Excerpt from Ultimate Clocks

delanceyplace header
Title: "Ultimate Clocks" Author: W. Wayt Gibbs 

Publisher: Scientific American, Special Edition: A Matter of Time
Date: Spring 2012  Pages: 62-63 

 

In today's excerpt - the technology of our daily lives has become so advanced that the need for accuracy in clocks presses hard the most accurate of today's clocks - which are accurate to five parts per

100,000,000,000,000,000 (or five in 1016). Improving this accuracy is absolutely necessary for such things as improved GPS navigation, improved satellite communication, and improved detection of faults in the massive communication networks we now depend on:

"Today those who would build a more accurate clock must advance into the frontiers of physics and engineering in several directions at once. They are cobbling lasers that spit out pulses a quadrillionth of a second long together with chambers that chill atoms to a few millionths of a degree above absolute zero. They are snaring individual ions in tar pits of light and magnetism and manipulating the spin of electrons in their orbits.  

 

"And thanks to major technical advances, the art of ultraprecise timekeeping is progressing with a speed not seen for 30 years or more. These days a good cesium beam clock, of the kind Symmetricom sells for $50,000, will tick off seconds true to about a microsecond a month, its frequency accurate to five parts in 1013. The primary time standard for the U.S., a cesium fountain clock installed in 1999 by the National Institute of Standards and Technology (NIST) at its Boulder, Colo., laboratory, is good to five parts in 1016 (usually written simply as 10-16). That is 1000 times the accuracy of NIST's best clock in 1975. Successful prototypes of new clock designs - devices that extract time from calcium atoms or mercury ions instead of cesium - have recently attained accuracy in the 10-18 range, a 100-fold improvement in a decade.  

 

"Accuracy may not be quite the right word. The second was defined in 1967 by international fiat to be 'the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom.' Leave aside for the moment what that means: the point is that to measure a second, you have to look at cesium. The best clocks now don't - so, strictly speaking, they don't measure seconds. That is one predicament the clock makers face.  

 

"Further down the road lies a more fundamental limitation: as Albert Einstein theorized and experiment has confirmed, time is not absolute. The rate of any clock slows down when gravity gets stronger or when the clock moves quickly relative to its observer - even a single photon emitted as an electron reorients its magnetic poles or jumps from one orbit to another. By putting ultraprecise clocks on the space station, scientists hope to put relativity theory through its toughest tests yet. But now that clocks have achieved a precision of 10-18 - proportions that correspond to a deviation of less than half a second over the age of the universe - the effects of relativity have started to test the scientists. No technology exists that can synchronize clocks around the world with such exactness.


"So why bother to improve atomic clocks? The duration of the second can already be measured to 14 decimal places, a precision 1,000 times that of any other fundamental unit. ... More stable and portable clock designs could ... be a big boon to navigation, enhancing the accuracy and reliability of the Global Positioning System and of Galileo, a competing system under development in Europe. Better clocks would help NASA track its satellites, enable utilities and communications firms to trace faults in their networks, and enhance geologists' ability to pinpoint earthquakes and nuclear bomb tests. Astronomers could use them to connect telescopes in ways that dramatically sharpen their images. And inexpensive, microchip-size atomic clocks are likely to have myriad uses not yet imagined."

Write a comment

Comments: 4
  • #1

    Chanel iPhone 6S Case (Tuesday, 29 September 2015 10:11)

    Noting that extreme temperatures damage a phone's ability to hold a full charge and therefore shorten the handset's lifespan, SquareTrade found that at zero degrees, the Samsung managed to last nearly two hours during a video call.

  • #2

    liebeszauber (Tuesday, 29 November 2016 09:01)

    sein – być

  • #3

    liebesmagie (Tuesday, 29 November 2016 11:36)

    abonent

  • #4

    oczyszczanie aury (Wednesday, 30 November 2016 23:03)

    tacheometr

Fri

13

Nov

2015

Are Languages Products of their Environment?


shutterstock_222422665_151112


DISCOVER MAGAZINE published this very interesting article: 


  Languages Are Products of Their Environments


The characteristics that make each language unique may actually be adaptations to the acoustics of different environments.

