International Bureau of Weights and Measures

The kilogram was defined as the mass of a single object.

The International Prototype of the Kilogram, a platinum-iridium cylinder conserved at the BIPM at Sèvres outside Paris.

For over 100 years, the kilogram was that cylinder, not a definition that pointed at the cylinder.

That cylinder was the kilogram.

One object.

The world's unit of mass was a lump of metal in a French suburb.

And the BIPM's own description of it's honest about the cost.

It ensured a common reference for the whole world, and it also meant the definition of the kilogram depended on one physical object.

What time is it on the moon? And how does time fly if you're having fun on the moon? Those questions are sort of on the agenda at the General Conference on Weights and Measures, which starts next week at the Palais du Congrès de Versailles.

The general conference is the supreme authority of the International Bureau of Weights and Measures, the body established by the Metre Convention in 1875, which has a mission to be the world focus for the International System of Measurement.

And Draft Resolution D at the congress is designed to advance the global discussion about establishing a universal lunar time.

And I'm very pleased to say that we are joined now by Dr. Annette Khoo, who is the director of the International Bureau of Weights and Measures, who joins us from Paris.

Dr. Khoo, welcome to Sunday Extra.

Thanks for having me.

It still needs to be done.

It's really right at the beginning.