My friends Glen and Kimba and I were hanging around last week and somehow our conversation shifted from Facebook to a discussion of particulate matter, focused ion beams and climate change.
My husband, Joe, happens to study atmospheric particles as part of his climate change research. A particle is a mere spec, but get a bunch of them together and they produce clouds and smog, among other things.
Each spec is made of molecules, and to figure out what they are, you need an electron microscope armed with a gizmo called a FIB (focused ion beam)
The FIB enables you to view particles three-dimensionally and on a molecular level. A two-dimensional view is insufficient. It cannot identify which molecules are on the particle’s sides or back; nor does it identify which are buried within its depths.
The FIB works like a bread slicer, only instead of slicing bread, it slices the particle. The particle is placed (staged) on a wafer (think of it as a plate) that is made of germanium. Wafers can also be made of silicon, carbon, etc. (Joe explained his preference for germanium, but I wasn’t listening because I was trying to grasp the whole bread slicer thing.)
Anyway, instead of making 20 cuts per loaf of bread, the FIB makes hundreds of cuts per particle. Each is measured in nanometers (1 millimeter = 1 million nanometers).
As the FIB slices the particle from the outside in, its innards (molecules) are revealed. The FIB then identifies the what’s in the molecules themselves, e.g., silicon, iron, carbon, copper, etc.
Why go through this rigmarole? Because if you can’t identify the elements floating about the atmosphere, you can’t tell which are contributing to climate change. For example, some elements absorb light, heating the atmosphere (bad), while others reflect light, cooling the atmosphere (not so bad).
And there you have it: focused ion beams, particulates, molecules and climate change. Impress your friends. (FYI, should you be impressed with me, my husband actually vetted the above.)
You also now know what my hubby does for a living, does for love. The FIB is the Other Woman with whom he spends an inordinate amount of time. Unless there really is another woman. Hmmm … is he FIB-ing?