[D66] The Illusion of Consensus: A Critique of the Voting Process Behind Planck’s Constant

[René Oudeweg]

The Illusion of Consensus: A Critique of the Voting Process Behind 
Planck’s Constant

The fixing of Planck’s constant as an exact value in the International 
System of Units (SI) was presented to the world as a triumph of modern 
science: elegant, inevitable, and grounded in the deepest laws of 
nature. In November 2018, the General Conference on Weights and Measures 
(CGPM) voted unanimously to redefine the kilogram by assigning an exact 
numerical value to Planck’s constant, thereby severing humanity’s last 
dependence on a physical artifact. The rhetoric was celebratory, the 
vote decisive, and the outcome portrayed as the natural endpoint of 
decades of progress.

Yet beneath this polished narrative lies a deeply troubling reality. The 
“voting process” that canonized Planck’s constant was less an act of 
scientific judgment than a ritual of institutional conformity. It 
exemplified how modern metrology, for all its claims to rigor and 
neutrality, can drift perilously close to technocratic dogma—where 
consensus is manufactured, dissent is marginalized, and numerical 
exactness is mistaken for epistemic certainty.

A Vote Without a Choice

To call the CGPM decision a “vote” is already misleading. By the time 
delegates raised their placards, the outcome was foreordained. National 
metrology institutes had spent decades and billions of dollars 
developing watt (Kibble) balances and silicon-sphere experiments 
explicitly to converge on a value of Planck’s constant. Careers, 
laboratories, and national prestige were already invested. Under these 
conditions, rejection was never a realistic option.

This was not a deliberative process in which competing foundational 
philosophies were weighed. It was an affirmation ceremony. The vote 
functioned less like democratic decision-making and more like 
ratification of an entrenched program whose momentum could not be 
stopped without institutional embarrassment. When unanimity is 
guaranteed in advance, it is not evidence of truth—it is evidence of 
structural pressure.

The Reversal of Measurement Logic

Historically, constants of nature were discovered, refined, and improved 
through measurement. Uncertainty was not a flaw but a reflection of 
epistemic humility. The redefinition inverted this logic. Planck’s 
constant was no longer to be measured; it was declared exact by fiat. 
Instruments would henceforth be calibrated to the constant, not the 
other way around.

This reversal was justified pragmatically, but the voting process failed 
to confront its philosophical cost. By fixing the constant, metrology 
abandoned the principle that physical reality constrains our numbers. 
Instead, numbers now constrain our descriptions of reality. Any future 
discrepancy is automatically assigned to experimental error, because the 
constant itself has been legislated beyond doubt.

This is not a minor technical shift; it is a profound epistemological 
gamble. And yet the vote treated it as administrative housekeeping.

Manufactured Consensus and Silenced Doubt

There were legitimate concerns—about long-term reproducibility, about 
dependence on extremely complex apparatus, about the narrowing of 
methodological diversity in mass realization. These concerns were 
largely absent from the public narrative of the vote, not because they 
did not exist, but because the institutional culture of metrology 
discourages visible dissent.

In a system where national institutes depend on international alignment 
for funding, legitimacy, and authority, disagreement becomes 
professionally hazardous. The CGPM vote thus reflected not a convergence 
of independent judgment, but the success of a tightly coordinated global 
bureaucracy in aligning its members behind a single course of action.

Consensus, in this context, was not discovered. It was engineered.

The Fetishization of Exactness

The language surrounding the vote revealed a deeper pathology: an almost 
theological reverence for “exact values.” Exactness was treated as 
synonymous with truth, stability, and progress, despite being a 
human-imposed abstraction. That Planck’s constant was declared exact to 
nine significant digits—digits derived from imperfect experiments—was 
presented as an intellectual victory rather than a conceptual compromise.

The voting process never seriously addressed the symbolic danger of this 
move: that metrology might begin to confuse definitional clarity with 
physical understanding. An exact number is not a deeper insight into 
nature. It is a bookkeeping decision. The vote collapsed this 
distinction, enshrining precision as virtue without interrogating meaning.

A Technocracy Mistaken for Science

Ultimately, the vote on Planck’s constant exposed the limits of 
governance by experts alone. Metrology prides itself on being 
apolitical, yet the process was saturated with institutional incentives, 
power dynamics, and reputational risk. The delegates did not merely vote 
on a constant; they voted to validate decades of collective investment, 
to lock in a particular technological pathway, and to foreclose 
alternative futures.

That the vote was unanimous should not reassure us. It should alarm us. 
Unanimity in a domain as foundational as measurement is not a sign that 
science has reached perfection; it is a sign that questioning has become 
inconvenient.

Conclusion

The fixing of Planck’s constant may well prove useful, robust, and 
enduring. This essay does not argue otherwise. What it condemns is the 
process by which the decision was sanctified—an exercise in procedural 
inevitability masquerading as collective wisdom. The CGPM vote did not 
weigh uncertainty; it abolished it by decree. It did not confront 
philosophical risk; it buried it beneath celebration.

In doing so, metrology traded a measure of its intellectual integrity 
for administrative elegance. The constant may now be exact, but the 
process that enshrined it was anything but.