[moptar]

There's a philosophy idea that in order to say we can "see" something, we have to be able to collect consistent information by several different methods. For example if all we have is a STM, then we don't know which parts of the image are artifacts and which are real so we haven't seen anything. But if we have an STM and crystallography, we can have more faith in the features that are common to both images - such as interatomic distances and the geometry of crystal structure. But we still couldn't say that we've seen the shape of an atom since that would look different in each instrument's image.

A great example is people who "discovered" lost cities under the sea. They saw regular patterns of lines on the seafloor in Google Earth and interpreted them as ancient roads or walls. But they were only seeing artifacts from ships that had sailed back and forth in straight lines collecting data. If they had looked both at those sonar scans and some other data for the same location, they would have only seen the lines on one image and been able to conclude that they were either an artifact of the sonar or below the level of sensitivity of the other instrument.