The universe is a dynamic and restless entity. After 14 billion years of cosmic evolution, humans feel alien to the celestial landscape and wonder about existence’s origin, seeking answers through different methods — philosophy, divinity, and of course, science. So what are the fundamental building stones of the universe, and how can we find them, measure them, and explain them?
The value of gravity, the amount of baryonic matter, the space-time expansion constant, and the speed of light are perhaps random predetermined values by the cosmos. Scientists have managed for the first time to successfully measure the value of one of these fundamental constants that allow our existence.
The science and other stuff to know
A century ago, Arnold Sommerfeld and his fellow physicists observed the light emitted by electrons and noted dark lines in the spectrum of the atoms analyzed. From these marks in the spectrum, they determined the value of a constant called the “fine structure” constant, which determines the strength of the electromagnetic force. They named it with the Greek letter alpha and found that its value is approximately equal to 1/137.
For decades this value intrigued physicists because, unlike other constants of nature, it is dimensionless — it has no units. It also appears repeatedly in Standard Model equations that describe the interaction between photons and electrons, the nuclear forces, and even gravity.
Recently, a research team from the Kastler Brossel Laboratory in Paris has made the most accurate measurement of the value of α. According to the results published in Nature α=1/137.035999206.
At first glance, a measurement to a few decimal places may seem trivial; after all, they have only increased the accuracy of the measurement. However, that is precisely where the discovery lies. The precision in this constant’s measurement will help physicists better understand the phenomena that occur at quantum scales and refine the Standard Model of Particle Physics.
“With the new determination of the fine structure constant, these predicted and experimental values agree to more than one part per trillion, providing an excellent consistency check of the Standard Model of particle physics, particularly its electromagnetic sector,” Massimo Passera of the National Institute of Nuclear Physics, who was not part of the research, told Scientific American.
The research director Andrei Pimenov suggested that the results obtained are relevant and that it is the first time that the value of α has been determined with this level of precision. “The main result of this work is the ability to obtain a fundamental physical constant in a direct experiment that does not depend on any other measurement or calibration. By contrast, no fundamental constants have been measured in previous work,” he told Physics World.