Attrition X - Antonia Bayle

Calenders.

A year is almost exactly 365 days...almost, but not quite. For millennia, people have tried to create calendars that account for that "not quite" bit. It's why we have leap days and why, just once, there was a February 30.

It's only relatively recently - say, the last 2,500 years or so - that people seemed to care all that much about the year. The knowledge that a year lasts roughly 365 days is quite ancient and independently discovered countless times throughout the world, but this knowledge didn't inform the creation of the first calendars.

That fell to another, far more easily observed physical phenomenon: the phases of the Moon. The time between two full moons is on average just over 29.5 days, meaning it was easy to build a lunar calendar in which the months, a word derived from "Moon" - alternate between 29 and 30 days. Adding twelve of these alternating months together gives a year of 354 days, which isn't a bad approximation of the length of a year, all things considered.

Most early calendars prioritized the cycles of the Moon over the length of the year, with years being defined so that they had a whole number of months. This means that a leap month has to be added every two or three years to keep the twelve lunar months roughly in sync with their respective times of the year.

Our current Gregorian calendar is the successor of the earlier Julian calendar, which traces back to a calender devised in Rome's founding. The Romans clearly weren't too bothered about overly precise timekeeping. For one thing, there were only ten months, which correspond to the modern March through December and totaled 304 days of the year. This, incidentally, is why the ninth through twelfth months have names - September, October, November, December - that derive from the Latin words for seven through ten. Those once were their positions in the Roman calendar. The end of the year between the final month December and first month March belonged to no specific month.

This is all shrouded in legend and tradition, but the story is that Numa Pompilius, the likely mythical second king of Rome, reformed the calendar by adding January and February to the beginning of the year and attempting to switch things back to a lunar calendar. Complicating matters was the Roman belief that odd numbers were lucky, so Numa made eight months last 29 days and four others be 31 days longs for a total of 356 days. But, of course, that was an even number, defeating the point of the whole odd-obsessed exercise, so one month was made even and, to minimize the bad fortune, shorter than all the others. Adding a leap month of 27 days and shortening February for an extra-long year of 377 or 378 days every so often kept Numa's calendar on track with the solar year.

While this system may seem hopelessly chaotic and unwieldy, Numa's calendar worked well enough for hundreds of years, only breaking down twice. The first instance came around 191 BCE, apparently due to the chaos wrought by the Carthaginian general Hannibal. The second breakdown occurred in the waning years of the Roman Republic, as the topic of when to add a leap month - more generally known as intercalation - became a charged political issue.

It isn't hard to see why. The republic was governed by a pair of consuls who both served for a term of one year. But depending on how it was defined, a year could be either 355, 377, or 378 days, which meant certain consuls would get to hold power for significantly longer than their predecessors and successors. As Julius Caesar and his political rivals jockeyed for control, the decision to add leap months stopped being about keeping the calendar aligned with the year and became solely political.

By the time Julius Caesar had assumed his title of "dictator in perpetuity" in 46 BCE, the calendar was badly out of alignment and nobody was really sure what day it was anymore. Centuries prior a Greek scholar - either Cleostratus or Eudoxus of Cnidus had determined the true length of the year was roughly 365.25 days long. Caesar enlisted the aid of the world's greatest philosophers and mathematicians to implement a new calendar, with the Alexandrian astronomer Sosigenes getting the main credit for the new calendar.

The result of all this was something very close to the calendar we use today, as two days were added to January, Sextilis - later renamed August by Caesar's successor, who not coincidentally was named Augustus - and December to bring them up to 31 days, and a single day was added to April, June, September, and November to get them to 30. It should be pointed out that the most logical thing to do would probably have been to have seven 30-day months and five 31-day months to get to 365, but for reasons unknown Caesar decided to keep February just 28 days long, giving it the small consolation of a leap day every four years to keep the calendar in line with the year. The new calendar was in place and went into effect in 45 BCE, with Caesar forced to add three leap months to 46 BCE - making the year an insane 445 days long - to bring the calendar back into alignment with the actual solar year.

