In Vienna, researchers have taken a major step toward that breakthrough. In doing so, they’ve pushed the boundaries on measurements of the fine-structure constant, an essential parameter that determines the electromagnetic force at the quantum level. The team has adopted a novel approach afforded by thorium nuclear clock technology. This innovative technique lets them track changes in the fine-structure constant with record-breaking accuracy. This creative new method allows scientists to detect changes in the constant with three times the orders of magnitude previous measures could detect. This momentous achievement represents a paradigm shift in the world of physics.
The fine-structure constant, roughly equal to 1/137, is central to our understanding of electromagnetic interactions. By studying thorium, which can exist in two states—a ground state with minimal energy and an excited state with slightly higher energy—the researchers aim to shed light on the stability and potential variations of this fundamental constant. TU Wien grew the thorium-containing crystals that served as the subject of these experiments. At the same time, researchers made laser spectroscopy measurements in Boulder, Colorado.
The Role of Thorium in Modern Physics
Thorium has been the focus of attention because of these remarkable nuclear properties. Each atomic nucleus of thorium can go through a phase transition, leading to changes in their shape and electric field. This unusual behavior makes thorium an excellent candidate for searching for variation of the fine-structure constant. The difference between the two energy states of thorium can be measured with remarkable accuracy, enabling a deeper understanding of electromagnetic interactions.
Prof. Thorsten Schumm, chief researcher on the project, said that their results were groundbreaking. He stated, “When the atomic nucleus changes its state, its shape also changes, and with it its electric field.” That splendid characteristic makes for ultra-precise measurements that were only achievable in the realm of dreams.
Since 1989, Jülich’s research team has been on the lookout for suitable atomic nucleus states such as thorium. The new thorium atomic clock opens the door to these high-precision investigations. It provides an excellent platform for subsequent research in the field of basic physics.
Investigating the Fine-Structure Constant
The fine-structure constant is one of four fundamental forces in nature, alongside gravity, electromagnetism, and the strong and weak nuclear forces. Each force is given a basic constant that indicates the strength of that force compared to the other forces. For decades, scientists have believed that these constants are constant – the same everywhere, and at all times.
Others suggest more extreme theories, in which the fine-structure constant changes with time or even oscillates over a specific period. Prof. Schumm noted, “Normally, we assume that such constants are universal—that they have the same value at all times and everywhere in the universe.” He further elaborated on the implications of their research: “There are theories that predict that the fine-structure constant changes slowly by a small amount or even oscillates periodically. This would dramatically change our conception of physics as a whole. In order to find this out, we need to measure the change of fine-structure constant with outlandishly high precision. Our thorium atomic clock now enables this for the first time.”
This innovative method has enabled researchers to detect variations in the fine-structure constant with six thousand times greater precision than ever before. With the right technological breakthroughs, these kinds of research stand to make discoveries about the most fundamental laws that govern our universe.
Future Implications for Physics
This science is now available Nature Communications. Its findings have important implications not just for experimental physics but for our theoretical understanding as well. As scientists continue to investigate the stability of the fine-structure constant, they may uncover new insights into the nature of forces at play within the universe.
The thorium nuclear clock technology would be a huge advance in enabling fundamental physics research. Not only does it improve the accuracy of measurements, it allows us to start asking questions about whether the laws of nature are truly constant.