Tonight will be the longest night in Earth's history

msn news ^ | Decembe 21, 2014 | Joseph Stromberg

[LucyT]

Today, you might already know, is the winter solstice. That means for people living in the Northern Hemisphere, it's the longest night of the year.

However, as science blogger Colin Schultz points out, tonight will also be the longest night ever. At any location in the Northern Hemisphere, in other words, tonight's period of darkness will be slightly longer than any other, ever — at least, since the planet started spinning right around the time it was first formed some 4.5 billion years ago.

The reason is that the rotation of the Earth is slowing over time. Every year, scientists estimate, the length of a day increases by about 15 to 25 millionths of a second.

[Lurkina.n.Learnin]

By day I mean the hours and minutes of light.

[Henchster]

Move all the fat people to the polar regions and the earth will slow down.

Actually, if you moved a huge mass to the EQUATOR it would slow down the Earth's rotation - in theory.

[luvie]

O. Noes! It will be all the way down to 70 on Christmas day!!

[GOPJ]

Does this mean it will also be the longest day in history NEXT year?

[smokingfrog]

I think you’re right — I got it backwards.

[smokingfrog]

http://aa.usno.navy.mil/cgi-bin/aa_rstablew.pl

[smokingfrog]

http://aa.usno.navy.mil/data/docs/RS_OneYear.php

[Texas Eagle]

Every year, scientists estimate, the length of a day increases by about 15 to 25 millionths of a second.

Good. I could use the extra sleep.

[Texas Eagle]

Every year, scientists estimate, the length of a day increases by about 15 to 25 millionths of a second.

What do you mean they "estimate"? You mean the science isn't even settled on THIS?

Why don't they take a vote and come up with a consensus.

[Lurkina.n.Learnin]

Thanks. I always look forward to when the days are getting longer.

[hoosiermama]

Good one !!!!! So true

[Jack Hammer]

With what we’ve got in the White House and congress, you could see this striding down Main Street with a neon sign on its head.

[GeronL]

I really miss that 25ths of a millisecond of sleep from last year

[GeronL]

How far in the future would we have to go to get 25 hour days

[Texas Eagle]

Yeah, but the earth is being pulled closer and closer to the sun which means the years will go by quicker even though the days are longer.

This is one gigantic cosmic bait-and-switch.

Stupid solar system.

[Chaguito]

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.

[Nateman]

The special mirrors placed on the moon by the Apollo missions causes a laser beamed to them to be reflected right back. That allows precise measurements of how the moon is moving away from the Earth. It's about 1-2 cm per year. This motion occurs as the Earth slows down because angular momentum is conserved.

[LucyT]

"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.