As the liquid nitrogen wafts across the ground like fog, the children are fascinated and move close together. Laura Seker-Haus and Philipp Anton Schafhauser from the Department of Mathematics, Natural Sciences and Computer Science (MNI) at the Technische Hochschule Mittelhessen ( THM ) make strawberry ice cream before their eyes in just a few minutes. The children who take part in the “Children’s Summer” holiday care run by the Sportjugend Wetzlar agree: “The ice cream is incredibly delicious.”
Before this practical chemical experiment, the children between the ages of six and 13 had already tried out physical experiments. Divided into small groups, the 33 girls and boys in the MNI department learned what magnetism is and what air can do. Especially for the children's summer of 2024, the scientific staff Dr. Kaija Spruck and Dr. Benjamin Ebinger and the teacher Samaneh Emami opened the physics laboratory doors.
The children slowly let iron filings trickle onto a glass plate under which a magnet is stuck. The chips immediately arrange themselves in a pattern and the children are fascinated. But there are astonished looks when Samaneh Emami creates a magnetic field and a small globe appears to float in the air. Of course the children want to try it out too. With a little patience, most people manage to create exactly the state in which the magnetic force compensates for the earth's gravity. “It’s called magnetic levitation,” explains the physicist.
In another part of the laboratory, Dr. Benjamin Ebinger asked the children to first find out whether air weighs anything. Most children assume that she has no weight. First, the children weigh what a gas bottle weighs with one liter of air, then Ebinger uses a vacuum pump to get the air out of the bottle and the children are allowed to weigh again. They find a difference of about a gram - so air weighs something. In a second experiment, Ebinger shows that air transports sounds. And explains: “Do you watch space films? You can almost always hear noises and conversations in space, but it's actually very quiet there. So the filmmakers are cheating a bit.”
Things get wet with Dr. Kaija Say yes. She has the children build a Cartesian diver - a small vessel filled with air and water that can rise and fall in a water bottle when the outside of the bottle is pressed with varying degrees of pressure. First, the girls and boys fill small baking aroma bottles with water just enough so that they float upright in a cup full of water with the opening pointing downwards. These are then carefully placed in a plastic bottle filled with water, the children squeeze the bottle, the baking aroma bottle sinks towards the floor, the pressure decreases and it rises again. “This technology is used in submarines, for example, so we built a mini submarine,” explains Spruck to the children.
The THM is a partner company of the children's summer, which is coordinated by IHK Lahn-Dill and organized by the sports youth in Wetzlar. School-age children between the ages of six and 13 experience a varied programme for four weeks during the summer holidays. THM employees and students can not only register their children for holiday care. The THM is participating in the offer with its “Family-Friendly University” initiative. There are also comparable offers for the THM locations Gießen and Friedberg.