The Race to Replace the Kilogram

This is an article about the measurement of mass by simple balance over 125 years. Why no one seems to care about this is a deep mystery to me...

The kilogram standard is losing weight for reasons that are not understood. Instead of trying to figure out why, the assumption is that there is a hidden error not unlike dark matter or dark energy but not nearly so sexy.

Even the fringe does not seem to care one iota about a simple measurement that does not make sense...why should the IPK be losing weight over time? My feeling is that this loss of mass, 0.56 ppb/yr, is telling science something very important...

I know it isn't considered a highly reputable source of information but this Wikipedia page has a good section called "Stability of the international prototype kilogram" that points out some of the difficulties of maintaining the prototype and its copies and how they are affected by their different treatments and storage conditions. The article does make a point of saying that it isn't just that the standard prototype is loosing mass but that there are variations between the various copies tested against it. How the complicated variations over time are described and explained will also affect what seems to be happening to the prototype mass.The article suggests that rather than not caring, the problem has been long studied by dedicated scientists. Kilogram Wikipedia

I haven't read the article, but such a phenomenon can be explained by the refinement of measurement methods.

Ever since Mandelbrot asked the question, "How long is the coastline of England?" we've known that measurement is dynamical -- James Gleick wrote in the afterword to Chaos: making a new science (20th anniversary edition) "When Yaneer Bar-Yam wrote a kilopage textbook Dynamics of Complex Systems in 2003, he took care of chaos proper in the first section of the first chapter (although 300 pages long)... then came Stochastic Processes, Modeling Simulation, Cellular Automata, Computation Theory, Scaling, Renormalization, Fractals, Neural Networks, Homogeneous Systems, Inhomogeneous Systems ..."

Aside such useful leading edge research, it just seems quaint to maintain a crude bar of metal to a common standard.

Hello Tom,

Happy to see you again on FQXi, but where were you ? hope your health is ok.

Excerpts:

Since 1889 the kilogram has been defined by reference to a single platinum-iridium cylinder held in a secret vault in Paris. It is the last unit of measurement still tied to a physical artifact.

But the ur-kilogram is losing mass. That, in part, is why the General Conference on Weights and Measures decided in 2011 to redefine the kilogram by pegging it to a quantum-mechanical constant.

This year the process of redefinition, which involves the official metrology laboratories of five nations and some of the most difficult measurements in all of science, enters its final phase.

...

Why force Le Grand K into retirement? For years metrologists have wanted the accuracy and reliability of an international mass standard linked to a fundamental constant of the universe rather than a Victorian-era lump of cosseted metal. But there is a more pressing reason for the change: Le Grand K appears to be losing mass. Once every 30 years or so Le Grand K is removed from its vault for cleaning and for comparison with six official copies, or temoins ("witnesses"), which are kept in the same vault. When the first two temoins were compared with Le Grand K in 1889, both matched the original. But measurements made shortly after the World War II and again in 1992 found that the copies outweighed Le Grand K slightly. It seems implausible that the copies would all somehow gain mass while Le Grand K remained unchanged. There is, of course, a more likely explanation. "We could assume," says BIPM director Michael Stock, "that the International Prototype Kilogram is losing some mass." That uncertainty is one of the reasons the General Conference on Weights and Measures--the governing body of the bureau--decided in 2011 to establish a new mass standard.

Weighing things should not be so difficult and this is the kind of measurement that limits the precision of physical constants. If mass is not constant, then every constant that has a mass dimension is also not constant.

When I first supposed aethertime, the inescapable truth was that mass and force would both have to change in concerted ways...albeit very slowly. Therefore I simply looked at the mass standard in order to falsify aethertime but instead, the IPK was losing mass at exactly the prediction of aethertime. Then I looked at pulsars and they had the same decay...the spin of the earth...the same decay...the period of the moon orbit...the same decay. Nothing was constant except for the mainstream science belief that constants are all constant.

