The Rise of
Type-Safe Physics

A global revolution in theoretical foundations using type theory, category theory, and formal verification.

-- Type safety prevents physical nonsense
velocity :: Quantity Velocity
velocity = distance |/| time  

-- This is a COMPILE-TIME error:
error = meter |+| second  
-- Cannot add Length to Time!

What is Type-Safe Physics?

Type-safe physics leverages advanced mathematics to construct physical theories where meaningless expressions cannot be written.

Dimensional Safety

Adding meters to seconds? That's a compile-time type error, not a runtime surprise.

Compositional

Complex theories built from verified components. Category theory ensures everything composes correctly.

Quantum Rigor

The no-cloning theorem follows from type structure alone—no physics input required!

Proofs as Programs

Under Curry-Howard, well-typed programs ARE proofs. The type checker is your proof assistant.

Learning Path

Master type-safe physics step by step, from foundational concepts to cutting-edge applications.

01

Foundations: Types & Dimensions

Estimated: 1-2 weeks

  • Introduction to type theory
  • Dimensional analysis as the original type system
  • Fourier's principle of dimensional homogeneity
  • The Buckingham Pi theorem
  • Implementing type-safe units in Haskell
Prerequisites: Basic programming, high school physics
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02

Category Theory Essentials

Estimated: 2-3 weeks

  • Categories, objects, and morphisms
  • Functors: structure-preserving maps
  • Natural transformations and the Yoneda lemma
  • Monoidal categories for composite systems
  • The Curry-Howard-Lambek correspondence
Prerequisites: Module 1, basic linear algebra
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03

Categorical Quantum Mechanics

Estimated: 3-4 weeks

  • The category FdHilb
  • States as morphisms, effects as dual states
  • †-compact closed categories
  • The ZX-calculus for quantum computation
  • No-cloning theorem from type structure
  • Quantum teleportation via string diagrams
Prerequisites: Modules 1-2, intro quantum mechanics
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04

Type-Safe Spacetime & Gravity

Estimated: 3-4 weeks

  • Fiber bundles as dependent types
  • Connections and parallel transport
  • Synthetic differential geometry
  • Einstein's equations type-theoretically
  • Singularities as type failures
Prerequisites: Modules 1-3, differential geometry basics
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05

Functorial Field Theory

Estimated: 4-6 weeks

  • TQFTs as functors from cobordisms
  • The classification of 2D TQFTs
  • Higher categories and extended TQFTs
  • The cobordism hypothesis
  • Factorization algebras
Prerequisites: All previous modules
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06

Towards Quantum Gravity

Advanced / Research-level

  • Type-safe formulations of spacetime
  • Spin networks as functors
  • Causal sets and partial orders
  • The emergent spacetime conjecture
  • Holography as functorial equivalence
Prerequisites: All previous modules, research experience
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See It In Action

The Haskell implementation demonstrates type safety in practice.

Type-Safe Dimensions

-- SI base units as types
type Length   = '(1, 0, 0, 0, 0, 0, 0)
type Time     = '(0, 1, 0, 0, 0, 0, 0)
type Velocity = '(1, -1, 0, 0, 0, 0, 0)

-- Operations check dimensions at compile time
velocity :: Quantity Velocity
velocity = (100 *| meter) |/| (5 *| second)

-- Kinetic energy: type enforces E = ½mv²
kineticEnergy :: Quantity Mass -> Quantity Velocity -> Quantity Energy
kineticEnergy m v = 0.5 *| (m |*| v |*| v)

Category Theory

-- Physical theories ARE categories
class Category cat where
  identity :: cat a a
  compose  :: cat b c -> cat a b -> cat a c

-- Physical laws are natural transformations
newtype NaturalTransformation f g = NatTrans
  { runNatTrans :: forall a. f a -> g a }

-- Naturality: α_B ∘ F(f) = G(f) ∘ α_A
-- This is VERIFIED by the type system!

Quantum States

-- States as morphisms I → H
ket0, ket1 :: State Qubit
ket0 = State $ V.fromList [1 :+ 0, 0 :+ 0]
ket1 = State $ V.fromList [0 :+ 0, 1 :+ 0]

-- Superposition
ketPlus = State $ V.fromList [r :+ 0, r :+ 0]
  where r = 1 / sqrt 2

-- Measurement probabilities: always non-negative!
measure :: State Qubit -> [(String, Double)]

Run the Code

git clone https://github.com/MagnetonIO/type-safe-physics
cd type-safe-physics/haskell
stack build && stack exec type-safe-physics-exe

The Paper

📄

The Rise of Type-Safe Physics:
A Global Revolution in Theoretical Foundations

Matthew B. Crawford & The YonedaAI Collaboration

A comprehensive survey of the emerging paradigm of type-safe physics—a revolutionary movement transforming theoretical physics across institutions worldwide. This paradigm leverages advanced mathematical structures from type theory, category theory, and formal verification to construct physical theories with unprecedented rigor and conceptual clarity.

Download PDF

Contents

  1. Introduction: The Crisis of Foundations
  2. Mathematical Foundations
  3. Historical Development
  4. The Framework of Type-Safe Physics
  5. Quantum Mechanics: The Type-Safe Formulation
  6. General Relativity: Geometry with Types
  7. Quantum Field Theory: Functorial and Type-Safe
  8. Quantum Gravity: The Ultimate Test
  9. Computational Tools and Implementation
  10. Global Adoption and Institutional Change
  11. Philosophical Implications
  12. Conclusion and Future Directions

Key Insights

"Physical theories should be formulated within formal systems that make it impossible to write down meaningless expressions."
"The no-cloning theorem is a theorem of type theory, not a peculiarity of Hilbert spaces."
"Physical consistency is a type property. A well-typed theory cannot contain certain classes of errors."
"Spacetime may not be fundamental but emergent from more fundamental categorical structures."