dagblog - Comments for "Weighing whether to wait a second, scientists put off decision for three years"

Never let it be said that

SleepinJeezus — Sun, 22 Jan 2012 13:30:50 +0000

In reply to Listen, Peracles, I'm wobbly

Never let it be said that Canadians don't have any stones.

I took the Ron Paul remark in

acanuck — Sun, 22 Jan 2012 03:59:32 +0000

In reply to I was just trying to make a

I took the Ron Paul remark in the spirit you intended, Trope. My gut feeling is that none of the delegates to this ITU meeting really thought through the can of bad-PR worms that this proposal would open.

The idea of dropping the leap second has been around for at least a decade, with similar arguments about simplifying and streamlining the functioning of navigation and communications systems.

But nobody has ever demonstrated the serious problems such a move is purportedly necessary to solve. After 40 years, it's fairly obvious that any software that might have been affected by insertion of a leap second has been successfully designed to accommodate the existing system.

I suspect by 2015 the issue may not even be on the agenda. And yes, curling rocks.

I was just trying to make a

Elusive Trope — Sun, 22 Jan 2012 01:15:30 +0000

In reply to Ron Paul? Gold standard? You

I was just trying to make a joke with the Paul remark.

I do think you make a solid argument about going with the Sun-Earth standard.

(and for what's it worth, I'm with you on the curling.)

Listen, Peracles, I'm wobbly

acanuck — Sun, 22 Jan 2012 01:07:08 +0000

In reply to So I get you're a wobbly, a

Listen, Peracles, I'm wobbly even by Canadian standards. But yeah, you pretty well nailed it. As for curling, I will happily sit down with a bottle of wine to watch a tournament, end to end, on TV. A superb, subtle and underappreciated game of strategy and skill.

So I get you're a wobbly, a

PeraclesPlease — Sun, 22 Jan 2012 00:02:16 +0000

In reply to Ron Paul? Gold standard? You

So I get you're a wobbly, a Sun worshiper, one of those oxygen loving tree huggers, and a moral relativist to boot. Or I could have saved time & typing with "Canadian".

I'm just worried that if we give you an role in a relatively straightforward & instantaneous concept like "leap second", you'll drag it out into something painfully akin to curling.

Ron Paul? Gold standard? You

acanuck — Sat, 21 Jan 2012 23:44:05 +0000

In reply to I just curious whether the

Ron Paul? Gold standard? You calling me a Luddite, Trope? I'll let that pass.

Yeah, I think the belief is that the atomic cycles being measured -- of various atoms, not just caesium -- are invariable. I've seen claims that the latest atomic clocks are accurate "within one second in a million years." Hard to prove or disprove; all we can say from the evidence is that -- once you factor out relativity effects -- atomic clocks do appear to stay remarkably in sync with other atomic clocks. Good enough.

I think it's crucial that we retain the Sun-Earth standard as a constant reminder of the wobbly, precarious platform from which we humans observe the universe. The length of the day and the year have changed radically over time, the climate has gone from molten to ice-encased to something in-between, the atmosphere has only recently become oxygen-rich, and we only recently developed lungs to take advantage of all that delicious oxygen. We're blessed with a Goldilocks sun, but even it flickers and sputters, and one day will burn out, killing all our descendants if we haven't already gotten around to that by accident or design. The whole process is fragile, it's messy, it's in constant flux. We can observe the passing show with wonder and awe, and try not to add unduly to the chaos. Or we can try desperately to freeze-frame the moment, which seems pretty pointless.

Now where was I? Oh yeah, about the proposal to ban the leap second ...

Atheist, I did see a piece by

acanuck — Sat, 21 Jan 2012 22:37:24 +0000

In reply to I like it. It makes a lot of

Atheist, I did see a piece by one critic of "decoupling" that listed redefinition of the second as one possible solution to the so-called problem. He wasn't pushing it as a serious proposal, however.

I think it's way too early to attempt, however. We have only half a century of data directly comparing the caesium standard with observations. I'd stick with the current system of intermittent adjustments for at least a century or two, in order to get an ever more accurate measure of the average solar second. Hell, we could designate a nice round date in advance -- say, 2500 -- for when we'll switch to the "new second."

It's not like we'll be messing with something that's cast in stone: the official UTC is determined by averaging the readings from dozens of atomic clocks around the globe, which differ by very tiny amounts depending on position. UTC had been in use for five years before we got around to introducing a correction so all read as if they were at mean sea level. (With altitude, even atomic clocks run slower due to relativity.)

And throughout the 1960s (before UTC but after adoption of the caesium second), another correction was used to keep atomic time in sync with GMT. So fiddling with the definition of the second is not breaking totally new ground.

Ah, for the good old days, when a meter was defined as the length of a metal bar in a Paris museum!

Can't forget the Zeeman

Elusive Trope — Sat, 21 Jan 2012 21:31:08 +0000

In reply to Like the word "hyperfine."

Can't forget the Zeeman Effect

Like the word "hyperfine."

Elusive Trope — Sat, 21 Jan 2012 21:26:27 +0000

In reply to I like it. It makes a lot of

Like the word "hyperfine." Had to look it up (does it answer my question below?)

The term hyperfine structure refers to a collection of different effects leading to small shifts and splittings in the energy levels of atoms, molecules and ions. The name is a reference to the fine structure which results from the interaction between the magnetic moments associated with electron spin and the electrons' orbital angular momentum. Hyperfine structure, with energy shifts typically orders of magnitude smaller than the fine structure, results from the interactions of the nucleus (or nuclei, in molecules) with internally generated electric and magnetic fields.

In atoms, hyperfine structure occurs due to the energy of the nuclear magnetic dipole moment in the magnetic field generated by the electrons, and the energy of the nuclear electric quadrupole moment in the electric field gradient due to the distribution of charge within the atom. Molecular hyperfine structure is generally dominated by these two effects, but also includes the energy associated with the interaction between the magnetic moments associated with different magnetic nuclei in a molecule, as well as between the nuclear magnetic moments and the magnetic field generated by the rotation of the molecule.

Yeah, ok, that makes sense.

I just curious whether the

Elusive Trope — Sat, 21 Jan 2012 21:11:18 +0000

In reply to Weighing whether to wait a second, scientists put off decision for three years

I just curious whether the belief is that the cycles of a caesium 133 is actually consistent and stable or the variations are so "small" that we cannot observe them, like the theoritical strings of M theory. And what impact do the other 8 dimensions of M theory have on time and space?

Given the natural world with its non-linear and turbulent irregularity of the unfolding, it is interesting that it is built upon the stable reiteration like the cycles of the caesium 133 - or is that the most subtle of all variation in those cycles ripple out to create the patterns of weather and human consciousness.

But, yeah, let restore the Sun-Earth standard as the definition of time. Maybe Ron Paul will take it up as a companion cause with the Gold standard.