The shrinking of the universe is what determines both charge and gravity forces and results in the growing of force. This is confusing to science. Constants that vary together are just not allowed by science...constants are constants.

There are constants that do not vary like the gyromagnetic ratio for example. The h/c^2 and alpha/c are also constants that do not vary. But mass does vary exactly as the IPK varies.

It will be interesting to see if the electron current loop that will replace the IPK will also vary in time. Also Lisa Pathfinder has gotten a 6 month extension and will measure changes in mass for 3 weeks...this should be enough to show the IPK mass loss since Lisa has two 1.6 kg Pt/Ag cubes that is weighs...

As you can see, measurement to me is a much more interesting topic than just the theories of the this and that...

Hello Steve,

It is indeed an interesting topic this loss of mass.Perhaps we have simply a kind of natural universal electromagnetic desintegration explaining this loss.

I have an other unknown about this matter not baryonic.If we have this dark matter and that this matter has a mass also ,that becomes intriguing because we must superimpose this matter not baryonic.A little if all mass had an other mass also to add.It is also the meaning of my equation E=mc²+ml²,we have a mass baryonic and an other not baryonic in logic.Like if we had forgotten this mass in fact.We have so a natural electromagnetic desintegration but also a mass not baryonic,furthermore this dark matter is 4 or 5X more important than our electromagnetic mass if I can say.It gives us a road towards entire entropy and its paradoxal infinity in the finite systems.Food for thought...

Well, obviously the topic of making sense of measurements is much more interesting to me than stringy or loopy or multiveresy thingys.

If it is true that mass simply dephases very slowly over time, that means that there will be a force associated with the mass loss of radiation as well. A star loses mass of x kg/s and moves with a velocity of y m/s and that dot product is now a force as kg m/s^2. This vector force couples the outer stars of a galaxy with its inner stars and keeps a galaxy rotation constant. This force happens to exactly match the force science calls cold dark matter halo around each galaxy to keep them rotating the way they rotate.

I call this vector force a gravity matterism since it comes from moving mass loss just like magnetism is a vector force that comes from moving charge. It is ironic that the unexplained mass loss of the IPK seems to explain why galaxies rotate the way they rotate...

Very relevant .I like this cold dark matter ,I consider in my model gravitation, dark matter,linked.Your analyse is interesting steve thanks for sharing.

Regards

The source is Current definitions of the SI units

Unit of time: The Second

The second is the duration of 9192631770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium 133 atom.

Unit of length:The Meter

The meter is the length of the path traveled by light in vacuum during a time interval of 1/299792458 of a second.

Unit of mass: The Kilogram

The kilogram is equal to the mass of the international prototype of the kilogram.

James' note: Under the conditions of using a weighing scale, of such small size that environmental conditions can be considered equal for both sides of the scale, weights are equal and the masses are equal. The kilogram is the amount of a material that balances a scale with the international prototype. The international prototype is made of platinum-iridium. The prototype is an artifact.

The kilogram is the only one of the three indefinable units of mechanics that relies upon an artifact to serve as a measure of its unit. The use of that artifact shows that the kilogram is not a defined property, but, rather lacks a definition. Its rule for measurement is substituted to serve in place of the missing definition. Mass can be measured, but is an unexplained property. All other units of mechanics are definable in terms of the meters, seconds, and kilograms. The unexplained property of mass spreads the influence of an unknown nature throughout all of mechanics.

The solution is to truly define the kilogram. Kilograms can be defined if they are removed from the trio of indefinable units. There is justification for taking this path. It is that all empirical evidence arrives as patterns in changes of velocities with respect to time. In other words, all empirical evidence uses combinations of only two units, the meter and the second.

Empirical evidence excludes all other units because all other units belong to properties that are inferred to exist by the patterns in changes of velocities with respect to time. All inferred properties, of which mass is one, owe the knowledge of their existence to empirical evidence, and, all that there is to know about them is communicated to us by empirical evidence. The units of kilograms must be definable in terms of meters and seconds only, as is the case for all inferred properties of mechanics.

