Povzetek – Poskusimo slediti poti, ki je pripeljala do napovedi Higgsovega bozona in njegovih lastnosti. Najprej obdelamo invariantnosti ali simetrije. Umeritveno invariantnost klasične elektrodinamike povežemo s kvantno mehaniko. To pripelje do enačbe gibanja za naelektrene delce v električnih in magnetnih poljih. Omenimo neuspel poskus, da bi z umeritveno teorijo opisali proton in nevtron. Umeritvena teorija pa uspešno zajame elektromagnetno in šibko interakcijo. V njej vpeljejo Higgsov bozon.

Abstract – An attempt is made to follow the way to the prediction of the Higgs boson and its characteristics. First the invariances or symmetries are considered. The gauge invariance of classical electrodynamics is connected with quantum mechanics. This leads to the equation of motion for charged particles in electric and magnetic fields. The unsuccessful attempt is mentioned to describe the proton and neutron within a gauge theory. A gauge theory, however, successfully encompasses the electromagnetic and weak interaction. In it the Higgs boson is introduced.

Abstract – The article deals with deep-sky observation. It reminds us that three steps are necessary for good observation: preparation, observation and analysis. It stresses the importance of putting effort in recording details (weather, time, coordinates of the observation site, height of the sky object, observation conditions (Bortle Dark-Sky Scale), sky quality (measuring with Sky Quality Meter) and commentary), which is the only way to quality in observation. The article also points out that students are difficult to motivate for in-depth observation of deep sky.

Abstract – Shadows are one example of phenomena that we experience in everyday life. We can prepare several experiments in the classroom. We only need a stick, a light source, a dark room and a wall. Varying the position of the stick (or the light source), we find a (mathematical) relation between the stick’s position and the length of the shadow on the wall.

Abstract – Experimental work in physics is important. Since students were not sufficiently effective in experimental work, I introduced a science day with physical experiments. During this day, students took the first steps in all parts of group work and tried various different experiments.

Abstract – First Slovenian Under the Balloon (celebrating bicentenary of the first Slovenian Flight) The life and work of the very first Slovene airman and the pioneer of ballooning is described. The physics of his achievements in the air should become a guide for future balloon flights in Slovenia.