THE END OF THE KILOGRAM

I have always known the kilogram as the unit of mass in the metric system, equal to 2.20462 pounds.  It is convenient that the kilogram is almost exactly the mass of one liter of water, and for that reason in 1795 became the standard of equivalence.  But note that almost exactly, which means something is awry.

Thus from 1889 (during the French Revolution) until last year, a kilogram was an actual chunk of platinum-iridium alloy stored in a climate-controlled safe in Sevres, France.  But a further change was necessary because this piece of metal actually lost 50 micrograms (weight of an eyelash) over the past 129 years.

At the same time the kilogram was standardized more than a century ago, the meter was accepted to be one ten-millionth the distance from the North Pole to the equator.  A metal bar was then crafted to be exactly one meter long.  But the shape of the Earth is changing, so too that bar.

So back to the kilogram, it is now merely an item linked to the Planck constant, which never changes, anywhere and anytime into the future.  I did not say this makes any sense at all, but:

The kilogram, symbol kg, is the SI unit of mass. It 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 meter and the second are defined in terms of c and ∆νCs.

What the heck is a Planck constant?  Simply, it is the matter release energy of a quanta.  How can something which starts with a decimal point followed by 33 zeros be measured?  They use a Kibble balance:

Invented by British scientist Bryan Kibble, it equates the mechanical energy exerted by the mass of an object with an equivalent amount of electrical energy.  You arrive at the Planck constant by using this balance and these equations:

This process works because, as in Einstein's energy equals mass times speed of light squared, mass and energy are alike.

The meter also underwent a similar re-standardization.  Light travels at 299,792,458 meters per second.  Forget that distance between the pole and equator.  Now the meter is the distance light travels in a vacuum in 1/299,792,458 of a second.  Now, this length will not change, like that bar of metal did.

Now, there is no need for a government or governing body to tell exactly what a kilogram is.  The kilogram is now a fundamental truth which anyone with the proper equipment can determine.  Look for a high school student to soon build a miniature version of a Kibble balance to do so.

Chances are that your feeble mind got the drift of how a kilogram or meter was determined. Few in America understand the metric system, and virtually no one can comprehend something like the Kibble balance.  A kindergarten student can visualize that one kilogram alloy in France.  Stephan Schlamminger (that's him to the left) an American scientist with the National Institute of Standards and Technology, went so far as getting this tattoo:

The conventional International System of Units (SI, because of the French way of speaking) actually had more than mass and distance:

• the kilogram (kg), for mass
• the second (s), for time
• the kelvin (K), for temperature
• the ampere (A), for electric current
• the mole (mol), for the amount of a substance
• the candela (cd), for luminous intensity
• the meter (m), for distance

But scientists as of 20May2019 re-defined the SI system to the following:

the caesium hyperfine frequency Cs; the speed of light in vacuum c; the Planck constant h; the elementary charge e; the Boltzmann constant k; the Avogadro constant NA; and the luminous efficacy of a defined visible radiation Kcd.

I can't identify with the above.  The kilogram was my link with science.  Here is the statement that rendered me obsolete:

As part of the redefinition, the international prototype kilogram was retired and definitions of the kilogram, the ampere, and the kelvin were replaced. The definition of the mole was revised. These changes have the effect of redefining the SI base units, though the definitions of the SI derived units in terms of the base units remain the same.

The USA, of course, is different, for we still use the British imperial units, like pounds and ounces.  The UK has converted, we have not, because big business dictates so to the Congress, and we lead, we don't follow.  How foolish.  Only Liberia and Myanmar follow our lead.  However, at least I know what a pound represents.  While Donald Trump has done everything possible to ruin it, we are still the greatest nation on Planet Earth.  But are we becoming obsolete?

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