Chakarawet Lab - Symmetry breaking as an evidence of a supernatural force

Symmetry Breaking as an Evidence of a Supernatural Force

As a part of undergraduate inorganic chemistry course, students learn the concept of symmetry. Symmetry governs every object from plants to virus to molecules, as well as non-objects, such as wavefunctions, molecular vibrations, energy states, etc. according to a rigorous mathematical description. Symmetry dictates that there be no difference between the object (or non-object) and its symmetry equivalent. For example, a butterfly below should be exactly equivalent to its mirror image.

Figure 1. A depiction of a butterfly which has a mirror symmetry passing through its middle (left), and its symmetry equivalent generated from reflecting the butterfly across the mirror symmetry (right).

Nonetheless, many instances of symmetry breaking are observed, such as in Figure 1 above if you look carefully. Many symmetry breaking instances in nature we currently have no explanation or little understanding of. Example includes the matter–antimatter symmetry violation, which enables excess matter, such as us, to exist.1 Particles and antiparticles have the same properties except opposite charge. For example, an electron has a mass of 9.109×10−31 kg and a charge of −1.602×10−19 C, while its antiparticle analog positron has the exact same mass with a charge of +1.602×10−19 C. When an electron and a positron run into each other, they combine and annihilate, resulting in the disappearance of both particles while giving off energy in the form of photons (light). This is the underlying concept of Positron Emission Tomography (PET) scan we use today for medical diagnosis. As our body is composed of electrons and other particles including protons and neutrons, our very existence relies on the fact that there is an excess abundance of matters compared to antimatters. Else, if there is no matter–antimatter symmetry violation, all matters would combine with antimatters and are annihilated. There will be no matter left in the universe, but only photons.

In chemistry, some molecules can exist in two forms related by mirror symmetry. Such molecules are called chiral molecules, example of which are amino acids and monosaccharides (sugars). The two forms are energetically identical; there is no way to prefer one form over the other as they exhibit the same properties (Figure 2). Yet, only one form exists in nature.

Figure 2. Left: naturally occurring D-alanine, an amino acid. Right: a non-natural L-alanine which is related to D-alanine by mirror symmetry. The two molecules are different but have the same physical properties.

The occurrence of only one form of chiral biological molecules is ubiquitous, but the reason for such preference is unclear. The current explanation of chiral symmetry breaking invokes the weak nuclear force, but a recent work reports that such force gives a very minimal energetic preference.2 These biological molecules are the core components of life, such as proteins and DNA, and nature somehow prefer only one configuration out of other possible symmetry-allowed states.

This is an implication of something “supernatural” in nature. Most scientists believe there are some mechanisms we have not yet understood which lead to symmetry breaking. From a different perspective, however, I believe this is consistent with the purposeful design of nature. There is a “supernatural” force which breaks this symmetry and allows life to exist. More than that, all lives are subject to the same universal mechanisms despite many symmetry-allowed possibilities, thus inferring a single chosen design from the Creator.

References

(1) Pascoli, S.; Turner, J. Matter–Antimatter Symmetry Violated. Nature 2020, 580, 323–324.

(2) Hawbaker, N. A.; Blackmond, D. G. Energy Threshold for Chiral Symmetry Breaking in Molecular Self-Replication. Nat. Chem. 2019, 11, 957–962.