be used, in electronic devices. Using a technique known as chirped pulse amplification, University of Michigan researchers produced laser pulses that deliver between 10 trillion and 1 quadrillion watts (10 – 1000 terawatts) of power per square centimeter for an extremely short instant – between 150 and 200 quadrillionths (10 – 15) of a second. Aimed at a target inside a vacuum chamber containing the isotopes of interest, the pulse vaporized some of the isotopes, which escaped in the form of ions (charged atoms). Intense magnetic fields associated with the pulses exerted forces on the ions, which deposited them at different locations on a nearby silicon disk depending on the isotope’s weight. With their technique, the researchers separated boron-10 from boron-11 and gallium-69 from gallium-71. It’s an open question if their technique will be feasible on the large scales required for separating isotopes at nuclear facilities, but the researchers are initially setting their sights on other applications, such as depositing pure thin films of isotopes directly onto microelectronic devices.

CHILLING MIRRORS WITH LIGHT. In astronomy the effect of atmospheric turbulence on the quality of images acquired by ground-based telescopes can be greatly reduced by “adaptive optics,” a corrective process in which parts of the telescope mirror are flexed mechanically by piezoelectric motors in an amount typically equal to a fraction of the wavelength of the incoming light.

In interferometric measurements adjustments in mirrors are also desirable, not because of turbulence in the intervening medium but because of thermal noise in the mirror itself. The LIGO and VIRGO interferometers, searching for gravity waves, need very still mirrors, the better to observe the flexing of spacetime on a scale far smaller than the size of an atom. A new technique might help in this regard. Physicists at the Ecole Normale Superieure and Universit-P.et M. Curie in Paris, can measure the thermal agitation of mirrors and reduce this unwanted noise by a factor of 20, with pressure from laser light. This corresponds to a spatial sensitivity of the mirror at a level of a billionth of an angstrom.

COUNTING UP TO 100 MILLION. The science of measurement, metrology, has been moving away from standards based on artifacts such as a meter stick and toward the use of quantum phenomena to provide reliable, accurate and, if possible, portable calibrations that can be used by researchers in the field. Examples are resistance defined inn terms of the quantum Hall effect and voltage in terms of the Josephson effect. Consider capacitance, the measure of how well a tiny reservoir can store electrical charge. NIST already has the best capacitance standard, accurate to 0.02 parts per million (ppm). But this device is cumbersome and, more importantly, its accuracy is frequency dependent. For rendering the value of capacitance in circuits operating outside a certain frequency range, the standard is no better than 2 ppm. A promising new approach to capacitance (pioneered at NIST) uses a single-electron transistor (SET), which contains at its heart a tiny refuge for electrons where the arriving charges can be counted one at a time, all the way up to 100 million or more. When combined with an accurate voltage measurement this becomes an accurate capacitance standard (C=Q/V). The SET approach has now achieved a measurement accuracy of about 2 ppm, and the NIST researchers hope soon to reach 0.1 ppm. The setup is relatively portable and its output is largely independent of frequency.

QUANTUM COOL. Physicists at Simon Fraser University in Vancouver are trying to get electrical circuits to cool themselves electrostatically. To do this they employ both quantum and classical physics. First, the classical: a gas can cool down by pushing against a piston; some of the gas’s thermal energy is converted into mechanical energy. Second, the quantum: electrons flowing from one GaAs layer into another via another a thin layer of AlGaAs will move with optimum efficiency if the electron energy matches a preferred “resonant” energy in the AlGaAs layer. This three-layer setup, called a quantum well, is at the heart of grocery-store laser scanners and CD players. As circuitry shrinks, disposing of waste heat from even tiny electric currents becomes an ever greater problem. The Simon Fraser researchers are proposing that the electrons in a quantum well cool themselves by moving against not a piston but against an opposing electric field, a field in addition to the one moving the electrons through their circuit. This way of combining the quantum (the electrons as waves tunneling through a thin layer) and the classical (the electrons as a working fluid in a sort of Carnot heat engine) might lead to a completely new category of microelectronic quantum device.

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Gates to cast wider net for Microsoft

How a change of jobs for the world’s richest man will affect how the rest of us work and play

Microsoft on trial: special report

Jane Martinson in New York

Saturday January 15, 2000

Bill Gates, the world’s richest man who created the world’s most highly valued company, once had a vision that a computer would sit on every office desk. Now his dreams have moved out of the office to encompass every aspect of our daily lives.

The man who founded Microsoft 25 years ago announced this week that he was going to step down as chief executive. But few industry rivals or analysts saw his decision to become “chief software architect” and chairman as a sign that the 44-year-old wanted to spend more time with his money. Warren Buffett, the world’s best-known investor and mentor to Mr Gates, said: “He certainly couldn’t step away from Microsoft – it’s his baby.”

A rival Silicon Valley executive admitted: “The one thing I’ve learnt in this business is never, ever underestimate Bill Gates. This is a hugely ambitious move for these guys”.

