diff --git a/Project.toml b/Project.toml
index 115f841..8fc2ac4 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "UnitSystems"
 uuid = "3a241a3c-2137-41aa-af5e-1388e404ca09"
 authors = ["Michael Reed"]
-version = "0.3.5"
+version = "0.3.6"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
diff --git a/README.md b/README.md
index 4ce7c76..a97246c 100644
--- a/README.md
+++ b/README.md
@@ -19,7 +19,7 @@ Specifications for dimensional units are in the [UnitSystems.jl](https://github.
 The three packages are designed so that they can be interchanged with compatibility.
 On its own `UnitSystems` is the fastest package, while `Similitude` (provides `Quantity` type) and `MeasureSystems` (introduces [Measurements.jl](https://github.com/JuliaPhysics/Measurements.jl) uncertainty) build additional features on top of `UnitSystems` base defintions.
 Additionally, in the `UnitSystems` repository there is an equivalent [Wolfram language paclet](https://reference.wolfram.com/language/guide/Paclets) `Kernel` and also an unmaintained Rust `src` implementation.
-Defaults are shared: `Metric`, `SI2019`, `CODATA`, `Conventional`, `International`, `InternationalMean`, `MetricEngineering`, `SI2019Engineering`, `GravitationalMetric`, `GravitationalSI2019`, `FPS`, `IPS`, `British`, `English`, `Survey`, `Gauss`, `LorentzHeaviside`, `EMU`, `ESU`, `IAU`, `IAUE`, `IAUJ`, `Hubble`, `Cosmological`, `CosmologicalQuantum`, `Meridian`, `Nautical`, `MPH`, `KKH`, `MTS`, `FFF`, `Planck`, `PlanckGauss`, `Stoney`, `Hartree`, `Rydberg`, `Schrodinger`, `Electronic`, `Natural`, `NaturalGauss`, `QCD`, `QCDGauss`, `QCDoriginal`.
+Defaults are shared: `Metric`, `SI2019`, `CODATA`, `Conventional`, `International`, `InternationalMean`, `MetricTurn`, `MetricGradian`, `MetricDegree`, `MetricArcminute`, `MetricArcsecond`, `MetricEngineering`, `GravitationalMetric`, `FPS`, `IPS`, `British`, `English`, `Survey`, `Gauss`, `LorentzHeaviside`, `EMU`, `ESU`, `IAU`, `IAUE`, `IAUJ`, `Hubble`, `Cosmological`, `CosmologicalQuantum`, `Meridian`, `Nautical`, `MPH`, `KKH`, `MTS`, `FFF`, `Planck`, `PlanckGauss`, `Stoney`, `Hartree`, `Rydberg`, `Schrodinger`, `Electronic`, `Natural`, `NaturalGauss`, `QCD`, `QCDGauss`, `QCDoriginal`.
 
 ```Julia
 julia> using UnitSystems # or Similitude or MeasureSystems
@@ -44,12 +44,12 @@ In most unit systems these extra constants have a value of `1` unless specified.
 
 Fundamental constants of physics are: `kB` Boltzmann's constant, `ħ` reduced Planck's constant, `𝘤` speed of light, `μ₀` vacuum permeability, `mₑ` electron rest mass, `Mᵤ` molar mass, `Kcd` luminous efficacy, `θ` angle measure, `λ` Gauss rationalization, `αL` Lorentz's constant, and `g₀` gravitational force reference.
 Primarily the `Metric` SI unit system is used in addition to the historic `English` engineering unit system.
-These constants induce derived values for `avogadro`, `boltzmann`, `molargas`, `planck`, `planckreduced`, `lightspeed`, `planckmass`, `atomicmass`, `protonmass`, `electronmass`, `newton`, `einstein`, `vacuumpermeability`, `vacuumpermittivity`, `electrostatic`, and
+These constants induce derived values for `avogadro`, `boltzmann`, `molargas`, `planck`, `planckreduced`, `lightspeed`, `planckmass`, `dalton`, `protonmass`, `electronmass`, `newton`, `einstein`, `vacuumpermeability`, `vacuumpermittivity`, `electrostatic`, and
 additional constants `molarmass`, `luminousefficacy`, `gravity`, `angle`, `turn`, `spat`, `stefan`, `radiationdensity`, `magnetostatic`, `lorentz`, `biotsavart`, `rationalization`, `vacuumimpedance`, `elementarycharge`, `magneton`, `conductancequantum`, `faraday`, `magneticfluxquantum`, `josephson`, `klitzing`, `hartree`, `rydberg`, `bohr`.
 
 Physics constant documentation is at https://geophysics.crucialflow.com/dev/constants
 
-Standardized unit/derived quantities are `hyperfine`, `loschmidt`, `wienwavelength`, `wienfrequency`, `mechanicalheat`, `solarmass`, `jupitermass`, `earthmass`, `lunarmass`, `earthradius`, `greatcircle`, `radarmile`, `hubble`, `cosmological`, `radian`, `steradian`, `degree`, `gradian`, `arcminute`, `arcsecond`, `second`, `minute`, `hour`, `day`, `gaussianmonth`, `siderealmonth`, `synodicmonth`, `year`, `gaussianyear`, `siderealyear`, `jovianyear`, `angstrom`, `inch`, `foot`, `surveyfoot`, `yard`, `meter`, `earthmeter`, `mile`, `statutemile`, `meridianmile`, `admiraltymile`, `nauticalmile`, `lunardistance`, `astronomicalunit`, `jupiterdistance`, `lightyear`, `parsec`, `bubnoff`, `ips`, `fps`, `fpm`, `ms`, `kmh`, `mph`, `knot`, `mps`, `barn`, `hectare`, `acre`, `surveyacre`, `liter`, `gallon`, `quart`, `pint`, `cup`, `fluidounce`, `teaspoon`, `tablespoon`, `grain`, `gram`, `earthgram`, `kilogram`, `tonne`, `ton`, `pound`, `ounce`, `slug`, `slinch`, `hyl`, `dyne`, `newton`, `poundal`, `poundforce`, `kilopond`, `psi`, `pascal`, `bar`, `barye`, `technicalatmosphere`, `atmosphere`, `inchmercury`, `torr`, `electronvolt`, `erg`, `joule`, `footpound`, `calorie`, `kilocalorie`, `meancalorie`, `earthcalorie`, `thermalunit`, `gasgallon`, `tontnt`, `watt`, `horsepower`, `horsepowerwatt`, `horsepowermetric`, `electricalhorsepower`, `tonsrefrigeration`, `boilerhorsepower`, `coulomb`, `earthcoulomb`, `ampere`, `volt`, `henry`, `ohm`, `siemens`, `farad`, `weber`, `tesla`, `abcoulomb`, `abampere`, `abvolt`, `abhenry`, `abohm`, `abmho`, `abfarad`, `maxwell`, `gauss`, `oersted`, `gilbert`, `statcoulomb`, `statampere`, `statvolt`, `stathenry`, `statohm`, `statmho`, `statfarad`, `statweber`, `stattesla`, `kelvin`, `rankine`, `celsius`, `fahrenheit`, `sealevel`, `boiling`, `mole`, `earthmole`, `poundmole`, `slugmole`, `slinchmole`, `katal`, `amagat`, `lumen`, `candela`, `lux`, `phot`, `footcandle`, `nit`, `apostilb`, `stilb`, `lambert`, `footlambert`, `bril`, `neper`, `bel`, `decibel`, `hertz`, `apm`, `rpm`, `kayser`, `diopter`, `gforce`, `galileo`, `eotvos`, `darcy`, `poise`, `reyn`, `stokes`, `rayl`, `mpge`, `langley`, `jansky`, `solarflux`, `curie`, `sievert`, `roentgen`, `rem`.
+Standardized unit/derived quantities are `hyperfine`, `loschmidt`, `wienwavelength`, `wienfrequency`, `mechanicalheat`, `eddington`, `solarmass`, `jupitermass`, `earthmass`, `lunarmass`, `earthradius`, `greatcircle`, `radarmile`, `hubble`, `cosmological`, `radian`, `steradian`, `degree`, `squaredegree`, `gradian`, `arcminute`, `arcsecond`, `second`, `minute`, `hour`, `day`, `gaussianmonth`, `siderealmonth`, `synodicmonth`, `year`, `gaussianyear`, `siderealyear`, `jovianyear`, `angstrom`, `inch`, `foot`, `surveyfoot`, `yard`, `meter`, `earthmeter`, `mile`, `statutemile`, `meridianmile`, `admiraltymile`, `nauticalmile`, `lunardistance`, `astronomicalunit`, `jupiterdistance`, `lightyear`, `parsec`, `bubnoff`, `ips`, `fps`, `fpm`, `ms`, `kmh`, `mph`, `knot`, `mps`, `barn`, `hectare`, `acre`, `surveyacre`, `liter`, `gallon`, `quart`, `pint`, `cup`, `fluidounce`, `teaspoon`, `tablespoon`, `grain`, `gram`, `earthgram`, `kilogram`, `tonne`, `ton`, `pound`, `ounce`, `slug`, `slinch`, `hyl`, `dyne`, `newton`, `poundal`, `poundforce`, `kilopond`, `psi`, `pascal`, `bar`, `barye`, `technicalatmosphere`, `atmosphere`, `inchmercury`, `torr`, `electronvolt`, `erg`, `joule`, `footpound`, `calorie`, `kilocalorie`, `meancalorie`, `earthcalorie`, `thermalunit`, `gasgallon`, `tontnt`, `watt`, `horsepower`, `horsepowerwatt`, `horsepowermetric`, `electricalhorsepower`, `tonsrefrigeration`, `boilerhorsepower`, `coulomb`, `earthcoulomb`, `ampere`, `volt`, `henry`, `ohm`, `siemens`, `farad`, `weber`, `tesla`, `abcoulomb`, `abampere`, `abvolt`, `abhenry`, `abohm`, `abmho`, `abfarad`, `maxwell`, `gauss`, `oersted`, `gilbert`, `statcoulomb`, `statampere`, `statvolt`, `stathenry`, `statohm`, `statmho`, `statfarad`, `statweber`, `stattesla`, `kelvin`, `rankine`, `celsius`, `fahrenheit`, `sealevel`, `boiling`, `mole`, `earthmole`, `poundmole`, `slugmole`, `slinchmole`, `katal`, `amagat`, `lumen`, `candela`, `lux`, `phot`, `footcandle`, `nit`, `apostilb`, `stilb`, `lambert`, `footlambert`, `bril`, `neper`, `bel`, `decibel`, `hertz`, `apm`, `rpm`, `kayser`, `diopter`, `gforce`, `galileo`, `eotvos`, `darcy`, `poise`, `reyn`, `stokes`, `rayl`, `mpge`, `langley`, `jansky`, `solarflux`, `curie`, `sievert`, `roentgen`, `rem`.
 
 Standard physics units are at https://geophysics.crucialflow.com/dev/units
 
@@ -60,7 +60,7 @@ Unit conversion documentation is at https://geophysics.crucialflow.com/dev/conve
 **Derived Unit conversions:**
 
 Mechanics: `angle`, `solidangle`, `time`, `length`, `area`, `volume`, `wavenumber`, `angularwavenumber`, `fuelefficiency`, `numberdensity`, `frequency`, `angularfrequency`, `frequencydrift`, `speed`, `acceleration`, `jerk`, `snap`, `crackle`, `pop`, `volumeflow`,
-`inertia`, `mass`, `massflow`, `lineardensity`, `areadensity`, `density`, `specificweight`, `specificvolume`, `force`, `specificforce`, `gravityforce`, `pressure`, `compressibility`, `viscosity`, `diffusivity`, `rotationalinertia`, `impulse`, `momentum`, `angularmomentum`, `yank`, `energy`, `specificenergy`, `action`, `fluence`, `power`, `powerdensity`, `intensity`, `spectralflux`, `soundexposure`, `impedance`, `specificimpedance`, `admittance`, `compliance`, `inertance`;
+`inertia`, `mass`, `massflow`, `lineardensity`, `areadensity`, `density`, `specificweight`, `specificvolume`, `force`, `specificforce`, `gravityforce`, `pressure`, `compressibility`, `viscosity`, `diffusivity`, `rotationalinertia`, `impulse`, `momentum`, `angularmomentum`, `yank`, `energy`, `specificenergy`, `action`, `fluence`, `power`, `powerdensity`, `irradiance`, `radiance`, `radiantintensity`, `spectralflux`, `spectralexposure`, `soundexposure`, `impedance`, `specificimpedance`, `admittance`, `compliance`, `inertance`;
 Electromagnetics: `charge`, `chargedensity`, `linearchargedensity`, `exposure`, `mobility`, `current`, `currentdensity`, `resistance`, `conductance`, `resistivity`, `conductivity`, `capacitance`, `inductance`, `reluctance`, `permeance`, `permittivity`, `permeability`, `susceptibility`, `specificsusceptibility`, `demagnetizingfactor`, `vectorpotential`, `electricpotential`, `magneticpotential`, `electricfield`, `magneticfield`, `electricflux`, `magneticflux`, `electricfluxdensity`, `magneticfluxdensity`, `electricdipolemoment`, `magneticdipolemoment`, `electricpolarizability`, `magneticpolarizability`, `magneticmoment`, `specificmagnetization`, `polestrength`;
 Thermodynamics: `temperature`, `entropy`, `specificentropy`, `volumeheatcapacity`, `thermalconductivity`, `thermalconductance`, `thermalresistivity`, `thermalresistance`, `thermalexpansion`, `lapserate`,
 `molarmass`, `molality`, `mole`, `molarity`, `molarvolume`, `molarentropy`, `molarenergy`, `molarconductivity`, `molarsusceptibility`, `catalysis`, `specificity`,
diff --git a/src/UnitSystems.jl b/src/UnitSystems.jl
index 5457cf3..cf0eaff 100644
--- a/src/UnitSystems.jl
+++ b/src/UnitSystems.jl
@@ -18,12 +18,12 @@ module UnitSystems
 
 import Base: @pure, length, time, angle, rem
 
-const Systems = (:Metric,:SI2019,:SI1976,:CODATA,:Conventional,:International,:InternationalMean,:MetricEngineering,:SI2019Engineering,:GravitationalMetric,:GravitationalSI2019,:MTS,:EMU,:ESU,:Gauss,:LorentzHeaviside,:Kennelly,:FPS,:IPS,:British,:English,:Survey,:FFF,:MPH,:KKH,:Nautical,:Meridian,:MeridianEngineering,:GravitationalMeridian,:IAU☉,:IAUE,:IAUJ,:Hubble,:Cosmological,:CosmologicalQuantum,:Planck,:PlanckGauss,:Stoney,:Hartree,:Rydberg,:Schrodinger,:Electronic,:Natural,:NaturalGauss,:QCD,:QCDGauss,:QCDoriginal)
