Posted by
timothy
on from the seconds-all-taste-the-same dept.
ygslash writes "The IERS has announced today that, after seven years, there will once again be a leap second this year. On December 31, 2005, the time 12:59 will last for 61 seconds."
Re:Should we really bother?
by
B.D.Mills
·
· Score: 5, Interesting
It depends on your definition of "significant".
I have calculated[1] that in 1000 years a leap second will be required about every two months. It's likely that at that time we would still be using time standards similar to those in use now.
On the other hand, in 1 million years, about 15 leap seconds will be required each day. Therefore, at some point timekeeping must necessarily divide the day into units that are not an integral number of seconds. We would have a situation where the record for the 100 metres dash is expressed in seconds, but the length of the second used for dividing up the day is not the same length. Such "stretched time" has already been used for the Spirit and Opportunity rovers on Mars.
[1] A common formula for approximating the evolution of delta-T over time is 31 * Cy^2, where Cy is expressed in centuries.
--
The only thing necessary for the triumph of evil is for good men to do nothing. - Edmund Burke
Its always bugged me how...
by
IronMagnus
·
· Score: 3, Interesting
Its always bugged me how in a leap year, we have an extra day... but a leap second is an entire extra second... if the terminology were consistent, that would mean a leap yer would equal one extra year.. or that a leap second was some fraction of a second longer than a normal one.
Re:Star Trek has it figured out.
by
toddbu
·
· Score: 4, Interesting
The only problem is that no one knows how its supposed to work.
They work much like warp speed - start out low and end high. The higher the epsiode number, the higher the range. I think that it's derived from fishing, where "the big one that got away" gets bigger each time the story is told.
-- If you don't want crime to pay, let the government run it.
Off by one error
by
Taral
·
· Score: 3, Interesting
Oh, joy. Everyone'll be off a second on the damn New Year's count... again!
-- Taral
WARN_(accel)("msg null; should hang here to be win compatible\n");
-- WINE source code
Re:Should we really bother?
by
Unordained
·
· Score: 3, Interesting
Not so many centuries ago, the concept of 'hour' was flexible, depending on the season. 12 day hours, 12 night hours, regardless of the ratio between them. Back to the old?
Re:Should we really bother?
by
antispam_ben
·
· Score: 2, Interesting
I have calculated[1] that in 1000 years a leap second will be required about every two months. It's likely that at that time we would still be using time standards similar to those in use now.
Simple solution, change the 60 Hz power line frequency to 59.9999885922 Hz, causing power-line synchronous clocks to slow down to match the daily rotation of the Earth (as referenced to the Sun).
On the other hand, in 1 million years, about 15 leap seconds will be required each day.
Simple solution, change the 59.9999885922 Hz power line frequency to 59.9895833333 Hz, causing power-line synchronous clocks to slow down to match the daily rotation of the Earth (as referenced to the Sun).
Therefore, at some point timekeeping must necessarily divide the day into units that are not an integral number of seconds.
More seriously, I can see where all watches (except the old-fashioned mechanical ones rich people have) will be synchronized to whichever standard the wearer specifies, receiving and converting from an absolote standard such as WWVB as "atomic clocks" do now. Most people will use the daily rotation of the Earth (as referenced to the Sun) standard, but perhaps the stopwatch function can use the "historically established" value for the duration of a second.
Having a watch that keeps several times with good accuracy and converts between them is not a problem now. There are several easily available low-power microcontrollers that will give reasonable battery life. To quote bad sci-fi, "We have the technology."
-- Tag lost or not installed.
Re:These guys must not be real nerds
by
VernonNemitz
·
· Score: 4, Interesting
The thing that bothers me is, when that big quake in Indonesia went off last year and caused that big tsunami, they talked about how the Earth's rotation SPEEDED UP. If it has already slowed down again in only one year, such that a leap second is needed, then that implies some other place has been bulging and may be about to give way. So, any Slashdotters who can pass this inference on to the geology folks, please do so pronto! Thanks!
Slashdot Mirror
It depends on your definition of "significant".
I have calculated[1] that in 1000 years a leap second will be required about every two months. It's likely that at that time we would still be using time standards similar to those in use now.
On the other hand, in 1 million years, about 15 leap seconds will be required each day. Therefore, at some point timekeeping must necessarily divide the day into units that are not an integral number of seconds. We would have a situation where the record for the 100 metres dash is expressed in seconds, but the length of the second used for dividing up the day is not the same length. Such "stretched time" has already been used for the Spirit and Opportunity rovers on Mars.
[1] A common formula for approximating the evolution of delta-T over time is 31 * Cy^2, where Cy is expressed in centuries.
The only thing necessary for the triumph of evil is for good men to do nothing. - Edmund Burke
Its always bugged me how in a leap year, we have an extra day... but a leap second is an entire extra second... if the terminology were consistent, that would mean a leap yer would equal one extra year.. or that a leap second was some fraction of a second longer than a normal one.
They work much like warp speed - start out low and end high. The higher the epsiode number, the higher the range. I think that it's derived from fishing, where "the big one that got away" gets bigger each time the story is told.
If you don't want crime to pay, let the government run it.
Oh, joy. Everyone'll be off a second on the damn New Year's count... again!
Taral
WARN_(accel)("msg null; should hang here to be win compatible\n");
-- WINE source code
Not so many centuries ago, the concept of 'hour' was flexible, depending on the season. 12 day hours, 12 night hours, regardless of the ratio between them. Back to the old?
I have calculated[1] that in 1000 years a leap second will be required about every two months. It's likely that at that time we would still be using time standards similar to those in use now.
Simple solution, change the 60 Hz power line frequency to 59.9999885922 Hz, causing power-line synchronous clocks to slow down to match the daily rotation of the Earth (as referenced to the Sun).
On the other hand, in 1 million years, about 15 leap seconds will be required each day.
Simple solution, change the 59.9999885922 Hz power line frequency to 59.9895833333 Hz, causing power-line synchronous clocks to slow down to match the daily rotation of the Earth (as referenced to the Sun).
Therefore, at some point timekeeping must necessarily divide the day into units that are not an integral number of seconds.
More seriously, I can see where all watches (except the old-fashioned mechanical ones rich people have) will be synchronized to whichever standard the wearer specifies, receiving and converting from an absolote standard such as WWVB as "atomic clocks" do now. Most people will use the daily rotation of the Earth (as referenced to the Sun) standard, but perhaps the stopwatch function can use the "historically established" value for the duration of a second.
Having a watch that keeps several times with good accuracy and converts between them is not a problem now. There are several easily available low-power microcontrollers that will give reasonable battery life. To quote bad sci-fi, "We have the technology."
Tag lost or not installed.
The thing that bothers me is, when that big quake in Indonesia went off last year and caused that big tsunami, they talked about how the Earth's rotation SPEEDED UP. If it has already slowed down again in only one year, such that a leap second is needed, then that implies some other place has been bulging and may be about to give way. So, any Slashdotters who can pass this inference on to the geology folks, please do so pronto! Thanks!