In case you haven’t heard, Saturday will be the longest day of the year. There are normally 86,400 seconds in a day, but this Saturday, June 30th, 2012, will last one second longer.
Here’s Why:
International Atomic Time is a very accurate and stable time scale. It is a weighted average of the time kept by about 200 atomic clocks in over 50 national laboratories worldwide. Atomic time is measured through vibrations of atoms in a metal isotope that resembles mercury, and can keep time to within a 10th of a billionth of a second a day.
Truth be told, the atomic clock loses one second over 200 million years. The result is extremely accurate time that can be transmitted by radio throughout North America where atomic watches and clocks can receive the signal.
Improved time and frequency standards have many applications. For instance, ultra precise clocks can be used to improve synchronization in precision navigation and positioning systems, telecommunications networks, and deep-space communications. But from their careful observations of the positions of the stars, astronomers have deduced that our Earth’s rotation is ever so slightly slowing down at a non-uniform rate, probably attributable to changes in the distribution of mass in the Earth’s interior. As a result, Earth falls out of step with our atomic clocks. When the difference between the two amounts to one second, a “leap-second” is inserted into the atomic time scale.
This will happen on Saturday when the final minute of June (as measured at the Greenwich meridian) will last 61 seconds. This will correspond to 7:59:60 p.m. Eastern Daylight Time.
If you want to see the extra second inserted into the time scale, go to: http://www.time.gov/
So . . . you’ve got one whole extra second on Saturday. What do you plan to do with it?
If you notice a hole in the upper left-hand corner of your Farmers' Almanac, don't return it to the store! That hole isn't a defect; it's a part of history. Starting with the first edition of the Farmers' Almanac in 1818, readers used to nail holes into the corners to hang it up in their homes, barns, and outhouses (to provide both reading material and toilet paper). In 1910, the Almanac's publishers began pre-drilling holes in the corners to make it even easier for readers to keep all of that invaluable information (and paper) handy.
1 comment
i never knew that now i can tell my whole family about it and mark it on my calander every year
Leave a Comment