a dot com slash science drop us a line at e.w. underscores site tech on facebook d w dot science. if you put a specific extremely large number of silicon atoms together to create a sphere of a certain size it will weigh exactly one kilogram scientists have succeeded in doing that and why to define what a kilogram is in terms of a natural constant in this case the of a god or a constant. it s a way to check the accuracy of another new definition in terms of the planck constant this has me. been adopted as the official definition of world wide difficult stuff but it is important anyway to take the measure of things. it s a weighty matter welcomed the new kilogram we now take a look at a project based on that new official definition. since 2017 thomas and his team at the technical university. have been working on