Mr Gates himself was excited by the prospect of his new job and said he would be devoting just as much to it as he did to handling the day-to-day responsibilities.

The father-of-two looked more like the 13-year-old computer programmer he once was when he said: “I’m returning to what I love most –focusing on technologies for the future.” The new job “will allow me to dedicate myself full-time to my passion – building great software and strategizing on the future”.

Most Microsoft watchers believe the new job reflects the company’s desire not to be left behind in the Internet age.

Although Microsoft was offering few hints about what it would reveal in the near future, industry analysts use the term a “networked future” to explain the way the world is expected to change. And it is this networked future that most analysts expect Gates to focus on in his new role.

Ashok Kumar, analyst at stockbrokers Piper Jaffray, said: “Microsoft will want to develop software for the network. [It recognizes] that we have migrated from a pc-centric world to one in which any mobile device can work.”

The term network basically describes a sort of limitless warehouse in the sky where individuals can access anything they need from anywhere on earth. This means that anything from an individual’s diary to contact details and books they want to read on holiday could be filed on to a computer and then downloaded when required.

There were signs the $500bn company was changing. Just 18 months ago Steve Ballmer, who is to take over as chief executive from his old college friend, was appointed president. Soon after, the company dumped its old mission statement and called for “Windows anywhere, any time and on any device.”

Bill Gates talked about the development of “next generation software” this week. But he wants nothing less than for consumers around the world to access anything they need from the latest movie to the latest Harvard research report from any device all using Microsoft software. While other companies such as Sun Microsystmes or Novell have focused on the huge market for business customers, Microsoft is likely to want to use its brand name to offer services to consumers as well as big business.

His interest in software has taken him into all sorts of areas. He has talked about a home where Microsoft software can lock your doors and turn off your lights at night. In building his $50m house near the Microsoft campus in Seattle, he attempted to prove that it already could .

His other software dreams include an involvement with a university research project at Carnegie Mellon looking at building an electronic model of the human brain. Mr Kumar said: “People have been trying to do this for ever. There’s hardly any limit to his ambitions.”

Change is in the nature of the net. Bill Gates himself appeared to accept this when he said this week: “These are dramatic times in our industry. As we look ahead… we recognize that we must refocus and reallocate our resources and talents.”

Gates is still sore at almost missing the potential of the net. The company failed to appreciate the impact of Netscape’s browser and was overtaken by smaller, hi-tech companies such as AltaVista and Yahoo!

The Seattle-based giant’s whole modus operandi has been called into question by the coming of the web. Although Windows has been used on more than 90% of the world’s computers for almost a decade, the company was slow to recognize that it would not be enough to control the web. One industry executive said yesterday: “The days when Microsoft could offer a few shrink-wrapped applications for Windows are gone.”

Richard Sherlund, an analyst at Goldman Sachs, said: “For Gates, I believe that this is about making the Internet work for Microsoft. That’s where his heart is.”

It has also been clear for some time, perhaps as far back as 1975 when Gates dropped out of Harvard to build an operating system, that his heart is not on business matters. He said this week that his new role will enable him to go home at night and think of “databases and user interfaces rather than business models and cost structures”. His decision was called a “wake-up call” by one industry executive. Not only is he respected for his passion for software, his very presence is expected to have an impact on the company’s beleaguered team of programmers.

Art Russell, an analyst at stockbroker’s Edward Jones, said: “He is frankly considered such a visionary that people just hang on his every word.”

Faced with “more competition than it had ever seen before” Microsoft will “get a lot more fire in its belly” because of his new job. The job change significantly comes as the hundreds of engineers who have been working on Windows 2000, the company’s latest software programme, are left with time on their hands.

The new job will also mean that Mr Gates can spend more time on new developments rather than his long-running battle with the government. He is widely considered to have seriously misjudged his behaviour during the landmark anti-monopoly battle. Partly in recognition of the fact that he was considered arrogant and condescending towards the law, Mr Gates has been forced to schmooze with Washington power players over the past year, something one executive described as “excruciating” for all concerned.

Bouncing around the stage this week, wearing his trademark v-necked pullover and geeky glasses, Mr Gates said: “I have had the same job for 25 years.

“We achieved a lot of the dreams we had, but today there are more opportunities than ever. I think it’s fair to say we haven’t seen the last of Bill Gates yet, either.

(Кстати, а кто заметил в этой статье грамматическую ошибку? Подсказка в конце.)

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One day in the Garden of Eden, Eve calls to God, “Lord, I have a problem!”

“What’s the problem, Eve?”

“Lord, I know you’ve created me and have provided this beautiful garden and all of these wonderful animals, and that hilarious comedy snake, but I’m just not happy.”

“Why is that, Eve?” came the reply from above.

“Lord, I am lonely. And I’m sick to death of apples.”

“Well, Eve, in that case, I have a solution. I shall create a man for you.”

“What’s a ‘man’, Lord?”

