3 ms·
This doesn't impact the actual weight of a kg. What this impacts is how the kg is defined, no longer does it rely on a physical kg. It used to literally be def
by shittyadmin 8y ago
This doesn't impact the actual weight of a kg. What this impacts is how the kg is defined, no longer does it rely on a physical kg.
It used to literally be defined as the mass of "IPK" - the international prototype kilogram. https://en.wikipedia.org/wiki/Kilogram#International_prototype_kilogram https://en.wikipedia.org/wiki/Kilogram#International_prototy...
This switch now defines it in terms of the force equivalent of the energy exerted by a single photon - if my understanding is correct.
Theoretically a more scientifically sound way of keeping 1 kg a constant permanently.
- cco 8y agoThat doesn't make sense to me, the definition has changed. The IPK was 1 kg and the copies of it were all slightly heavier or lighter, for argument let's say IPK1 was 1.1 kg and IPK2 was 0.9 kg. Now that we have a constant for the mass of 1 kg, all of those IPK's will now have a new mass relative to the new definition. Unless the new definition was based on the current IPK and set its mass as of today as the standard, and that standard now will be unchanging?
- ekimekim 8y ago> Unless the new definition was based on the current IPK and set its mass as of today as the standard, and that standard now will be unchanging? Correct. The current IPK will still be 1kg to within margin of error at the time the new definition comes into effect, but any further changes to it will make it, for the first time, drift away from that value.