What specific contribution did Sir William Herschel make regarding the infrared sensor lineage?
He provided the target (the radiation region) by proving its existence in 1800.
Sir William Herschel's role was foundational but pre-electronic; he did not invent the modern infrared sensor. His essential contribution was the discovery of the phenomenon itself—the invisible calorific rays—in 1800. This established the physical region of the spectrum that subsequent scientists needed to design technology to measure effectively. The actual invention of the electronic sensor, capable of converting IR radiation into a reliable, quantifiable electrical signal, was a gradual achievement spanning nearly two centuries, built upon the work of developers creating thermopiles, bolometers, and eventually, quantum detectors based on semiconductor physics.
