Trail of BitsAdding token A to token B in a DeFi formula is as meaningless as adding meters to seconds. Different dimensions, meaningless result.
Physicists learn this on day one. Smart contract developers rarely think about it, but the same rules apply to on-chain arithmetic.
During an audit, we caught a function passing decimals where assets were expected. Dimensional analysis spotted it instantly. https://blog.trailofbits.com/2026/03/24/spotting-issues-in-defi-with-dimensional-analysis/
Spotting issues in DeFi with dimensional analysis
Dimensional analysis from physics can be applied to DeFi smart contracts to catch arithmetic and logic bugs by ensuring formulas maintain consistent dimensions across tokens, prices, and liquidity calculations. The post demonstrates how explicit dimensional annotations in code comments, like those used in Reserve Protocol, can prevent vulnerabilities and improve auditability.