+const Systems = (:Metric,:SI2019,:SI1976,:CODATA,:Conventional,:International,:InternationalMean,:MetricTurn,:MetricDegree,:MetricArcminute,:MetricArcsecond,:MetricGradian,:MetricEngineering,:GravitationalMetric,:MTS,:EMU,:ESU,:Gauss,:LorentzHeaviside,:Kennelly,:FPS,:IPS,:British,:English,:Survey,:FFF,:MPH,:KKH,:Nautical,:Meridian,:IAU☉,:IAUE,:IAUJ,:Hubble,:Cosmological,:CosmologicalQuantum,:Planck,:PlanckGauss,:Stoney,:Hartree,:Rydberg,:Schrodinger,:Electronic,:Natural,:NaturalGauss,:QCD,:QCDGauss,:QCDoriginal)
 const Dimensionless = (:coupling,:finestructure,:electronunit,:protonunit,:protonelectron,:darkenergydensity)
 const Constants = (:lightspeed,:planck,:planckreduced,:electronmass,:molarmass,:boltzmann,:permeability,:rationalization,:lorentz,:luminousefficacy,:gravity) #angle
-const Physics = (:turn,:spat,:atomicmass,:protonmass,:planckmass,:gravitation,:gaussgravitation,:einstein,:hartree,:rydberg,:bohr,:electronradius,:avogadro,:molargas,:stefan,:radiationdensity,:vacuumpermeability,:vacuumpermittivity,:electrostatic,:magnetostatic,:biotsavart,:elementarycharge,:faraday,:vacuumimpedance,:conductancequantum,:klitzing,:josephson,:magneticfluxquantum,:magneton)
-const Derived = (:hyperfine,:loschmidt,:wienwavelength,:wienfrequency,:mechanicalheat,:solarmass,:jupitermass,:earthmass,:lunarmass,:earthradius,:greatcircle,:radarmile,:hubble,:cosmological,
-    :radian,:steradian,:degree,:gradian,:arcminute,:arcsecond,
+const Physics = (:turn,:spat,:dalton,:protonmass,:planckmass,:gravitation,:gaussgravitation,:einstein,:hartree,:rydberg,:bohr,:electronradius,:avogadro,:molargas,:stefan,:radiationdensity,:vacuumpermeability,:vacuumpermittivity,:electrostatic,:magnetostatic,:biotsavart,:elementarycharge,:faraday,:vacuumimpedance,:conductancequantum,:klitzing,:josephson,:magneticfluxquantum,:magneton)
+const Derived = (:hyperfine,:loschmidt,:wienwavelength,:wienfrequency,:mechanicalheat,:eddington,:solarmass,:jupitermass,:earthmass,:lunarmass,:earthradius,:greatcircle,:radarmile,:hubble,:cosmological,
+    :radian,:steradian,:degree,:squaredegree,:gradian,:bradian,:arcminute,:arcsecond,
     :second,:minute,:hour,:day,:gaussianmonth,:siderealmonth,:synodicmonth,:year,:gaussianyear,:siderealyear,:jovianyear,
     :angstrom,:inch,:foot,:surveyfoot,:yard,:meter,:earthmeter,:mile,:statutemile,:meridianmile,:admiraltymile,:nauticalmile,:lunardistance,:astronomicalunit,:jupiterdistance,:lightyear,:parsec,
     :barn,:hectare,:acre,:surveyacre,
@@ -43,7 +43,7 @@ const Derived = (:hyperfine,:loschmidt,:wienwavelength,:wienfrequency,:mechanica
     :kayser,:diopter,:gforce,:galileo,:eotvos,:darcy,:poise,:reyn,:stokes,:rayl,
     :mpge,:langley,:jansky,:solarflux,:curie,:sievert,:roentgen,:rem)
 const Kinematic = (:solidangle,:time,:length,:area,:volume,:wavenumber,:angularwavenumber,:fuelefficiency,:numberdensity,:frequency,:angularfrequency,:frequencydrift,:speed,:acceleration,:jerk,:snap,:crackle,:pop,:volumeflow) #angle
-const Mechanical = (:inertia,:mass,:massflow,:lineardensity,:areadensity,:density,:specificweight,:specificvolume,:force,:specificforce,:gravityforce,:pressure,:compressibility,:viscosity,:diffusivity,:rotationalinertia,:impulse,:momentum,:angularmomentum,:yank,:energy,:specificenergy,:action,:fluence,:power,:powerdensity,:intensity,:spectralflux,:soundexposure,:impedance,:specificimpedance,:admittance,:compliance,:inertance)
+const Mechanical = (:inertia,:mass,:massflow,:lineardensity,:areadensity,:density,:specificweight,:specificvolume,:force,:specificforce,:gravityforce,:pressure,:compressibility,:viscosity,:diffusivity,:rotationalinertia,:impulse,:momentum,:angularmomentum,:yank,:energy,:specificenergy,:action,:fluence,:power,:powerdensity,:irradiance,:radiance,:radiantintensity,:spectralflux,:spectralexposure,:soundexposure,:impedance,:specificimpedance,:admittance,:compliance,:inertance)
 const Electromagnetic = (:charge,:chargedensity,:linearchargedensity,:exposure,:mobility,:current,:currentdensity,:resistance,:conductance,:resistivity,:conductivity,:capacitance,:inductance,:reluctance,:permeance,:permittivity,:permeability,:susceptibility,:specificsusceptibility,:demagnetizingfactor,:vectorpotential,:electricpotential,:magneticpotential,:electricfield,:magneticfield,:electricflux,:magneticflux,:electricfluxdensity,:magneticfluxdensity,:electricdipolemoment,:magneticdipolemoment,:electricpolarizability,:magneticpolarizability,:magneticmoment,:specificmagnetization,:polestrength)
 const Thermodynamic = (:temperature,:entropy,:specificentropy,:volumeheatcapacity,:thermalconductivity,:thermalconductance,:thermalresistivity,:thermalresistance,:thermalexpansion,:lapserate)
 const Molar = (:molarmass,:molality,:molaramount,:molarity,:molarvolume,:molarentropy,:molarenergy,:molarconductivity,:molarsusceptibility,:catalysis,:specificity)
@@ -110,7 +110,7 @@ Base.display(U::Coupling) = println("Coupling{αG = $(coupling(U)), α = $(fines
 
 Fundamental constants of physics are: `kB` Boltzmann's constant, `ħ` reduced Planck's constant, `𝘤` speed of light, `μ₀` vacuum permeability, `mₑ` electron rest mass, `Mᵤ` molar mass, `Kcd` luminous efficacy, `θ` angle measure, `λ` Gauss rationalization, `αL` Lorentz's constant, and `g₀` gravitational force reference.
 Primarily the `Metric` SI unit system is used in addition to the historic `English` engineering unit system.
-These constants induce derived values for `avogadro`, `boltzmann`, `molargas`, `planck`, `planckreduced`, `lightspeed`, `planckmass`, `atomicmass`, `protonmass`, `electronmass`, `newton`, `einstein`, `vacuumpermeability`, `vacuumpermittivity`, `electrostatic`, and
+These constants induce derived values for `avogadro`, `boltzmann`, `molargas`, `planck`, `planckreduced`, `lightspeed`, `planckmass`, `dalton`, `protonmass`, `electronmass`, `newton`, `einstein`, `vacuumpermeability`, `vacuumpermittivity`, `electrostatic`, and
 additional constants `molarmass`, `luminousefficacy`, `gravity`, `angle`, `turn`, `spat`, `stefan`, `radiationdensity`, `magnetostatic`, `lorentz`, `biotsavart`, `rationalization`, `vacuumimpedance`, `elementarycharge`, `magneton`, `conductancequantum`, `faraday`, `magneticfluxquantum`, `josephson`, `klitzing`, `hartree`, `rydberg`, `bohr`.
 
 Standardized unit/derived quantities are `$(listext(Derived))`.
@@ -123,7 +123,7 @@ Mechanics: `angle`, `$(listext(Kinematic))`, `$(listext(Mechanical))`;
 Electromagnetics: `$(listext(Electromagnetic))`;
 Thermodynamics: `$(listext(Thermodynamic))`,
 `$(listext(Molar))`, `$(listext(Photometric))`.
-""" #`Rᵤ,mᵤ,σ,ħ,μ₀,ε₀,kₑ,𝘦,𝔉,RK,Z₀,G₀`
+""" #`Rᵤ,Da,σ,ħ,μ₀,ε₀,kₑ,𝘦,𝔉,RK,Z₀,G₀`
 struct UnitSystem{kB,ħ,𝘤,μ₀,mₑ,Mᵤ,extra}
     @pure UnitSystem{kB,ħ,𝘤,μ₀,mₑ,Mᵤ,extra}() where {kB,ħ,𝘤,μ₀,mₑ,Mᵤ,extra} = new{kB,ħ,𝘤,μ₀,mₑ,Mᵤ,extra}()
 end # UnitSystem{kB,ħ,𝘤,μ₀,mₑ,Mᵤ,(Kcd,θ,λ,αL,g,C,τ,𝟐,𝟑,𝟓,𝟕,𝟏𝟏,𝟏𝟗,𝟒𝟑)}
@@ -215,13 +215,6 @@ function DimensionSystem(U::UnitSystem,L,M,T,I,Θ,N,J,A,Λ,G,C)
     UnitSystem(kB,ħ,c,μ0,me,Mu,Kcd,A,λ,αL,g₀,universe(U),τ,x,y,z,u,v,w,p)
 end
 
-"""
-    AstronomicalSystem(U::UnitSystem) = EntropySystem(U,𝟏,𝟏,𝟏/gravitation(U))
-
-Constructs new `UnitSystem` from `U` with `mass` rescaled by `newton` gravitational constant. An example of this type is `AstronomicalSystem(Metric)`.
-"""
-AstronomicalSystem(u) = EntropySystem(u,one(u),one(u),inv(gravitation(u)))
-
 """
     ElectricSystem(U::UnitSystem,Ω,V) = EntropySystem(U,𝟏,𝟏,V^2/Ω,𝟏,vacuumpermeability(U)/Ω)
 
@@ -253,16 +246,26 @@ This means `EntropySystem` also constructs the examples listed there.
 function EntropySystem(u,t,l,m,θ=one(u))
     EntropySystem(u,t,l,m,θ,permeability(u)/(m*l),molarmass(u)/m,gravity(u),m*l*l/(t*t))
 end
-function EntropySystem(u,t,l,m,θ,μ0,Mu=molarmass(u)/m,g0=gravity(u),e=m*l*l/(t*t),λ=one(u),αL=one(u))
-    UnitSystem(
+function EntropySystem(u,t,l,m,θ,μ0,Mu=molarmass(u)/m,g0=gravity(u),e=m*l*l/(t*t),λ=one(u),αL=one(u),Kcd=luminousefficacy(u)*e/t*g0)
+    normal(UnitSystem(
         boltzmann(u)*θ/e/g0,
         planckreduced(u)/t/e/g0,
         lightspeed(u)*t/l,
         μ0,
         electronmass(u)/m,
         Mu,
-        luminousefficacy(u)*e/t*g0,
-        angle(u),λ,αL,g0,universe(u),twopi(u),two(u),three(u),five(u),seven(u),eleven(u),nineteen(u),fourtythree(u))
+        Kcd,
+        angle(u),λ,αL,g0,universe(u),twopi(u),two(u),three(u),five(u),seven(u),eleven(u),nineteen(u),fourtythree(u)))
+end
+
+"""
+    AstronomicalSystem(U::UnitSystem,t,l,m)
+
+Constructs new `UnitSystem` from `U` rescaled along `time`, `length`, `mass`, and dimensionless `boltzmann` and `molarmass` constants.
+Examples are `Hubble`, `Cosmological`, `CosmologicalQuantum`.
+"""
+function AstronomicalSystem(u,t,l,m,e=m*lightspeed(u)^2)
+    EntropySystem(u,t,l,m,e/boltzmann(u),spat(u),one(u),one(u),e,one(u),one(u),one(u))
 end
 
 @pure unit(x,y=1) = isapprox(y,x,rtol=eps()^0.9) ? y : x
@@ -291,7 +294,7 @@ for unit ∈ (Convert...,:angle)
     @eval begin
         @pure @inline $unit(v::Real,U::UnitSystem) = isquantity(U) ? evaldim($unit)(v,U) : $unit(v,U,Metric)
         @pure @inline $unit(v::Real,U::UnitSystem,S::UnitSystem) = isquantity(U,S) ? evaldim($unit)(v,U,S) : (u=$unit(U,S);isone(u) ? v : v/u)
-        @pure @inline $unit(v::Real,U::UnitSystem{kB,ħ,𝘤,μ₀,mₑ},S::UnitSystem{kB,ħ,𝘤,μ₀,mₑ}) where {kB,ħ,𝘤,μ₀,mₑ} = v
+        @pure @inline $unit(v::Real,U::UnitSystem{kB,ħ,𝘤,μ₀,mₑ,Mᵤ,extra},S::UnitSystem{kB,ħ,𝘤,μ₀,mₑ,Mᵤ,extra}) where {kB,ħ,𝘤,μ₀,mₑ,Mᵤ,extra} = v
     end
     if unit ∉ (Constants...,:angle,:permeability)
         @eval @pure @inline $unit(U::UnitSystem) = isquantity(U) ? evaldim($unit)(U) : $unit(Natural,U)
diff --git a/src/derived.jl b/src/derived.jl
index 26446db..f07e526 100644
--- a/src/derived.jl
+++ b/src/derived.jl
@@ -16,10 +16,12 @@
 
 @pure radian(U::UnitSystem) = angle(one(U),U,Metric)
 @pure steradian(U::UnitSystem) = solidangle(one(U),U,Metric)
-@pure degree(U::UnitSystem) = angle(turn(U)/two(U)^3/three(U)^2/five(U),U,Metric)
-@pure gradian(U::UnitSystem) = angle(turn(U)/two(U)^4/five(U)^2,U,Metric)
-@pure arcminute(U::UnitSystem) = degree(U)/two(U)^2/three(U)/five(U)
-@pure arcsecond(U::UnitSystem) = arcminute(U)/two(U)^2/three(U)/five(U)
+@pure degree(U::UnitSystem) = angle(one(U),U,MetricDegree)
+@pure squaredegree(U::UnitSystem) = solidangle(one(U),U,MetricDegree)
+@pure gradian(U::UnitSystem) = angle(one(U),U,MetricGradian)
+@pure arcminute(U::UnitSystem) = angle(one(U),U,MetricArcminute)
+@pure arcsecond(U::UnitSystem) = angle(one(U),U,MetricArcsecond)
+@pure bradian(U::UnitSystem) = angle(turn(U)/two(U)^8,U,Metric)
 
 @pure apm(U::UnitSystem) = one(U)/minute(U)
 @pure rpm(U::UnitSystem) = turn(U)/minute(U)
diff --git a/src/derivedocs.jl b/src/derivedocs.jl
index 13b6d55..6c3469c 100644
--- a/src/derivedocs.jl
+++ b/src/derivedocs.jl
@@ -116,69 +116,187 @@ $yobi
 @doc """
 $(unitext(:radian,"angle(𝟏,U,Metric)"))
 
-Unit of `angle` which is dimensionless.
+Unit of `angle` which is dimensionless (rad).
 ```Julia
-julia> radian(MetricEngineering)
+julia> radian(MetricEngineering) # rad
 $(radian(MetricEngineering))
-```
-""" radian
 
