Posts Tagged ‘timekeeping’
“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).
“Maps are a way of organizing wonder”*…
… and of understanding where places and things actually are. As John Nelson elegantly demonstrates, we sometimes need that remedial help…
If learned early on, a foundationally incorrect view of the world can perpetuate, as students naturally build knowledge in light of a past, incorrect, understanding. Something as basic as our assumptions about the relative locations of Earth’s continents is an interesting, and actually sort of fun, example of how we can get things wrong right off the bat. Ultimately, everything is learned, but some curious geographic errors tend to persist more than others.
So what are some tantalizing locational mistakes that seemingly come pre-installed in American students’ minds that geography teachers wrestle to overcome?
So glad you asked! Here is a cherry-picked handful of examples that we’ll dive into…
- The northiness of Africa
- The northiness of Europe
- The eastiness of South America…
Some common geographic mental misplacements, beautifully illustrated: “Misconceptions,” from @John_M_Nelson @Esri.
See also the companion piece, “Enclaves & Exclaves” and John’s personal blog, “Adventures In Mapping.”
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As we grasp geography, we might recall that it was on this date in 1830 that U. S. Secretary of the Navy John Branch established the Depot of Charts and Instruments, a humble undertaking with an annual budget of $330; its primary function was the restoration, repair, and rating of navigational instruments. But from that seed grew the United States Naval Observatory, a scientific and military facility that produces geopositioning, navigation, and timekeeping data for the United States Navy and the United States Department of Defense. It is one of the oldest scientific agencies in the U. S., and remains the country’s leading authority for astronomical and timing data for all purposes.
“Time and tide wait for no man”*…
The week both arranges and imposes on our time…
Among many collective discoveries during the pandemic confinement of 2020, Americans learned just how attached we are to our seven weekdays. As complaints about temporal disorientation mounted that April, we focused not on the clock – the classic metonym for the power and experience of time – but rather on the calendar, and specifically the weekly one. A Cleveland news station affiliated with the Fox Media network entertained viewers with a daily feature, much circulated on the internet, entitled ‘What Day Is It? With Todd Meany’ – the answer to which was always a weekday, not a Gregorian calendar date…
Weeks serve as powerful mnemonic anchors because they are fundamentally artificial. Unlike days, months and years, all of which track, approximate, mimic or at least allude to some natural process (with hours, minutes and seconds representing neat fractions of those larger units), the week finds its foundation entirely in history. To say ‘today is Tuesday’ is to make a claim about the past rather than about the stars or the tides or the weather. We are asserting that a certain number of days, reckoned by uninterrupted counts of seven, separate today from some earlier moment. And because those counts have no prospect of astronomical confirmation or alignment, weeks depend in some sense on meticulous historical recordkeeping. But practically speaking, weekly counts are reinforced by the habits and rituals of other people. When those habits and rituals were radically obscured or altered in 2020, the week itself seemed to unravel…
The history of weekly timekeeping, which is only about 2,000 years old. Although taboos and cosmologies in several different cultures attached significance to seven-day cycles much earlier, there is no clear evidence of any society using such cycles to track time in the form of a common calendar before the end of the 1st century CE. As the scholars Ilaria Bultrighini and Sacha Stern have recently documented, it was in the context of the Roman Empire that a standardised weekly calendar emerged out of a combination and conflation of Jewish Sabbath counts and Roman planetary cycles. The weekly calendar, from the moment of its effective invention, reflected a union of very different ways of counting days…
The crucial formation of our modern experience of weekly time took place around the first half of the 1800s, with the rising prominence of… the differentiated weekly schedule…
The week is the most artificial and most recent of the ways we account for time, but it’s effectively impossible to imagine our shared lives without it: “How we became weekly,” by David Henkin in @aeonmag.
See also Jill Lepore‘s characteristically informative review of Henkin’s book on the week: “How the Week Organizes and Tyrannizes Our Lives” (source of the image above)
* Geoffrey Chaucer
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As we mark time, we might recall that it was on this date in 1839 that John William Draper took a daguerreotype of the moon (the “governor” of months, while the sun determines days, seasons, and years); it was the first celestial photograph (or astrophotograph) made in the U.S. (He exposed the plate for 20 minutes using a 5-inch telescope and produced an image one inch in diameter.) Draper’s picture of his sister, taken the following year, is the oldest surviving photographic portrait.
“One cannot walk down an avenue, converse with a friend, enter a building, browse beneath the sandstone arches of an old arcade without meeting an instrument of time.”*…
Time has ordered human life for millennia….
