Практикум

A

SUPERSYMMETRY IN ATOMIC NUCLEI. A new experiment provides solid evidence that fermions (objects with half-integral spin) and bosons (objects with integral-valued spin) are both governed by the same nuclear physics laws. (The operative term for this egalitarianism, supersymmetry, should not be confused with a similar word used in particle physics to denote the equivalence of fundamental bosons and fermions such as photons and quarks, and of all the physical forces, at energies approaching 10^19 GeV.) The nuclear shell model, dating from 1948, attempts to describe the nucleons (protons and neutrons) in an atomic nucleus as sorting themselves into shells much as electrons do in the atom as a whole. A further innovation in nuclear theory, the interacting boson model (c1974), holds that nucleons can even pair up within their shells, protons with protons and neutrons with neutrons. Individual nucleons are fermions but nucleon pairs are effectively bosons and as such are immune from Pauli's exclusion principle. This allows the pairs to fall into a sort of ground state, leaving only the outermost nucleons to determine the nature of the nucleus's energy level diagram (again analogous to an element's chemistry being determined mostly by its outermost "valence"

electrons). In atomic energy diagrams the levels are separated by, at most, electron volts; in nuclear diagrams the levels are typically separated by100 keV or so. Studying these diagrams

involves shooting beams (often of protons or deuterons) into a sample, in which nuclei can be promoted into a variety of excited states, and then detecting the telltale particles and high-energy photons (gammas) that come out. Nuclei that have an even number of protons and an even number of neutrons possess perhaps a dozen excited energy levels below energy of 2 MeV, and are relatively easy to probe experimentally. Pt-194 is an example. When the target nucleus has an odd number of either protons (e.g., Au-195) or neutrons (e.g., Pt-195), the number of low-energy excited states might be 20, making it harder to predict an energy diagram. Extending the interacting boson model further to nuclei with an odd number of both protons and neutrons (a nucleus which would consist, in effect, of many bosons and at least two unpaired fermions) entails another level of difficulty.

Harder still is experimentally mapping the energy level diagram for such a nucleus since it would have one hundred or more low-lying excited states. Nevertheless, an intrepid Swiss-German collaboration has now done exactly this for Au-196, a nucleus with 79 protons and 117 neutrons. Using high-resolution detectors they were able to sort through the complex

energy-level terrain of Au-196, as well as those for the other three nuclei mentioned above, with results very close to theoretical predictions, demonstrating thereby that a single set of equations could indeed account for nuclei with all the different combinations of even or odd number of neutrons and protons. This is evidence for supersymmetry in nuclei: nuclear forces seem to treat fermions and bosons equivalently, at least for these four nuclei. According to Richard Casten of Yale, who is not a team member, this new research represents an important step forward in applying the interacting boson model.

(Metz et al., Physical Review Letters, 23 August 1999.)

FACULTY POSITIONS FOR WOMEN are increasing slowly in number at US university physics departments. A new AIP report (1997-98 Academic Workforce Report) shows that in the recent half decade (from 1994 to 1998) the percentage of full professors who are women stayed the same (3%) but the percentage of women associate professors increased from 8 to 10% and assistant professors increased from 12 to 17%. Where do these new slots come from? Partly from a very modest increase (2%) in the overall size of the faculty and partly through retirement, which for several years has held steady at a rate of 2% (43% of these came as a result of retirement incentives).

 B

Mr. Manners' Guide to Foreign Policy

We’ve all experienced the following excruciating scenario. You’re having dinner with a couple whose relationship is rocky. But instead of pretending to get along, the two of them are constantly sniping, making mean-spirited digs at one another. She makes fun of his haircut, and invites you to share in the joke; he complains that her paella is too salty, and looks to you for support. They want you to take sides, but you just feel a sour disdain for them both. They’ve broken the cardinal rule of entertaining:  don’t air your dirty laundry in polite company.

Coincidentally, that is also the cardinal rule of international diplomacy. Whatever domestic squabbles there may be, a nation should speak with one voice in foreign affairs. Politics stops at the water’s edge, as the saying goes.

