Content - Magneticity
Making experiences stick.
Electricity is, to be sure, not something directly perceptible. But you use of it, you can find out how it behaves and can predict what it will do. In the Electronics Laboratory, you don't have to be an expert to find out quickly and in a practical fashion how diodes, transistors and capacitors function. From electric lights and audio amplifiers to electric motors and generators, you can find out in one session what was previously shrouded in mystery inside a mains socket!
It is well known that an electric current is always accompanied by a magnetic field. Although it is invisible, magnetism is as real as light and sound - and often remarkably strong.
Lodestones (naturally magnetic rocks) have been known to humans for thousands of years. Legend has it that more than two thousand years ago a shepherd was the first to notice the phenomenon. Black chips of magnetite and lodestone would stick to the metal tip of his shepherd's staff.
Today we know that magnetic and electrical forces are different aspects of the same phenomena, electromagnetism. The moving charges of an electric current create a magnetic field.
Perceptible - but still magical!
We invite you to come and play with the dozens of surprising experiments in this exhibition. You will quickly grasp that magnets are very strange things. They can be hard to control and can even attract non-magnetic metals.
Stop at the "Electromagnetic Games” station , where you can not only feel varying frequency and strength of magnetic fields, but also get an idea of phase shifting, and even feel the shape of electrical signals.
Here you can also get insight into how oddly magnetic forces act on moving non-magnetic pieces of metal.
The exhibit "Floating Paper Clips” shows clearly how you can have a strong magnetic field using a massive coil carrying an electric current, without the use of any iron. You can experience the same feeling as the French physicist, Arago, only much more impressively than was possible for this contemporary of the famous Ampère in the early 19th century. On the massive round table, dozens of compass needles forget where north is and point nose to tail round the conductor, as soon as the strong current is switched on.
Just as surprising are the effects of magnetic forces on light - for example the Faraday-effect, where the plane of polarisation gets rotated, or the Zeeman-effect, where the wavelength of light produced by individual atoms in the magnetic field is affected.
Eddy Currents a go-go
The exhibit "Eddy Currents" is an example of this. This is a phenomenon that often gets lost in the shadows of school physics. Because of this, we have several exhibits on this phenomenon, providing multiple opportunities to learn about eddy currents.
The building bricks of our world are magnetic
In order to understand magnetism, a visit to the "particle zoo" is needed. The particle components of atoms - electrons, protons, and neutrons are themselves permanent magnets. The spin of electrons is responsible for the behaviour of strongly magnetic materials like iron and cobalt.
What happens when materials are magnetised and demagnetised is amazing. You can find out about this at the exhibit "Weiss regions” (also called "Magnetic Domains”). What is also astounding is the "Barkhausen Effect”, (both can be found in the Youth Laboratory) where the sudden changes in the direction of magnetisation of these microscopic domains can be made audible!
Ferrofluid - a rather special stuff!
Ferrofluid is an extraordinary liquid, a mixture of half magnetic powder and half oil. The pointy structure of Ferrofluid, shows the three-dimensionality of a magnetic field and is surprisingly and strangely attractive.
Pièce de résistance
An artistic highlight of the exhibition is the techno artwork "Dancing Trees" created by iron dust. Tiny particles of iron-filings cover a field of magnets. At the push of a button the dust particles vibrate and perform amazing energetic dances, "choreographed" to music, such as the Flight of the Bumblebee, by Rimski-Korssakov.
Finally, the phenomena seen at the "Turntable”, "Magnetic Clouds” and "Magnetic Waves” exhibits must be the most magical representations of natural phenomena that you can ever find - pure art!