The Tower of the Winds, in the Greek city of Athens… is one of the best-preserved buildings from the ancient world. This octagonal marble tower, sited close to a busy marketplace at the foot of the hill of the famous Acropolis, rises forty-two feet into the air and measures twenty-six feet across, and it was an astonishing sight for the people of this crowded and vibrant city. The external walls were covered in brightly colored reliefs and moldings representing the eight winds, with each of the eight walls, and a semi-circular annex, carrying a sundial. Inside the ceiling was painted a stunning blue color covered with golden stars. At the center of the imposing interior was a water clock, which was fed from a sacred source high up on the hill of the Acropolis called the Clepsydra, a name which became synonymous with all water clocks. The clock is believed once to have driven a complex mechanical model of the heavens themselves, like a planetarium, orrery, or armillary sphere.
Nobody is quite sure when the Tower of the Winds was built, but it was probably about 140 bc. As with the sundial at the Roman Forum, we can think of it as an early public clock tower, giving Athenians the time of day as they went about their daily business at the market and elsewhere, and giving order to their lives. It was also symbolic of a wider order. The gods of the winds, depicted on its decorative panels, were allegories of world order; the stars inside, together with the water clock and its mechanical replica of the heavens, were symbolic of a cosmic order. Certainly, it was an astonishing spectacle.
But, also like the sundial proudly installed by Valerius in Rome, the Tower of the Winds may have carried a further message. If, as some historians believe, the structure was built by Attalos II, king of the Greek city of Pergamon, to commemorate the Athenian defeat of the Persian Navy in 480 bc, then it could serve as a vivid peacetime reminder of the military strength of the state—and the discipline needed to maintain it…
In empires around the world, the sight and sound of time from high towers had begun to organize the lives of the people, and project a message of power and order.
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It is tempting, in the twenty-first century, to feel that we are the first generation to resent being governed by the clock as we go about our daily lives; that we are no longer in control of what we do and when we do it because we must follow the clock’s orders. During our long warehouse shifts, sitting at our factory workstations, or enduring seemingly never-ending meetings at the office, we might grumble that the morning is dragging on, but we cannot eat because the clock has not yet got around to lunchtime. But these feelings are nothing new. In fact, while the public sundial was new to Romans in 263 bc, it had been in widespread use long before that in other cities around the world; the first water clocks date back even further than sundials, more than 3,500 years to ancient Babylon and Egypt.
It is easy to think that public clocks are an inevitable feature of our lives. But by looking more closely at their history, we can understand better what they used to mean—and why they were built in the first place. Because wherever we are, as far back as we care to look, we can find that monumental timekeepers mounted high up on towers or public buildings have been put there to keep us in order, in a world of violent disorder.
Public time has been on the march for thousands of years: “Monumental Timekeepers,” an except from David Rooney‘s (@rooneyvision) About Time- A History of Civilization in Twelve Clocks. Via @longnow.
* Alan Lightman
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As we watch the clock, we might send timely birthday greetings to George Alfred Leon Sarton; he died on this date in 1956. A chemist by training, his primary interest lay in the past practices and precepts of his field…an interest that led him to found the discipline of the history of science as an independent field of study. His most influential work was the Introduction to the History of Science (three volumes totaling 4,296 pages), which effectively founded that discipline. Sarton ultimately aimed to achieve an integrated philosophy of science that connected the sciences and the humanities– what he called “the new humanism.” His name is honored with the prestigious George Sarton Medal, awarded by the History of Science Society.
“Time … thou ceaseless lackey to eternity”*…
Source art: Chronos and His Child by Giovanni Francesco Romanelli
The human mind has long grappled with the elusive nature of time: what it is, how to record it, how it regulates life, and whether it exists as a fundamental building block of the universe…
Quanta‘s fascinating timeline traces our evolving understanding of time through a history of observations in culture, physics, timekeeping, and biology: “Arrows of Time”
* Shakespeare, The Rape of Lucrece
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As we try to Be Here Now, we might send amusingly insightful birthday greetings to Richard Philips Feynman; he was born on this date in 1918. A theoretical physicist, Feynman was probably the most brilliant, influential, and iconoclastic figure in his field in the post-WW II era.
Richard Feynman was a once-in-a-generation intellectual. He had no shortage of brains. (In 1965, he won the Nobel Prize in Physics for his work on quantum electrodynamics.) He had charisma. (Witness this outtake [below] from his 1964 Cornell physics lectures [available in full here].) He knew how to make science and academic thought available, even entertaining, to a broader public. (We’ve highlighted two public TV programs hosted by Feynman here and here.) And he knew how to have fun. The clip above brings it all together.
– From Open Culture (where one can also find Feynman’s elegant and accessible 1.5 minute explanation of “The Key to Science.”)
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