This is heavy: The kilogram is getting an update

This is a replica of the International Prototype Kilogram at the International Bureau of Weights and Measures, in Sevres, near Paris. (AP Photo/Christophe Ena)
Updated 13 November 2018
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This is heavy: The kilogram is getting an update

SEVRES, France: The kilogram is getting an update.
No, your bathroom scales won’t suddenly become kinder and a kilo of fruit will still weigh a kilo. But the way scientists define the exact mass of a kilogram is about to change.
Until now, its mass has been defined by the granddaddy of all kilos: a golf ball-sized metal cylinder locked in a vault in France. For more than a century, it has been the one true kilogram upon which all others were based.
No longer.
Gathering in Versailles, west of Paris, governments are expected on Friday to approve plans to instead use a scientific formulation to define the exact mass of a kilo. The change is expected to have practical applications in industries and sciences that require ultra-precise measurements of mass.
And it will mean redundancy for the so-called Grand K, the kilo that has towered above them all since 1889.
Made of a corrosion-resistant alloy of 90 percent platinum and 10 percent iridium , the international prototype kilo has rarely seen the light of day. Yet its role has been crucial, as the foundation for the globally accepted system for measuring mass upon which things like international trade depend.
Three different keys, kept in separate locations, are required to unlock the vault where the Grand K and six official copies — collectively known as “the heir and the spares” — are entombed together under glass bell-jars at the International Bureau of Weights and Measures, in Sevres on the western outskirts of Paris.
Founded by 17 nations in 1875 and known by its French initials, the BIPM is the guardian of the seven main units humanity uses to measure its world : the meter for length, the kilogram for mass, the second for time, the ampere for electric current, the kelvin for temperature, the mole for the amount of a substance and the candela for luminous intensity.
Of the seven, the kilo is the last still based on a physical artefact, the Grand K. The meter, for example, used to be a meter-long metal bar but is now defined as the length that light travels in a vacuum in 1/299,792,458th of a second.
“This, if you like, is a moment of celebration because it’s like the last standard remaining from 1875 that will finally be replaced by new innovation,” Martin Milton, the BIPM director, said in an Associated Press interview. “Everything else has been recycled and replaced and improved. This is the last improvement that dates back to the original conception in 1875. So that’s a tribute to what was done in 1875, that it’s lasted this long.”
Only exceedingly rarely, and exceedingly carefully, have the BIPM’s master kilos been gingerly taken out so that other kilos sent back to Sevres from around the world could be compared against them, to be sure they were still properly calibrated, give or take the mass of a dust particle or two.
Although many Americans commonly think of weight in pounds and ounces, the United States is officially a kilo country, too: It was one of the original 17 founders of the BIPM in 1875. The United States’ primary kilo is called K20 and was assigned to the country in 1889 by the BIPM, along with another, K4. One kilo is equivalent to 2.2 pounds.
The US also has six other platinum-iridium kilos: K79, 85, 92, 102, 104 and 105. They are all looked after by the National Institute of Standards and Technology, a branch of the US Commerce Department.
To verify their mass, K20 and other kilos from around three dozen other countries were measured in Sevres against the BIPM’s master kilos in a painstaking calibration exercise from 1988 to 1992. K20 was most recently then measured again at the BIPM in 2014.
Even as humans argued, fought and slaughtered each other by the tens of millions in the 20th century, they shared the kilo. The kilo allocated to China in 1983, as it started to embrace market reforms that subsequently turned it into an economic behemoth, was the first manufactured with ultra-high precision diamond machining. Allocated to Japan in 1894, K39 was later ceded to South Korea in 1958.
The kilo is “a tribute to man’s ability to collaborate,” Milton says. “It’s been called a great work of peace, actually, because it’s one of the areas where all of the states of the world come together with absolutely the same objective.”
The metal kilo is being replaced by a definition based on Planck’s constant, which is part of one of the most celebrated equations in physics but also devilishly difficult to explain . Suffice to say that the update should, in time, spare nations the need to occasionally send their kilos back to Sevres for calibration against the Grand K. Scientists instead should be able to accurately calculate an exact kilo, without having to measure one precious lump of metal against another.
Milton says the change will have applications in computing, manufacturing, pharmaceuticals, the study of climate change and other sciences where precise measurements are required.
“The system will be intrinsically correct by reference to the laws of science, the laws of nature,” he said. “We won’t have to depend on just assuming that one particular object never changes.”


Meghan Markle’s father appeals to British queen over rift with daughter

Updated 17 December 2018
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Meghan Markle’s father appeals to British queen over rift with daughter

  • Meghan’s father said he had not had contact with his daughter for months and repeated text messages to Meghan had gone unanswered
  • Kensington Palace did not immediately comment on the interview

LONDON: Meghan Markle’s father directly appealed to Britain’s Queen Elizabeth on Monday to intercede and end his estrangement from his daughter, the wife of Prince Harry.
Former US actress Meghan, now the Duchess of Sussex, married Harry, the queen’s grandson and sixth-in-line to the throne, in a glittering ceremony at Windsor Castle in May.
But the immediate build-up to the wedding was overshadowed by her father, Thomas, a former lighting director for US TV soaps and sitcoms, who pulled out days beforehand after undergoing heart surgery.
Meghan’s father said he had not had contact with his daughter for months and repeated text messages to Meghan had gone unanswered.
When asked what message he had for Queen Elizabeth, 92, Thomas Markle said: “I would appreciate anything she can do and I would think that she would want to resolve the family problems.”
“All families, royal or otherwise, are the same and they should all be together certainly around the holidays,” Markle added.
Markle said that Meghan, 37, had not sent him a Christmas card but that he was hopeful that they could at some time build their relationship.
“Please reach out to me,” he said of Meghan. “I love my daughter very much and she has to know that... Just send me a text.”
“All I can say is that I’m here she knows it and I’ve reached out to her and I need her to reach back to me. I love her very much,” Markle said. “This can’t continue forever.”
Harry, 34, and Meghan are expecting their first child in the spring of 2019.
“I am certainly hoping that everything goes well and that they produce a beautiful baby and I’ll get to see a little Meghan or a little Harry — that would be very nice and I look forward to that happening,” Markle said.
“I think she’ll make a great Mom.”
Markle dismissed reports that Meghan could at times be rude. She was, he said, very polite as she had been raised on Hollywood stages.
When asked if she was a social climber, her father said: “She’s always been a very controlling person and that’s part of her nature but she has never been rude.”
Kensington Palace did not immediately comment on the interview.