This rule was broken flagrantly last week when the Republican majority in the United States Senate voted to reject the Comprehensive Test Ban Treaty, which President Clinton had ardently wanted to pass. The treaty would have imposed a worldwide ban upon nuclear tests, to be verified by a global network of sensors and inspections. This was the first major international accord to be rejected by the Senate since the Treaty of Versailles in 1920.

In the American media, the Test Ban Treaty was portrayed as something about which reasonable people could disagree. In the rest of the world, however, there is no disagreement: all reasonable people think the Senate’s decision was, frankly, insane. (Likewise, the unreasonable people around the world were relieved that they could continue testing nuclear bombs.) The rejection is mystifying because the treaty would have guaranteed America’s global nuclear dominance—something the Republicans surely favour. So what happened?

The blame may be placed not just on personalities, but on institutions. It is partly the result of America’s peculiar constitutional system of separated powers, which entrusts the Executive branch with foreign policy, but then gives the Legislative branch the responsibility for ratifying treaties, approving ambassadors, declaring war, and dispensing money.

Even in the best circumstances, this separation makes them a strange couple to socialize with:  he (the President) loves to entertain, and will wine and dine the guests into the wee hours with rambling anecdotes and off-colour jokes, whereas she (the Congress) hates company, and keeps a miserly watch on every drop of liquor the guests consume. (The sexes could, of course, be reversed.) Still, the system works tolerably well most of the time.

But the delicate balance is upset when two clashing personalities are thrown together in the shotgun marriage of divided government. Sometimes—as is the case now—the couple will just genuinely detest each other. And so their guests sit in stunned silence as she witheringly criticizes his every culinary decision, from the China pattern to the Turkey recipe. He sits, shrunken and pathetic, giving his visitors an exasperated look that says, "You see what I have to put up with every day?" Making matters worse, everyone at the table is painfully aware that, only a few months ago, she came to the brink of throwing him out altogether.

The guests, meanwhile, are put in the impossible position of either doing nothing while the evening is ruined or clumsily taking sides in a domestic argument. (The leaders of France, Germany, and Britain gingerly did the latter, taking the remarkable step of writing a joint Op-Ed piece to lobby the Senate in favour of the treaty. It didn’t help.) The President gets sympathy from foreign opinion even while the country he is supposed to be leading notoriously shirks basic duties, like paying its UN dues.

The system finally breaks down when the couple’s mutual loathing reaches the point where one will thwart the other’s wishes even if it means embarrassing them both. (The Founding Fathers, in all their wisdom, could not have foreseen a creature as spiteful as Jesse Helms.) So it is with the Test Ban Treaty, killed by the Senate even though it was so clearly in America’s interests. In other words, she has taken his prized bottle of Chateau Lafite ‘53 and abruptly dumped it down the sink. It hurts them both. But it hurts him more.

American foreign policy is at its worst when the world is made to witness an unseemly display like it saw last week. It was more than a bad decision. It was distasteful.

C 

 GRANDPA AND GRANDMA

Grandpa and Grandpa were sitting in their porch  rockers watching the beautiful sunset and reminiscing  about "the good old days," when Grandma turned to  Grandpa and said, "Honey, do you remember when we  first started dating and you used to just casually  reach over and take my hand?" Grandpa looked over at her, smiled and obligingly took her aged hand in his.

 With a wry little smile, Grandma pressed a little farther, "Honey, do you remember how after we were engaged, you'd  sometimes lean over and suddenly kiss me on the cheek?"   Grandpa leaned slowly toward Grandma and gave her a lingering kiss on her wrinkled cheek.

Growing bolder still, Grandma said, "Honey, do you remember how, after we were first married, you'd kind of nibble on  my ear?" Grandpa slowly got up from his rocker and headed  into the house. Alarmed, Grandma said, "Honey, where are you going?"

Grandpa replied, "To get my teeth!"

A LIGHTER LOOK AT MARRIAGE

Getting married is very much like going to a continental restaurant with friends. You order what you want, then when you see what the other fellow has, you wish you had ordered that.

