"Correction: the longest day was in 1912."
" http://www.vox.com/2014/12/21/7424371/winter-solstice and links therein.
"Since then, they have gotten shorter because of global warming or something."
From the article:
Correction: The article below said that, due to the rotation of the Earth gradually slowing down over time, this winter solstice would feature the longest night ever.
I got this wrong. The Earth's rotation is gradually slowing on an extremely long timescale, but on a shorter year-to-year basis, geologic factors can alter the speed as well.
Data indicates that the rotation speed has actually sped up slightly over the past forty years (likely due to melting of ice at the poles and the resulting redistribution of the Earth's mass), and before that, the trend was up-and-down for most of the 20th century — so, as far as we know, the longest night in Earth's history likely occurred in 1912. I apologize for the error. Thanks to Steve Allen and Ryan Hardy for pointing it out.
Thank you for the update, Chaguito. FreeRepublic strives for accuracy.
Also check out # 77.