Posts Tagged ‘leap second’
“You may delay, but time will not”*…
It turns out that our feeling that things are speeding up has some basis in science…
Earth’s changing spin is threatening to toy with our sense of time, clocks and computerized society in an unprecedented way — but only for a second.
For the first time in history, world timekeepers may have to consider subtracting a second from our clocks in a few years because the planet is rotating a tad faster than it used to. Clocks may have to skip a second — called a “negative leap second” — around 2029, a study in the journal Nature said Wednesday.
“This is an unprecedented situation and a big deal,” said study lead author Duncan Agnew, a geophysicist at the Scripps Institution of Oceanography at the University of California, San Diego. “It’s not a huge change in the Earth’s rotation that’s going to lead to some catastrophe or anything, but it is something notable. It’s yet another indication that we’re in a very unusual time.”
Ice melting at both of Earth’s poles has been counteracting the planet’s burst of speed and is likely to have delayed this global second of reckoning by about three years, Agnew said.
“We are headed toward a negative leap second,” said Dennis McCarthy, retired director of time for the U.S. Naval Observatory who wasn’t part of the study. “It’s a matter of when.”…
The full story: “A faster spinning Earth may cause timekeepers to subtract a second from world clocks,” from @AP.
For (even) more on leap seconds on their history, see “Will We Have a Negative Leap Second?“, by Demetrios Matsakis (also a retired director of time for the U.S. Naval Observatory).
See also: “Climate change is altering Earth’s rotation enough to mess with our clocks” (gift article): “in that one second, the Earth rotated about four football fields”
* Benjamin Franklin
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As we muse on measurement, we might send carefully-observed birthday greetings to Sir Harold Spencer Jones; he was born on this date in 1890. An astronomer (indeed, for 23 years the tenth Astronomer Royal), he specialized in positional astronomy, particularly the motion and orientation of the Earth in space… a focus that helped him contribute to knowledge of the Earth’s rotation and improved timekeeping– efforts that led to Spencer Jones’ election (in 1947) as the first President of the Royal Institute of Navigation (which, In 1951, named its highest award, the Gold Medal, in his honor).
“You’re gonna need a bigger boat”*…
We’re running out of names; Elizabeth Gibney explains…
By the 2030s, the world will generate around a yottabyte of data per year — that’s 1024 bytes, or the amount that would fit on DVDs stacked all the way to Mars. Now, the booming growth of the data sphere has prompted the governors of the metric system to agree on new prefixes beyond that magnitude, to describe the outrageously big and small.
Representatives from governments worldwide, meeting at the General Conference on Weights and Measures (CGPM) outside Paris on 18 November, voted to introduce four new prefixes to the International System of Units (SI) with immediate effect. The prefixes ronna and quetta represent 1027 and 1030, and ronto and quecto signify 10−27 and 10−30. Earth weighs around one ronnagram, and an electron’s mass is about one quectogram.
This is the first update to the prefix system since 1991, when the organization added zetta (1021), zepto (10−21), yotta (1024) and yocto (10−24). In that case, metrologists were adapting to fit the needs of chemists, who wanted a way to express SI units on the scale of Avogadro’s number — the 6 × 1023 units in a mole, a measure of the quantity of substances. The more familiar prefixes peta and exa were added in 1975…
Prolific generation of data drove the need for prefixes that denote 1027 and 1030: “How many yottabytes in a quettabyte? Extreme numbers get new names,” from @LizzieGibney in @Nature.
And in other news from the world of metrics: “Do not adjust your clock: scientists call time on the leap second.”
* Jaws
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As we try to keep up, we might recall that it was on this date in 1968 that 60 Minutes, which had premiered two months earlier, introduced its trademark “ticking stopwatch” opening logo/transition. 60 Minutes is, of course, the most-watched television news show in history.
