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Welcome, 77 artists, 40 different points of Attica welcomes you by singing Erotokritos an epic romance written at 1713 by Vitsentzos Kornaros

Thursday, July 11, 2013

Hang on 9,192,631,770 oscillations ? time is accurate enough for me already

Must scientists at the Paris Observatory really give the world's timekeepers more ammunition in their war on the unpunctual?

There is a paradox at the heart of scientific endeavour. As Homer Simpson put it: "How come they can send a man to the moon but can't make my shoes smell good?"

I felt similarly on hearing the thrilling if intellectually discombobulating news that scientists at the Paris Observatory claim to have found a more accurate way to measure time.

Will their research help temporal slackers like me in the war against punctuality? If I'm late for an appointment can I cite the new Parisian redefinition of the second as mitigation in a dog-ate-my-homework manner? Unlikely. It's hard then for me to see the benefits of what is evidently very clever scientific research. In my view, public funding of scientific research should be further slashed until it really addresses the most important spatio-temporal matters in my universe.

Idiot, you retort: don't you realise that telecommunications, satellite navigation and the stock markets rely on ever-better time measurements? That atomic clocks stop planes crashing into each other? That you wouldn't be making mobile phone calls so readily if it weren't for atomic clocks facilitating the simultaneous transmission of thousands of calls down the same wire?

Hold on. Wasn't time already measured sufficiently accurately? In the olden days it was relatively simple to grasp how time was measured. One complete rotation of the Earth equalled a day and the rest of the units we used to measure time could be made up of subdivisions. We have, incidentally, always measured time in terms of distance.

Then someone noticed that the Earth wobbled as it rotated on its axis, making some days longer than others. That's why, before 1967, you so often heard British Rail announcers deploy the stock get-out clause: "We would like to apologise for the late running of the 11.43. This is because of unscheduled undulations in the Earth's rotation interfering with our temporal measurement paradigm. But we should make up time after Reading." If we were going to get serious about measuring time, we had to do better than that.

That is when all our problems began. Ever since 1967, the measurement of time has been so accurate that the slacker era of excuses for being late is over. We're pursued ever more ardently by time's winged chariot, driven by temporal technicians who insist that we be punctual, present and correct.

Since 1967 the definition of a second has been the duration of 9,192,631,770 oscillations of the microwave radiation absorbed or emitted when a caesium atom jumps between two particular energy states. (If you're getting that glazed look you experience when Brian Cox gets technical, I can only apologise.) And, currently, the best way to measure that frequency is with what scientists poetically call an atomic fountain, whereby a laser beam propels atoms of gaseous caesium upwards and then the atoms' emissions are probed once by a microwave as they rise and then again as they fall. Such a caesium fountain clock will keep time to within one second over 100 million years.

But that's not accurate enough for Dr Jerome Lodewyck and his team of in Paris. They have devised an optical lattice clock that they hope will be even more accurate. "In our clocks we use laser beams," Lodewyck explains. "Laser beams oscillate much faster than microwave radiation, and in a sense we divide time in much shorter intervals so we can measure time more precisely." Optical lattice clocks lose just one second every 300 million years.

Thanks for giving the world's timekeepers more ammunition in the war against the unpunctual. How can the slackers of the world resist this onward march of temporal tweaking?

Consider the French philosopher Henri Bergson, who argued that while how we measure time and redefine the units of its measurement is important for the advancement of science, all of that activity misses much of what is valuable in what it is to be a human. He distinguished between time and duration: the former is a homogeneous medium that can be divided into periods of equal length; the latter is heterogeneous and so can never be divided into such instants. Arguably, it is duration that is more important than time in human life. When we hear music it is not just a succession of disconnected notes but a continuity. The world in other words is experienced not moment by moment but in a continuous fashion. If you're the guard confronting an angry mob on the stationary train outside Bodmin Parkway that's never going to make it to Penzance on time, use Bergson to placate them

The Greek philosopher Zeno devised four paradoxes of motion to prove that to we can never move past a single point because each point is infinitely divisible and it is impossible to cross an infinite space. That's why that Bodmin to Penzance train will never, as a matter of fact, reach its destination. For thinkers such as Zeno and Parmenides, time and space were unreal and any attempts to measure them doomed to self-contradiction.

That defence, after the millennia, remains the best retort to the temporal technicians such as Lodewyck whose work may well have the unacceptable result of getting human beings to run on time.


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