Physical Background

Modern physics

The physical laws that explain the behavior of all objects that surround us were developed hundreds of years ago. We summarize them under the term classical physics.

Everything that surrounds us is made up of small building blocks, the atoms. These in turn consist of even smaller particles such as electrons, protons or neutrons. In the last century, researchers discovered that some of the laws of classical physics no longer apply when considering such particles. They therefore developed new laws: Quantum physics was born.

The laws of quantum physics are less easy to understand than the laws of classical physics - they often seem to contradict our everyday experience and common sense. In order to be able to explain quantum physical properties and phenomena clearly, we use models, i.e. comparative ideas to what we know and understand. For example, we imagine electrons as small globules in order to make them clear and understandable, even if that doesn't quite correspond to reality: On the basis of the model, in this case our globule idea, one can correctly predict most observations, also in quantum physics. However, current research assumes that in reality electrons have no expansion at all, so that their diameter is exactly zero. So while we can keep our idea of the globule, we need to remind ourselves from time to time that reality is a little more complicated than our model.


The phenomenon that gave quantum physics its name is quantization: In the study of microscopic systems, physicists discovered that many measurable quantities can only assume very specific values. For example, electrons bound to an atomic nucleus can only assume certain energy values.

Wave-particle duality

Another central insight of quantum physics is the wave-particle duality. In experiments with light, it was found that it has properties of both waves and particles: Light propagates in space like water waves and can be amplified or weakened by superposition of wave crests and troughs. At the same time, however, it is also possible to detect light particles that are not distributed over space, but can only be found at a specitic point in time at a certain place. These light particles are called photons. Also for other quantum objects (electrons, atoms, molecules, etc.) wave-particle duality could be demonstrated.


Magnetism and magnetism-based technologies in the 21st century

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