2 Comments

Tue

03

Jun

2014

The Case for Reparations

 

The Case for Reparations

 

Two hundred fifty years of slavery. Ninety years of Jim Crow. Sixty years of separate but equal. Thirty-five years of racist housing policy. Until we reckon with our compounding moral debts, America will never be whole.

 

By Ta-Nehisi Coates

May 21, 2014

 


Chapters

  1. I. “So That’s Just One Of My Losses”
  2. II.  “A Difference of Kind, Not Degree”
  3. III. “We Inherit Our Ample Patrimony”
  4. IV. “The Ills That Slavery Frees Us From”
  5. V. The Quiet Plunder
  6. VI. Making The Second Ghetto
  7. VII. “A Lot Of People Fell By The Way”
  8. VIII. “Negro Poverty is not White Poverty”
  9. IX. Toward A New Country
  10. X. “There Will Be No ‘Reparations’ From Germany”
0 Comments

Mon

02

Jun

2014

A Look At 19th Century Children In The USA

PHILADELPHIA — DINNER with your children in 19th-century America often required some self-control. Berry stains in your daughter’s hair? Good for her. Raccoon bites running up your boy’s arms? Bet he had an interesting day.

 

As this year’s summer vacation begins, many parents contemplate how to rein in their kids. But there was a time when Americans pushed in the opposite direction, preserved in Mark Twain’s cat-swinging scamps. Parents back then encouraged kids to get some wildness out of their system, to express the republic’s revolutionary values.

The New York Times

Sunday Review

By JON GRINSPAN MAY 31, 2014

 

A late 19th century family taking a stroll down a set of railroad tracks
A late 19th century family taking a stroll down a set of railroad tracks

American children of the 19th century had a reputation. Returning British visitors reported on American kids who showed no respect, who swore and fought, who appeared — at age 10 — “calling for liquor at the bar, or puffing a cigar in the streets,” as one wrote. There were really no children in 19th-century America, travelers often claimed, only “small stuck-up caricatures of men and women.”

 

This was not a “carefree” nation, too rough-hewed to teach proper manners; adults deliberately chose to express new values by raising “go-ahead” boys and girls. The result mixed democracy and mob rule, assertiveness and cruelty, sudden freedom and strict boundaries. Visitors noted how American fathers would brag that their disobedient children were actually “young republicans,” liberated from old hierarchies. Children were still expected to be deferential to elders, but many were trained to embody their nation’s revolutionary virtues. “The theory of the equality” was present at the ballot box, according to one sympathetic Englishman, but “rampant in the nursery.”

 

Boys, in particular, spent their childhoods in a rowdy outdoor subculture. After age 5 or so they needed little attention from their mothers, but were not big enough to help their fathers work. So until age 10 or 12 they spent much of their time playing or fighting.

 

The writer William Dean Howells recalled his ordinary, violent Ohio childhood, immersed in his loose gang of pals, rarely catching a “glimpse of life much higher than the middle of a man.” Howells’s peers were “always stoning something,” whether friends, rivals or stray dogs. They left a trail of maimed animals behind them, often hurt in sloppy attempts to domesticate wild pets.

 

And though we envision innocents playing with a hoop and a stick, many preferred “mumbletypeg” — a game where two players competed to see who could throw a knife closer to his own foot. Stabbing yourself meant a win by default.

 

Left to their own devices, boys learned an assertive style that shaped their futures. The story of every 19th-century empire builder — Carnegie, Rockefeller, Vanderbilt — seems to begin with a striving 10-year-old. “Boy culture” offered training for the challenges of American manhood and a reprieve before a life of labor.

