Cosmos Engine

Emergent physics simulation at planetary scale.

10+ million particles forming composite structures with emergent properties. Stars that generate stellar wind from plasma dynamics. Planets with layered internal structure that deforms and fractures under tidal stress. Spacecraft that crumple and tear under impact – not from damage models, but from physics.

Cosmos Engine is a design vision for a next-generation 3D particle simulation platform where complex phenomena emerge from simple physical rules. This repository contains the complete design documentation – from mesoscale force models to GPU kernel architectures, from a Scheme-inspired scripting DSL to distributed computation strategies.

The Core Insight

Complexity emerges from simplicity. Rather than programming explicit behaviors for stars, planets, and collisions, Cosmos Engine defines a minimal set of physical interactions at the mesoscale:

• Gravity via Particle Mesh (O(N) FFT-based, toroidal topology, GPU-native)
• Contact forces via Hertzian spring-damper model
• Structural bonds via dynamic spring networks with fatigue and plastic deformation
• Thermal dynamics from kinetic energy distributions and radiation transfer
• Electromagnetic forces from charge distributions and plasma currents

From these building blocks, everything else emerges: stellar wind, tidal disruption, crater formation, atmospheric drag, phase transitions, orbital resonances, crystal growth, and phenomena we haven’t anticipated.

Why Mesoscale?

Each Cosmos Engine particle represents a significant chunk of matter – 1000 tons of asteroid rock, 1 km^3 of planetary mantle, millions of tons of stellar plasma. This is deliberate. Molecular forces (Lennard-Jones, Morse potentials) belong at the atomic scale. At Cosmos Engine’s mesoscale, the emergent properties of molecular interactions are already baked into material properties: density, stiffness, breaking strength, thermal conductivity. See Scale Rationale for the full argument.

Design Documents

Core Physics

Spatial Systems

Composite Bodies & Stellar Physics

Particle Management

Scripting & Events

GPU & Performance

Networking & Distribution

Architecture

Library Design

Vision

Building the Reference PDF

The master design document is a LaTeX file. Build it with:

cd docs
pdflatex emergent_physics_design.tex
pdflatex emergent_physics_design.tex   # second pass for TOC/refs
Copy

A pre-built PDF is included at docs/emergent_physics_design.pdf.

The Unified Simulation Loop

Everything in Cosmos Engine runs through one pipeline per frame:

1. Particles generate fields – mass distributions create gravity fields (PM grid), kinetic energy creates temperature fields, charge creates EM fields
2. Fields affect particles – each particle samples all fields at its 3D position, accumulating forces from gradients
3. Forces update particles – symplectic integration (velocity Verlet or higher-order) preserves long-term energy conservation
4. Contact resolution – spatial hash detects overlapping particles, spring-damper model resolves penetration
5. Structures evolve – spring networks stretch, compress, and break; new bonds form when particles come into sustained contact
6. Properties emerge – temperature, pressure, angular momentum, material phase arise from collective particle behavior

This loop runs at 60+ FPS on 10M+ particles via GPU-accelerated Particle Mesh gravity and multi-resolution spatial hashing.