Monday, March 29, 2010


No so long ago, atoms were a theory. A very powerful theory with a great deal evidence to support it, but a theory nonetheless. Now we can take pictures of them.

The latest scanning transmission electron microscope at the Oak Ridge National Laboratory can resolve small atoms like the nitrogen and boron atoms shown in these images.

Sometimes, the things we can do just astonish me.


Unknown said...

What are we actually looking at here? What are the dark parts and what are the light parts? Why such a regular pattern?

Are we essentially looking at indirect electromagnetic effects, or are we looking directly at physical nuclei?

Sorry for the battery of questions, but I'm most curious.

John said...

We are looking at clouds of electrons. The regular lattice is the pattern of the crystal sheet. Atoms are light, voids are dark.

It is interesting to me that while we now think of atoms as mostly empty space, they show up in these images as distinct physical objects, with a definite size. Seen in this way, the electron clouds that make up most of every atom have a very regular form.