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Why Tomorrow is Going to Be One Second Longer than Today

2 minute read

For all those who wish there were more time in the day, your prayers have been answered.

On Tuesday, June 30, the Earth will get a bonus second as a way to compensate for the gradual slowing down of the Earth’s rotation: at 8 p.m., Eastern time, the entire planet will relax for one extra second longer. Instead of the customary, 86,400-second Earth rotation, Tuesday will make the day 86,401 seconds long.

The last time we had a ‘leap second,” TIME explained why:

Leap seconds were introduced to keep our notion of time in line with an ongoing slowdown in Earth’s rotation, caused by volcanoes, earthquakes and other natural phenomena. While that slowing rotation is extraordinarily gradual, over long periods it adds up to notable chunks of time, potentially throwing our concept of time off from Earth’s day-and-night cycle — or even seasonal schedules.

The “leap second” attempts to rectify this by inserting an extra second into a day to give the Earth time to “catch up” to where it’s supposed to be based on the traditional solar cycle. The leap second was established as an international standard in 1972, and there have been 25 such seconds added since that year.

 

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Harsh land. Windswept valleys in northern #Africa
"Harsh land. Windswept valleys in northern #Africa"—Alexander Gerst via Twitter on July 6, 2014Alexander Gerst—ESA
Land use in South Africa, you can see where water is.
"Land use in South Africa, you can see where water is."—Alexander Gerst via Twitter on July 9, 2014.Alexander Gerst—ESA
Irrigation in the #Sahara #Desert looks like a challenging task from up here... #BlueDot
"Irrigation in the #Sahara #Desert looks like a challenging task from up here... #BlueDot"—Alexander Gerst via Twitter on July 28, 2014Alexander Gerst—ESA
An open history book of our planet: the #Sahara Desert
"An open history book of our planet: the #Sahara Desert"—Alexander Gerst via Twitter on July 26, 2014Alexander Gerst—ESA
An open history book of our planet: the # Sahara Desert
"An open history book of our planet: the # Sahara Desert"—Alexander Gerst via Twitter on July 26, 2014Alexander Gerst—ESA/SIPA USA
Close-up of gigantic Salar of Uyuni in Bolivia. You can even see the salt fields and the 'Cactus Island'
"Close-up of gigantic Salar of Uyuni in Bolivia. You can even see the salt fields and the 'Cactus Island'."—Alexander Gerst via Twitter on July 15, 2014.Alexander Gerst—ESA
The #Moon was still behind the horizon. A #FataMorgana of atmospherical refraction #BlueDot
"The #Moon was still behind the horizon. A #FataMorgana of atmospherical refraction #BlueDot"—Alexander Gerst via Twitter on July 14, 2014Alexander Gerst—ESA/SIPA USA
When I took this photo, I was sure these are clouds. But now I'm not so sure... #BlueDot
"When I took this photo, I was sure these are clouds. But now I'm not so sure... #BlueDot"—Alexander Gerst via Twitter on July 7, 2014Alexander Gerst—ESA
Nasa: Astronaut Alexander Gerst pictures
"Probably a river in Kazakhstan or slightly west of it."—Alexander Gerst via Twitter on July 29, 2014Alexander Gerst—ESA/SIPA USA
An open history book of our planet: the #Sahara Desert
"An open history book of our planet: the #Sahara Desert"—Alexander Gerst via Twitter on July 26, 2014Alexander Gerst—ESA
Human-made fires in East Africa. Can you spot them?
"Human-made fires in East Africa. Can you spot them?"—Alexander Gerst via Twitter on July 9, 2014Alexander Gerst—ESA

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