-@doc """
-$(unitext(:steradian,"solidangle(𝟏,U,Metric)"))
+julia> radian(MetricDegree) # deg
+$(radian(MetricDegree))
 
-Unit of `solidangle` which is dimensionless.
-```Julia
-julia> steradian(MetricEngineering)
-$(steradian(MetricEngineering))
+julia> radian(MetricArcminute) # amin
+$(radian(MetricArcminute))
+
+julia> radian(MetricArcsecond) # asec
+$(radian(MetricArcsecond))
+
+julia> radian(MetricGradian) # gon
+$(radian(MetricGradian))
 ```
-""" steradian
+""" radian
 
 @doc """
-$(unitext(:degree,"angle(τ/𝟐^3/𝟑^2/𝟓,U,Metric)"))
+$(unitext(:degree,"angle(𝟏,U,MetricDegree)"))
 
-Unit of `angle` which divides a `turn` into `360` parts.
+Unit of `angle` which divides a `turn` into `360` parts (rad).
 ```Julia
-julia> degree(MetricEngineering)
+julia> degree(MetricEngineering) # rad
 $(degree(MetricEngineering))
+
+julia> degree(MetricDegree) # deg
+$(degree(MetricDegree))
+
+julia> degree(MetricArcminute) # amin
+$(degree(MetricArcminute))
+
+julia> degree(MetricArcsecond) # asec
+$(degree(MetricArcsecond))
+
+julia> degree(MetricGradian) # gon
+$(degree(MetricGradian))
 ```
 """ degree
 
 @doc """
-$(unitext(:gradian,"angle(τ/𝟐^4/𝟓^2,U,Metric)"))
+$(unitext(:gradian,"angle(𝟏,U,MetricGradian)"))
 
-Unit of `angle` which divides a `turn` into `400` parts.
+Unit of `angle` which divides a `turn` into `400` parts (rad).
 ```Julia
-julia> gradian(MetricEngineering)
+julia> gradian(MetricEngineering) # rad
 $(gradian(MetricEngineering))
+
+julia> gradian(MetricDegree) # deg
+$(gradian(MetricDegree))
+
+julia> gradian(MetricArcminute) # amin
+$(gradian(MetricArcminute))
+
+julia> gradian(MetricArcsecond) # asec
+$(gradian(MetricArcsecond))
+
+julia> gradian(MetricGradian) # gon
+$(gradian(MetricGradian))
 ```
 """ gradian
 
 @doc """
-$(unitext(:arcminute,"degree(U)/𝟐^2/𝟑/𝟓"))
+$(unitext(:bradian,"angle(τ/𝟐^8,U,Metric)"))
 
-Unit of `angle` which divides a `degree` into `60` parts.
+Unit of `angle` which divides a `turn` into `𝟐^8` or `256` parts (rad).
 ```Julia
-julia> arcminute(MetricEngineering)
+julia> bradian(MetricEngineering) # rad
+$(bradian(MetricEngineering))
+
+julia> bradian(MetricDegree) # deg
+$(bradian(MetricDegree))
+
+julia> bradian(MetricArcminute) # amin
+$(bradian(MetricArcminute))
+
+julia> bradian(MetricArcsecond) # asec
+$(bradian(MetricArcsecond))
+
+julia> bradian(MetricGradian) # gon
+$(bradian(MetricGradian))
+```
+""" bradian
+
+@doc """
+$(unitext(:arcminute,"angle(𝟏,U,MetricArcminute)"))
+
+Unit of `angle` which divides a `degree` into `60` parts (rad).
+```Julia
+julia> arcminute(MetricEngineering) # rad
 $(arcminute(MetricEngineering))
+
+julia> arcminute(MetricDegree) # deg
+$(arcminute(MetricDegree))
+
+julia> arcminute(MetricArcminute) # amin
+$(arcminute(MetricArcminute))
+
+julia> arcminute(MetricArcsecond) # asec
+$(arcminute(MetricArcsecond))
+
+julia> arcminute(MetricGradian) # gon
+$(arcminute(MetricGradian))
 ```
 """ arcminute
 
 @doc """
-$(unitext(:arcsecond,"arcminute(U)/𝟐^2/𝟑/𝟓"))
+$(unitext(:arcsecond,"angle(𝟏,U,MetricArcsecond)"))
 
-Unit of `angle` which divides a `arcminute` into `60` parts.
+Unit of `angle` which divides a `arcminute` into `60` parts (rad).
 ```Julia
-julia> arcsecond(MetricEngineering)
+julia> arcsecond(MetricEngineering) # rad
 $(arcsecond(MetricEngineering))
+
+julia> arcsecond(MetricDegree) # deg
+$(arcsecond(MetricDegree))
+
+julia> arcsecond(MetricArcminute) # amin
+$(arcsecond(MetricArcminute))
+
+julia> arcsecond(MetricArcsecond) # asec
+$(arcsecond(MetricArcsecond))
+
+julia> arcsecond(MetricGradian) # gon
+$(arcsecond(MetricGradian))
 ```
 """ arcsecond
 
+# solidangle
+
+@doc """
+$(unitext(:steradian,"solidangle(𝟏,U,Metric)"))
+
+Unit of `solidangle` which is dimensionless (rad²).
+```Julia
+julia> steradian(MetricEngineering) # rad²
+$(steradian(MetricEngineering))
+
+julia> steradian(MetricDegree) # deg²
+$(steradian(MetricDegree))
+
+julia> steradian(MetricArcminute) # amin²
+$(steradian(MetricArcminute))
+
+julia> steradian(MetricArcsecond) # asec²
+$(steradian(MetricArcsecond))
+
+julia> steradian(MetricGradian) # gon²
+$(steradian(MetricGradian))
+```
+""" steradian
+
+@doc """
+$(unitext(:squaredegree,"solidangle(𝟏,U,MetricDegree)"))
+
+Unit of `solidangle` which is a `degree` squared (rad²).
+```Julia
+julia> squaredegree(MetricEngineering) # rad²
+$(squaredegree(MetricEngineering))
+
+julia> squaredegree(MetricDegree) # deg²
+$(squaredegree(MetricDegree))
+
+julia> squaredegree(MetricArcminute) # amin²
+$(squaredegree(MetricArcminute))
+
+julia> squaredegree(MetricArcsecond) # asec²
+$(squaredegree(MetricArcsecond))
+
+julia> squaredegree(MetricGradian) # gon²
+$(squaredegree(MetricGradian))
+```
+""" squaredegree
+
 # time
 
 @doc """
 $(unitext(:second,"time(𝟏,U,Metric)"))
 
-Unit of `time` defined by `hyperfine` transition frequency of Cs-133 atom.
+Unit of `time` defined by `hyperfine` transition frequency of Cs-133 atom (s).
 ```Julia
 julia> second(Metric) # s
 $(second(Metric))
@@ -194,7 +312,7 @@ $(second(IAU))
 @doc """
 $(unitext(:minute,"𝟐^2*𝟑*𝟓*second(U)"))
 
-Unit of `time` defined by 60 `second` intervals.
+Unit of `time` defined by 60 `second` intervals (s).
 ```Julia
 julia> minute(Metric) # s
 $(minute(Metric))
@@ -210,7 +328,7 @@ $(minute(IAU))
 @doc """
 $(unitext(:hour,"𝟐^2*𝟑*𝟓*minute(U)"))
 
-Unit of `time` defined by 60 `minute` intervals.
+Unit of `time` defined by 60 `minute` intervals (s).
 ```Julia
 julia> hour(Metric) # s
 $(hour(Metric))
@@ -226,7 +344,7 @@ $(hour(IAU))
 @doc """
 $(unitext(:day,"𝟐^3*𝟑*hour(U)"))
 
-Unit of `time` defined by 24 `hour` intervals.
+Unit of `time` defined by 24 `hour` intervals (s).
 ```Julia
 julia> day(Metric) # s
 $(day(Metric))
@@ -242,7 +360,7 @@ $(day(IAU))
 @doc """
 $(unitext(:year,"aⱼ*day(U)"))
 
-Unit of `time` defined by Julian calendar year interval.
+Unit of `time` defined by Julian calendar year interval (s).
 ```Julia
 julia> year(Metric) # s
 $(year(Metric))
@@ -258,7 +376,7 @@ $(year(IAU))
 @doc """
 $(unitext(:radarmile,"𝟐*nauticalmile(U)/lightspeed(U)"))
 
-Unit of `time` delay from a two-way `nauticalmile` radar return.
+Unit of `time` delay from a two-way `nauticalmile` radar return (s).
 ```Julia
 julia> radarmile(Metric)
 $(radarmile(Metric))
@@ -906,6 +1024,9 @@ $(grain(CGS))
 
 julia> grain(English) # lb
 $(grain(English))
+
+julia> grain(QCD) # mₚ
+$(grain(QCD))
 ```
 """ grain
 
@@ -2402,8 +2523,14 @@ $(unitext(:candela,"luminousintensity(𝟏,U,Metric)"))
 
 Common unit of `luminousintensity` (cd).
 ```Julia
-julia> candela(MetricEngineering) # cd
-$(candela(Metric))
+julia> candela(MetricEngineering) # lm⋅rad⁻²
+$(candela(MetricEngineering))
+
+julia> candela(MetricDegree) # lm⋅deg⁻²
+$(candela(MetricDegree))
+
+julia> candela(MetricGradian) # lm⋅gon⁻²
+$(candela(MetricGradian))
 
 julia> candela(CGS) # cd
 $(candela(CGS))
@@ -2466,8 +2593,14 @@ $(unitext(:nit,"luminance(𝟏,U,Metric)"))
 
 Metric unit of `luminance` (lx⋅rad⁻²).
 ```Julia
-julia> nit(Metric) # nt
-$(nit(Metric))
+julia> nit(MetricEngineering) # nt
+$(nit(MetricEngineering))
+
+julia> nit(MetricDegree) # lm⋅m⁻²deg⁻²
+$(nit(MetricDegree))
+
+julia> nit(MetricGradian) # lm⋅m⁻²gon⁻²
+$(nit(MetricGradian))
 
 julia> nit(CGS) # sb
 $(nit(CGS))
@@ -2482,8 +2615,14 @@ $(unitext(:apostilb,"luminance(𝟐/turn(U),U,Metric)"))
 
 Metric unit of `luminance` (lx⋅rad⁻²).
 ```Julia
-julia> apostilb(Metric) # nt
-$(apostilb(Metric))
+julia> apostilb(MetricEngineering) # nt
+$(apostilb(MetricEngineering))
+
+julia> apostilb(MetricDegree) # lm⋅m⁻²deg⁻²
+$(apostilb(MetricDegree))
+
+julia> apostilb(MetricGradian) # lm⋅m⁻²gon⁻²
+$(apostilb(MetricGradian))
 
 julia> apostilb(CGS) # sb
 $(apostilb(CGS))
@@ -2498,8 +2637,14 @@ $(unitext(:stilb,"luminance(𝟏,U,Gauss)"))
 
 Historic unit of `luminance` (lx⋅rad⁻²).
 ```Julia
-julia> stilb(Metric) # nt
-$(stilb(Metric))
+julia> stilb(MetricEngineering) # nt
+$(stilb(MetricEngineering))
+
+julia> stilb(MetricDegree) # lm⋅m⁻²deg⁻²
+$(stilb(MetricDegree))
+
+julia> stilb(MetricGradian) # lm⋅m⁻²gon⁻²
+$(stilb(MetricGradian))
 
 julia> stilb(CGS) # sb
 $(stilb(CGS))
@@ -2514,8 +2659,14 @@ $(unitext(:lambert,"luminance(𝟐/turn(U),U,Gauss)"))
 
 Historic unit of `luminance` (nt).
 ```Julia
-julia> lambert(Metric) # nt
-$(lambert(Metric))
+julia> lambert(MetricEngineering) # nt
+$(lambert(MetricEngineering))
+
+julia> lambert(MetricDegree) # lm⋅m⁻²deg⁻²
+$(lambert(MetricDegree))
+
+julia> lambert(MetricGradian) # lm⋅m⁻²gon⁻²
+$(lambert(MetricGradian))
 
 julia> lambert(CGS) # sb
 $(lambert(CGS))
@@ -2530,8 +2681,14 @@ $(unitext(:footlambert,"luminance(𝟐/turn(U),U,English)"))
 
 English unit of `luminance` (nt).
 ```Julia
-julia> footlambert(Metric) # nt
-$(footlambert(Metric))
+julia> footlambert(MetricEngineering) # nt
+$(footlambert(MetricEngineering))
+
+julia> footlambert(MetricDegree) # lm⋅m⁻²deg⁻²
+$(footlambert(MetricDegree))
+
+julia> footlambert(MetricGradian) # lm⋅m⁻²gon⁻²
+$(footlambert(MetricGradian))
 
 julia> footlambert(CGS) # sb
 $(footlambert(CGS))
@@ -2546,8 +2703,14 @@ $(unitext(:bril,"centi*nano*lambert(U)"))
 