 

But these unsupervised boys also formed gangs that harassed the mentally ill, the handicapped and racial and ethnic minorities. Boys played an outsize role in the anti-Irish pogroms in 1840s Philadelphia, the brutal New York City draft riots targeting African-Americans during the Civil War and attacks on Chinese laborers in Gilded Age California. These children did not invent the bigotry rampant in white America, but their unrestrained upbringing let them enact what their parents mostly muttered.

 

Their sisters followed a different path. Girls were usually assigned more of their mothers’ tasks. An 8-year-old girl would be expected to help with the wash or other physically demanding tasks, while her brother might simply be too small, too slow or too annoying to drive the plow with his father. But despite their drudgery, 19th-century American girls still found time for tree climbing, bonfire building and waterfall-jumping antics. There were few pretty pink princesses in 19th-century America: Girls were too rowdy and too republican for that.

 

So how did we get from “democratic sucklings” to helicopter parents? Though many point to a rise of parental worrying after the 1970s, this was an incremental change in a movement that began a hundred years earlier.

 

In the last quarter of the 19th century, middle-class parents launched a self-conscious project to protect children. Urban professionals began to focus on children’s vulnerabilities. Well-to-do worriers no longer needed to raise tough dairymaids or cunning newsboys; the changing economy demanded careful managers of businesses or households, and restrained company men, capable of navigating big institutions.

 

Demographics played a role as well: By 1900 American women had half as many children as they did in 1800, and those children were twice as likely to live through infancy as they were in 1850. Ironically, as their children faced fewer dangers, parents worried more about their protection.

 

Instead of seeing boys and girls as capable, clever, knockabout scamps, many reconceived children as vulnerable, weak and naïve. Reformers introduced child labor laws, divided kids by age in school and monitored their play. Jane Addams particularly worked to fit children into the new industrial order, condemning “this stupid experiment of organizing work and failing to organize play.”

 

There was good reason to tame the boys and girls of the 19th century, if only for stray cats’ sake. But somewhere between Jane Addams and Nancy Grace, Americans lost track of their larger goal. Earlier parents raised their kids to express values their society trumpeted.

 

“Precocious” 19th-century troublemakers asserted their parents’ democratic beliefs and fit into an economy that had little use for 8-year-olds but idealized striving, self-made men. Reformers designed their Boy Scouts to meet the demands of the 20th century, teaching organization and rebalancing the relationship between play and work. Both movements agreed, in their didactic ways, that playtime shaped future citizens.

 

Does the overprotected child articulate values we are proud of in 2014? Nothing is easier than judging other peoples’ parenting, but there is a side of contemporary American culture — fearful, litigious, controlling — that we do not brag about but that we reveal in our child rearing, and that runs contrary to our self-image as an open, optimistic nation. Maybe this is why sheltering parents come in for so much easy criticism: A visit to the playground exposes traits we would rather not recognize.

 

There is, however, a saving grace that parents will notice this summer. Kids are harder to guide and shape, as William Dean Howells put it, “than grown people are apt to think.” It is as true today as it was two centuries ago: “Everywhere and always the world of boys is outside of the laws that govern grown-up communities.” Somehow, they’ll manage to go their own way.

 

________________________________

 

A National Endowment for the Humanities fellow at the Massachusetts Historical Society who is writing a book on the role of young people in 19th-century American democracy.

0 Comments

Mon

21

Apr

2014

Investigating Family's Wealth, China's Leader Signals a Change

From The New York Times 

By CHRISTOPHER DREW and JAD MOUAWAD

APRIL 19, 2014

 

HONG KONG — His son landed contracts to sell equipment to state oil fields and thousands of filling stations across China. His son’s mother-in-law held stakes in pipelines and natural gas pumps from Sichuan Province in the west to the southern isle of Hainan. And his sister-in-law, working from one of Beijing’s most prestigious office buildings, invested in mines, property and energy projects.

 

In thousands of pages of corporate documents describing these ventures, the name that never appears is his own: Zhou Yongkang, the formidable Chinese Communist Party leader who served as China’s top security official and the de facto boss of its oil industry.





