Light waves inside an airtight box made of 2-inch thick wood will not completely dissipate to zero. While visible light will eventually be absorbed, other electromagnetic waves like X-rays and radio waves can penetrate the wood, meaning they won't be blocked. The wood will emit infrared radiation based on its temperature, contributing to the overall energy dynamics inside the box. Although visible light may taper off asymptotically, it could theoretically bounce around indefinitely if the right conditions are met. Ultimately, light cannot be contained indefinitely in such a box, as it will diminish significantly over time.