The fine structure constant is a fundamental constant in nature, and its measurement is crucial in physics. Recently, researchers at the University of Vienna have discovered a unique way to measure it. 1/137, also known as the fine structure constant, is considered to be a key number in physics. It plays an important role in atomic and particle physics.
In physics, the fine structure constant (fine structure constant), whose value is about 1/137 (in fact, the exact value of the fine structure constant is: 0.007297351+/-0.000000006, or 1/137.03599913), is the basic physical characterization of the strength of electromagnetic interactions between elementary charged particles constants.
A light source (left) sends a beam of light through a special material that changes the direction of polarization – through an angle determined by a fine structure constant.
While fine structure constants have traditionally been measured indirectly through calculations and measurements of other physical quantities, researchers at the University of Vienna have developed an experiment that allows direct measurement of fine structure constants in the form of angles.
The fine structure constant describes the strength of the electromagnetic interaction. It indicates how strongly charged particles (e.g., electrons) respond to electromagnetic fields. If the fine structure constant had a different value, our universe would look completely different – atoms would have different sizes, so all chemistry would work differently, and nuclear fusion in stars would be completely different.
A widely discussed question is whether the fine structure constant is really a constant, or whether it is possible to change its value slightly over billions of years.
“Most important physical constants have a specific unit – for example, the speed of light, which can be expressed in units of meters per second,” said Professor Andrey Pimenov from the Institute of Solid State Physics at the University of Vienna.” This is different from the fine structure constant. It has no units, it’s just a number – so it’s dimensionless.”
Usually, however, when measuring fine structures, various quantities with different physical units must be measured, and then the value of the fine structure constant is inferred from these results.” In our experiments, on the other hand, the fine structure constant itself becomes directly visible,” Andrey Pimenov said.
A laser beam is linearly polarized – the light oscillates exactly in the vertical direction. The beam is then directed at a special layer of material only a few nanometers thick, which has the property of changing the direction of polarization of light.
“There’s nothing unusual about a material rotating the polarization of a laser beam, as such. Different materials can do this; the thicker the layer of material, the more the laser’s polarization can be rotated. But we are dealing with a completely different effect here,” explains Professor Pimenov.” In our case, the polarization is not rotating continuously – it is jumping.”
When passing through the film, the light makes a quantum jump in the direction of polarization. After passing through, the light wave oscillates in a different direction than it did before. And when the size of this jump is calculated, a surprising result emerges: the quantum of this angular change is precisely the fine structure constant.
We thus have direct access to something rather unusual: a rotating quantum. The fine structure constant becomes immediately visible as an angle.