At the cocktail party, one woman said to another, "Aren't you wearing your wedding ring on the wrong finger?" The other replied, "Yes I am, I married the wrong man."

A little boy asked his father, "Daddy, how much does it cost to get married?" And the father replied, "I don't know, son, I'm still paying for it."

When a newly married man looks happy, we know why. But when a ten-year married man looks happy - we wonder why.

Married life is very frustrating. In the first year of marriage, the man speaks and the woman listens. In the second year, the woman speaks and the man listens. In the third year, they both speak and the neighbors listen.

After a quarrel, a wife said to her husband, "You know, I was a fool when I married you." And the husband replied, "Yes, dear, but I was in love and didn't notice it."

A man inserted an 'ad' in the classifieds: "Wife wanted". Next day he received a hundred letters. They all said the same thing: "You can have mine."

When a man opens the door of his car for his wife, you can be sure of one thing: either the car is new or the wife.

The most effective way to remember your wife's birthday is to forget it once.

When a man steals your wife, there is no better revenge than to let him keep her.

Marriage is the triumph of imagination over intelligence. Second marriage is the triumph of hope over experience.

 Random Thoughts ....... Early bird gets the worm, but the second mouse gets the cheese.

I almost had a psychic girlfriend but she left me before we met. I drive way too fast to worry about cholesterol. I intend to live forever - so far, so good. If Barbie is so popular, why do you have to buy her friends? Mental backup in progress - Do Not Disturb! Quantum Mechanics: The dreams stuff is made of. Support bacteria - they're the only culture some people have. Televangelists: The Pro Wrestlers of religion. When everything's coming your way, you're in the wrong lane. Many people quit looking for work when they find a job. When I'm not in my right mind, my left mind gets pretty crowded. Everyone has a photographic memory. Some don't have film. I used to have an open mind but my brains kept falling out. Why do psychics have to ask you for your name?

III-6

Предложные обороты

Широкое распространение в научно-техническом языке имеют следующие предложные обороты: 

According to In accordance with

согласно с, в соответствии с, по:

According to official figures there are several million unemployed in Russia.	По официальным данным в России несколько миллионов безработных.
In accordance with its peaceful policy the Bulgaria always advocates peaceful means for settling international disputes.	В соответствии со своей мирной политикой, Болгария всегда стоит за использование мирных средств для урегулирования международных спорных вопросов.

 

As to
	что касается:
As for

As to power development in the USSR, it was conducted on planned lines.

Что касается развития энергетики в СССР, то она осуществлялась в плановом порядке.

Because of из-за, вследствие:

Because of hard ice conditions expedition had to winter in the Arctic.

Из-за тяжелых ледовых условий экспедиция была вынуждена зазимовать в Арктике.

By means of посредством, при помощи:

By means of free market we hoped to increase productivity of our factories and works.

При помощи свободного рынка мы надеялись повысить производительность наших фабрик и заводов.

 Due to благодаря, из-за, вследствие:

We can communicate over long distances due to invention of the radio.

Мы можем осуществлять связь на больших расстояниях, благодаря изобретению радио.

 Owing to по причине, вследствие, из-за:

Owing to the bad weather the ship was two days behind the schedule.

Вследствие плохой погоды корабль опоздал на два дня.

 In case (of) в случае:

In case of need we shall all go to defend our country.

В случае необходимости мы все встанем на защиту нашей страны.

In spite of
	несмотря на
Despite

In spite of all efforts at improvement, the efficiency of heat engine remains low.	Несмотря на все попытки усовершенствования, эффективность теплового двигателя остается низкой.
Despite all difficulties scientists succeeded in harnessing atomic energy.	Несмотря на все трудности, ученым удалось овладеть атомной энергией.

 Instead of вместо:

Instead of carrying out international agreements certain nations are violating them.

Вместо выполнения международных соглашений, некоторые страны нарушают их.

 Thanks to благодаря:

Thanks to invention of the SATCOM ships can be tracked everywhere in the ocean.

Благодаря изобретению спутниковой связи, нахождение кораблей можно отслеживать в любом месте океана.