Archive for sunset
instantanea di Venezia² [jatp]
Posted in pictures, Travel with tags Campo San Geremia, Chiesa dei Santi Geremia e Lucia, jatp, sunset, Venezia, Venice on April 16, 2023 by xi'an
instantanea di Venezia¹ [jatp]
Posted in pictures, Travel with tags Ca' Foscari University, Cannaregio Canal, jatp, San Giobbe, sunset, Tre Archi, Venezia, Venice on April 15, 2023 by xi'an
kuva Lapista⁻²³ [jatp]
Posted in Mountains, pictures, Running, Travel with tags -23⁰, Arctic Chill, cross-country skiing, Finland, jatp, Kittilä, Lapland, Levi, morning run, pine trees, snow, sunset on March 24, 2023 by xi'an
snapshot from Martinique⁵ [jatp]
Posted in Kids, Mountains, pictures, Running, Travel with tags Anse couleuvre, Antille, Antilles, Caribean sea, jatp, Martinique, rainforest, sunset on February 4, 2023 by xi'an
optimal leap year
Posted in Books, Kids, Mountains, pictures, R with tags Australia, daylight saving time, Gregorian calendar, Kata Tjuta, leap year, Mounts Olga, R, sunset on November 19, 2022 by xi'an
A riddle about leap years: a solar year consists of approximately 365.24217 mean solar days, which is why there is a leap year approximately every four years. Approximately because the Gregorian calendar plans 97 and not 100 leap years over 400 years. Is this the optimal solution? No, since the Gregorian difference is 3.3 10⁻⁴ day per year, or 0.132 day per 400 years, while using 85 leap years over every 351 years leads to a difference of 4.76 10⁻⁶ day per year, or 0.002 day per 400 years… (With a further gain by a factor 4 with 116 leap years every 479 years.) This can be found by a basic R code
for(N in 10:1000)
for(L in 1:N){
p=abs(L/N-.24217)
if(p<T){T=p;lo=L;no=N}}
Xi'an's Og 