 Reference unit of `luminance` (nt).
 ```Julia
-julia> bril(Metric) # nt
-$(bril(Metric))
+julia> bril(MetricEngineering) # nt
+$(bril(MetricEngineering))
+
+julia> bril(MetricDegree) # lm⋅m⁻²deg⁻²
+$(bril(MetricDegree))
+
+julia> bril(MetricGradian) # lm⋅m⁻²gon⁻²
+$(bril(MetricGradian))
 
 julia> bril(CGS) # sb
 $(bril(CGS))
@@ -2577,8 +2740,11 @@ $(unitext(:apm,"𝟏/minute(U)"))
 
 Actions per minute `apm` unit of `frequency` (s⁻¹).
 ```Julia
-julia> apm(MetricEngineering) # s⁻¹
-$(apm(MetricEngineering))
+julia> apm(Metric) # s⁻¹
+$(apm(Metric))
+
+julia> apm(MPH) # h⁻¹
+$(apm(MPH))
 
 julia> apm(IAU) # D⁻¹
 $(apm(IAU))
@@ -2588,12 +2754,27 @@ $(apm(IAU))
 @doc """
 $(unitext(:rpm,"turn(U)/minute(U)"))
 
-Revolutions per minute `rpm` unit of `angularfrequency` (s⁻¹).
+Revolutions per minute `rpm` unit of `angularfrequency` (rad⋅s⁻¹).
 ```Julia
 julia> rpm(MetricEngineering) # rad⋅s⁻¹
 $(rpm(MetricEngineering))
 
-julia> rpm(IAU) # D⁻¹
+julia> rpm(MetricGradian) # gon⋅s⁻¹
+$(rpm(MetricGradian))
+
+julia> rpm(MetricDegree) # deg⋅s⁻¹
+$(rpm(MetricDegree))
+
+julia> rpm(MetricArcminute) # amin⋅s⁻¹
+$(rpm(MetricArcminute))
+
+julia> rpm(MetricArcsecond) # asec⋅s⁻¹
+$(rpm(MetricArcsecond))
+
+julia> rpm(MPH) # rad⋅h⁻¹
+$(rpm(MPH))
+
+julia> rpm(IAU) # rad⋅D⁻¹
 $(rpm(IAU))
 ```
 """ rpm
diff --git a/src/initdata.jl b/src/initdata.jl
index cf77db0..98882e8 100644
--- a/src/initdata.jl
+++ b/src/initdata.jl
@@ -20,14 +20,14 @@ const kibi,mebi,gibi,tebi,pebi,exbi,zebi,yobi = 𝟐^10,𝟐^20,𝟐^30,𝟐^40,
 
 const fur,°R,K,HOUR,k = 𝟐^2*𝟑*𝟓*𝟏𝟏*ft,𝟓/𝟑^2,𝟑^2/𝟓,𝟐^4*𝟑^2*𝟓^2,kG*τ/(𝟐^7*𝟑^4*𝟓^3)
 const mₑ,μ₀ = αinv^2*R∞*𝟐*𝘩/𝘤,𝟐*𝘩/𝘤*α/𝘦^2 # ≈ 4π*(1e-7+5.5e-17), exact charge
-const ħ,μₚₑ,Rᵤ,αL,αG,Mᵤ = 𝘩/τ,μₚᵤ/μₑᵤ,NA*kB,centi/𝘤,(mₑ/mP)^2,NA*mₑ/μₑᵤ
+const ħ,μₚₑ,μₑₚ,Rᵤ,αL,αG,Mᵤ = 𝘩/τ,μₚᵤ/μₑᵤ,μₑᵤ/μₚᵤ,NA*kB,centi/𝘤,(mₑ/mP)^2,NA*mₑ/μₑᵤ
 const pc,G,DAY,nm = au*𝟐^7*𝟑^4*𝟓^3/τ,𝘤*ħ/mP^2,𝟐^7*𝟑^3*𝟓^2,sqrt(GME/g₀)*τ/𝟐^5/𝟑^3/𝟓^2
 const GM☉ =au^3*k^2/DAY^2; const th = 𝟏𝟎^3*pc/H0; const ΛC = 𝟑*ΩΛ*(th*𝘤)^-2
-const lc,mc,ρΛ = 𝟐*sqrt(τ/ΛC),𝘤^2/(𝟐*sqrt(τ*ΛC*G)),ΛC*𝘤^4/(𝟐^2*τ)/G
-const lcq,mcq = sqrt.(sqrt.((𝘤*ħ/ρΛ,ρΛ*ħ^3/𝘤^5)))
+const lc,mc,ρΛ,𝘦ₙ = 𝟐*sqrt(τ/ΛC),𝘤^2/(𝟐*G*sqrt(τ*ΛC)),ΛC*𝘤^4/(𝟐^2*τ)/G,𝘦/√α
+const lcq,mcq = sqrt.(sqrt.((𝘤*ħ/ρΛ,ρΛ*ħ^3/𝘤^5))); const 𝘦ᵣ = 𝘦ₙ/√(𝟐*τ)
 const tcq,em,mi = lcq*sqrt(mcq/sqrt(sqrt(ρΛ*(𝘤*ħ)^3))),sqrt(GME/g₀)*τ/𝟐^9/𝟓^7,𝟐^5*𝟑*𝟓*𝟏𝟏
 
-@pure sackurtetrode(U::UnitSystem,P=atm,T=𝟏,m=atomicmass(U)) = normal(log((Constant(exp(5/2))*boltzmann(U)*sqrt(boltzmann(U)/gravity(U)/turn(U)/planckreduced(U)^2)^3)*(T/P*sqrt(m*T)^3)))
+@pure sackurtetrode(U::UnitSystem,P=atm,T=𝟏,m=dalton(U)) = normal(log((Constant(exp(5/2))*boltzmann(U)*sqrt(boltzmann(U)/gravity(U)/turn(U)/planckreduced(U)^2)^3)*(T/P*sqrt(m*T)^3)))
 
 const Universe = Coupling(αG,α,μₑᵤ,μₚᵤ,ΩΛ)
 
@@ -37,13 +37,13 @@ export MetricSystem, ConventionalSystem, RankineSystem
 export AstronomicalSystem, ElectricSystem, GaussSystem, EntropySystem
 
 """
-    MetricSystem(Mu=Mᵤ,μ0=μ₀,Ru=Rᵤ,g0=𝟏,h=𝘩)
+    MetricSystem(Mu=Mᵤ,μ0=μ₀,Ru=Rᵤ,g0=𝟏,θ=𝟏,h=𝘩)
 
-Constructs new `UnitSystem` from `molarmass` constant, `vacuumpermeability`, `molargas` constant, `gravity` force reference, and `planck` constant.
+Constructs new `UnitSystem` from `molarmass` constant, `vacuumpermeability`, `molargas` constant, `gravity` force reference, `angle` scale, and `planck` constant.
 
-Examples include `SI2019`, `Metric`, `SI2019Engineering`, `MetricEngineering`, `SI1976`. In addition, the `ConventionalSystem` constructor further builds on `MetricSystem`, resulting in variations.
+Examples include `SI2019`, `Metric`, `SI2019Engineering`, `MetricEngineering`, `SI1976`, `MetricDegree`, `MetricGradian`. In addition, the `ConventionalSystem` constructor further builds on `MetricSystem`, resulting in variations.
 """
-MetricSystem(Mu=Mᵤ,μ0=μ₀,Ru=Rᵤ,g0=𝟏,h=𝘩,me=αinv^2*R∞*𝟐*h/𝘤) = UnitSystem(Ru*me/Mu/μₑᵤ/g0,h/τ/g0,𝘤,μ0,me,Mu,Kcd*(mₑ/me)^2*(h/𝘩)*g0,𝟏,𝟏,𝟏,g0,Universe,τ,𝟐,𝟑,𝟓,𝟕,𝟏𝟏,𝟏𝟗,𝟒𝟑)
+MetricSystem(Mu=Mᵤ,μ0=μ₀,Ru=Rᵤ,g0=𝟏,θ=𝟏,h=𝘩,me=αinv^2*R∞*𝟐*h/𝘤) = UnitSystem(Ru*me/Mu/μₑᵤ/g0,h/τ/g0,𝘤,μ0,me,Mu,Kcd*(mₑ/me)^2*(h/𝘩)*g0,θ,𝟏,𝟏,g0,Universe,τ,𝟐,𝟑,𝟓,𝟕,𝟏𝟏,𝟏𝟗,𝟒𝟑)
 
 """
     ConventionalSystem(RK,KJ,Ru=Rᵤ,g0=𝟏) = MetricSystem(milli,𝟐*RK/𝘤*α,Ru,g0,𝟐^2/RK/KJ^2)
@@ -52,7 +52,7 @@ Constructs new `UnitSystem` from von `klitzing` constant and `josephson` constan
 
 Examples include `Conventional` (based on 1990) and `CODATA` (based on 2014).
 """
-ConventionalSystem(klitz,joseph,Ru=Rᵤ,g0=𝟏) = MetricSystem(milli,𝟐*klitz/𝘤*α,Ru,g0,(𝟐*𝟐)/klitz/(joseph*joseph))
+ConventionalSystem(klitz,joseph,Ru=Rᵤ,g0=𝟏,θ=𝟏) = MetricSystem(milli,𝟐*klitz/𝘤*α,Ru,g0,θ,(𝟐*𝟐)/klitz/(joseph*joseph))
 
 """
     RankineSystem(U::UnitSystem,l,m,g0=𝟏) = EntropySystem(U,𝟏,l,m,°R,vacuumpermeability(U)/m/l/g0,kilo*molarmass(U),g0)
@@ -67,8 +67,13 @@ RankineSystem(u,l,m,g0=𝟏) = EntropySystem(u,𝟏,l,m,°R,UnitSystems.vacuumpe
 
 const SI2019 = Quantity(MetricSystem())
 const Metric = Quantity(MetricSystem(milli,τ/𝟐^6/𝟓^7))
-const SI2019Engineering = Quantity(MetricSystem(Mᵤ,μ₀/g₀,Rᵤ,g₀))
+#const SI2019Engineering = Quantity(MetricSystem(Mᵤ,μ₀/g₀,Rᵤ,g₀))
 const MetricEngineering = Quantity(MetricSystem(milli,τ/𝟐^6/𝟓^7/g₀,Rᵤ,g₀))
+const MetricTurn = Quantity(MetricSystem(milli,τ/𝟐^6/𝟓^7,Rᵤ,𝟏,𝟏/τ))
+const MetricDegree = Quantity(MetricSystem(milli,τ/𝟐^6/𝟓^7,Rᵤ,𝟏,𝟐^3*𝟑^2*𝟓/τ))
+const MetricArcminute = Quantity(MetricSystem(milli,τ/𝟐^6/𝟓^7,Rᵤ,𝟏,𝟐^5*𝟑^3*𝟓^2/τ))
+const MetricArcsecond = Quantity(MetricSystem(milli,τ/𝟐^6/𝟓^7,Rᵤ,𝟏,𝟐^7*𝟑^4*𝟓^3/τ))
+const MetricGradian = Quantity(MetricSystem(milli,τ/𝟐^6/𝟓^7,Rᵤ,𝟏,𝟐^4*𝟓^2/τ))
 const SI1976 = Quantity(MetricSystem(milli,τ/𝟐^6/𝟓^7,Constant(8.31432)))
 const CODATA = Quantity(ConventionalSystem(RK2014,KJ2014,Rᵤ2014))
 const Conventional = Quantity(ConventionalSystem(RK1990,KJ1990))
@@ -93,19 +98,19 @@ const FPS = Quantity(RankineSystem(Metric,ft,lb))
 const IPS = Quantity(RankineSystem(Metric,ft/𝟐^2/𝟑,lb*g₀*𝟐^2*𝟑/ft))
 #const IPS2019 = Quantity(RankineSystem(SI2019,ft/𝟐^2/𝟑,lb*g₀*𝟐^2*𝟑/ft))
 
-#const Astronomical = Quantity(AstronomicalSystem(Metric))
-const Hubble = Quantity(EntropySystem(Metric,th,𝘤*th,𝟏))
-const Cosmological = Quantity(EntropySystem(Metric,lc/𝘤,lc,mc))
-const CosmologicalQuantum = Quantity(EntropySystem(Metric,tcq,lcq,mcq))
+#const Astronomical = Quantity(EntropySystem(Metric,𝟏,𝟏,𝟏/G))
+const Hubble = Quantity(AstronomicalSystem(Metric,th,𝘤*th,mₑ))#ħ/th/𝘤^2/mP^2))
+const Cosmological = Quantity(AstronomicalSystem(Metric,lc/𝘤,lc,mc))
+const CosmologicalQuantum = Quantity(AstronomicalSystem(Metric,tcq,lcq,mcq))
 #const EMU2019 = Quantity(EntropySystem(SI2019,𝟏,centi,milli))
 #const ESU2019 = Quantity(EntropySystem(SI2019,𝟏,centi,milli,𝟏,kilo*μ₀/𝘤^2))
 #const Mixed = Quantity(EntropySystem(Metric,𝟏,𝟏,𝟏,𝟏,μ₀))
 const Nautical = Quantity(EntropySystem(Metric,HOUR,nm,em^3,𝟏,τ*𝟑^3/𝟐^10/𝟓^12,milli))
 const Meridian = Quantity(EntropySystem(Metric,𝟏,em,em^3,𝟏,τ/𝟐^6/𝟓^7,milli))
-const MeridianEngineering = Quantity(EntropySystem(Metric,𝟏,em,em^3,𝟏,τ/𝟐^6/𝟓^7*em/g₀,milli,g₀/em))
-const GravitationalSI2019 = Quantity(EntropySystem(SI2019,𝟏,𝟏,g₀))
+#const MeridianEngineering = Quantity(EntropySystem(Metric,𝟏,em,em^3,𝟏,τ/𝟐^6/𝟓^7*em/g₀,milli,g₀/em))
+#const GravitationalSI2019 = Quantity(EntropySystem(SI2019,𝟏,𝟏,g₀))
 const GravitationalMetric = Quantity(EntropySystem(Metric,𝟏,𝟏,g₀))
-const GravitationalMeridian = Quantity(EntropySystem(Metric,𝟏,em,g₀*em^2,𝟏,τ/𝟐^6/𝟓^7*em/g₀,milli))
+#const GravitationalMeridian = Quantity(EntropySystem(Metric,𝟏,em,g₀*em^2,𝟏,τ/𝟐^6/𝟓^7*em/g₀,milli))
 const IAU☉ = Quantity(EntropySystem(Metric,DAY,au,GM☉/G))
 const IAUE = Quantity(EntropySystem(Metric,DAY,LD,GME/G))
 const IAUJ = Quantity(EntropySystem(Metric,DAY,JD,GMJ/G))
@@ -129,10 +134,10 @@ const QCD = Quantity(UnitSystem(𝟏,𝟏,𝟏,𝟏,inv(μₚₑ)))
 const QCDGauss = Quantity(UnitSystem(𝟏,𝟏,𝟏,𝟐*τ,inv(μₚₑ)))
 const QCDoriginal = Quantity(UnitSystem(𝟏,𝟏,𝟏,𝟐*τ*α,inv(μₚₑ)))
 