“This man will be a flawed creature, with aggressive tendencies, an enormous ego and an inability to emphasize or listen to you properly. All in all, he’ll give you a hard time. But, he’ll be bigger and faster and more muscular than you. He’ll be really good at lighting and kicking a ball about and hunting fleet-footed ruminants, and not altogether bad in the sack.”

“Sounds great,” says Eve, with an ironically raised eyebrow.

“Yeah, well. He’s better than a poke in the eye with a burnt stick. But, you can have him on one condition.”

“What’s that, Lord?”

“You’ll have to let him believe that I made him first.”

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A man walked into a bar and ordered a glass of white wine. He took a sip of the wine, then tossed the remainder into the bartender’s face. Before the bartender could recover from the surprise, the man began weeping. “I’m sorry,” he said. “I’m really sorry. I keep doing that to bartenders. I can’t tell you how embarrassing it is to have a compulsion like this.”

Far from being angry, the bartender was sympathetic. Before long, he was suggesting that the man see an analyst about his problem.

“I happen to have the name of a psychoanalyst,” the bartender said. “My brother and my wife have both been treated by him, and they say he’s as good as they come.”

The man wrote down the name of the doctor, thanked the bartender, and left. The bartender smiled, knowing he’d done a good deed for a fellow human being.

Six months later, the man was back. “Did you do what I suggested?” the bartender asked, serving the glass of white wine. “I certainly did,” the man said. “I’ve been seeing the psychoanalyst twice a week.” He took a sip of the wine.

Then he three the remainder into the bartender’s face.

The flustered bartender wiped his face with a towel. “The doctor doesn’t seem to be doing you any good,” he sputtered.

“On the contrary,” the man said, “he’s done me world of good.”

“But you threw the wine in my face again!” the bartender exclaimed.

“Yes,” the man said. “But it doesn’t embarrass me anymore.”

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Certain little girl, when asked her name, would reply, “I’m Mr. Sugarbrown’s daughter.”

Her mother told her this was wrong, she must say, “I’m Jane Sugarbrown.”

The Vicar spoke to her in Sunday School, and said, “Aren’t you Mr. Sugarbrown’s daughter?”

She replied, “I thought I was, but mother says I’m not.”

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Two newlyweds are riding in the back of a limo on the way to their honeymoon boat cruise. The husband says, “Honey, I want to stop and pick up some condoms before we go.” “Good idea,” she says. “While you’re in there, pick me up some Dramamine.”

The groom gets out, walks into the drugstore and says to the clerk, “I’d like a box of condoms and a package of Dramamine, please.”

“Yes sir, says the clerk, “but do you mind if I ask you a question? If it makes you nauseous, why do you do it?”

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Six months after the waiter died, his widow went to see a medium, who promised she would contact the dead man.

During the séance, the widow was sure she saw her husband standing in the corner, dressed in his waiter’s outfit.

“Arnold!” she cried. “Come closer and speak to me!”

A hoarse voice from the corner wailed, “I can’t. It’s not my table.”

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There was a husband and his wife sitting next to a drunk in a bar.

Suddenly the drunk stands up and yells, “ATTENTION ALL” and farts loudly.

The wife is extremely embarrassed, and the husband looks at the drunk and says” Excuse me, you just farted before my wife.”

The drunk replies,” I’m sorry I didn’t know it was her turn.”

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A young female teacher was giving an assignment to her Grade 6 class one day. It was a large assignment so she started writing high up on the chalkboard. Suddenly there was a giggle from one of the boys in the class.

She quickly turned and asked, “What’s so funny Pat?”

“Well teacher, I just saw one of your garters.”

“Get out of my classroom,” she yells, “I don’t want to see you for three days.”

The teacher turns back to the chalkboard. Realizing she had forgotten to title the assignment; she reaches to the very top of the chalkboard. Suddenly there is an even louder giggle from another male student. She quickly turns and asks,

“What’s so funny Billy?”

“Well miss, I just saw both fo your garters.”

Again she yells, “Get out of my classroom!” This time the punishment is more severe, “I don’t want to see you for three weeks.”

Embarrassed and frustrated, she drops the eraser when she turns around again. So she bends over to pick it up. This time there is a burst of laughter from another male student. She quickly turns to see Little Johnny leaving the classroom.

“Where do you think you are going?” she asks.

“Well teacher, from what I just saw, my school days are over.”

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A lawyer defending a man accused of burglary tried this creative defense: “My client merely inserted his arm into the window and removed a few trifling articles. His arm is not himself, and I fail to see how you can punish the whole individual for an offense committed by his limb.”

“Well put,” the judge replied. “Using your logic, I sentence the defendant’s arm to one year’s imprisonment. He can accompany it or not, as he chooses.”

The defendant smiled. With his lawyer’s assistance he detached his artificial limb, laid it on the bench, and walked out.

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Подсказка:

He said this week that his new role will (would) enable him to go home at night and think of “database and user interfaces rather than business models and cost structures”.