Hans Hollmann facts for kids

Hans Erich (Eric) Hollmann (born November 4, 1899 – died November 19, 1960) was a smart German electronics expert. He made many important discoveries that helped create radar, which is like a special way to "see" things using radio waves.

Early Life and Studies

Hans Hollmann was born in Solingen, Germany. Even when he was a teenager, he loved radio technology. He read lots of technical magazines. During World War I, he became a prisoner of war in France. He didn't return to Germany until 1920. After that, he studied at the Technical University in Darmstadt. He earned his doctorate degree in 1928.

Amazing Microwave Research

For his doctorate, Hans Hollmann worked on something very new. He developed a special transmitter and receiver for "ultra-short waves." These waves are also called centimetre and decimetre waves, which are a type of microwave. His work caught the eye of a big company called Telefunken. This research later helped Telefunken create the very first microwave telecommunication system. This system allowed people to send information using these special waves.

Working on New Technologies

In 1930, Hollmann moved to the Heinrich-Hertz Institute in Berlin. There, he kept studying microwaves. He also worked on cathode ray tubes, which were used in early televisions and computer screens. Besides that, he explored the ionosphere (a part of Earth's atmosphere) and even helped with radio astronomy, which is about studying space using radio waves. In 1933, he became a teacher at the Technical University in Berlin.

Developing Early Radar Systems

In January 1934, two people, Hans-Karl von Willisen and Paul-Günther Erbslöh, started a company called Gesellschaft für elektroakustische und mechanische Apparate (GEMA). Hans Hollmann joined them as a helper and advisor.

Together, in the autumn of 1934, GEMA built a system that could find ships. It used a method called "interference detection." This system used 50-centimetre waves and could spot ships up to 10 kilometres away!

By 1935, they improved the technology. They started using "pulse-modulation." This allowed them to measure the exact distance to a target. They developed two main uses for this new technology:

• For ships, they created the Seetakt system. It used 80-centimetre waves.
• For land, they made a version called Freya. This system used 120-centimetre waves.

Radar in World War II

Another company, Telefunken, also started working on radar in 1933, based on Hollmann's ideas. They developed a radar system called Würzburg. This system was for shorter distances and helped aim guns.

During World War II, the Freya and Würzburg radar systems often worked together. Freya would first find incoming aircraft from far away. Then, Würzburg would quickly calculate the exact distance and height of the planes. This helped soldiers know where to aim.

Books and Later Life

In 1935, Hans Hollmann wrote two important books about microwaves. They were called Physics and Technique of Ultra-short Waves and Seeing with Electromagnetic Waves. These books were so good that they inspired scientists in other countries to develop their own centimetre radar systems, even though some parts of the books were kept secret.

During the war, he looked after many research places in countries that Germany had taken over. He even helped save many scientists from being sent to Germany. He also started a special lab in Lichterfelde, Berlin, which worked on making transmitters for the Navy. His own home and laboratory were destroyed during the war.

After the war, he was not allowed to work on microwaves anymore. So, he started exploring many other areas in electronics.

In 1947, the US Government asked him to work for NASA in California. He accepted the offer. In 1949, he sent a copy of a book called Cybernetics: Or Control and Communication in the Animal and the Machine to his friend Max Bense. This book was about cybernetics, which is the study of how systems control themselves and communicate. This made Max Bense very interested in the topic.

Hans Hollmann was married to Gisela Schimmelbusch and they had three children. He passed away in Los Angeles in 1960.