-export SI, MKS, SIE, ME, GSI2019, GSI, GM, CGS, CGS2019, CGSm, CGSe, HLU, FFF, AE, EE, BG
+export SI, MKS, ME, GM, CGS, CGS2019, CGSm, CGSe, HLU, FFF, AE, EE, BG # SIE, GSI, GSI2019
 export EnglishEngineering, BritishGravitational, AbsoluteEnglish, EnglishUS, EE2019, IAU
-const SI, MKS, SIE, ME, IAU = SI2019, Metric, SI2019Engineering, MetricEngineering, IAU☉
-const GSI2019, GSI, GM = GravitationalSI2019, GravitationalSI2019, GravitationalMetric
+#const SIE, GSI2019, GSI = SI2019Engineering, GravitationalSI2019, GravitationalSI2019
+const SI, MKS, ME, GM, IAU = SI2019, Metric, MetricEngineering, GravitationalMetric, IAU☉
 const CGS, CGSm, CGSe, HLU = Gauss, EMU, ESU, LorentzHeaviside
 const EnglishEngineering, BritishGravitational, BG = English, British, British
 const EnglishUS, AbsoluteEnglish, AE, EE = Survey, FPS, FPS, English
diff --git a/src/kinematic.jl b/src/kinematic.jl
index 19c0051..ba4b5db 100644
--- a/src/kinematic.jl
+++ b/src/kinematic.jl
@@ -149,7 +149,10 @@ $(time(PlanckGauss,Metric))
 @pure specificvolume(U::UnitSystem,S::UnitSystem) = unit(volume(U,S)/mass(U,S))
 @pure action(U::UnitSystem,S::UnitSystem) = unit(energy(U,S)*time(U,S))
 #@pure stiffness(U::UnitSystem,S::UnitSystem) = unit(force(U,S)/length(U,S))
-@pure intensity(U::UnitSystem,S::UnitSystem) = unit(power(U,S)/area(U,S))
+@pure irradiance(U::UnitSystem,S::UnitSystem) = unit(power(U,S)/area(U,S))
+@pure radiance(U::UnitSystem,S::UnitSystem) = unit(irradiance(U,S)/solidangle(U,S))
+@pure radiantintensity(U::UnitSystem,S::UnitSystem) = unit(power(U,S)/solidangle(U,S))
+@pure spectralexposure(U::UnitSystem,S::UnitSystem) = unit(force(U,S)/speed(U,S))
 @pure diffusivity(U::UnitSystem,S::UnitSystem) = unit(speed(U,S)*length(U,S))
 @pure viscosity(U::UnitSystem,S::UnitSystem) = unit(force(U,S)/speed(U,S)/length(U,S))
 @pure lineardensity(U::UnitSystem,S::UnitSystem) = unit(mass(U,S)/length(U,S))
diff --git a/src/kinematicdocs.jl b/src/kinematicdocs.jl
index 3bad694..5f2ce5f 100644
--- a/src/kinematicdocs.jl
+++ b/src/kinematicdocs.jl
@@ -660,21 +660,75 @@ $(stiffness(English,Metric))
 """ stiffness=#
 
 @doc """
-$(convertext(:intensity,"power(U,S)/area(U,S)"))
+$(convertext(:irradiance,"power(U,S)/area(U,S)"))
 
 Heat flux density or irradiance or `power` per `area` (W⋅m⁻², kg⋅s⁻³), unit conversion factor.
 
 ```Julia
-julia> intensity(CGS,Metric) # kg⋅g⁻¹
-$(intensity(CGS,Metric))
+julia> irradiance(CGS,Metric) # kg⋅g⁻¹
+$(irradiance(CGS,Metric))
 
-julia> intensity(CGS,English) # lb⋅g⁻¹
-$(intensity(CGS,English))
+julia> irradiance(CGS,English) # lb⋅g⁻¹
+$(irradiance(CGS,English))
 
-julia> intensity(English,Metric) # kg⋅lb⁻¹
-$(intensity(English,Metric))
+julia> irradiance(English,Metric) # kg⋅lb⁻¹
+$(irradiance(English,Metric))
 ```
-""" intensity
+""" irradiance, intensity
+
+@doc """
+$(convertext(:radiance,"irradiance(U,S)/solidangle(U,S)"))
+
+Radiance or `irradiance` per `solidangle` (W⋅m⁻²⋅sr⁻¹, kg⋅s⁻³⋅sr⁻¹), unit conversion factor.
+
+```Julia
+julia> radiance(CGS,Metric) # kg⋅g⁻¹
+$(radiance(CGS,Metric))
+
+julia> radiance(CGS,English) # lb⋅g⁻¹
+$(radiance(CGS,English))
+
+julia> radiance(English,Metric) # kg⋅lb⁻¹
+$(radiance(English,Metric))
+```
+""" radiance
+
+@doc """
+$(convertext(:radiantintensity,"power(U,S)/solidangle(U,S)"))
+
+Radiant intensity or `power` per `solidangle` (W⋅sr⁻¹, W⋅rad⁻²), unit conversion factor.
+
+```Julia
+julia> radiantintensity(CGS,Metric) # W⋅s⋅erg⁻¹
+$(radiantintensity(CGS,Metric))
+
+julia> radiantintensity(English,Metric) # W⋅s⋅ft⁻¹⋅lb⁻¹
+$(radiantintensity(English,Metric))
+```
+""" radiantintensity
+
+@doc """
+$(convertext(:spectralexposure,"force(U,S)/speed(U,S)"))
+
+Spectral exposure or `fluence` per `frequency` (N⋅s⋅m⁻¹, J⋅s⋅m⁻²), unit conversion factor.
+
+```Julia
+julia> spectralexposure(CGS,Metric) # kg⋅g⁻¹
+$(spectralexposure(CGS,Metric))
+
+julia> spectralexposure(CGS,English) # lb⋅g⁻¹
+$(spectralexposure(CGS,English))
+
+julia> spectralexposure(CODATA,Metric) # kg⋅kg⁻¹
+$(spectralexposure(CODATA,Metric))
+
+julia> spectralexposure(Conventional,Metric) # kg⋅kg⁻¹
+$(spectralexposure(Conventional,Metric))
+
+julia> spectralexposure(English,Metric) # kg⋅lb⁻¹
+$(spectralexposure(English,Metric))
+```
+""" spectralexposure
 
 @doc """
 $(convertext(:diffusivity,"speed(U,S)*length(U,S)"))
diff --git a/src/physics.jl b/src/physics.jl
index 0b9cc56..3275e10 100644
--- a/src/physics.jl
+++ b/src/physics.jl
@@ -13,7 +13,7 @@
 #   https://crucialflow.com
 
 @pure avogadro(U::UnitSystem,C::Coupling=universe(U)) = molarmass(U,C)*electronunit(C)/electronmass(U,C)
-@pure atomicmass(U::UnitSystem,C::Coupling=universe(U)) = electronmass(U,C)/electronunit(C)
+@pure dalton(U::UnitSystem,C::Coupling=universe(U)) = electronmass(U,C)/electronunit(C)
 @pure protonmass(U::UnitSystem,C::Coupling=universe(U)) = protonelectron(C)*electronmass(U,C)
 @pure gaussgravitation(U::UnitSystem,C::Coupling=universe(U)) = sqrt(normal(gravitation(IAU)))*radian(U)/day(U)
 @pure einstein(U::UnitSystem,C::Coupling=universe(U)) = two(U)*spat(U)*gravitation(U,C)/lightspeed(U,C)^4
@@ -45,6 +45,7 @@
 @pure amagat(U::UnitSystem) = loschmidt(U)/avogadro(U)
 @pure wienwavelength(U::UnitSystem) = planck(U)*lightspeed(U)/boltzmann(U)/Constant(4.965114231744276303)
 @pure wienfrequency(U::UnitSystem) = Constant(2.821439372122078893)*boltzmann(U)/planck(U)
+@pure eddington(U::UnitSystem) = mass(𝟏,U,Cosmological)
 @pure solarmass(U::UnitSystem) = mass(GM☉/G,U,Metric)
 @pure earthmass(U::UnitSystem) = mass(GME/G,U,Metric)
 @pure jupitermass(U::UnitSystem) = mass(GMJ/G,U,Metric)
diff --git a/src/physicsdocs.jl b/src/physicsdocs.jl
index fec6015..5ce8759 100644
--- a/src/physicsdocs.jl
+++ b/src/physicsdocs.jl
@@ -36,7 +36,7 @@ $αG
 julia> ΩΛ # darkenergydensity(Universe)
 $ΩΛ
 ```
-""" Universe, μₑᵤ, μₚᵤ, μₚₑ, αinv, αG, meu, mpu, mpe, ainv, aG, ΩΛ, electronunit, protonunit, protonelectron, finestructure, coupling, darkenergydensity
+""" Universe, μₑᵤ, μₚᵤ, μₚₑ, μₑₚ, αinv, αG, meu, mpu, mpe, ainv, aG, ΩΛ, electronunit, protonunit, protonelectron, finestructure, coupling, darkenergydensity
 
 @doc """
 $(unitext(:turn,"2π/angle(U)"))
@@ -45,6 +45,18 @@ Complete rotation `angle` of revolution from a full circle.
 ```Julia
 julia> turn(MetricEngineering)
 $(turn(MetricEngineering))
+
+julia> turn(MetricDegree)
+$(turn(MetricDegree))
+
+julia> turn(MetricArcminute)
+$(turn(MetricArcminute))
+
+julia> turn(MetricArcsecond)
+$(turn(MetricArcsecond))
+
+julia> turn(MetricGradian)
+$(turn(MetricGradian))
 ```
 """ turn
 
@@ -55,6 +67,18 @@ Complete spherical `solidangle` around point from a full sphere.
 ```Julia
 julia> spat(MetricEngineering)
 $(spat(MetricEngineering))
+
+julia> spat(MetricDegree)
+$(spat(MetricDegree))
+
+julia> spat(MetricArcminute)
+$(spat(MetricArcminute))
+
+julia> spat(MetricArcsecond)
+$(spat(MetricArcsecond))
+
+julia> spat(MetricGradian)
+$(spat(MetricGradian))
 ```
 """ spat
 
@@ -100,9 +124,9 @@ $(molarmass(International))
 """ molarmass, Mᵤ, Mu
 
 @doc """
-$(unitext(:avogadro, "molargas(x)/boltzmann(x) # Mᵤ/atomicmass(x)"))
+$(unitext(:avogadro, "molargas(x)/boltzmann(x) # Mᵤ/dalton(x)"))
 
-Avogadro `NA` is `molarmass(x)/atomicmass(x)` number of atoms in a 12 g sample of C₁₂.
+Avogadro `NA` is `molarmass(x)/dalton(x)` number of atoms in a 12 g sample of C₁₂.
 ```Julia
 julia> avogadro(SI2019) # mol⁻¹
 $(avogadro(SI2019))
@@ -317,8 +341,14 @@ $(electronmass(Conventional))
 julia> electronmass(International) # kg
 $(electronmass(International))
 
-julia> electronmass(Metric)/atomicmass(Metric) # Da
-$μₑᵤ
+julia> electronmass(Metric)/dalton(Metric) # Da
+$(electronmass(Metric)/dalton(Metric))
+
+julia> electronmass(QCD) # mₚ
+$(electronmass(QCD))
+
+julia> electronmass(Hartree) # mₑ
+$(electronmass(Hartree))
 
 julia> electronmass(Metric)*lightspeed(Metric)^2 # J
 $(electronmass(Metric)*lightspeed(Metric)^2)
@@ -332,29 +362,32 @@ $(electronmass(English))
 """ electronmass, mₑ, me
 
 @doc """
-$(unitext(:atomicmass,"Mᵤ/avogadro(U) # $(molarmass(SI2019)) ≈ 0.001-3.5e-13"))
+$(unitext(:dalton,"molarmass(U)/avogadro(U)"))
 
-Atomic mass unit `mᵤ` of 1/12 of the C₁₂ carbon-12 atom's mass  (kg or slugs).
+Atomic mass unit `Da` of 1/12 of the C₁₂ carbon-12 atom's mass  (kg or slugs).
 ```Julia
-julia> atomicmass(Metric) # kg
-$(atomicmass(Metric))
+julia> dalton(Metric) # kg
+$(dalton(Metric))
+
+julia> dalton(Hartree) # mₑ
+$(dalton(Hartree))
 
-julia> atomicmass(Metric)/electronmass(Metric) # mₑ
-$(atomicmass(Metric)/electronmass(Metric))
+julia> dalton(QCD) # mₚ
+$(dalton(QCD))
 
-julia> atomicmass(Metric)*lightspeed(Metric)^2 # J
-$(atomicmass(Metric)*lightspeed(Metric)^2)
+julia> dalton(Metric)*lightspeed(Metric)^2 # J
+$(dalton(Metric)*lightspeed(Metric)^2)
 
-julia> atomicmass(SI2019)*lightspeed(SI2019)^2/elementarycharge(SI2019) # eV⋅𝘤⁻²
-$(atomicmass(SI2019)*lightspeed(SI2019)^2/elementarycharge(SI2019))
+julia> dalton(SI2019)*lightspeed(SI2019)^2/elementarycharge(SI2019) # eV⋅𝘤⁻²
+$(dalton(SI2019)*lightspeed(SI2019)^2/elementarycharge(SI2019))
 
-julia> atomicmass(British) # lb
-$(atomicmass(British))
+julia> dalton(British) # lb
+$(dalton(British))
 ```
-""" atomicmass, mᵤ, mu
+""" dalton, Da, mu, mᵤ, atomicmass
 
