The fixed exchange rate between pounds and kg is obsolete and inappropriate for a modern economy and is the kind of thing BREXIT was supposed to free us from.
It's wonderful that we have different miles and feet for different purposes, and even different exchange rates between them.
Let the Europeans suffer under the yoke of the rigid and procrustean french measurement system. Let freedom of expression flourish!
"Since the revision of the SI on 20 May 2019, we can now compare the gravitational force on an object with an electromagnetic force using a Kibble balance. This allows the kilogram to be defined in term of a fixed numerical value of the Planck constant, a constant which will not change over time."
"A Kibble balance is an electromechanical measuring instrument that measures the weight of a test object very precisely by the electric current and voltage needed to produce a compensating force. It is a metrological instrument that can realize the definition of the kilogram unit of mass based on fundamental constants."
"One important reason for the change is that Big K is not constant. It has lost around 50 micrograms (about the mass of an eyelash) since it was created. But, frustratingly, when Big K loses mass, it's still exactly one kilogram, per the current definition. When Big K changes, everything else has to adjust."
Not sure if this is a joke about weights changing over time or in different places due to gravitational differences - but if you mean mass that was true until fairly recently, the kg is no longer defined by the mass of a specific physical item.
"Since 1 July 1959, the international avoirdupois pound (symbol lb) has been defined as exactly 0.45359237 kg. In the United Kingdom, the use of the international pound was implemented in the Weights and Measures Act 1963. (a) the yard shall be 0.9144 metre exactly; (b) the pound shall be 0.45359237 kilogram exactly."
"The kilogram is defined by taking the fixed numerical value of the Planck constant, ℎ, to be 6.626 070 15 × 10-34 when expressed in the unit J s, which is equal to kg m2 s−1, where the metre and the second are defined in terms of the speed of light, , and the hyperfine transition frequency of the caesium-133 atom..."
Nothing new. Rando hacker news poster, vs say... the International Standards Organization on Weights and measures. Hmm... I am going to place my faith in say... a group of people who's degrees far outnumber most of the colleges I studied at.
No, the speed of light is not defied in the "flattest" one of them. Please do your homework. "The speed of light is a universal constant denoted by c."
In my second college physics class, the final exam was one single question: "Derive the speed of light." I got a grade of 4/10, which put me at the top two students in the class. The class was a 5 1/2 month exercise in brutality of math. I would suggest you get a few college physics classes under your belt.
Incorrect. It is two-way you’re measuring. Always. Yes, including in circuit designs
Nope it can't. See https://www.youtube.com/watch?v=pTn6Ewhb27k&t=0s for a good explanation.