Caesar had been told that the year was almost 365.25 days long. The difference is small enough that adding a leap day every four years seems like a perfectly decent approximation, and the discrepancy isn't the sort of thing easily noticed over the length of a human lifetime.

The problem is that the solar year is actually 365.24219 days, or 11 minutes and 14.784 seconds short of the year as defined by the Julian calendar. Caesar should have been aware of this problem, considering the Greek polymath Hipparchus had come up with that measurement back in the 2nd century BCE. But perhaps for ease of use - and the fact that this discrepancy wouldn't represent any real problems for at least a thousand years - the makers of the Julian calendar ignored this problem.

By the 16th century, the problem could no longer be put to one side. The calendar had drifted nearly two weeks from the actual solar year, meaning anything to do with the lunar calendar was now hopelessly out of sync. The specific impetus to reform the calendar came from Pope Gregory XIII. Because the date of the Easter celebration was tied to the timing of the spring equinox, the Catholic Church wanted to restore the calendar so that the equinox again fell on its "correct" date of March 21. This date was actually when the equinox fell on 325 CE, the year of the Council of Nicaea that had first established when Easter would fall. By that time, the equinox had already drifted three days from when Julius Caesar first promulgated his calendar, meaning the equinox should arguably fall on March 24...but then, one arbitrary date is really as good as another.

For this new Gregorian calendar to work, two major changes were required. First, ten days would need to be deleted in order to correct the drift. Italian astronomer and key contributor to the new calendar Aloysius Lilius argued this should be accomplished by skipping leap days for the next forty years, but his German colleague Christopher Clavius persuaded the Pope that it would be better to simply skip ten days all in one go. That's just what the Church and a handful of Catholic countries did on Thursday, October 5, 1582, which they immediately followed with Friday, October 14. Most other countries that later made the switch also decided to simply skip ahead to realign the calendar, such as when Great Britain and its American colonies jumped from September 2 to September 14 in 1752.

The other crucial reform of the Gregorian calendar was to fix the number of leap years. We often say February 29 happens once every four years, but that elides over the precise point our current calendar is meant to fix. The leap day actually occurs 97 times every 400 years, as years divisible by 100 but not 400 (so 1900 and 2100, but not 2000) are no longer leap years. That effectively makes the Gregorian year 365.2425 days long, which means the calendar won't lose a day for roughly 5,000 years.

The 19th century astronomer John Herschel actually proposed a way to improve even that level of precision by skipping the leap day on years divisible by 4000 - it wasn't accepted, but obviously there's still plenty of time to implement his idea. Still, on timescales of multiple thousands of years, it's not worth worrying about a day here or there, as the very gradual slowing of the Earth's rotation is going to throw off the calendar anyway.

Bump for Sorcerer / Cleric or Warden

Where is Old Zealand?

Old Mexico is Mexico. Old York is York. But where is Old Zealand?
The first Western explorer to land on what is now known as New Zealand was a Dutchman named Abel Tasman. When he arrived in the 1640s, Tasman thought he had landed on a portion of Staten Landt, which is an island off the tip of Argentina, and he named it so. (Tasman was a little confused; it had been a long trip).
Soon after, Dutch cartographers Hendrik Brouwer and Joan Blaeu figured out that these large islands weren't actually part of South America, and Blaeu named the area Nieuw Zeeland after Zeeland, the westernmost province of the Netherlands. Zeeland is also made of islands, and its name means "sea land" in Dutch.
Englishman James Cook made three voyages to Nieuw Zeeland in the 1770s. The purpose of his original trip was to chart the path of Venus from the South Pacific, but Cook and his crew got lost and ended up in Nieuw Zeeland, which was relatively unexplored by Westerners since Tasman's original voyage. Cook charted most of the area's coastline, and he is responsible for anglicizing the name to "New Zealand."


Bump for Crusader and Troubador.

Putting resources to good use

The first armored presidential limo was used by President Franklin Roosevelt just as the United States was entering WW II. This particular Cadillac convertible originally belonged to the gangster Al Capone. It was seized in 1932 when Capone was charged with tax evasion.