 @doc """
-$(unitext(:protonmass,"protonunit(U)*atomicmass(U)"))
+$(unitext(:protonmass,"protonunit(U)*dalton(U)"))
 
 Proton mass `mₚ` of subatomic particle with `+𝘦` elementary charge  (kg or mass).
 ```Julia
@@ -364,11 +397,14 @@ $(protonmass(Metric))
 julia> protonmass(SI2019)*lightspeed(SI2019)^2/elementarycharge(SI2019) # eV⋅𝘤⁻²
 $(protonmass(SI2019)*lightspeed(SI2019)^2/elementarycharge(SI2019))
 
-julia> protonmass(Metric)/atomicmass(Metric) # mᵤ
-$(protonmass(Metric)/atomicmass(Metric))
+julia> protonmass(Metric)/dalton(Metric) # Da
+$(protonmass(Metric)/dalton(Metric))
 
-julia> protonmass(Metric)/electronmass(Metric) # mₑ
-$(protonmass(Metric)/electronmass(Metric))
+julia> protonmass(Hartree) # mₑ
+$(protonmass(Hartree))
+
+julia> protonmass(QCD) # mₚ
+$(protonmass(QCD))
 ```
 """ protonmass, mₚ, mp
 
@@ -383,14 +419,14 @@ $(planckmass(Metric)*lightspeed(Metric)^2/elementarycharge(Metric))
 juila> planckmass(Metric) # kg
 $(planckmass(Metric))
 
-juila> planckmass(Metric)/atomicmass(Metric) # mᵤ
-$(planckmass(Metric)/atomicmass(Metric))
+juila> planckmass(Metric)/dalton(Metric) # Da
+$(planckmass(Metric)/dalton(Metric))
 
 juila> planckmass(Metric)*lightspeed(Metric)^2/elementarycharge(Metric)/sqrt(𝟐^2*τ) # eV⋅𝘤⁻²
 $(planckmass(Metric)*lightspeed(Metric)^2/elementarycharge(Metric)/sqrt(𝟐^2*τ))
 
-juila> planckmass(Metric)/sqrt(𝟐^2*τ) # kg
-$(planckmass(Metric)/sqrt(𝟐^2*τ))
+julia> planckmass(PlanckGauss) # mP
+$(planckmass(PlanckGauss))
 ```
 """ planckmass, mP
 
@@ -739,8 +775,8 @@ $(elementarycharge(EMU))
 julia> elementarycharge(ESU) # statC
 $(elementarycharge(ESU))
 
-julia> elementarycharge(Planck) # sqrt(4π/αinv)
-$(elementarycharge(Planck))
+julia> elementarycharge(Hartree) # 𝘦
+$(elementarycharge(Hartree))
 ```
 """ elementarycharge, 𝘦, ee
 
@@ -1009,6 +1045,9 @@ $(electronradius(CODATA))
 
 julia> electronradius(Conventional) # m
 $(electronradius(Conventional))
+
+julia> electronradius(Hartree) # a₀
+$(electronradius(Hartree))
 ```
 """ electronradius, rₑ, re
 
@@ -1195,6 +1234,12 @@ $(solarmass(IAUE))
 
 julia> solarmass(IAUJ) # MJ
 $(solarmass(IAUJ))
+
+julia> solarmass(QCD) # mₚ
+$(solarmass(QCD))
+
+julia> solarmass(Metric)/dalton(Metric) # Da
+$(solarmass(Metric)/dalton(Metric))
 ```
 """ solarmass, mₛ
 
@@ -1217,6 +1262,12 @@ $(earthmass(IAU))
 
 julia> earthmass(IAUJ) # MJ
 $(earthmass(IAUJ))
+
+julia> earthmass(QCD) # mₚ
+$(earthmass(QCD))
+
+julia> earthmass(Metric)/dalton(Metric) # Da
+$(earthmass(Metric)/dalton(Metric))
 ```
 """ earthmass
 
@@ -1239,6 +1290,12 @@ $(jupitermass(IAU))
 
 julia> jupitermass(IAUE) # ME
 $(jupitermass(IAUE))
+
+julia> jupitermass(QCD) # mₚ
+$(jupitermass(QCD))
+
+julia> jupitermass(Metric)/dalton(Metric) # Da
+$(jupitermass(Metric)/dalton(Metric))
 ```
 """ jupitermass
 
@@ -1264,6 +1321,12 @@ $(lunarmass(IAUE))
 
 julia> lunarmass(IAUJ) # MJ
 $(lunarmass(IAUJ))
+
+julia> lunarmass(QCD) # mₚ
+$(lunarmass(QCD))
+
+julia> lunarmass(Metric)/dalton(Metric) # Da
+$(lunarmass(Metric)/dalton(Metric))
 ```
 """ lunarmass
 
@@ -1272,8 +1335,20 @@ $(unitext(:gaussgravitation,"sqrt(gravitation(U)*solarmass(U)/astronomicalunit(U
 
 Gaussian  gravitational constant `k` of Newton's laws (Hz or rad⋅D⁻¹).
 ```Julia
-julia> gaussgravitation(Metric)
-$(gaussgravitation(Metric))
+julia> gaussgravitation(MetricEngineering)
+$(gaussgravitation(MetricEngineering))
+
+julia> gaussgravitation(MetricGradian)
+$(gaussgravitation(MetricGradian))
+
+julia> gaussgravitation(MetricDegree)
+$(gaussgravitation(MetricDegree))
+
+julia> gaussgravitation(MetricArcminute)
+$(gaussgravitation(MetricArcminute))
+
+julia> gaussgravitation(MetricArcsecond)
+$(gaussgravitation(MetricArcsecond))
 
 juila> gaussgravitation(MPH)
 $(gaussgravitation(MPH))
@@ -1286,7 +1361,7 @@ $(gaussgravitation(IAU))
 @doc """
 $(unitext(:gaussianyear,"turn(U)/gaussgravitation(U)"))
 
-Orbit `time` defined by `gaussgravitation` constant `kG` for neglible `mass` satellite.
+Orbit `time` defined by `gaussgravitation` constant `kG` for neglible `mass` satellite (s).
 ```Julia
 julia> gaussianyear(Metric) # s
 $(gaussianyear(Metric))
@@ -1302,7 +1377,7 @@ $(gaussianyear(IAU))
 @doc """
 $(unitext(:siderealyear,"gaussianyear(U)/√(𝟏+earthmass(IAU)+lunarmass(IAU))"))
 
-Orbit `time` defined by `gaussgravitation` constant `kG` and the Earth-Moon system `mass`.
+Orbit `time` defined by `gaussgravitation` constant `kG` and Earth-Moon system `mass` (s).
 ```Julia
 julia> siderealyear(Metric) # s
 $(siderealyear(Metric))
@@ -1318,7 +1393,7 @@ $(siderealyear(IAU))
 @doc """
 $(unitext(:jovianyear,"τ*day(U)*√(jupiterdistance(U)^3/solarmass(U)/gravitation(U))/√(𝟏+jupitermass(IAU))"))
 
-Orbit `time` defined by `jupiterdistance` and the Sun-Jupiter system `mass`.
+Orbit `time` defined by `jupiterdistance` and the Sun-Jupiter system `mass` (s).
 ```Julia
 julia> jovianyear(Metric) # s
 $(jovianyear(Metric))
@@ -1334,7 +1409,7 @@ $(jovianyear(IAU))
 @doc """
 $(unitext(:gaussianmonth,"τ*sqrt(lunardistance(U)^3/earthmass(U)/gravitation(U))"))
 
-Orbit `time` defined by `lunardistance` and `earthmass` for neglible `mass` satellite.
+Orbit `time` defined by `lunardistance` and `earthmass` for neglible `mass` satellite (s).
 ```Julia
 julia> gaussianmonth(Metric) # s
 $(gaussianmonth(Metric))
@@ -1350,7 +1425,7 @@ $(gaussianmonth(IAU))
 @doc """
 $(unitext(:siderealmonth,"gaussianmonth(U)/√(𝟏+lunarmass(IAU))"))
 
-Orbit `time` defined by standard `lunardistance` and the Earth-Moon system `mass`.
+Orbit `time` defined by standard `lunardistance` and the Earth-Moon system `mass` (s).
 ```Julia
 julia> siderealmonth(Metric) # s
 $(siderealmonth(Metric))
@@ -1366,7 +1441,7 @@ $(siderealmonth(IAU))
 @doc """
 $(unitext(:synodicmonth,"𝟏/(𝟏/siderealmonth(U)-𝟏/siderealyear(U))"))
 
-Orbit `time` defined by `siderealmonth` and `siderealyear` of the Sun-Earth-Moon system.
+Orbit `time` defined by `siderealmonth` and `siderealyear` of Sun-Earth-Moon system (s).
 ```Julia
 julia> synodicmonth(Metric) # s
 $(synodicmonth(Metric))
@@ -1412,10 +1487,10 @@ $(greatcircle(IAU))
 """ greatcircle
 
 @doc """
-    sackurtetrode(U::UnitSystem,P=atm,T=𝟏,m=mᵤ) = log(kB*T/P*sqrt(m*kB*T/τ/ħ^2)^3)+5/2
+    sackurtetrode(U::UnitSystem,P=atm,T=𝟏,m=Da) = log(kB*T/P*sqrt(m*kB*T/τ/ħ^2)^3)+5/2
     dimensionless : [𝟙], [𝟙], [𝟙], [𝟙], [𝟙]
 
-Ideal gas entropy density for pressure `P`, temperature `T`, atomicmass `m` (dimensionless).
+Ideal gas entropy density for pressure `P`, temperature `T`, atomic mass `m` (dimensionless).
 ```Julia
 julia> sackurtetrode(Metric)
 $(sackurtetrode(Metric))
@@ -1451,4 +1526,26 @@ $(mechanicalheat(British))
 ```
 """ mechanicalheat
 
+@doc """
+    eddington(U::UnitSystem) = mass(𝟏,U,Cosmological)
+
+Approximate number of protons in the `Universe` as estimated by Eddington (kg or lb).
+```Julia
+julia> 𝟐^2^2^3/α # mₚ
+$(𝟐^2^2^3/α)
+
+julia> eddington(QCD) # mₚ
+$(eddington(QCD))
+
+julia> eddington(Metric) # kg
+$(eddington(Metric))
+
+julia> eddington(IAU) # M☉
+$(eddington(IAU))
+
+julia> eddington(Cosmological)
+$(eddington(Cosmological))
+```
+""" eddington
+
 include("derivedocs.jl")
diff --git a/src/systems.jl b/src/systems.jl
index 15e0f14..72c951a 100644
--- a/src/systems.jl
+++ b/src/systems.jl
@@ -19,10 +19,10 @@ export byte,kibi,mebi,gibi,tebi,pebi,exbi,zebi,yobi
 export slug, ft, KJ1990, KJ2014, RK1990, RK2014, mₑ1990, mₑ2014, temp, units, °R, T₀, eV
 export slugs, kilograms, lbm, meters, feet, rankine, kelvin, moles, molecules, universal
 export Universe, UnitSystem, US, universe, HOUR, DAY, th, lc, mc, tcq, lcq, mcq
-export similitude, 𝟙, F, M, L, T, Q, Θ, N, J, A, Λ, C, sackurtetrode
+export similitude, 𝟙, F, M, L, T, Q, Θ, N, J, A, Λ, C, sackurtetrode,atomicmass,intensity
 export °R, τ, 𝟏𝟎, 𝟐, 𝟑, 𝟓, nm, 𝟏, mₑ, μ₀, Mᵤ, Rᵤ, αG, GG, slug, ħ, μₚₑ, αL, 𝟕, 𝟏𝟏, 𝟏𝟗, 𝟒𝟑
 
-const EMU2019,ESU2019,stiffness = EMU,ESU,fluence
+const EMU2019,ESU2019,stiffness,intensity,atomicmass = EMU,ESU,fluence,irradiance,dalton
 
 # == Metric is different
 const eV = electronvolt(SI2019)
@@ -32,7 +32,7 @@ const μB = magneton(SI2019) #
 const ε₀ = vacuumpermittivity(SI2019) #
 const kₑ = electrostatic(SI2019) #
 const mₚ = protonmass(SI2019)
-const mᵤ = atomicmass(SI2019)
+const Da = dalton(SI2019)
 const 𝔉 = faraday(SI2019) #
 const Φ₀ = magneticfluxquantum(SI2019) #
 const Z₀ = vacuumimpedance(SI2019) #
@@ -73,12 +73,13 @@ const universal = molargas
 
