Philipp Lenard facts for kids
Quick facts for kids
Philipp Lenard
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Philipp Lenard in 1900
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| Born |
Philipp Eduard Anton von Lenard
7 June 1862 |
| Died | 20 May 1947 (aged 84) Messelhausen, Germany
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| Citizenship | Hungarian in Austria-Hungary (1862–1907), German (1907–1947) |
| Alma mater | University of Heidelberg |
| Known for | Cathode rays |
| Scientific career | |
| Doctoral advisor | R. Bunsen G. H. Quincke |
Philipp Eduard Anton von Lenard (born June 7, 1862 – died May 20, 1947) was a scientist from Hungary and Germany. He was a physicist, which means he studied how the world works. In 1905, he won the Nobel Prize in Physics. This award was for his important work on something called cathode rays.
Lenard also did a lot of research on the photoelectric effect. He found out that the speed of electrons coming from a material depends on the type of light, not how bright the light is. Later in his life, Lenard became a strong nationalist and had negative views towards Jewish people. He supported Adolf Hitler and his ideas.
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Philipp Lenard's Early Life
Philipp Lenard was born in a city called Pressburg. This city is now known as Bratislava and is in Hungary. He was born on June 7, 1862. His family was of German background. His father, Philipp von Lenardis, sold wine.
In 1880, Lenard started studying science. He went to universities in Vienna and Budapest. In 1883, he moved to Heidelberg, Germany. There, he studied physics with famous scientists. He earned his special science degree, called a doctoral degree, in 1886.
After his studies, Lenard worked in many different cities. These included Aachen, Bonn, and Kiel. In 1907, he returned to the University of Heidelberg. He became the head of a science institute there. He also became a member of important science groups.
Lenard's Science Discoveries
Studying Cathode Rays
Lenard started studying cathode rays in 1888. These rays are streams of tiny particles. They are made in special glass tubes with very little air inside. It was hard to study these rays. They were trapped inside the sealed tubes.
Lenard found a clever way to study them. He made small, thin metal windows in the glass tubes. These windows were strong enough to hold the air out. But they were thin enough to let the rays pass through. This allowed him to study the rays outside the tube. These windows are now called Lenard windows.
He used special paper that glowed when the rays hit it. This helped him see and measure the rays. Lenard noticed that the rays were absorbed by materials. The more dense the material, the more rays it absorbed. This showed that the rays were tiny particles.
Lenard proved that cathode rays are streams of tiny, negatively charged particles. He called them "quanta of electricity." Today, we call these particles electrons. He also showed that atoms are mostly empty space. He thought atoms had small, neutral parts called "dynamids."
The Photoelectric Effect
Lenard also experimented with a Crookes tube. He shined ultraviolet light on metals in a vacuum. This made rays that were like cathode rays. He made an important discovery. The energy of these rays did not depend on how bright the light was. Instead, it depended on the light's color or wavelength. Shorter wavelengths of light made more energetic rays.
Later, Albert Einstein explained this effect. He said light acts like tiny packets of energy called photons. Einstein won the Nobel Prize for his explanation. Lenard received his Nobel Prize in 1905 for his work on this effect.
Studying Weather and Rain
In 1892, Lenard studied something called the Lenard effect. This happens when water drops break apart. It causes electric charges to separate. This is also known as "spray electrification." It can happen near waterfalls.
He also studied raindrops. He built a special wind tunnel. This tunnel could hold water droplets still. He found that large raindrops are not tear-shaped. They are actually shaped more like a hamburger bun.
Lenard's Later Life and Views
Philipp Lenard was a strong German nationalist. He believed German science was the best. He thought other countries, especially England, copied German ideas. He joined the National Socialist Party early on.
He promoted "Deutsche Physik" (German Physics). He said that the ideas of Albert Einstein were "Jewish physics." He called Einstein's theory of relativity a "Jewish fraud." Lenard became an advisor to Adolf Hitler. He was seen as a leader for "Aryan physics."
Lenard stopped working as a professor in 1931. After World War II, in 1945, he lost his honorary positions. This was because of his support for the Nazi Party. A school named after him was also renamed. Philipp Lenard died in 1947.
Awards and Honors
- 1896: Rumford Medal from the Royal Society
- 1896: Matteucci Medal from the Italian Society of Sciences
- 1897: Prix La Caze from the French Academy of Sciences
- 1905: Nobel Prize for Physics
- 1932: Franklin Medal from the Franklin Institute
- 2008: A crater near the north pole of the moon was named after him.