Bump for Crusader and Troubador, maybe a Wizard.

Ice Cream was served to new arrivals at Ellis Island. However, since most people hadn’t encountered it before, they simply figured it was butter and spread it on their toast.

Bump for Crusader, Troubador, Illusionist.

The sudden falling sensation when beginning to fall asleep is called a Hypnic jerk, and is closely related to epileptic seizures.

New quote from Izam. "Reviving Pyrroh... Again ~ 2 Seconds ~"

Bump for Troubador, Berserker/Shadowknight and Sorcerer.

Are you guys good yet

I doubt it but I'll ask around. HBU?

Grats on clearing AoM!

Ebofus family pet:

The Duckbill Platypus is one of the few mammals to produce venom. Both males and females have a pair of spurs on their hind limbs. The male’s pair of spurs delivers a cocktail of poisons that, while excruciatingly painful, is not lethal to most animals.

Bump for Troubador, Crusader/Berserker and Sorcerer

The eye of the Colossal Squid is the largest of any known animal, at up to 11 inches in diameter.

Bump for Troubador, Sorcerer

The phrase "rule of thumb" is derived from and old English law which stated that you couldn't beat your wife with anything wider than your thumb.

Bump for Troubador, Sorcerer

copypasta is not appreciated in this thread.

Put some effort into it, unlike your conjuring.

Algebraic Limerick.

12+144+20+3√4 + (5x11)=9²+0

..........7

A dozen, a gross and a score
Plus three times the square root of four
Divided by seven
Plus five times eleven
Is nine squared and not a bit more.

Bump for Stuff.

Dayum

This guy with the outdated forum sig, and he wants to bag on me??

DAYUM is right!!!!!



Bump for a Troubador and a Sorcerer

Don't make fun of my forum signature. I work very hard to maintain level 95. You may think its outdated, but you, my friend, are wrong.

Incoming!


Do you live anywhere near the lines on this map of the globe? If so, on May 8, give or take a few hours, you may have to, well, duck.

On April 27th, a Russian Soyuz spacecraft launched carrying a Progress supply capsule headed for the International Space Station. The spacecraft was carrying thousands of kg of food, supplies, and equipment, in addition to fuel to drive the spacecraft and the mass of the spacecraft itself.

The initial parts of the launch went fine, but as the spacecraft was approaching the final part of its launch the signals received on the ground from the spacecraft became intermittent and within a few hours they were lost completely. Russian engineers continued to try to contact the capsule and the capsule got close enough to the ISS to be visible by the astronauts, but the capsule itself has remained silent for over a week.

Unable to burn its engines or correct its course, the capsule is now in a decaying orbit around Earth. It needs to burn its engines to move higher and reach the ISS; instead, friction with the atmosphere is now causing the spacecraft to slow down and descend towards Earth.

The exact time is difficult to project as it is influenced by solar activity; a more active sun actually causes the upper layers of Earth’s atmosphere to rise higher and increases the friction on orbiting objects. Engineers worldwide can make educated guesses about when and where it will come down and narrow it down to within a few orbits, but that leaves error bars of several hours and most of the planet.

As the capsule enters the atmosphere it will break apart and much of the material inside will burn up due to friction, but several large parts of the capsule are likely strong enough to make it to the surface. Estimates suggest about 20% of the mass, likely over 1000 kg, will come down on the surface in an area potentially hundreds of kilometres wide.

Based on these orbits it is estimated that there is a 60% or so chance of it entirely hitting water, which is conveniently very close to the percentage of Earth’s surface covered by water anyway.

While Russians seem to be good at exploiting eq2 mechanics, they don't seem so good at aerospace engineering.

Bump for Mystic / Wizard / Troubador

Profound Poem.

I dig, you dig, we dig,
he dig, she dig, they dig....

It's not a beautiful poem,
but it's very deep.

Bump for stuff

The placement of a donkey's eyes in its head enables it to see all four feet at all times.

Bump for Troubador and Shadowknight

In the United States, one pound of potato chips costs two hundred times more than one pound of potatoes.

Bump for Troubador, Shadowknight