Worlds Most Famous Clock Reaches 150

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It’s one of the world’s most iconic land marks. Standing proudly over the Houses of Parliament, Big Ben celebrates its 150th birthday. Yet despite living in an age of atomic clocks and NTP time servers, it is one of the most used timepieces in the world with hundreds of thousands of Londoners relying on its chimes to set their watches to.

Big Ben is actually the name of the main bell inside the clock that creates the quarter hourly chimes but the bell didn’t start chiming when the clock was first built. The clock began keeping time on 31 May 1859, while the bell didn’t strike for the first time until July 11.

Some claim the twelve tonne bell was named after Sir Benjamin Hall the Chief Commissioner of Works who worked on the clock project (and was said to be a man of great girth). Others claim the bell was named after heavyweight boxer Ben Caunt who fought under the moniker Big Ben.

The five-tonne clock mechanism works like a giant wristwatch and is wound three times a week. Its accuracy if in tuned by adding or removing old pennies on the pendulum which is quite far removed from the accuracy that modern atomic clocks and NTP server systems generate with near nanosecond precision.

While Big Ben is trusted by tens of thousands of Londoners to provide accurate time, the modern atomic clock is used by millions of us every day without realising it. Atomic clocks are the basis for the GPS satellite navigation systems we have in our cars they also keep the internet synchronised by way of the NTP time server (Network Time Protocol).

Any computer network can be synchronised to an atomic clock by using a dedicated NTP server. These devices receive the time from an atomic clock, either via the GPS system or specialist radio transmissions.

The World in Perfect Synchronization

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Synchronization is something we are familiar with everyday of our lives. From driving down the highway to walking crowded street; we automatically adapt our behaviour to synchronize with those around us. We drive in the same direction or walk the same thoroughfares as other commuters as failing to do so would make our journey a lot more difficult (and dangerous).

When it comes to timing, synchronisation is even more important. Even in our day to day dealings we expect a reasonable amount of synchronisation from people. When a meeting starts at 10am we expect everybody to be there within a few minutes.

However, when it comes to computer transactions across a network, accuracy in synchronisation becomes even more important where accuracy to a few seconds is too inadequate and synchronisation to the millisecond becomes essential.

Computers use time for every transaction and process they do and you only have to think back to the furore caused by the millennium bug to appreciate the importance computer’s place on time. When there is not precise enough synchronisation then all sorts of errors and problems can occur, particularly with time sensitive transactions.

Its not just transactions that can fail without adequate synchronisation but time stamps are used in computer log files so if something goes wrong or if a malicious user has invaded (which is very easy to do without adequate synchronisation) it can take a long time to discover what went wrong and even longer to fix the problems.

A lack of synchronisation can also have other effects such as data loss or failed retrieval it can also leave a company defenceless in any potential legal argument as a badly or unsynchronised network can be impossible to audit.

Millisecond synchronisation is however, not the headache many administrators assume it is going to be. Many opt to take advantage of many of the online timeservers that are available on the internet but in doing so can generate more problems than it solves such as having to leave the UDP port open in the firewall (to allow the timing information through) not-to-mention no guaranteed level of accuracy from the public time server.

A better and simpler solution is to use a dedicated network time server that uses the protocol NTP (Network Time Protocol). A NTP time server will plug straight into a network and use the GPS (Global Positioning System) or specialist radio transmissions to receive the time direct from an atomic clock and distribute it amongst the network.

The Concept of Time

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Time is something that we are all familiar with, it governs our lives even more so than money and we are constantly ‘at war’ with time as we battle to conduct our daily tasks before it runs out.

Yet when we start to examine time we discover that the concept of time we begin to realise that a non-ending linear distance between different events that we call time is purely a human invention.

Of course time exists but it certainly doesn’t follow the rules that the human concept of time does. It is not never ending or constant and changes and warps depending on speed of observers and the pull of gravity. In fact it was Einstein’s theories on relativity that gave human kind its first glimpse as to what time really is and how it affects our daily lives.

Einstein described a four-dimensional space-time, where time and space are inextricably woven together. This space-time gets warped and bent by gravity slowing time (or our perception of it). Einstein also, he suggested that the speed of light was the only constant in the universe and time altered depending on the relative speed to it.

When it comes to keeping track of time, Einstein’s theories can hamper any attempts at chronology. If both gravity and relative speed can affect time then it becomes difficult to measure time accurately.

We long ago abandoned the idea of using the celestial bodies and Earth’s rotation as a reference for our timekeeping as it was recognised in the early twentieth century that Earth’s rotation wasn’t at all accurate or reliable. Instead, we have depended n the oscillations of atoms to keep track of time. Atomic clocks measure atomic ticks of particular atoms and our concept of time is based on these ticks with every second being equal to over 9 billion oscillation of the caesium atom.

Even though we now base time on atomic oscillations, technologies such as GPS satellites (Global Positioning System) still have to counter the effects of lower gravity. In fact the effects of time can be monitored so accurately thanks to atomic clocks that those at different altitudes above sea level run at slightly differing speeds which has to be compensated for.

Atomic clocks can also be used to synchronise a computer network ensuring that they are running as accurately as possible. Most NTP time servers operate by utilising and distributing the time signal broadcast by an atomic clock (either through GPS or long wave) using the protocol NTP (Network Time Protocol).