A few years ago, I wrote a post called “The Metaphysics of Left and Right (No, Not Politics; the Freakin Directions!),” in which I suggested that our ability to tell left from right, even as young children, and when facing a completely symmetrical landscape like the plane of the ocean, is somehow suggestive of a deeper truth about the nature of consciousness and dualism. As part of this philosophical (and very possibly harebrained) rumination, I explored how difficult it would be to communicate our definitions of left and right to a distant extraterrestrial civilization using only words or very simple pictures. One way, I argued, would be to use the inherent chirality of certain molecules, whose structure our hypothetical E.T. would recognize.
So, you can imagine my delight at discovering that one of my favorite YouTube channels, PBS Space Time, devoted an entire episode to this very subject. As host Matt O’Dowd explains, all biological life displays a mysterious homochirality, or bias toward either left- or right-handedness over the other. All DNA, for example, spirals the same way. Similarly, all sugar and amino acid molecules are not only chiral but unflippable. That is, their mirror images are never found in nature. And when these reversed molecules are deliberately created in a lab, they are biologically useless and, often, highly toxic. Not to mention totally…unnatural.
Even now, in the 21st Century, no one is sure why this handedness in nature exists, although it is theorized that it might be connected to the most fundamental laws of nature—specifically, the asymmetry of the weak force.
It’s pretty cool. Check it out….
Ash Clifton, Writer 