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The Future of Time: UTC and the Leap Second
rlseaman writes "UTC ("Coordinated Universal Time") is very close to being redefined to no longer track Earth rotation. Clocks everywhere — on your wall, wrist, phone or computer — would stop keeping Solar time. 'American Scientist' says: 'Before atomic timekeeping, clocks were set to the skies. But starting in 1972, radio signals began broadcasting atomic seconds and leap seconds have occasionally been added to that stream of atomic seconds to keep the signals synchronized with the actual rotation of Earth. Such adjustments were considered necessary because Earth's rotation is less regular than atomic timekeeping. In January 2012, a United Nations-affiliated organization could permanently break this link by redefining Coordinated Universal Time.'"
Here's the full PDF version.
Do you normally read all American Scientist articles? I don't, so I appreciate this article being brought to my attention (though I'm not planning to pay to read it). The purpose of /. is to point out interesting information so that we can read it further. The summary is supposed to be an accurate summary of the article; since an abstract is already provided, why shouldn't it be used?
A taco shell script? Inconceivable!
The CB App. What's your 20?
The Download: PDF Only link on the right hand side of the first linked page (Cornell) gives you a PDF of the same article.
Oh no... it's the future.
... could we also get rid of Daylight Savings Time?
Seriously this has been an issue for along time - GPS time does not include leap seconds and I am tired of having to write software that let's user adjust for the variable amount of leap seconds - nobody really cares if the earths rotation is synchronized with " UTC"
Those who doesn't care about synchronisation already have the option to use TAI. They should use that instead of redefining UTC.
will simply ignore UTC and continue to show the time based on the earth's rotation. All this means is that UTC loses any small shred of relevance that it once may have had to the common man. So go ahead, redefine UTC and we can all just go back to using GMT for our reports, syslog messages, traps etc. that all have far more to do with the time as experienced by users than the time as experienced by a cesium atom. I expect that soon after the decision is made someone will start gmt.pool.ntp.org and utc.pool.ntp.org and we'll have a choice.
Nullius in verba
If UTC would be redefined to no longer be adjusted to Earth's rotation, then what would be the point of having UTC at all? We already have a time scale that counts seconds without adjusting to Earth's rotation: TAI
Please correct me if I got my facts wrong.
It's called TAI. Redefining UTC is just plain stupid - it was created to track sol. If someone doesn't like the fact that doing so requires occasional adjustments, then they chose to use the wrong time scale. Those who use UTC as intended shouldn't have to live with the problems which will result if it is unlocked from solar time, just to keep those who made a poor choice happy.
(GMT hasn't been in use for a long time, although most people use the term interchangeably with UTC).
"National Security is the chief cause of national insecurity." - Celine's First Law
The metric system is originally based upon an earth derived measurement called the meter. 1m ~ 1/10,000 the distance from the equator to the poles, 1g = the weight of 1cc of pure water at STP, etc. That all the measurements are base 10 is not what makes it "metric", it's that they're derived from the (originally) earth centric meter. Our time system is also derived from earth centric measurements, called day and year.
Base 10 time would be a huge adjustment for society. While using a 100,000 "MetSec" day and a 100 "MetSec" "MetMin" would produce units fairly close to the existing second and minute measurements, a "MetHour" would be much longer or much shorter than an hour, either 14.4 minutes (100 MetHours/day), or 2.4 hours (10 MetHours/day). And that doesn't do anything to address the leap second issue, nor does it alter the ~ 365.25 MSD year.
The bottom line is that as long as we maintain the concept of a day and year and all the associated stuff (seasons, equinoxes, solstices, etc.), all of which are critical to agriculture and survival, there has been no system of time keeping proposed that is significantly better than what we have. The universe is not going to arbitrarily adapt it's cycles to make it easy for our minds and computers to keep track of time.
And that's without considering relativistic time dilation. While most people never have to worry about time dilation effects, the atomic clocks that create UT1 and GPS satellites have to compensate for relativistic differences caused by differences in local gravity and speed, both of which are affected by altitude.
Perhaps Douglas Adams said it best, "Time is an illusion, lunchtime doubly so."
make imaginary.friends COUNT=100 VISIBLE=false