Since near the show’s inception in 1968, the opening of 60 Minutes features a stopwatch. The Aristo (Heuer) design first appeared in 1978. On October 29, 2006, the background changed to red, the title text color changed to white, and the stopwatch was shifted to the upright position. This version was used from 1992 to 2006 (the Square 721 type was changed in 1998). Source
“Creativity is that marvelous capacity to grasp mutually distinct realities and draw a spark from their juxtaposition”*…
Artist Bill Domonkos:
I view my work as a collision and recombination of ideas. My process unfolds gradually and spontaneously—using found materials such as archive film footage, photographs, and the internet. I experiment by combining, altering, editing and reassembling using digital technology, special effects and animation to create a new kind of experience. I am interested in the absurd, as well as moments of sublime beauty—to renew and transform materials, experiences and ideas. The extraordinary thing about cinema is its ability to suggest the ineffable—something that cannot or should not be expressed in words, only hinted at through sounds and images. It is this elusive, dreamlike quality that informs my work.
Check out more of the work that The Boston Globe‘s Michael Hardy calls “Spooky. Hypnotic. Lush. Witty. Sublime.” at his site, and on his Tumblr, devoted to GIFs like those above.
* Max Ernst
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As we amuse ourselves with animation, we might recall that it was on this date in 1972 that the first leap second was added to a day. The modern definition of a “second” was settled in 1874 by European scientists working from Muslim scholars’ improvement on Ptolemy’s Second Century calculations. But in the early 1960’s astronomers realized that the rotation of the earth is irregular– fundamentally, it is slowing. Coordinated Universal Time (CUT), calculated with an atomic clock, was systematically slowed each year, for a decade, to compensate…. But that meant that CUT and UTC (the time standard used by broadcasters, transportation providers, and other commercial and military users, a standard still fixed on the original definition of the “second”) were diverging. To true them up, the leap second was added to the UTC. Since 1972, a total of 25 seconds have been added– that’s to say, the Earth has slowed down 25 seconds compared to atomic time since then. (But this does not mean that days are 25 seconds longer nowadays: only the days on which the leap seconds are inserted have 86,401 instead of the usual 86,400 seconds.)
Hands up, Mother Nature!…
From The Firearm Blog:
Celebrated science fiction author Philip K. Dick published Project Plowshare as a serial between November 1965 and January 1966. The story, later expanded into the novel Zap Gun, is set in a world where seemingly deadly new weapons are “plowshared” into consumer products. It is ironic that just a few years after that novel was set, a defense giant is quite literally turning a new weapon system into an agricultural tool.
Defense giant Raytheon is well known for putting the “ray” into raygun. They developed the infamous Active Denial System that is designed to zap rioters with a non-lethal millimeter “pain ray”.
Active Denial System at Moody Air Force Base, Ga.
Raytheon realized that technology which can heat human skin at a distance can also be used to heat crops that are vulnerable to frost. One crop that is very sensitive to frost is grapes. In 2005 Ontario’s overall yield of processed grapes fell by 54% due to injuries sustained by the grapes during winter. In 2007 California experienced $800 million in crop losses due to freezing temperatures with navel oranges being the hardest hit.
Existing methods of frost prevention include heaters, wind machines, sprinklers and helicopters in emergencies. These methods all have significant downsides. They are either noisy, costly, inefficient or are only effective under certain environmental conditions.
Two moths ago Raytheon deployed a prototype of their newly developed Tempwave system to an Ontario vineyard. Tempwave sits atop a 25 feet pole and is powered by the grid. When its sensors detect weather conditions that may result in frost, its low-level microwave delivers energy directly to the crop without wasting energy on heating the intervening air. As long as the Tempwave system has enough power delivered to it, frost protection is guaranteed.
Tempwave proof of concept in a California orchard
Read the whole story– and the Raytheon press release– here.
As we read by the glow of our handguns, we might recall that it was on this date in 1972, the first “leap second day,” that one second was added to the world’s time in order to keep atomic clocks in sync with the Earth’s rotation. Since the adoption of this system in 1972, due firstly to the initial choice of the value of the second (1/86400 mean solar day of the year 1900) and secondly to the general slowing down of the Earth’s rotation (despite “the ice-skater effect”), it has been necessary to add over 20 seconds to Coordinated Universal Time (UTC).
The U.S. Naval Observatory Master Clock
CLOCK, n. A machine of great moral value to man, allaying his concern for the future by reminding him what a lot of time remains to him.
–Ambrose Bierce, The Devil’s Dictionary, 1911
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