Circular definitions are to be avoided. For example, kilograms cannot be defined in terms that include units of joules. Since all units of mechanics are definable using just the three indefinable units of seconds, meters, and kilograms, the only way to avoid a circular definition for kilograms is to define kilograms in terms of properties of mechanics that do not include kilograms in the definitions of their own units. That leaves only the properties of velocity and acceleration because they are the only properties of mechanics that do not include kilograms in the definitions of their units.

I have defined mass and put it to work extensively reconstructing the equations of fundamental physics, but, I don't look for acceptance of my definition here. Time and words have shown that that is not likely. However, I do present this message as the explanation for why mass should have been and could have been a defined property right from the time it was first introduced.

The equations f/m=a shows that the units of force divided by mass must be the units of acceleration. The units of acceleration are meters/second/second. Both mass and force can be defined using only the naturally indefinable units of empirical evidence. The solution that I find that works is for mass to have the units of inverse acceleration. This is the best choice of the two properties of mechanics that will not lead to a circular definition for kilograms.

The units of acceleration support this view. They are: The plural of (the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second)/(The duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom)/(The duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom).

James Putnam

You see...there is life in the simple minded measurement of mass.

In a way, mass is the only true measurement because it does depend on an artifact, which is an object of reality. One century ago, science decided that a 1 kg bar of Pt/Ir alloy would be the measure of mass. Alas, the IPK has been losing mass and so now science wants to shift mass to the watt scale.

In the future, a superconducting electron loop of energy will define mass instead of a balance and the hope is that mass will not vary with time with the watt balance.

It will be very interesting to see if the watt balance is any better after 100 years than the IPK. My prediction is that the watt balance, which is based on energy and E = mc^2 and not mass balance will also show a constant drift.

"In a way, mass is the only true measurement because it does depend on an artifact, which is an object of reality."

Physical rules for physical measurements depend upon objects of reality. Those rules are sufficient for making use of material objects, but are not sufficient for understanding material objects. The understanding comes with physics definitions. An object having a kilogram of mass measures in weight as equal to the weight of the prototype. Weight is a force. Mass is not a force. The indirect measurement of a kilogram of mass is indicative of the use of indirect explanations of mass. There is no definition of mass nor is the kilogram a defined unit. Kilogram is introduced into mechanics equations as one of three fundamental indefinable units representing one of three fundamental indefinable properties. Mass and its unit of kilogram both could have been and should have been defined just as all other inferred-to-exist, by patterns of changes of velocities of objects, properties of mechanics and their units are defined.

James Putnam

Of course, the definition of mass is beside the point. It is the measurement of the decay of mass over time that is the point, not its definition. My point is that this decay is real and reveals the true nature of the universe...I am alone in that belief...see IPK decay

The rest of the world believes that the decay of the of the IPK artifact is due to some kind of unknown process. Similarly, that the average decays of millisecond pulsars is the same constant but that does not seem to impress anyone. Every measurement that I have looked at shows this decay, just like the earth's spin shows this same decay constant. Of course, 0.26 ppb/yr is a very small change and its measurement is complicated because while mass decays at this rate, force actually increases at this same rate.

All due to the universe pulse decay...Measurement precision is getting better and the intrinsic nature of the IPK decay, millisecond pulsar, and earth spin will be either validated or falsified within the next several years.

The excerpts quoted from the article suggest otherwise. I stepped in to expose the loose use of the word 'definition' for physics purposes that goes uncorrected by physicists. You are not impressed, but, I may have made my point to readers. I will drop it since there is no other chance for progress to be made with it here. I did see that you believe that cleaning techniques have improved to the point that the chance for contamination is eliminated making the change of weight of the prototypes due only to a change in the mass of the prototype. I do find your references to other decay rates that compare in magnitude to be something that needs to be explained. Perhaps your explanation is correct. Correctness is the goal or should be. Therefore, should you be correct, I would hurry to congratulate you.

