Can someone please interpret the microscope image below? How does it prove that the knife "became buckled and bent"?

enter image description here

We examined hones and knives under a microscope at MIT. The cutting edge of a Victorinox chef’s knife became buckled and bent after being dulled on a glass cutting board.

I think that "cutting edge" above refers to "edge" below.

enter image description here

  • 3
    I am extremely unsure what answer you are looking for. Look at the picture, the edge isn't smooth.
    – Johannes_B
    Aug 12, 2020 at 5:07
  • Yah ... what are you asking? What three variables?
    – FuzzyChef
    Aug 12, 2020 at 5:40

1 Answer 1


The edge of the knife (which you correctly identify in the second picture) is shown hugely magnified as the 'bottom edge of the grey slab' in your first picture. We clearly see that this edge is not straight and smooth, but roughed up and curved upwards. This is what is meant by "buckled and bent".

Note that your image does not show a "function of three variables", as was stated in the original question (unless you mean a function with a binary output describing whether there is knife material at a given (x,y,z)-coordinate); it is a (two-dimensional projection of a) three-dimensional microscope image.

  • It's not just roughed up, it actually curves upwards (look at the far end of the blade, near x=0, you may need to zoom in). It may be better to think of it as photo with 3d scale bars than a graph, though that's not quite true either - it must be a composite image
    – Chris H
    Aug 12, 2020 at 11:24
  • 1
    @ChrisH I believe it's an SEM (Scanning Electron Microscope) image, which is indeed (simplifying massively) a composite image of a series of scan lines across the surface. I have added your point about the edge curving upwards to the answer.
    – LSchoon
    Aug 12, 2020 at 11:59

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.