David Goodsell is a molecular biologist at The Scripps Research Institute in California, and he has written a hippie-beautiful introductory text to molecular biology, The Machinery of Life (2nd edition, Springer 2010), which Scientific American calls “an impressive and original book.”
I call it “hippie-beautiful” because the watercolors that illustrate life’s molecular machines were painted by the author and have the faint echo of 1960s poster art.
And I’m a hippie-sympathetic California English teacher.
So, let’s blog this book, shall we?
Here’s the opening paragraph of the text proper (vii):
Imagine that we had some way to look directly at the molecules in a living organism. An x-ray microscope would do the trick, or since we’re dreaming, perhaps an Asimov-style nanosubmarine (unfortunately, neither is currently feasible). Think of the wonders we could witness firsthand: antibodies attacking a virus, electrical signals racing down nerve fibers, proteins building new strands of DNA. Many of the questions puzzling the current cadre of scientists would be answered at a glance. But the nanoscale world of molecules is separated from our everyday world of experience by a daunting million-fold difference in size, so the world of molecules is completely invisible.
So, here’s the first thing I didn’t know: scientists can’t actually directly see what’s going on at the molecular level. The molecular world is, largely, colorless precisely because, according to Goodsell (3-4),
Molecules are so small that they are smaller than the wavelength of light, so there is no way to ‘see’ them directly with a light microscope.
And so this is where he gets his poetic license in his watercolors of them: he can highlight interactions and functions with groovy colors even as we keep in mind that, in fact, most molecular structures are basically like organisms in the deep-sea, completely functioning beneath the radar of light waves, and thus in darkness (viii):
The colors, of course, are completely arbitrary since most of these molecules are colorless. I have chosen them to highlight the functional features of the molecules and cellular environments.
And so, I surmise, a nanosubmarine could not have color either.