Electromagnetic radiation can be classified into two major types depending on its ability to detach electrons from atoms: ionising and non-ionising. The aforementioned categorization is significant due to the effects of ionising radiation on human tissue (e.g. carcinogenesis). However, many students around the globe cannot distinguish these two…

We describe recent experiments at CERN in which antihydrogen, an atom made entirely of antimatter, has been held in a magnetic minimum neutral atom trap and subjected to microwave radiation to induce a resonant quantum transition in the anti-atom. We discuss how this, the first experiment to observe an interaction between an antihydrogen atom and…

Catt's anomaly is a sort of "thought experiment" (a "gedankenexperiment") where electrons seem to travel at the speed of light. Although its author argued with conviction for many years, it has a clear and satisfactory solution and it can be considered indubitably just an apparent paradox. Nevertheless, it is curious and…

Scientists use models to describe and explain observed physical phenomena and to predict the outcomes of new phenomena. Choosing a productive model for describing or explaining a phenomenon is a routine part of the work of scientists but a rare exercise for our students. Students have difficulties understanding the meaning of the word "model" and…

Proton beams have been colliding at 7 TeV in the Large Hadron Collider (LHC) since 30 March 2010, meaning that the LHC research programme is underway. Particle physicists around the world are looking forward to using the data from these collisions, as the LHC is running at an energy three and a half times higher than previously achieved at any…

Mainly used in the 1960s, bubble chambers played a major role in particle physics. Now replaced with modern electronic detectors, we believe they remain an important didactic tool to introduce particle physics as they provide visual, appealing and insightful pictures. Sadly, this rare type of detector is mostly accessible through open-door events…