A visitor at the Zhou family's ancestral graves in Xiqliantou, eastern China.  Intrigue surrounds the family after a spate of arrests.  Sim Chi Yim for the New York Times
A visitor at the Zhou family's ancestral graves in Xiqliantou, eastern China. Intrigue surrounds the family after a spate of arrests. Sim Chi Yim for the New York Times

But President Xi Jinping has targeted Mr. Zhou in an extraordinary corruption inquiry, a first for a Chinese party leader of Mr. Zhou’s rank, and put his family’s extensive business interests in the cross hairs.

 

Even by the cutthroat standards of Chinese politics, it is a bold maneuver. The finances of the families of senior leaders are among the deepest and most politically delicate secrets in China. The party has for years followed a tacit rule that relatives of the elite could prosper from the country’s economic opening, which rewarded loyalty and helped avert rifts in the leadership.

Zhou Family Ties

1 Comments

Fri

13

Nov

2015

Are Languages Products of their Environment?


shutterstock_222422665_151112


DISCOVER MAGAZINE published this very interesting article: 


  Languages Are Products of Their Environments


The characteristics that make each language unique may actually be adaptations to the acoustics of different environments.

2 Comments

Tue

03

Jun

2014

The Case for Reparations

 

The Case for Reparations

 

Two hundred fifty years of slavery. Ninety years of Jim Crow. Sixty years of separate but equal. Thirty-five years of racist housing policy. Until we reckon with our compounding moral debts, America will never be whole.

 

By Ta-Nehisi Coates

May 21, 2014

 


Chapters

  1. I. “So That’s Just One Of My Losses”
  2. II.  “A Difference of Kind, Not Degree”
  3. III. “We Inherit Our Ample Patrimony”
  4. IV. “The Ills That Slavery Frees Us From”
  5. V. The Quiet Plunder
  6. VI. Making The Second Ghetto
  7. VII. “A Lot Of People Fell By The Way”
  8. VIII. “Negro Poverty is not White Poverty”
  9. IX. Toward A New Country
  10. X. “There Will Be No ‘Reparations’ From Germany”
0 Comments

Mon

02

Jun

2014

A Look At 19th Century Children In The USA

PHILADELPHIA — DINNER with your children in 19th-century America often required some self-control. Berry stains in your daughter’s hair? Good for her. Raccoon bites running up your boy’s arms? Bet he had an interesting day.

 

As this year’s summer vacation begins, many parents contemplate how to rein in their kids. But there was a time when Americans pushed in the opposite direction, preserved in Mark Twain’s cat-swinging scamps. Parents back then encouraged kids to get some wildness out of their system, to express the republic’s revolutionary values.

The New York Times

Sunday Review

By JON GRINSPAN MAY 31, 2014

 

A late 19th century family taking a stroll down a set of railroad tracks
A late 19th century family taking a stroll down a set of railroad tracks

Read More 0 Comments

Mon

21

Apr

2014

Investigating Family's Wealth, China's Leader Signals a Change

From The New York Times 

By CHRISTOPHER DREW and JAD MOUAWAD

APRIL 19, 2014

 

HONG KONG — His son landed contracts to sell equipment to state oil fields and thousands of filling stations across China. His son’s mother-in-law held stakes in pipelines and natural gas pumps from Sichuan Province in the west to the southern isle of Hainan. And his sister-in-law, working from one of Beijing’s most prestigious office buildings, invested in mines, property and energy projects.

 

In thousands of pages of corporate documents describing these ventures, the name that never appears is his own: Zhou Yongkang, the formidable Chinese Communist Party leader who served as China’s top security official and the de facto boss of its oil industry.





A visitor at the Zhou family's ancestral graves in Xiqliantou, eastern China.  Intrigue surrounds the family after a spate of arrests.  Sim Chi Yim for the New York Times
A visitor at the Zhou family's ancestral graves in Xiqliantou, eastern China. Intrigue surrounds the family after a spate of arrests. Sim Chi Yim for the New York Times

Read More 1 Comments