Unitates Stoneyanae sunt systema mensurae a physico Hibernico Georgio Johnstone Stoney anno 1881 creatum et primum exemplum
systematis unitatum naturalium(en)(d) propositum – quod est grex unitatum sic excogitatum ut quaedam selectae quantitates physicae constantes(d) et systema plene definiant et in ipso systemate includantur.

Georgius Stoney fuit primus qui intellexit onus electricum quantitates discretas tantum accipere posse; hoc ei suasit ut significationem universalem in minima unitate videret. Talis minima unitas (i.e. onus electricum electronis), una cum aliis tribus quantitatibus constantibus quas item is putavit universales (eae sunt celeritas lucis, constans gravitationis et constans Coulombiana), sivit eum systema creare, quod hodie in honorem eius appellatur.

Unitates
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Ad novum systema mensurae definiendum, Georgius Stoney has quantitates constantes elegit:

* c, celeritatem lucis in vacuo
* G, constantem gravitationis
* ke, constantem Coulombianam
* e, onus electricum electronis

Nonnulli auctores posteriores, praesertim post reformationem unitatum primariarum systematis metrici(en)(d) anni 2019, in locum constantis Coulombianae (ke) aliquando 1/4πε0 substituunt (ubi ε0 est constans permittivitatis vacui(en)).

| Nomen | Dimensio | Aequatio | Mensura ad SI versa |
| --- | --- | --- | --- |
| Longitudo Stoneyana | longitudo (L) | {\displaystyle l\_{\text{S}}={\sqrt {\frac {Gk\_{e}e^{2}}{c^{4}}}}={\sqrt {\frac {Ge^{2}}{4\pi \epsilon \_{0}c^{4}}}}={\sqrt {\frac {\alpha \hbar G}{c^{3}}}}} | 1.3807 × 10−36 m |
| Massa Stoneyana | massa (M) | {\displaystyle m\_{\text{S}}={\sqrt {\frac {k\_{e}e^{2}}{G}}}={\sqrt {\frac {e^{2}}{4\pi \epsilon \_{0}G}}}={\sqrt {\frac {\alpha \hbar c}{G}}}} | 1.8592 × 10−9 kg |
| Tempus Stoneyanum | tempus (T) | {\displaystyle t\_{\text{S}}={\sqrt {\frac {Gk\_{e}e^{2}}{c^{6}}}}={\sqrt {\frac {Ge^{2}}{4\pi \epsilon \_{0}c^{6}}}}={\sqrt {\frac {\alpha \hbar G}{c^{5}}}}} | 4.6054 × 10−45 s |
| Onus electricum Stoneyanum | onus electricum (Q) | {\displaystyle q\_{\text{S}}={\sqrt {\frac {\alpha \hbar c}{k\_{e}}}}={\sqrt {4\pi \epsilon \_{0}\alpha \hbar c}}=e} | 1.6022 × 10−19 C |
|

Constantes quae systema Stoneyanum definiunt, cum per ipsas unitates Stoneyanas exprimantur, partem numeralem habent unius:

{\displaystyle {\begin{aligned}c&=1\ l\_{\text{S}}\cdot t\_{\text{S}}^{-1}\\G&=1\ l\_{\text{S}}^{3}\cdot t\_{\text{S}}^{-2}\cdot m\_{\text{S}}^{-1}\\k\_{\text{e}}&=1\ l\_{\text{S}}^{3}\cdot t\_{\text{S}}^{-2}\cdot m\_{\text{S}}\cdot q\_{\text{S}}^{-2}\\e&=1\ q\_{\text{S}}\end{aligned}}}
Secundum ipsum systema pars numeralis constantis Planckianae minutae(en) est

{\displaystyle \hbar ={\frac {1}{\alpha }}~l\_{\text{S}}^{2}\cdot t\_{\text{S}}^{-1}\cdot m\_{\text{S}}\approx 137.036~l\_{\text{S}}^{2}\cdot t\_{\text{S}}^{-1}\cdot m\_{\text{S}}^{~},}
ubi α est constans structurae politae(en).

Proportio inter unitates Planckianae et unitates Stoneyanas est {\displaystyle {\sqrt {{1}/{\alpha }}}\approx 11.7}. Idcirco: {\displaystyle l\_{\text{S}}={\sqrt {\alpha }}\,l\_{\text{P}};} {\displaystyle m\_{\text{S}}={\sqrt {\alpha }}\,m\_{\text{P}};} {\displaystyle t\_{\text{S}}={\sqrt {\alpha }}\,t\_{\text{P}};} {\displaystyle q\_{\text{S}}={\sqrt {\alpha }}\,q\_{\text{P}}.}

Notae
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1. ↑  Ray, T. P. "Stoney's fundamental units." Irish Astronomical Journal, Vol. 15, P. 152, 1981 15 (1981): 152.
2. ↑  Stoney, G. Johnstone (mense Maii 1881). "LII. On the physical units of nature". *The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science* **11** (69): 381–390
3. ↑  Barrow, John D.; Tipler, Frank (1988), *The anthropic cosmological principle*, Oxford University Press, p. 291, ISBN 978-0-192-82147-8
4. ↑  Flowers, Jeff; Petley, Brian (2004), "Constants, Units and Standards", *Astrophysics, clocks and fundamental constants*, Springer, p. 79, ISBN 978-3-540-21967-5
5. ↑  Haec appellatio a Vicipaediano e lingua indigena in sermonem Latinum conversa est. Extra Vicipaediam huius locutionis testificatio vix inveniri potest.
6. ↑  Duff, M. J.; Okun, L. B.; Veneziano, G. (3 Martii 2002), "Trialogue on the number of fundamental constants", *Journal of High Energy Physics* **2002** (3): 3, arXiv:physics/0110060

Nexus interni
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* Constans Coulombiana
* Constans gravitationis
* Systema internationale unitatum
* Unitates Planckianae