Changing direction and quoting from your link: "Thus the universe is in some sense ultimately driven by noise and not by purpose. The butterfly effect is a an example of classical noise from the flapping butterfly wing and that even that slight noise can effect the course of a hurricane. Noise is what limits the precision of any measurement of a source property and when the fluctuations of noise dominate purpose, classical chaos drives purpose, not choice."

Does this noise you refer to communicate meanings? What I want to know is it purposeful in the physics sense as the orderly flapping butterfly wing is? Or, is it meant to convey meaninglessness, disorder, and lawlessness? If it does compare to the butterfly's flight, then, what meaning in the physics sense does it convey?

James Putnam

As usual, you have very thoughtful comments and that helps me a lot to refine my discourse.

The issue of mass change of the IPK is whether the sisters are growing mass or the IPK is shrinking mass since the balance simply measures a difference. My contention is that the cleaning procedure does exactly what it is designed to do...keep the secondaries constant. However, cleaning does result in measureable decrease and then increase as the sister recovers over time.

Thus it is the IPK that loses mass over time and so the artifact has an artifact...but what if it is not an artifact of the artifact...what if the measurement is actually revealing an underlying property of the universe?

Truthfully, when I first looked at the IPK many years ago, my presumption that this mass measurement would falsify aethertime. Aethertime arose from a set of independent assumptions that showed the property of mass decay coupled with force growth with time. I was quite surprised to not only find that the IPK mass decayed with time at the right rate, but also that a lot of other clocks also showed the same decay constant.

There still could be some measurement that will falsify aethertime, but I have not yet found one.

The issue of observer in the Fqxi has got me thinking about the fact that the source is not discussed with nearly the same reverence as the observer. And yet there is no observer without a source and the photon exchange that forms a transient bond between observer and source is what people should include in any discourse.

However, without an agreement about the natures of observer, photon, and source, the discourse is futile and resolves nothing. The precision of every measurement is limited by noise, which is something that we all can agree to or there is no sense in further discourse.

There are then two fundamentally different kinds of noise: the classical noise of chaos like the butterfly effect and the quantum noise of phase entanglement, which is more like the neural choices the butterfly makes. Once again, without an agreement about the role of quantum phase in limiting precision, there is no sense in further discourse.

Classical noise is the result of chaos and every effect like a butterfly wing is in principle knowable, just buried in complexity. Quantum phase noise, however, has effects without absolutely knowable causes. In other words, quantum effects have inherently unknowable causes that entangle other sources and other locations.

This bothers a lot of people but it does not make any sense to argue about quantum phase noise. Either your spectrometer measures quantum phase or it does not measure quantum phase. Period.

It is very difficult to entangle the quantum phases of macroscopic sources like butterflies for very long periods. But there is quantum phase noise in the path of the butterfly and the neural choices that a butterfly makes for its path. The butterfly therefore contributes to the classical noise of chaos as well as the quantum phase noise of choice. Each neural moment of a butterfly is a quantum superposition of past actions as well as future possibilities.

This means the butterfly path is somewhat but not absolutely predictable. In some sense, the butterfly is on all possible paths for some short period before dephasing occurs and the butterfly future occurs.

The solution is not to truly define the kilogram...the solution is to have a measurement for mass that does not change in time. Thus far, that has not been possible. Thus far, the variation in the IPK is assumed to be some unknown artifact. Just like dark matter, science ignores measurements that do not conform to the norm.

All science wants is a mass measurement that does not wander all over the place in time. The IPK is drifting in a systematic manner and that is not acceptable to mainstream science. Instead of arguing about measurements like this, conferences argue about the meaning of nothing...go figure...

James, mass is foundational. It is what exists, the material substance. Kilograms are units not properties, they allow comparison of the amount of fermion particles in a substance (How much stuff). Mass is a link between physics and chemistry.