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Everything from pantometry-units, so that use pantometry_core::units::* is enough
to write dimensioned physics.
Modules§
- vector
- Vector quantities: three components sharing one dimension.
Structs§
- QVec3
- Three components of one dimension, stored in SI base units.
- Qty
- A quantity, with the seven SI base dimensions in its type.
Constants§
- BOLTZMANN
- Boltzmann constant, J·K⁻¹ (exact by definition).
- C
- Speed of light in vacuum, m·s⁻¹ (exact by definition).
- G0
- Standard gravity, m·s⁻².
- PLANCK
- Planck constant, J·s (exact by definition).
- STEFAN_
BOLTZMANN - Stefan-Boltzmann constant, W·m⁻²·K⁻⁴ — radiative exchange lives on this.
Functions§
- photon_
energy - Energy of one photon at a vacuum wavelength:
E = hc/λ.
Type Aliases§
- Acceleration
- Metres per second squared.
- Acceleration
Vec - An acceleration, m·s⁻².
- Amount
- Moles.
- Angular
Momentum - kg·m²·s⁻¹ — the rotational counterpart of momentum, and conserved for the same reason.
- Area
- Square metres.
- Charge
- Coulombs.
- Concentration
- kg·m⁻³ as a concentration of one species dissolved in another.
- Conductance
- W·K⁻¹ — how fast heat crosses a joint,
UA. - Conductivity
- S/m — the reciprocal of
Resistivity, and what a finite-volume solve actually wants, because conductances in parallel add where resistances do not. - Current
- Amperes.
- Current
Density - A/m² — current per unit area. What actually flows, and the thing
Iis an integral of. - Damping
- N·s·m⁻¹ — a dashpot’s
c. Force proportional to velocity, and the only place a mechanical simulation loses energy on purpose. - Density
- kg·m⁻³. Note that a glass catalogue quotes g/cm³, a factor of a thousand away —
see
Density::g_per_cm3. - Diffusivity
- m²·s⁻¹ — thermal diffusivity
α = k/(ρ c_p), and also mass diffusivity. - Dimensionless
- A pure ratio: reflectance, duty cycle, refractive index, Strehl.
- Dynamic
Viscosity - Pa·s — dynamic viscosity, the
μof Darcy’s law and of Stokes drag. - Electric
Field - V/m — the gradient of a potential.
- Energy
- Joules.
- Force
- Newtons.
- Force
Vec - A force, newtons.
- Frequency
- Cycles per second. Dimensionally identical to an angular velocity, since a radian is m/m — the type system cannot and should not pretend otherwise.
- Heat
Capacity - J·K⁻¹ — mass times specific heat. How much heat a thing can hide before it shows up as a temperature.
- Irradiance
- Power per unit area, W·m⁻². What a detector face actually receives.
- Latent
Heat - J·kg⁻¹ — the heat a phase change costs at no change in temperature.
- Length
- Metres.
- Length
Vec - A position or a displacement, m. The same dimension, and deliberately the same type: the difference between them is a choice of origin, not of physics.
- Luminous
Intensity - Candelas.
- Mass
- Kilograms.
- Mass
Flow - kg·s⁻¹ — a mass flow rate. What a brew scale reads the derivative of.
- Moment
OfInertia - kg·m² — how hard a body is to spin up about an axis.
- Momentum
- kg·m·s⁻¹ — mass times velocity, and the thing a closed system conserves exactly rather than nearly.
- Momentum
Vec - A momentum, kg·m·s⁻¹. The vector a closed system conserves component by component — and see the note in the workspace README on why the smallest component is what binds a conservation audit.
- Power
- Watts.
- Pressure
- Pascals. Also the unit of an energy density and of a stress, which are the same dimension and not a coincidence.
- Resistance
- Ohms — volts per ampere.
- Resistivity
- Ω·m — resistance times length. The property of a material, where
Resistanceis the property of a particular piece of one. - Specific
Heat - J·kg⁻¹·K⁻¹ — the
c_pthat says how much heat a gram of glass can hide. - Stiffness
- N·m⁻¹ — a spring’s
k, and the penalty stiffness a contact is modelled with. - Temperature
- Absolute temperature. Kelvin only — see
Temperature::celsius. - Thermal
Conductivity - W·m⁻¹·K⁻¹ — the
kof Fourier’s law. - Thermal
Expansion - K⁻¹ — the coefficient that turns absorbed light into a focus shift.
- Time
- Seconds.
- Velocity
- Metres per second.
- Velocity
Vec - A velocity, m·s⁻¹.
- Voltage
- Volts.
- Volume
- Cubic metres.