 # constant aliases
 
-const US,mpe, meu, mpu, ainv, aG = UnitSystem,μₚₑ, μₑᵤ, μₚᵤ, αinv, αG
-const Mu,Ru,SB,hh,cc,m0,e0,ke,me,mp,mu,ee,FF,Z0,G0,Eh,a0,re,g0,lP,aL,ϵ₀ = Mᵤ,Rᵤ,σ,𝘩,𝘤,μ₀,ε₀,kₑ,mₑ,mₚ,mᵤ,𝘦,𝔉,Z₀,G₀,Eₕ,a₀,rₑ,g₀,ℓP,αL,ε₀
-export κ, G, GG, NA, kB, Rᵤ, σ, 𝘩, ħ, 𝘤, μ₀, ε₀, kₑ, mₑ, mₚ, mᵤ, 𝘦, 𝔉, Φ₀, Z₀, G₀, Eₕ, R∞, a₀, rₑ, KJ, RK, Ru, SB, hh, cc, m0, e0, ke, me, mp, mu, ee, FF, Z0, G0, Eh, a0, re, μB
+const US,mpe, mep, meu, mpu, ainv, aG = UnitSystem,μₚₑ, μₑₚ, μₑᵤ, μₚᵤ, αinv, αG
+const Mu,Ru,SB,hh,cc,m0,e0,ke,me,mp,mu,mᵤ,ee,FF,Z0,G0,Eh,a0,re,g0,lP,aL,ϵ₀ = Mᵤ,Rᵤ,σ,𝘩,𝘤,μ₀,ε₀,kₑ,mₑ,mₚ,Da,Da,𝘦,𝔉,Z₀,G₀,Eₕ,a₀,rₑ,g₀,ℓP,αL,ε₀
+export κ, G, GG, NA, kB, Rᵤ, σ, 𝘩, ħ, 𝘤, μ₀, ε₀, kₑ, mₑ, mₚ, Da, 𝘦, 𝔉, Φ₀, Z₀, G₀, Eₕ, R∞, a₀, rₑ, KJ, RK, Ru, SB, hh, cc, m0, e0, ke, me, mp, mu, mᵤ, ee, FF, Z0, G0, Eh, a0, re, μB
 export αG, αinv, μₚₑ, μₑᵤ, μₚᵤ, mpe, meu, mpu, mP, δμ₀, Mᵤ, Mu, RH, Ry, ΔνCs, Kcd, ainv
 export cal, kcal, calₜₕ, kcalₜₕ, calᵢₜ, kcalᵢₜ, ℓP, g₀, g0, atm, lbm, BTUJ, BTUftlb, aG
-export lP, tP, TP, lS, tS, mS, qS, lA, tA, mA, qA, lQCD, tQCD, mQCD, ϵ₀, αL, aL
+export lP, tP, TP, lS, tS, mS, qS, lA, tA, mA, qA, lQCD, tQCD, mQCD, ϵ₀, αL, aL, μₑₚ, 𝘦ₙ
+export GM☉, GME, GMJ, LD, JD, lb, fur, ftUS, Rᵤ2014, Ωᵢₜ, Vᵢₜ, em, mi, 𝘦ᵣ
 
 @doc """
     Constant{D} <: Real
@@ -151,6 +152,151 @@ $(luminousefficacy(SI2019))
 ```
 """ SI2019, SI
 
+@doc """
+    MetricTurn = MetricSystem(milli,𝟐*τ/𝟏𝟎^7,Rᵤ,𝟏,𝟏/τ)
+
+Standard `MetricTurn` system based on exact `molarmass` and `vacuumpermeability`.
+
+```Julia
+julia> boltzmann(MetricTurn) # J⋅K⁻¹
+$(boltzmann(MetricTurn))
+
+julia> planckreduced(MetricTurn) # J⋅s⋅τ⁻¹
+$(planckreduced(MetricTurn))
+
+julia> lightspeed(MetricTurn) # m⋅s⁻¹
+$(lightspeed(MetricTurn))
+
+julia> vacuumpermeability(MetricTurn) # H⋅m⁻¹
+$(vacuumpermeability(MetricTurn))
+
+julia> electronmass(MetricTurn) # kg
+$(electronmass(MetricTurn))
+
+julia> molarmass(MetricTurn) # kg⋅mol⁻¹
+$(molarmass(MetricTurn))
+
+julia> luminousefficacy(MetricTurn) # lm⋅W⁻¹
+$(luminousefficacy(MetricTurn))
+```
+""" MetricTurn
+
+@doc """
+    MetricDegree = MetricSystem(milli,𝟐*τ/𝟏𝟎^7,Rᵤ,𝟏,𝟐^3*𝟑^2*𝟓/τ)
+
+Standard `MetricDegree` system based on exact `molarmass` and `vacuumpermeability`.
+
+```Julia
+julia> boltzmann(MetricDegree) # J⋅K⁻¹
+$(boltzmann(MetricDegree))
+
+julia> planckreduced(MetricDegree) # J⋅s⋅deg⁻¹
+$(planckreduced(MetricDegree))
+
+julia> lightspeed(MetricDegree) # m⋅s⁻¹
+$(lightspeed(MetricDegree))
+
+julia> vacuumpermeability(MetricDegree) # H⋅m⁻¹
+$(vacuumpermeability(MetricDegree))
+
+julia> electronmass(MetricDegree) # kg
+$(electronmass(MetricDegree))
+
+julia> molarmass(MetricDegree) # kg⋅mol⁻¹
+$(molarmass(MetricDegree))
+
+julia> luminousefficacy(MetricDegree) # lm⋅W⁻¹
+$(luminousefficacy(MetricDegree))
+```
+""" MetricDegree
+
+@doc """
+    MetricArcminute = MetricSystem(milli,𝟐*τ/𝟏𝟎^7,Rᵤ,𝟏,𝟐^5*𝟑^3*𝟓^2/τ)
+
+Standard `MetricArcminute` system based on exact `molarmass` and `vacuumpermeability`.
+
+```Julia
+julia> boltzmann(MetricArcminute) # J⋅K⁻¹
+$(boltzmann(MetricArcminute))
+
+julia> planckreduced(MetricArcminute) # J⋅s⋅amin⁻¹
+$(planckreduced(MetricArcminute))
+
+julia> lightspeed(MetricArcminute) # m⋅s⁻¹
+$(lightspeed(MetricArcminute))
+
+julia> vacuumpermeability(MetricArcminute) # H⋅m⁻¹
+$(vacuumpermeability(MetricArcminute))
+
+julia> electronmass(MetricArcminute) # kg
+$(electronmass(MetricArcminute))
+
+julia> molarmass(MetricArcminute) # kg⋅mol⁻¹
+$(molarmass(MetricArcminute))
+
+julia> luminousefficacy(MetricArcminute) # lm⋅W⁻¹
+$(luminousefficacy(MetricArcminute))
+```
+""" MetricArcminute
+
+@doc """
+    MetricArcsecond = MetricSystem(milli,𝟐*τ/𝟏𝟎^7,Rᵤ,𝟏,𝟐^7*𝟑^4*3/τ)
+
+Standard `MetricArcsecond` system based on exact `molarmass` and `vacuumpermeability`.
+
+```Julia
+julia> boltzmann(MetricArcsecond) # J⋅K⁻¹
+$(boltzmann(MetricArcsecond))
+
+julia> planckreduced(MetricArcsecond) # J⋅s⋅asec⁻¹
+$(planckreduced(MetricArcsecond))
+
+julia> lightspeed(MetricArcsecond) # m⋅s⁻¹
+$(lightspeed(MetricArcsecond))
+
+julia> vacuumpermeability(MetricArcsecond) # H⋅m⁻¹
+$(vacuumpermeability(MetricArcsecond))
+
+julia> electronmass(MetricArcsecond) # kg
+$(electronmass(MetricArcsecond))
+
+julia> molarmass(MetricArcsecond) # kg⋅mol⁻¹
+$(molarmass(MetricArcsecond))
+
+julia> luminousefficacy(MetricArcsecond) # lm⋅W⁻¹
+$(luminousefficacy(MetricArcsecond))
+```
+""" MetricArcsecond
+
+@doc """
+    MetricGradian = MetricSystem(milli,𝟐*τ/𝟏𝟎^7,Rᵤ,𝟏,𝟐^4*𝟓^2/τ)
+
+Standard `MetricGradian` system based on exact `molarmass` and `vacuumpermeability`.
+
+```Julia
+julia> boltzmann(MetricGradian) # J⋅K⁻¹
+$(boltzmann(MetricGradian))
+
+julia> planckreduced(MetricGradian) # J⋅s⋅gon⁻¹
+$(planckreduced(MetricGradian))
+
+julia> lightspeed(MetricGradian) # m⋅s⁻¹
+$(lightspeed(MetricGradian))
+
+julia> vacuumpermeability(MetricGradian) # H⋅m⁻¹
+$(vacuumpermeability(MetricGradian))
+
+julia> electronmass(MetricGradian) # kg
+$(electronmass(MetricGradian))
+
+julia> molarmass(MetricGradian) # kg⋅mol⁻¹
+$(molarmass(MetricGradian))
+
+julia> luminousefficacy(MetricGradian) # lm⋅W⁻¹
+$(luminousefficacy(MetricGradian))
+```
+""" MetricGradian
+
 @doc """
     MetricEngineering = MetricSystem(milli,𝟐*τ/𝟏𝟎^7,Rᵤ,g₀)
 
@@ -183,7 +329,7 @@ $(gravity(MetricEngineering))
 ```
 """ MetricEngineering, ME
 
-@doc """
+#=@doc """
     SI2019Engineering = MetricSystem(Mᵤ,μ₀,Rᵤ,g₀)
 
 Systeme International d'Unites based on kilogram and kilopond (kilogram-force) units.
@@ -213,7 +359,7 @@ $(luminousefficacy(SI2019Engineering))
 julia> gravity(SI2019Engineering) # kg⋅m⋅kgf⁻¹⋅s⁻²
 $(gravity(SI2019Engineering))
 ```
-""" SI2019Engineering, SIE
+""" SI2019Engineering, SIE=#
 
 @doc """
     SI1976 = MetricSystem(milli,𝟐*τ/𝟏𝟎^7,8.31432)
@@ -416,7 +562,7 @@ $(luminousefficacy(Meridian))
 ```
 """ Meridian
 
-@doc """
+#=@doc """
     MeridianEngineering = EntropySystem(MetricEngineering,𝟏,em,em^3,𝟏,τ/𝟐^6/𝟓^7/g₀^2,milli)
 
 Modern ideal engineering `UnitSystem` variant of the original French `Meridian` system.
@@ -449,7 +595,7 @@ $(luminousefficacy(MeridianEngineering))
 julia> gravity(MeridianEngineering) # keg⋅em⋅kegf⁻¹⋅s⁻²
 $(gravity(MeridianEngineering))
 ```
-""" MeridianEngineering
+""" MeridianEngineering=#
 
 
 cgstext(US,AMP,cgs=eval(US)) = """
@@ -665,7 +811,7 @@ $(luminousefficacy(GravitationalMetric))
 ```
 """ GravitationalMetric, GM
 
-@doc """
+#=@doc """
     GraviationalSI2019 = EntropySystem(SI2019,𝟏,𝟏,g₀)
 
 Gravitational Systeme International d'Unites based on `hyl` and `kilopond` units.
@@ -692,9 +838,9 @@ $(molarmass(GravitationalSI2019))
 julia> luminousefficacy(GravitationalMetric) # lm⋅s⋅m⁻¹⋅kgf⁻¹
 $(luminousefficacy(GravitationalMetric))
 ```
-""" GravitationalSI2019, GSI, GSI2019
+""" GravitationalSI2019, GSI, GSI2019=#
 
-@doc """
+#=@doc """
     GravitationalMeridian = EntropySystem(Metric,𝟏,em,g₀*em^3,𝟏,τ/𝟐^6/𝟓^7/g₀,milli)
 
 Gravitational `UnitSystem` variant of the original French `Meridian` unit defintion.
@@ -724,7 +870,7 @@ $(molarmass(GravitationalMeridian))
 julia> luminousefficacy(GravitationalMeridian) # lm⋅s⋅em⁻¹⋅kegf⁻¹
 $(luminousefficacy(GravitationalMeridian))
 ```
-""" GravitationalMeridian
+""" GravitationalMeridian=#
 
 @doc """
     MTS = EntropySystem(SI2019,𝟏,𝟏,kilo)
@@ -881,7 +1027,7 @@ $(sqrt(gravitation(IAUJ)*solarmass(IAUJ)/jupiterdistance(IAUJ)^3))
 """ IAUJ
 
 #=@doc """
-    Astronomical = AstronomicalSystem(Metric)
+    Astronomical = EntropySystem(Metric,𝟏,𝟏,𝟏/gravitation(Metric))
 
 Astronomical `UnitSystem` defined by making the `newton` gravitational constant 1.
 
@@ -913,7 +1059,7 @@ $(gravitation(Astronomical))
 """ Astronomical=#
 
 @doc """
-    Hubble = EntropySystem(Metric,th,𝘤*th,𝟏)
+    Hubble = AstronomicalSystem(Metric,th,𝘤*th,mₑ)
 
 Hubble `UnitSystem` defined by `hubble` parameter.
 
@@ -948,7 +1094,7 @@ $(cosmological(Hubble))
 """ Hubble
 
 @doc """
-    Cosmological = EntropySystem(Metric,lc/𝘤,lc,mc)
+    Cosmological = AstronomicalSystem(Metric,lc/𝘤,lc,mc)
 
 Cosmological scale `UnitSystem` defined by `darkenergydensity`.
 
@@ -983,7 +1129,7 @@ $(cosmological(Cosmological))
 """ Cosmological
 
 @doc """
-    CosmologicalQuantum = EntropySystem(Metric,tcq,lcq,mcq)
+    CosmologicalQuantum = AstronomicalSystem(Metric,tcq,lcq,mcq)
 
 Cosmological quantum scale `UnitSystem` defined by `darkenergydensity`.
 
@@ -1290,17 +1436,17 @@ $(textunits(PlanckGauss,:PlanckGauss))
 
 The well known `PlanckGauss` values for `length`, `time`, `mass`, and `temperature` are:
 ```Julia
-julia> length(PlanckGauss,Metric) # ℓP
-$(length(PlanckGauss,Metric))
+julia> length(PlanckGauss,SI2019) # ℓP
+$(length(PlanckGauss,SI2019))
 
-julia> time(PlanckGauss,Metric) # tP
-$(time(PlanckGauss,Metric))
+julia> time(PlanckGauss,SI2019) # tP
+$(time(PlanckGauss,SI2019))
 
-julia> mass(PlanckGauss,Metric) # mP
-$(mass(PlanckGauss,Metric))
+julia> mass(PlanckGauss,SI2019) # mP
+$(mass(PlanckGauss,SI2019))
 
-julia> temperature(PlanckGauss,Metric) # TP
-$(temperature(PlanckGauss,Metric))
+julia> temperature(PlanckGauss,SI2019) # TP
+$(temperature(PlanckGauss,SI2019))
 ```
 """ PlanckGauss
 
@@ -1313,40 +1459,40 @@ $(textunits(Stoney,:Stoney))
 
 The well known `Stoney` values for `length`, `time`, `mass`, and `charge` are:
 ```Julia
-julia> length(Stoney,Metric) # lS
-$(length(Stoney,Metric))
+julia> length(Stoney,SI2019) # lS
+$(length(Stoney,SI2019))
 
-julia> time(Stoney,Metric) # tS
-$(time(Stoney,Metric))
+julia> time(Stoney,SI2019) # tS
+$(time(Stoney,SI2019))
 
-julia> mass(Stoney,Metric) # mS
-$(mass(Stoney,Metric))
+julia> mass(Stoney,SI2019) # mS
+$(mass(Stoney,SI2019))
 
-julia> charge(Stoney,Metric) # qS
-$(charge(Stoney,Metric))
+julia> charge(Stoney,SI2019) # qS
+$(charge(Stoney,SI2019))
 ```
 """ Stoney
 
 @doc """
     Hartree = UnitSystem(𝟏,𝟏,𝟏/α,𝟐*τ*α^2,𝟏)
 
-Hartree atomic `UnitSystem` with `lightspeed` of `αinv` and `permeability` of `𝟐*τ*α^2`.
+Hartree atomic `UnitSystem` based on `bohr` radius and `elementarycharge` scale.
 
