Scientists who study the foundations of our material world live in hope that their greatest age of discovery still lies before us. They have good reason.
Ancient philosophers were once preoccupied with how to describe a world made of four elements – earth, air, fire and water. Today, the elements of the periodic table number 118, the latest named in 2016.
In the vast unexplored landscape of materials that can be constructed from these ingredients, there are major discoveries waiting to be made. And there is the tantalizing prospect of even more fundamental breakthroughs that illuminate why the laws of nature work the way they do.
One recent case involves superconductors, a type of material that can transmit an electric current without loss. Superconductors have long been known to exist, but so far only at temperatures that are too cold or pressures too high to allow for their use in everyday circumstances. Researchers who work with such materials have laboured for decades to find ways to make them more practical.
That was the situation in July when scientists working at Quantum Energy Research Centre, a company based in Seoul, South Korea, reported their apparent discovery of a room temperature superconductor based on a modified form of the mineral lead apatite.
News of the substance, dubbed LK-99 by its discoverers, quickly percolated through the physics community and prompted a burst of news coverage.
At stake is the promise of a new era in electricity transmission and storage. For a world desperately looking to keep the lights on without further cooking the planet, such a development would be a godsend.
Add to that another property of superconductors called the Meissner effect, a form of magnetic repulsion that can allow objects to levitate. From there it is a short step to imagine trains without wheels efficiently gliding over superconducting rails, like a science fiction dream made real.
Other scientists swiftly tried to reproduce the results claimed by the South Korean team but have been unable to do so. Most experts now judge that LK-99 is not a superconductor after all. Yet the failure illustrates the optimism that underlies the larger scientific enterprise.
The episode shows how much has been learned by the global research community after years of working with materials and exploring their properties. The fact that the discoverers’ claims received serious attention signals a consensus among scientists that there are big breakthroughs in the field that have yet to be made. If there is skepticism about one find in particular, there is also confidence in the quest.
That confidence extends to the other high profile physics result that emerged this summer, involving the mysterious behaviour of muons, and the search for a new unified theory of energy and matter.
Muons are subatomic particles that decay microseconds after they are created. Despite this fleeting lifespan, their properties can be measured with high precision as they whiz around in a magnetic field. Such measurements can then be tested against the predictions of the Standard Model of particle physics, the reigning theory that describes how the basic constituents of matter operate.
In 2021, researchers at Fermilab, a U.S. national research facility near Chicago, announced a slight deviation in the way the muon wobbles in response to magnetic forces when compared with predictions. The difference is minuscule, seemingly inconsequential – 0.00233184110 – but physicists are eagerly searching for any crack in the smooth edifice of the Standard Model, something that might offer a glimpse at a deeper, more powerful, theory of everything.
In August, new results were released, with the experiment’s precision increasing by a factor of two. The results show that the muon anomaly persists. Whether it is truly a sign of a new theory will now depend on a further refinement of calculations with the Standard Model which may or may not resolve the discrepancy.
Indeed, since the muon experiments rely on superconducting magnets, it’s an example of how one area of research can advance another. Science proceeds by asking questions with new tools and then turning the answers back into novel ways to explore reality, and new questions. In this feedback loop lies our best assurance of living a world where wonders never cease.