The act of "dancing" is not limited to humans, as scientists recently discovered. According to a group of Hollander and Chinese researchers, when two carbon monoxide molecules collide in high speed in a vacuum, they can exhibit a square dance-like behavior.
Our universe, despite its empty appearance, is filled with carbon-based molecules. While some are organics, such as polycyclic aromatic hydrocarbons (PAHs), and others are small inorganics like methane, ethane, and carbon monoxide (CO). When studying star and planet formation, astrophysicists need to zoom in on the emission signature of these interstellar molecules.
Take CO for example, the simple compound composed of only carbon and oxygen atoms represents a structurally stable molecule. They are the perfect candidates for observing the inter-molecule transfer of kinetic energy (also known as rotational energy).
Using advanced imaging techniques and fully quantum theory, the team of physicists found that in 1 out of 20 collisions, a CO duo would end up performing a "dance" move. They first rotate in place and turn their "backs" to each other, and then continue traveling on their original trajectory while spinning faster than they were. This motion resembles a "do-si-do" move in the square dancing term.
The "dance" behavior transferred most of the rotational energy to the involved CO molecules with little energy lost in deflection. The authors suspected that this type of energy exchange process is not an isolated phenomenon, and they hope to observe similar "dance" moves in collisions of other molecules as well.
This exciting discovery is published in the journal Science.
Source: C&EN via Youtube