Representative photograph of a left hand.
| Photo Credit: Tarun Savvy/Unsplash
Handedness is an inclination to desire the use of one hand over the yr, and we’re accordingly labelled right-handed or left-handed. Today is International Left-handers’ Day, noticed to understand left-handedness in a world numerically dominated by righties.
Humans are predominantly right-handed however our planet itself is a lefty, rotating from west to east. So is the photo voltaic system. According to a 2011 examine, there are extra spiral galaxies rotating counter-clockwise, a.ok.a. left-handed spiral galaxies, than their right-handed counterparts.
There is left-handedness inside ourselves as nicely. Amino acids, the essential constructing blocks of life, are left-handed. The coronary heart within the human physique is on the left facet.
While our handedness in us is for others to clarify, my curiosity as a physicist lies elsewhere. In a normal sense, left and proper are relative orientations in house and are flipped by a mirror. Other than that, one facet isn’t implicitly roughly particular.
But this isn’t the entire reality since nature doesn’t have equal preferences for each configurations. For instance, the subatomic particles often called neutrinos are left-handed. This means a neutrino’s quantum spin is aligned parallel to however in the other way of its momentum. Neutrinos are the second most considerable particle within the universe (after photons) and so they might simply as nicely have been right-handed – but they aren’t.
For one other, there are three basic forces in nature aside from gravitation. Of these, the sturdy power operates between protons and neutrons and the electromagnetic power, between charged particles. They are each left-right symmetric: they obey the legislation of parity conservation. But there’s a fourth power, often called the weak nuclear power (answerable for radioactive decay), and it breaks left-right symmetry.
The Chinese-American physicist Chien-Shiung Wu confirmed in an experiment in 1956 that the weak power doesn’t preserve parity. After she revealed her findings, her colleagues Chen-Ning Yang and Tsung-Dao Lee obtained the Nobel Prize for physics in 1957 for figuring out the speculation of the violation. Their makes an attempt to have her nominated for her personal Nobel Prize have been in useless.
That the weak nuclear power defies parity symmetry was an necessary second within the historical past of physics. Among different penalties, the violation gave physicists a technique to develop a concept to clarify why there may be extra matter than antimatter within the universe at this time although each ought to have been created in equal quantities after the Big Bang.
Taken collectively, physicists are very inquisitive about why nature as we all know it has any choice for one handedness over the opposite. Where does this choice come from? There are not any prepared solutions however researchers are pursuing them at each the molecular and the astronomical scales.
Qudsia Gani is an assistant professor within the Department of Physics, Government College for Women, Srinagar.