 $(textunits(Hartree,:Hartree))
 
 The well known `Hartree` atomic unit values for `length`, `time`, `mass`, and `charge` are:
 ```Julia
-julia> length(Hartree,Metric) # lA
-$(length(Hartree,Metric))
+julia> length(Hartree,SI2019) # lA
+$(length(Hartree,SI2019))
 
-julia> time(Hartree,Metric) # tA
-$(time(Hartree,Metric))
+julia> time(Hartree,SI2019) # tA
+$(time(Hartree,SI2019))
 
-julia> mass(Hartree,Metric) # mA
-$(mass(Hartree,Metric))
+julia> mass(Hartree,SI2019) # mA
+$(mass(Hartree,SI2019))
 
-julia> charge(Hartree,Metric) # qA
-$(charge(Hartree,Metric))
+julia> charge(Hartree,SI2019) # qA
+$(charge(Hartree,SI2019))
 ```
 """ Hartree
 
@@ -1356,6 +1502,21 @@ $(charge(Hartree,Metric))
 Rydberg `UnitSystem` with `lightspeed` of `𝟐/α` and `permeability` of `π*α^2`.
 
 $(textunits(Rydberg,:Rydberg))
+
+The well known `Rydberg` atomic unit values for `length`, `time`, `mass`, and `charge` are:
+```Julia
+julia> length(Rydberg,SI2019) # lR
+$(length(Rydberg,SI2019))
+
+julia> time(Rydberg,SI2019) # tR
+$(time(Rydberg,SI2019))
+
+julia> mass(Rydberg,SI2019) # mR
+$(mass(Rydberg,SI2019))
+
+julia> charge(Rydberg,SI2019) # qR
+$(charge(Rydberg,SI2019))
+```
 """ Rydberg
 
 @doc """
@@ -1383,17 +1544,17 @@ $(textunits(Natural,:Natural))
 
 The well known `Natural` values for `length`, `time`, `mass`, and `charge` are:
 ```Julia
-julia> length(Natural,Metric)
-$(length(Natural,Metric))
+julia> length(Natural,SI2019)
+$(length(Natural,SI2019))
 
-julia> time(Natural,Metric)
-$(time(Natural,Metric))
+julia> time(Natural,SI2019)
+$(time(Natural,SI2019))
 
-julia> mass(Natural,Metric)
-$(mass(Natural,Metric))
+julia> mass(Natural,SI2019)
+$(mass(Natural,SI2019))
 
-julia> charge(Natural,Metric)
-$(charge(Natural,Metric))
+julia> charge(Natural,SI2019)
+$(charge(Natural,SI2019))
 ```
 """ Natural
 
@@ -1408,68 +1569,68 @@ $(textunits(NaturalGauss,:NaturalGauss))
 @doc """
     QCD = UnitSystem(𝟏,𝟏,𝟏,𝟏,𝟏/μₚₑ)
 
-Qunatum chromodynamics `UnitSystem` with `electronmass` of `𝟏/μₚₑ` or `𝟏/$μₚₑ`.
+Qunatum chromodynamics `UnitSystem` based on the `protonmass` scale.
 
 $(textunits(QCD,:QCD))
 
 The well known `QCD` values for `length`, `time`, `mass`, and `charge` are:
 ```Julia
-julia> length(QCD,Metric) # lQCD
-$(length(QCD,Metric))
+julia> length(QCD,SI2019) # lQCD
+$(length(QCD,SI2019))
 
-julia> time(QCD,Metric) # tQCD
-$(time(QCD,Metric))
+julia> time(QCD,SI2019) # tQCD
+$(time(QCD,SI2019))
 
-julia> mass(QCD,Metric) # mQCD
-$(mass(QCD,Metric))
+julia> mass(QCD,SI2019) # mQCD
+$(mass(QCD,SI2019))
 
-julia> charge(QCD,Metric)
-$(charge(QCD,Metric))
+julia> charge(QCD,SI2019) # qQCD
+$(charge(QCD,SI2019))
 ```
 """ QCD
 
 @doc """
     QCDGauss = UnitSystem(𝟏,𝟏,𝟏,𝟐*τ,𝟏/μₚₑ)
 
-Qunatum chromodynamics (Gauss) `UnitSystem` with `electronmass` of `𝟏/μₚₑ`.
+Qunatum chromodynamics (Gauss) `UnitSystem` based on the `protonmass` scale.
 
 $(textunits(QCDGauss,:QCDGauss))
 
 The well known `QCDGauss` values for `length`, `time`, `mass`, and `charge` are:
 ```Julia
-julia> length(QCDGauss,Metric) # lQCD
-$(length(QCDGauss,Metric))
+julia> length(QCDGauss,SI2019) # lQCD
+$(length(QCDGauss,SI2019))
 
-julia> time(QCDGauss,Metric) # tQCD
-$(time(QCDGauss,Metric))
+julia> time(QCDGauss,SI2019) # tQCD
+$(time(QCDGauss,SI2019))
 
-julia> mass(QCDGauss,Metric) # mQCD
-$(mass(QCDGauss,Metric))
+julia> mass(QCDGauss,SI2019) # mQCD
+$(mass(QCDGauss,SI2019))
 
-julia> charge(QCDGauss,Metric)
-$(charge(QCDGauss,Metric))
+julia> charge(QCDGauss,SI2019) # qQCD
+$(charge(QCDGauss,SI2019))
 ```
 """ QCDGauss
 
 @doc """
     QCDoriginal = UnitSystem(𝟏,𝟏,𝟏,𝟐*τ*α,𝟏/μₚₑ)
 
-Qunatum chromodynamics (original) `UnitSystem` with `permeability` of `4π*α`.
+Qunatum chromodynamics (original) `UnitSystem` scaled by `protonmass` and `elementarycharge`.
 
 $(textunits(QCDoriginal,:QCDoriginal))
 
 The well known `QCDoriginal` values for `length`, `time`, `mass`, and `charge` are:
 ```Julia
-julia> length(QCDoriginal,Metric) # lQCD
-$(length(QCDoriginal,Metric))
+julia> length(QCDoriginal,SI2019) # lQCD
+$(length(QCDoriginal,SI2019))
 
-julia> time(QCDoriginal,Metric) # tQCD
-$(time(QCDoriginal,Metric))
+julia> time(QCDoriginal,SI2019) # tQCD
+$(time(QCDoriginal,SI2019))
 
-julia> mass(QCDoriginal,Metric) # mQCD
-$(mass(QCDoriginal,Metric))
+julia> mass(QCDoriginal,SI2019) # mQCD
+$(mass(QCDoriginal,SI2019))
 
-julia> charge(QCDoriginal,Metric)
-$(charge(QCDoriginal,Metric))
+julia> charge(QCDoriginal,SI2019) # qQCD
+$(charge(QCDoriginal,SI2019))
 ```
 """ QCDoriginal
diff --git a/test/runtests.jl b/test/runtests.jl
index f89ab17..1ac05ac 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -2,10 +2,10 @@ using UnitSystems, Test
 
 for S ∈ UnitSystems.Systems
     U = eval(S)
-    S ∉ () && @testset "UnitSystem: $S" begin
+    S ∉ (:MetricTurn,:MetricGradian,:MetricDegree,:MetricArcminute,:MetricArcsecond) && @testset "UnitSystem: $S" begin
         S≠:FFF && @testset "Dimensionless constants" begin
-            @test μₑᵤ ≈ electronmass(U)/atomicmass(U)
-            @test μₚᵤ ≈ protonmass(U)/atomicmass(U)
+            @test μₑᵤ ≈ electronmass(U)/dalton(U)
+            @test μₚᵤ ≈ protonmass(U)/dalton(U)
             @test μₚₑ ≈ protonmass(U)/electronmass(U)
             @test 1/αinv ≈ (elementarycharge(U)/charge(PlanckGauss,U))^2
             @test αG ≈ (electronmass(U)/mass(PlanckGauss,U))^2
@@ -25,7 +25,7 @@ for S ∈ UnitSystems.Systems
                 @test lightspeed(U) ≈ electronmass(U)^2*gravitation(U)/planckreduced(U)/αG
             end
             S≠:FFF && @testset "planck" begin
-                @test planck(U) == 2π*planckreduced(U)
+                @test planck(U) == turn(U)*planckreduced(U)
                 @test planck(U) ≈ 2elementarycharge(U)*lorentz(U)/josephson(U)
                 @test planck(U) ≈ 8/αinv/rationalization(U)/lightspeed(U)/vacuumpermeability(U)/josephson(U)^2
                 @test planck(U) ≈ 4lorentz(U)^2/josephson(U)^2/klitzing(U)
@@ -49,22 +49,22 @@ for S ∈ UnitSystems.Systems
             end
         end
         @testset "Atomic constants" begin
-            @testset "atomicmass" begin
-                @test atomicmass(U) ≈ molarmass(U)/avogadro(U)
-                @test atomicmass(U) ≈ electronmass(U)/μₑᵤ
-                @test atomicmass(U) ≈ protonmass(U)/μₚᵤ
-                @test atomicmass(U) ≈ 2rydberg(U)*planck(U)/μₑᵤ/lightspeed(U)*αinv^2*gravity(U)
-                @test atomicmass(U) ≈ planckmass(U)*sqrt(αG)/μₑᵤ
+            @testset "dalton" begin
+                @test dalton(U) ≈ molarmass(U)/avogadro(U)
+                @test dalton(U) ≈ electronmass(U)/μₑᵤ
+                @test dalton(U) ≈ protonmass(U)/μₚᵤ
+                @test dalton(U) ≈ 2rydberg(U)*planck(U)/μₑᵤ/lightspeed(U)*αinv^2*gravity(U)
+                @test dalton(U) ≈ planckmass(U)*sqrt(αG)/μₑᵤ
             end
             @testset "protonmass" begin
-                @test protonmass(U) ≈ μₚᵤ*atomicmass(U)
+                @test protonmass(U) ≈ μₚᵤ*dalton(U)
                 @test protonmass(U) ≈ μₚᵤ*molarmass(U)/avogadro(U)
                 @test protonmass(U) ≈ μₚₑ*electronmass(U)
                 @test protonmass(U) ≈ μₚₑ*2rydberg(U)*planck(U)/lightspeed(U)*αinv^2*gravity(U)
                 @test protonmass(U) ≈ planckmass(U)*μₚₑ*sqrt(αG)
             end
             @testset "electronmass" begin
-                @test electronmass(U) ≈ μₑᵤ*atomicmass(U)
+                @test electronmass(U) ≈ μₑᵤ*dalton(U)
                 @test electronmass(U) ≈ μₑᵤ*molarmass(U)/avogadro(U)
                 @test electronmass(U) ≈ protonmass(U)/μₚₑ
                 @test electronmass(U) ≈ 2rydberg(U)*planck(U)/lightspeed(U)*αinv^2*gravity(U)
@@ -101,26 +101,26 @@ for S ∈ UnitSystems.Systems
         end
         @testset "Thermodynamic constants" begin
             @testset "molarmass" begin
-                @test molarmass(U) ≈ atomicmass(U)*avogadro(U)
+                @test molarmass(U) ≈ dalton(U)*avogadro(U)
                 @test molarmass(U) ≈ avogadro(U)*electronmass(U)/μₑᵤ
                 @test molarmass(U) ≈ avogadro(U)*protonmass(U)/μₚᵤ
                 @test molarmass(U) ≈ avogadro(U)*2rydberg(U)*planck(U)/μₑᵤ/lightspeed(U)*αinv^2*gravity(U)
             end
             @testset "avogadro" begin
                 @test avogadro(U) ≈ molargas(U)/boltzmann(U)
-                @test avogadro(U) ≈ molarmass(U)/atomicmass(U)
+                @test avogadro(U) ≈ molarmass(U)/dalton(U)
                 @test avogadro(U) ≈ molarmass(U)*μₑᵤ/electronmass(U)
                 @test avogadro(U) ≈ molarmass(U)*μₑᵤ*lightspeed(U)/αinv^2/2rydberg(U)/planck(U)/gravity(U)
             end
             @testset "boltzmann" begin
                 @test boltzmann(U) == molargas(U)/avogadro(U)
-                @test boltzmann(U) ≈ atomicmass(U)*universal(U)/molarmass(U)
+                @test boltzmann(U) ≈ dalton(U)*universal(U)/molarmass(U)
                 @test boltzmann(U) ≈ electronmass(U)*universal(U)/μₑᵤ/molarmass(U)
                 @test boltzmann(U) ≈ 2molargas(U)*rydberg(U)*planck(U)/molarmass(U)/μₑᵤ/lightspeed(U)*αinv^2*gravity(U)
             end
             @testset "molargas" begin
                 @test molargas(U) == boltzmann(U)*avogadro(U)
-                @test molargas(U) ≈ boltzmann(U)*molarmass(U)/atomicmass(U)
+                @test molargas(U) ≈ boltzmann(U)*molarmass(U)/dalton(U)
                 @test molargas(U) ≈ boltzmann(U)*molarmass(U)*μₑᵤ/electronmass(U)
                 @test molargas(U) ≈ boltzmann(U)*molarmass(U)*μₑᵤ*lightspeed(U)/αinv^2/2planck(U)/rydberg(U)/gravity(U)
             end