News and Comment

Leap Seconds: A Public Dialogue

Thursday 17 April 2014

In 2015 the world will take a decision about whether we should continue to have an international coordinated time based on the earth’s rotation, or move to rely fully on atomic clocks.  It is not the first time a vote has taken place on the question, but no international agreement has been reached to date. This time the Minister responsible for the UK position, David Willetts, has opted to hold a national public dialogue with stakeholders and the general public to debate the issues in depth. The National Measurement Office (now the National Measurement and Regulation Office), in conjunction with Sciencewise, has commissioned OPM Group and RK Partnership to run this dialogue. The discussions will start on April 30, with a National Stakeholder Workshop in London and the launch of an online discussion. Public workshops will begin at the end of May and be held throughout June in Belfast, Birmingham, Cardiff and Edinburgh. A National Summit will bring all the findings from the dialogues together in July.

This is a tricky topic for public debate since it covers some fairly technical issues. Time is measured very precisely by the average of several hundred atomic clocks, with a Coordinated Universal Time (UTC) transmitted by radio signal. The problem with precisely measuring time in this way, is that it is not directly in sync with the earth’s rotation, which is not uniform and is slowing very slightly. This means we have two methods of telling time which have a very slight discrepancy between each other. To keep them in synch, a ‘leap second’ is occasionally added to atomic time to bring it in line with solar time.

At least five months notice is given before adding a leap second. However, they can still cause computer glitches. Websites have previously crashed when leap seconds are added. Whilst there have never been any recorded problems,  there are also concerns the time stamping of financial transactions could be open to fraudulent practices and civil and military navigational systems could encounter difficulties. Hence, some organisations and countries would like to stop adding leap seconds to atomic time.

The dialogues will bring together stakeholders and the public to discuss these issues. The differences between atomic time and solar time are small: at the end of the century they would differ by two minutes if we stopped adding leap seconds. It may be the general public thinks this is such a small difference they would not notice, let alone care if we moved to atomic time. Alternatively, there could be public frustration if governments decided, without seeking views, to choose a method of measuring time which has only existed for the last half a century over one which has been in existence for thousands of years. Indeed, time being related to earth’s rotation and the solar system might have particular importance to people of certain faiths or philosophies.

Over the next few months we will be exploring the philosophical and technological dimensions of measuring time with the general public and stakeholders. We will work with stakeholders to identify key issues and make these accessible for public debate. We will run reconvened workshops in all four regions of the UK. The first will help the public understand the problem and different stakeholder perspectives. The second will see if there can be convergence around public and stakeholder views around particular issues. The outcomes will be used to inform the Minister’s position.

Whilst workshop participation will be by invite only, we will have an open discussion board and survey on a dedicated leap seconds website. This will be complemented by pop-up dialogues at specific science events. We will release further details when the dialogue begins.

If you have any further questions about the dialogue, please contact more information on the methodology and the outcome of the dialogue, please see the Leap Seconds UK Public Dialogue case study and Final Report.