There’s some debate over who invented the compound microscope, but many credit the Dutch eyeglass maker Zacharias Jansen and his father Hans with creating the first such device in the 1590s. At any rate, the timing makes sense: By the turn of the 16th century, the use of glass lenses for vision correction was widespread in Europe, laying the groundwork for the microscope’s use of overlapping lenses for increased magnification.

As early scientists worked to refine the microscope, adding and reconfiguring lenses to increase magnification, they also had to contend with the distortion that came with using multiple lenses. Distortion occurs when light of different colors passes through a lens, because different wavelengths will refract at different angles. This produces a situation called chromatic aberration, when the lens can’t focus all colors of light to the same point of convergence. White light passing through an unsuitable lens, for example, will leave specks of color around the object being viewed. Accordingly, microscopists in the 17th and 18th centuries experimented with various types of glass for their lenses alongside the mechanics of the microscopes themselves, working to increase magnification without losing image quality.

But the promise that Hooke saw in the technology began to fade by the turn of the 18th century as microscope development stagnated. The scientific community, Hooke complained, believed there was “no more to be done” with the microscope. The statement was a bit melodramatic—the microscope had gained traction as a scientific tool—but it contained a grain of truth: Hooke and his colleagues at the Royal Society hadn’t fully convinced the scientific community of the device’s potential.

Today, of course, we recognize microscopy as essential to research in medicine, the life sciences, chemistry, and physics. The limitations of optic or light microscopes have given way to the power of electron microscopes, which enable us to see things thousands of times smaller than a wavelength of light.

Despite the achievements of modern microscopy, “seeing is believing” has a different flavor than it did centuries ago. Cleanly magnified images are no longer the end goal of scientific pursuit; instead, it’s the data into which we translate such images. The microscope may now be a symbol of scientific practice, but data has become the real currency of knowledge, both scientific and otherwise. Microscopy and its related observational methods have given way to “data science” as the most reliable way of knowing. Nevertheless, the rise of the microscope in Hooke’s era tells us quite a lot about the role of data in ours.

In 1665, Hooke published Micrographia, a work that included striking illustrations of what he saw under his microscope—images the likes of which most people had never seen before. Among the drawings of pieces of flint, cork, and foliage, Micrographia’s most compelling illustrations were also the most unsettling: close-ups of insect eyes, the spiny legs of fleas and mites, the stingers of bees. Hooke’s verbal descriptions of the images hardly mitigated their striking visual effect. As he wrote of the bee’s stinger, for example:

The top of the Sting or Dagger is very easily thrust into an Animal's body … By an alternate and successive retracting and emitting of the Sting in and out of the sheath, the little enraged creature by degrees makes his revengeful weapon pierce the toughest and thickest Hides of his enemies …

The vivid language of Hooke’s descriptions—stingers as “daggers” and bees as “enraged creatures” wielding “revengeful weapons”—was a type of distortion in it own right. But in some ways, Hooke undercut his own belief that the image was more reliable than the word: He was known to tinker with the scale of his illustrations, adjust the orientation of the images for illustration, and cherry-pick certain details to focus on. Micrographia portrayed its findings as the visual truths of nature, untainted by the duplicitousness of words, but it was shaped by subjective choices.