**Friction as Constraint and Opportunity** Friction drains efficiency everywhere—from engines that overheat, to grinding transmissions, to the delays of war where seconds cost lives. Modern society spends heavily on lubricants, bearings, fiber optics, and other tools to reduce these inefficiencies. Money itself often buys ways around friction, whether through private jets, concierge medicine, or premium access at theme parks. Friction acts as a hidden tax on time and energy, and the greatest arbitrage opportunities lie in owning the bottlenecks and funding the hacks that overcome them. **The Paradox of Friction** Friction isn’t always bad. Many critical systems depend on it: nuclear reactors need control rods to slow reactions, neurons use synaptic gaps to prevent seizures, and DNA uses checkpoints to avoid dangerous mutations. The real question isn’t whether friction is needed but where, what kind, and how much can be tolerated before paying to escape it. This balance defines the **Friction Frontier**. **Investment Implications** The investment strategy is to own both bottlenecks and breakthroughs. In AI, the bottlenecks are physical and slow-moving: TSMC’s chipmaking timelines, concrete curing, rare-earth mining, power grids, and submarine cables. AI may move fast in design, but real-world progress depends on these constraints. Profitable plays include not just heavy equipment makers like Caterpillar and critical monopolies like ASML, but also the “lubricants”—tools, robotics, and infrastructure that let AI bypass roadblocks. The greatest fortunes will be made at the Friction Frontier: capturing value in what can’t be rushed while also enabling what makes speed possible.