Time: just how accurate do we need to be?

13 March 2012

A few weeks ago in this column, I reported on the leap second and the stalemate on whether or not we should retain this particular international time correction. Well, returning to the time theme again, my attention was caught last week by a proposed new time-keeping system, tied to the orbiting of a neutron around an atomic nucleus, which promises such unprecedented accuracy that it neither gains nor loses 1/20th of a second in 14 billion years - the age of the Universe.

“This is nearly 100 times more accurate than the best atomic clocks we have now,” proclaims one of the researchers, Professor Victor Flambaum, who heads up the Department of Theoretical Physics at the University of New South Wales (UNSW) in Sydney, Australia. Professor Flambaum says this discovery would allow scientists to test fundamental physical theories at unprecedented levels of precision and provide an unmatched tool for applied physics research.

In a paper to be published in the journal Physical Review Letters - with US researchers at the Georgia Institute of Technology and the University of Nevada – Professor Flambaum and UNSW colleague Dr Vladimir Dzuba report that their proposed single-ion clock would be accurate to 19 decimal places.

The exquisite accuracy of atomic clocks is widely used in applications ranging from GPS navigation systems and high-bandwidth data transfer, to tests of fundamental physics and system synchronisation in particle accelerators.

“With these clocks currently pushing up against significant accuracy limitations, a next-generation system is desired to explore the realms of extreme measurement precision and further diversified applications unreachable by atomic clocks,” says Professor Flambaum. “Atomic clocks use the orbiting electrons of an atom as the clock pendulum. But we have shown that by using lasers to orient the electrons in a very specific way, one can use the orbiting neutron of an atomic nucleus as the clock pendulum, making a so-called nuclear clock with unparalleled accuracy.”

My goodness, whatever next! The discovery of the Higgs Boson?

DECC launches first open CCS R&D competition
Last week, energy secretary Edward Davey fired the starting pistol on a race to accelerate developments in the field of carbon capture and storage (CCS). A competition - worth up to £20m to successful bidders - is seeking better and cheaper CCS components and systems for pilot scale demonstration that will ultimately support the development of the technology. The government regards CCS as being a crucial strategy in the UK's battle to meet its carbon emissions reduction targets, though arguments abound against CCS - namely, the high cost and the length of time before the technology becomes widely available for implementation, and the problems associated with storing CO2 in geological formations.

The competition is in addition to the £1bn already committed to funding commercial scale CCS projects under DECC’s CCS commercialisation programme, the competition for which kicks off in the coming weeks. The government is hoping that by opening up the field in this way, the cash incentive will spur innovations that might be incorporated into the UK supply chain, thus reducing the cost of future commercial CCS deployment in the UK. The CCS industry is estimated to be worth as much as £6.5bn a year by the late 2020s, and Edward Davey wants the UK to become a major player.

Having taken the baton from his predecessor, Davey has reconfirmed CCS as a key element in the government’s carbon emissions reduction strategy - one that will not only play a role in the development of a low carbon energy mix, but which might possibly see the UK eventually becoming a world leader in this field. The UK’s first carbon capture pilot, opened at Ferrybridge last year, is held up by Davey as an example of what CCS could ultimately mean to the UK in terms of jobs and growth.

This latest £20m fillip to CCS R&D in the UK is part of a four year, £125m cross-government programme to be delivered by the Department of Energy and Climate Change, the Technology Strategy Board, the Energy Technologies Institute and the Research Councils.

Ten thousand holes in Blackburn, Lancashire
Well, I suppose I stretch a point with that famous Beatles lyric, but apparently a mysterious ‘hole’ has been discovered beneath Manchester’s Arndale shopping centre and it is exercising the minds of two Manchester-based academics.

The mysterious space (a term used in preference to ‘hole’ in the University’s statement) - underneath a branch of Topshop, to be exact - has been identified as the initial stages of a long forgotten underground railway through the city centre. According to Dr Martin Dodge from The University of Manchester and Richard Brook from the Manchester School of Architecture, the `void' (even better) was the beginnings of a station intended to be part of a 2.3 mile-long route.

The space – forgotten for decades and closed off to the public but rediscovered by the two lecturers - is about 30 feet below the surface and was built to link the Arndale to the new station. A new book published last week containing architects' drawings and previously unseen maps of the ‘Picc-Vic’ tunnel formed part of a short exhibition curated by the two academics, which, unfortunately, closed its doors all too soon last Saturday.

The exhibition – esoterically titled: Infra_MANC - showed how close Manchester came to a brave new world of helipads, multiple urban motorways, tunnels and moving pavements. The proposals for Manchester’s tube railway advanced over 20 years, culminated in the receipt of Parliamentary powers in 1972 and formal plans to commence construction works in September 1973 with a target completion date of 1978.

Three underground stations below the Central Library, Whitworth Street and a brand new station under the junction of Market Street and Cross Street to serve the Arndale Centre and the surrounding commercial area would have been built. The mainline train stations of Piccadilly and Victoria would have been connected for the first time, while moving walkways (also in subways) would have joined Piccadilly Gardens, St. Peter's Square and Oxford Road station.

"Manchester has long desired to have an underground railway crossing the city centre and perhaps the earliest plan was put forward in 1839,” explains Dr Dodge. "In the 1960s and 70s, the Picc-Vic tunnel was a proposed rail route beneath the city centre and would have formed the centrepiece of a new electrified railway network for the region. Our research has unearthed new engineering plans and architectural drawings that reveal how Manchester just missed out on having its own mini tube system.

According to Dodge and Brook, the Picc-Vic scheme encompassed four major routes, with trains every ten minutes outside the centre and every two and a half minutes inside. It would have involved two eighteen feet diameter tunnels costing a tidy sum; the infrastructure grant application was eventually turned down in August 1973 by the then transport minister, John Peyton. The Chancellor of the Exchequer at the time, Anthony Barber said: `there is no room for a project as costly as Picc-Vic before 1975 at the earliest'.

The two academics also investigated what they refer to as "vague, half rumours” that the Guardian Underground Telephone Exchange (GUTE) may also have had its own impact on the Picc-Vic proposals. That exercise, however, proved a dead-end; the project team did know the location of the GUTE, but were forced to sign the Official Secrets Act in 1971, despite the tunnels being declassified in 1968.

Les Hunt
Editor

Reader comment:

From Mr Rod Dalitz:
As a crude generalisation (remembering "All generalisations are false"), when a huge improvement in accuracy becomes available, surprising new ways will be found to use that. Sure, for everyday purposes, a few seconds is unimportant, but for serious engineering like GPS, and for fundamental science like the neutrino speed measurement, nanoseconds matter.
Leap seconds used to appear a trivial correction, but increasingly time measurement is so unimaginably precise, that clunky physical processes like the rotation of the earth, and the orbit of the earth round the sun (which reminds me to mention the precession of the orbit of Mercury ...) are crude in comparison.