geek learn science

The kilogram needs redefining. Bonus: the roundest thing on Earth

We have moved all our measurement units from the prototypes that were stored in France to something more “absolute”. A meter is defined now as the distance the light travels in 1/300 000 000 seconds, a second is about 9 billion oscillations of electrons between two ground states in Caesium 133. Now it’s the turn of the kilogram.

The scientists decided that they should redefine the kilogram in such a way that the Planck constant should be 6.62606896×10^−34 J·s.

Now, there is also another method to define 1 kilogram. You take a silicon sphere so round that you can even count the number of silicon atoms in it and you get a fairly “absolute” kilogram. That could do too 😀

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.