What happens when you misuse a scanning electron microscope (SEM)?

 

 

 

 

 

 

 

 

 

 

 

 

 

You can badly misinterpret what you see. I saw an article by Mick West at Metabunk on August 12, 2025 titled “Self-healing” Ceramic Material from Skinwalker Ranch – SEM (Scanning Electron Microscope) Analysis. A YouTube video at the History Channel on August 14, 2025 titled High-Tech Materials Discovered Deep in Mesa (Season 6) | The Secret of Skinwalker Ranch shows what they thought they saw - that holes were changing (beginning at 4 minutes and 40 seconds). Mick’s article has an excellent discussion with a reply from Arnold Kruize.

 

What they saw actually is a well-known imaging defect: the charging of a nonconductive specimen. Charging is discussed in a reference book by Joseph I. Goldstein et al. titled Scanning Electron Microscopy and X-Ray Microanalysis (Fourth edition, 2018). The preview at Google Books shows the table of contents discusses charging starting on page 134, and coating the specimen with a conductive material to solve the problem is discussed on page 463.

 

I began using an SEM many decades ago, and continued to use it as a tool for failure analysis. Seeing one being badly misused was appalling.

 

An image showing an SEM came from Wikimedia Commons.