Date: Mon, 6 Dec 1999 20:46:40 -0500 (EST) From: "Crist J. Clark" <cjc@cc942873-a.ewndsr1.nj.home.com> To: jack@germanium.xtalwind.net (jack) Cc: grog@lemis.com (Greg Lehey), freebsd-chat@FreeBSD.ORG Subject: Re: New Millenium (was: So, what do we call the 00's?) Message-ID: <199912070146.UAA52538@cc942873-a.ewndsr1.nj.home.com> In-Reply-To: <Pine.BSF.4.21.9912051414240.40078-100000@germanium.xtalwind.net> from jack at "Dec 5, 1999 06:02:39 pm"
next in thread | previous in thread | raw e-mail | index | archive | help
jack wrote, > Today Greg Lehey wrote: > > > OK. I've come to generally accept this opinion. Let's look at a few > > more: > > > > When is the turn of the century? By the same logic, that's also in > > 2001. > > Yes it is. > By definition a century is 100 years; any 100 years. > A person born in 1900, who lives to be 100, will celebrate their > first century (100 years) on their birthday in 2000. > > A person born in 1901, who lives to be 100, will celebrate their > first century (100 years) on their birthday in 2001. > > The "birth date" of the Gregorian calander was Jan 1 1, not > Jan 1 0, so its one hundredth "birthday" (the end of its first > century) was Jan 1 101. Its 2000th birthday (the end of its > twentieth century) will be Jan 1 2001. > > > When is the beginning of the next decade? By the same logic, that's > > also in 2001. > > That is also correct. > A decade is ten years; any ten years. The decade of "the > nineties" is from 1990 though 1999. In this case we count the > "zero year" as there was a year 1990, IIRC. My first decade was > from my birth in Jun 1951 through my tenth birthday in June 1961. > > The ten years from 1 through 10 inclusive were the common era's > first decade, not 0 to 9 since the calendar wasn't "born" until > year 1. The second decade of the common era started Jan 1 of the > year 11. Jan 1 2001 marks the end of the two hundredth decade of > the Gregorian calander. What has fascinated me is how people talk about 2000 as if it were the end of the millennium, but also talk about the 1900's as the 20th century and the 21st in the 2000's. There the situation is reversed. Becuase the hundreds place _was_ '0' during the 1st century, the hundred's place of the year differs by one from the ordinal number of the century. Why weren't these people celebrating the end of the millennium when we went from the 19th to 20th century? I guess people will fudge on one year... but 100? :) [snip] > From a truly logical/scientific viewpoint, if you define a year > as one revolution of the earth around the sun then this would be > the ~4.5 [Paulo]millionth millenium. That might not be a good way to define a year. You need to specify an arbitrary date when the Earth passed from planetoid to 'Earth,' and then it's still not a particularly useful number since the time it takes the Earth to go around the sun is not a constant. And how do you define 'going around the sun?' Relative to the 'fixed stars' (other stars in our galaxy) I assume. But they move along with us as the galaxy rotates and also have relative motion among themselves... hmmm... A NASA site has the following info (a _complete_ URL ;), http://sulu.lerc.nasa.gov/dictionary/y.html year A period of one revolution of the earth around the sun. The period of one revolution with respect to the vernal equinox, averaging 365 days 5 hours 48 minutes 45.68 seconds in 1955, is called a tropical, astronomical, equinoctial, natural, or solar year. The period with respect to the stars, averaging 365 days 6 hours 9 minutes 9.55 seconds in 1955, is called a sidereal year. The period of revolution from perihelion to perihelion, averaging 365 days 6 hours 13 minutes 53.16 seconds in 1955, is an anomalistic year. The period between successive returns of the sun to a sidereal hour angle of 80 degrees is called a fictitious or Besselian year. A civil year is the calendar year of 365 days in common years, or 366 days in leap years. A light year is a unit of length equal to the distance light travels in one year, 9.460 X 10E12 kilometers. The term year is occasionally applied to other intervals such as an eclipse year, the interval between two successive conjunctions of the sun with the same node of the moon's orbit, a period averaging 346 days 14 hours 52 minutes 52.23 seconds in 1955, or a great or Platonic year, the period of one complete cycle of the equinoxes around the ecliptic, about 25,800 years. Of course, using rotations around the sun over the entire Earth's history (or seconds since the Big Bang) is somewhat problematic since your 4.5 million millennia comes with quite an error bar. I'd be born in 4 500 001 970 +/-500 000 000 or so. ;) -- Crist J. Clark cjclark@home.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199912070146.UAA52538>