I usually start the semester in my General Chemistry class with that question and so I thought it was a great way to start this blog, which is going to be a collaboration between me and my General Chemistry students.
This is the highest-resolution-yet atomic force microscopy (AFM) image of a molecule from our friends at IBM (as published in Science,http://www.sciencemag.org/cgi/content/full/325/5944/1110) and it is really cool. It clearly shows the five six membered rings of carbon atoms and even shows, dimly, the 14 hydrogens around the outside.
So is seeing believing? Not really. An AFM image is "seeing" only in the sense that watching TV is "seeing." The image is the result of a very complex experiment and lots of data manipulation. But visualization on the atomic scale is incredible and brings with it the possibility of manipulation of single atoms.
I have not seen an atom, you have not seen an atom, and no one else will ever see an atom. Understanding why the evidence, about the masses and ratios of masses of elements in compounds and before and after reactions, that Dalton drew on to construct a modern atomic theory ... and why that evidence was and is as persuasive about the existence of atoms and molecules as "seeing" an AFM picture is today ... is to my mind a crucial demonstration of scientific literacy. To a scientist, seeing is not necessarily believing and inference about things unseen is just as important.
hat tip: Greg Laden's Blog
Posted by Michael Fuson
No comments:
Post a Comment