In classical physics, A vacuum is utter emptiness, the true manifestation of nothingness.But according to quantum physics, empty space is not TRUE Sky. Instead, “virtual” particles flit about, appearing and disappearing too quickly to be detected. Scientists know that these virtual particles exist. This is to measurably fine-tune the quality of regular particles.
One of the key properties that these expandable particles change is the tiny magnetic field produced by a single electron, known as the magnetic moment.In theory, if scientists could describe all types of virtual particles in existence, they could do the math and figure out exactly how It is swimming in this virtual pool of particles that has distorted the electron’s magnetic moment. With sufficiently accurate equipment, they could check their work against reality. Determining this value as accurately as possible will help physicists pinpoint which virtual particles are messing with the electron’s magnetic moment.
In February, four researchers at Northwestern University announced they had done just that. their result is physical review letter, reports the electronic magnetic moment with astonishing accuracy. With 14 decimal places, it is more than twice as accurate as the previous measurement in 2008.
It may seem excessive. But it’s not just about mathematical accuracy. By measuring the magnetic moment, scientists are testing the standard model, the theoretical cornerstone of particle physics. Like the physical version of the periodic table, it is laid out as a chart of all particles known in nature. Elementary particles that make up matter, such as quarks and electrons, and particles that carry or mediate forces, such as gluons and photons. The model also comes with a set of rules for how these particles behave.
But physicists know that the Standard Model is incomplete. Some elements may be missing. Model-based predictions often disagree with observations of the real universe. It cannot explain important conundrums such as how the universe expanded to its current size after the Big Bang, or how the universe could exist. The model also says nothing about dark matter holding galaxies together or dark energy driving the expansion of the universe. Perhaps its most significant flaw is its inability to explain gravity. Incredibly accurate measurements of known particles are therefore key to understanding what is missing, as they help physicists focus on gaps in the Standard Model.
“The Standard Model is our best description of physical reality,” says Gerald Gabriels, a physicist at Northwestern University who co-authored the new study and the 2008 results. “It’s a very successful theory in that it can predict essentially anything that can be measured and tested on Earth, but it misleads the universe.”
In fact, the most accurate prediction that the standard model makes is the value of the electron’s magnetic moment. If the predicted magnetic moment does not match what was seen in the experiment, the discrepancy could be a clue that an undiscovered virtual particle is at work. I always say yes,” says Xing Fan, a physicist at Northwestern University who spearheaded the work as a Harvard graduate student. “The only way you can test it is by comparing your theory to the real world.”
