Friday, April 21, 2006

Never buy from usaphotonation.com!!!!

I never have experience like this. I received an email from them this morning and they wanted me to call them. I thought that it should be related to my credit card issue since this is usual for some companies. First of all, the sales guy mentioned that the price in his website is the after-rebate price, I have to pay $100 more up front. That's fine. I noticed that already, and I am going to get that $100 back anyway. And then he asked me that I would like to have an upgrade or not. Well.... okay, that's not a big problem, and I thought may be I could get some special discounts or something on the lens or asscessories. However, he told me that the price I paid was just the camera itself with the lens. There will be no battery, no charger, no cables, no CD, no manual... I got nothing expect the body! If I want to have all those, I have to paid about $300 more. He said that he could provide me another $100 off, a "special discount" from him! What the hell is that!? I asked him why this piece of information is not on his site. Then he asked me to go to his site and search for "350dusa". (I won't get the result if I entered "350d usa".) Click on one of the search results and then I was brought to a page which looks exactly the same as I had seen before except the price! He asked me to click on the content link and asked me to compare those 2 pages. At that point, I finally figure out the problem. If they say camera, then that's just the camera. You won't know that until you call them! If you want to have the battery or something else, you must use their special keyword to search for the usa kit! Otherwise, you are out of luck! I argued with him immediately! Are they suppose to provide all the information right there? Am I suppose to know and search with that keyword? Am I suppose to click on all those "hidden" links with unclear contents and figure out the differences? He said that I was harassing him! What? He then said that my shipping address is a suite address, and should I argue with him with that $100 something!? This is ridiculous! Yes, I can afford that, but so what? Even if I am richer than Bill Gates, I still care how I spend my every single dollar!!! In addition, it's not just money problem, they cheated!!! Obviously at last I cancelled the order. I swear I won't do any business with them, and I strongly recommend anyone who is reading this NOT to buy from them!!!!!!!!!!!!!!!!

Thursday, April 20, 2006

西方曆法的演變

古羅馬曆法(Roman Calendar)

現時所用的西方曆法,源於古羅馬的太陽曆。 據估計,古羅馬城是由傳奇的領袖Romulus大約建於公元前753年。初期是承繼希臘曆法,在公元前738年實行。羅馬曆法可以說是非常混亂,無人了解其法則,現時的知識很多都是來自估計。羅馬曆法定一年有304日, 分10個月(六個月30日及4個月31日),以三月份(March)作為新年及一年之始。這十個月的名稱分別是Martius, Aprilis, Maius, Junius, Quintilis, Sextilis, September, October, November 及 December,最後的六個字是表示五至十的拉丁文。但與一太陽年約365日相比相差了61日,當時的羅馬人似乎忽略這些日子,只把它當成無名稱及不定期的月份,成為年與年之間無一定規律的冬日。

後來為了補償這少了的日數,第二任的羅馬領袖Numa Pompilius (公元前715-673),於公元前713年,在年之前加上January及年開尾加上February兩個月份造成一年12個月共355日。至西元前452年,羅馬人將February移至January及March之間。雖然加了兩個月成355日 但仍與回歸年不吻合。為了調整至回歸年,Numa Pompilius 每隔一年下令在February之後加上一個特別月Intercalaris或Mercedinus,Mercedinus一般有22或23日。

儒略曆(Julian Calendar)

到公元前46 年,情況非常混亂,古羅馬儒略凱撒(Julius Caesar)要在Mercedinus的特別月加入90日,才能恢復月份的季節。他根據埃及亞歷山大狄天文家索西琴(Sosigenes)建議,修訂古羅馬曆而制定儒略曆(Julian Calendar)。將一年分為十二個月,規定單數月為31日,雙數月為30日,通常二月是29日(平年),每四年設置一閏年,閏年的二月加多一日成為 30日。因此平年有6*31+5*30+29=365日,二閏年有6*31+6*30=366。四年總共有365*3+366=1461日,平均每年日數為1461/4=365.25,較準確回歸年365.2422相差0.0078日,即是每128年會有一日偏差。

至公元前8 年,羅馬議會將八月改成奧古斯都皇帝(Augustus Caesar)之名,稱為August。同時將八月改為大月而成31日,使它和紀念凱撒(Julius Caesar)的七月(July)日數相同,以顯示他和凱撒的功業同等偉大。而八月後的大小月全都反過來,即將九月和十一月改為30日,而十月和十二月則改為31日,八月所增的一日由二月裡扣減,因此平年二月變成28日,閏年二月變成29日。每年平均日數不變即365.25日。

凱撒死後,羅馬當局曾錯誤地在一段時間入面每三年置一閏,後來奧古斯都皇帝(Emperor Augustus)在至公元前8年至至公元後4年間取消閏年設置,使儒略曆恢復原先的規劃。

格勒哥里曆(Gregorian calendar)

由於儒略曆(Julian Calendar)平均每年日數為365.25,較準確回歸年365.2422相差0.0078日,即每100年會有0.78日偏差。到公元後16世紀,偏差已經累積至十多天。曆法偏差使到宗教節日亦有錯誤。

早在13世紀時,培根(Roger Bacon)及其他人已指出曆法錯誤,須要收改。但教會廷多年來都無任何行動。到16世紀,復活節有時在春分之前到來,而不是根據公元後325年Council of Nicaea 所定的日子出現。至1563 AD,Pope Pius V召開彌撒議會(Council of Trent)上嘗試修正春分及復活節日期問題。目的是重新確立春分點不能遲過3月21日及確立復活節前的滿月的日期。

格勒哥里十三世(Gregory XIII)是繼任Pope Pius V成為天主教教皇。他也是彌撒議會的成員。根據天文學家Aloysius Lilius及Christopher Clavius建議,從現有曆法中減去十天使春分出現在3月21日,因為他們觀察到春分點發生在3月11日。格勒哥里十三世接受建議。執行以下改革並稱為格勒哥里曆。

1.將1582年10月5日至1582年10月14日這10日取消。

2.每個可被 4 整除的年份是一個閏年。

3.但00結尾的年份一定要被 400 整除,才能算是閏年。否則不是閏年。因此,1700,1800,1900,2100 和 2200 年都不是閏年。而1600,2000,和 2400年是閏年。

由以上可知,格勒哥里曆以400年為一循環。400年共有365 * 400 + 97 = 146097日,平均每年有146097 / 400 = 365.2425日。與準確回歸年365.2422相比只差0.0003日。因此3千3百多年才會產生一日的偏差。

各國執行格勒哥里曆時間表

羅馬教廷宣佈1852年10月4日後面緊跟著就是15日。其他天主教國家也很快跟著這麼做了,例如意大利,波蘭,葡萄牙和西班牙等等。但是新教國家不願意追隨。由其是希臘等東正教國家直到20世紀初才修改。英國及其殖民地(包括現在的美國)在1752年執行。所以1752年9月2日後面跟著1752年9月14日。中國則在辛亥革命後才修改。