MetaFilter posts tagged with Time and calendar

Why the World Didn't End Yesterday

jammy — Sat, 22 Dec 2012 14:19:27 -0800

NASA explains Why the World Didn't End Yesterday Most impressive, to Carson, was their expansive sense of time. “The times Mayas used dwarf those currently used by modern astronomers,” he explains. “According to our science, the Big Bang occurred 13.7 billion years ago. There are dates in Mayan ruins that stretch back a billion billion times farther than that.” The Maya Long Count Calendar was designed to keep track of such long intervals. “It is the most complex calendar system ever developed.” Written using modern typography, the Long Count Calendar resembles the odometer in a car. Because the digits rotate, the calendar can ‘roll over’ and repeat itself; this repetition is key to the 2012 phenomenon. According to Maya theology, the world was created 5125 years ago, on a date we would write ‘August 11, 3114 BC.’ At the time, the Maya calendar looked like this: 13.0.0.0.0. On Dec. 21, 2012, it is exactly the same: 13.0.0.0.0. In the language of Maya scholars, ’13 Bak’tuns’ elapsed between the two dates. This was a significant interval in Maya theology, but, stresses Carlson, not a destructive one.

All this and I didn't link to the Time Cube

metaBugs — Mon, 18 May 2009 14:45:54 -0800

Timepieces! Ancient calendars, ancient clocks, beautiful clocks, atomic clocks and the clocks built into your brain that determine how you perceive time and form memories. All the good stuff is inside: How we count and perceive time is fascinating. Very early civilisations developed sophisticated calendars: the Sumerians 5,000 years ago in what's now Iraq; Stonehenge 4,000 years ago (and more recently, ManhattanHenge); the Chinese calendar system between 3,500 - 4,000 years ago; Calendars from North American societies dating from 500BC; the Julian Calendar from 45BC; and finally our current Gregorian calendar in 1582. Much younger but arguably just as important as the other calendars is Epoch or Unix time, the common time counted by UNIX and LINUX-based computers worldwide, providing a foundation for communication across networks. (previously) More recently, clocks have become crucial. Harrison's very beautiful series of clocks (H1, H2, H3, H4) were accurate enough to calculate longitude and opened the seas for reliable trade, exploration and systematic mapping. The spread of fast travel by rail lead to the standardisation of time zones, with towns in Britain and the USA moving from local solar time to "railway time". Knowing the right time rapidly became a commodity: three generations of the Belville family made their living by providing London's clock-owning homes and businesses with the correct time. Our best atomic clocks can now be accurate to within 1 second every 300 million years and are essential for systems like GPS and global communications. At the other end of the scale, the Long Now foundation wants to build a clock to measure 10,000 years. If you'd prefer something a little more practical, you could always get this wall-mounted 100 year alarm clock instead. We have a multitude of different clocks ticking away inside our brains and bodies. An healthy heart, for example, will keep a steady rhythm indefinitely without any signals from the brain. Our second best-known timekeeper is the suprachiasmatic nucleus. It keeps us on an amazingly accurate cycle that averages 24h11m +- 16 minutes, keeping our bodies to this cycle even if forced to live a 28-hour day or living in a light-free cave with no watch. This 24-hour cycle controls an amazing array of bodily functions, including hormone levels, body temperature, your immune system's activity and much more. It gets re-adjusted daily by sunlight so we can trick it into adopting longer days, which will be useful for when humans get to Mars. Jet-lag sufferers (whose "deep sleep" clock becomes detached from their REM sleep clock) know that this isn't nearly enough, so will be interested that eating breakfast after at least 16 hours without food beats jet lag by immediately kicking your cycle into "morning" mode, at least in mice and one Formula 1 driver (about 50 minutes in, probably UK only). Shorter times (fractions of seconds to hours) are counted by several different systems including the basal ganglia and the parietal lobe. The rate at which these clocks tick determines how fast we perceive the world and form memories; so by altering these ticks we can seem to speed time up or slow it down. It's well known that various drugs can affect our perceptions of time: Caffeine makes time go slower, anaesthetics make it speed up. THC can give a sense of timelessness, possibly by blocking a a clock circuit that measures time in the seconds to minutes range. Memory load, time of day and mood also have effects, but surprisingly, one of the biggest factors seems to be body temperature. Just like in The Matrix, fear really does make time seem to go slower, letting us pick out details that otherwise we couldn't perceive. Some people claim that they've learned to exploit this in sports and actually stretch their perception of time to see the ball moving slower to get an advantage. Finally, this is what started me down this train of thought: a thought-provoking radio programme from the BBC, in which an astrophysicist, a classicist and an author talk about what time means to them.

Off the Grid

Miko — Mon, 22 Jan 2007 11:32:23 -0800

Time of the Season: Conceptual artist Chris Hardman of Antenna Theater has reimagined the calendar. His ECOcalendar abandons the grid concept, instead unrolling like a scroll to define days vertically. Each day appears in its unique position along the arc of gradual seasonal change, with graphics linking stars to tides to the terrestrial world . Radio interview here.

Once more around the sun

signal — Mon, 25 Dec 2006 09:13:29 -0800

2007 Calendar: It contextualizes every hour, even on a year’s time scale: if someone marks the calendar, then looks back in even as little as an hour, they will be able to see time’s inexorable march. ...a sort of graph paper for personal life.

The year the stars fell: Lakota Winter Counts

madamjujujive — Tue, 26 Apr 2005 07:47:58 -0800

Lakota Winter Counts. Lakota and other plains tribes counted time by winters. An appointed recorder would choose one major event to mark the year, depicting that event by name and symbol. Early records dating back to the 10th century were often painted on buffalo skins; more recent winter counts were recorded as text journals. These fascinating records offer insight into natural and historic events for our land that precede accounts of European settlers. - more -

And I thought a few hours of jet lag was bad.

John Kenneth Fisher — Sun, 30 Jan 2005 06:47:36 -0800

For 170 years, crossing the Channel from the UK to France would have brought you 11 days forward in time, and crossing back would have brought you 11 days earlier. Why? Because the Church of England wasn't about to adopt a new Calendar instituted by a Catholic pope. After all, if the old style was good enough for Caesar.... In fact, it took over 300 years for the new Gregorian Calendar to come into use throughout Europe, causing, no doubt, more than a few missed lunch dates as people forgot to convert between them as they traveled. There are, of course, many other calendars in use around the world, and no shortage of people suggesting that let's do the time warp again.