The MPP system expresses all physical quantities in terms of fundamental constants, specifically Planck units. This document provides information about how traditional units (both SI and Imperial) are represented within this system.
The system is built on these fundamental constants:
π
(Pi): The geometry constantP
(Planck length): The smallest physical unit of lengthħ
(Reduced Planck constant): Fundamental quantum unitG
(Gravitational constant): Determines strength of gravitationk
(Boltzmann constant): Relates energy and temperatureτ
(Planck time): Time light takes to travel 1 Planck lengthc
(Speed of light): Defined as P / τα
(Fine structure constant): Fundamental physical constant (~1/137)N_A
(Avogadro constant): Foundational unit for amount of substanceThe core philosophy of MPP is to express all physical quantities in terms of fundamental constants, ultimately deriving them from Planck units. For example:
P
)M_P
)t_P
)T_P
)Imperial units are defined in terms of SI units, which are themselves defined in Planck units:
Ideally, all units within MPP are represented as symbolic expressions derived from fundamental constants like P
, ħ
, c
, etc. This allows for algebraic manipulation and maintains the system’s symbolic closure. For instance, a meter would be a symbolic expression involving P
and a rational scaling factor.
src/units.rs
While the ideal is pure symbolic representation, the src/units.rs
module provides practical definitions for common SI and other units. These definitions often involve direct numerical values (e.g., f64
or BigInt
) for interoperability and to bridge the gap with conventional unit systems.
For example, units.meter()
might return a representation that, for practical purposes, uses a standard numerical value for the meter. However, the system’s underlying goal is to ensure that these practical units can be related back to their symbolic, Planck-unit-derived forms. Tests in tests/planck_units.rs
focus on verifying these fundamental symbolic derivations.
The system aims to provide both:
src/units.rs
that offers conventional unit values, while striving to maintain consistency with the symbolic foundation.This dual approach allows MPP to be both theoretically rigorous and practically usable.
Some units and constants are considered foundational to the MPP system:
The MPP system tracks physical dimensions to ensure consistency. The dimension system includes: