Passage: Historians of science once treated the laboratory notebook as a transparent window—a faithful record of what the researcher saw and did. Recent scholars have grown skeptical of that view. A notebook, they argue, is not a mirror but an instrument of persuasion: the experimenter decides which trials to log and which to dismiss as 'noise,' which numbers to circle and which to leave un-remarked. By the time a result is written down, it has already been interpreted. This is not to accuse scientists of dishonesty. It is to observe that even the most scrupulous record is shaped by the questions its author thought worth asking—and that what a notebook omits can reveal as much as what it preserves.