On entropy, compute, and the gap between physics and product

A laptop is warm because it is doing work. The warmth is the cost of imposing order (a structured output, a coherent sentence, a sorted list) on a substrate that, left alone, prefers disorder. Engineering is, very precisely, the local and temporary reversal of entropy, paid for in joules.

Compute is the modern unit of this payment. Every inference is a small negotiation with the second law: energy in, structure out, heat as the receipt. The recent rise in model capability is, viewed from far enough away, a rise in how much structure we can afford to extract per joule. The frontier is not really about intelligence. It is about the price of order.

Founders work in the gap between what physics permits and what a product can defensibly charge for. Physics sets the ceiling: the speed of light across a die, the bandwidth of a memory bus, the thermodynamic floor of a switching transistor. Product sets the floor: what a user will notice, pay for, return to. Almost all interesting engineering happens in the narrow corridor between these two surfaces, and the corridor is where companies are actually built.

The mistake is to treat either boundary as fixed. Physics is fixed; our distance from it is not. Product is fluid; what users tolerate today they will not tolerate in three years. The job is to keep closing the gap from both sides: pushing the implementation toward the physical limit, and pushing the product toward what the new limit makes possible.