Jean-Daniel Colladon facts for kids

Colladon's "light pipe", shown in an 1884 article

Jean-Daniel Colladon (born December 15, 1802, in Geneva – died June 30, 1893) was an important Swiss scientist. He was known for his work in physics, especially with light and sound.

Discovering How Light Travels

Colladon first studied law, but he was more interested in science. He worked with famous scientists like Ampère and Fourier.

The "Light Pipe" Experiment

In 1842, Colladon showed a cool experiment. He used a tube to guide sunlight to a table. The light stayed inside the tube because of something called total internal reflection. This means light bounces off the inside walls of the tube, just like a ball bouncing off a wall.

When the light hit a stream of water, it followed the water's curve! This happened because the light kept reflecting inside the water stream. Colladon shared this discovery in a science journal called Comptes rendus.

Paving the Way for Fiber Optics

Colladon's experiment was a big step towards modern optical fiber. Optical fibers are tiny glass or plastic strands that carry light signals over long distances. They are used for the internet, phones, and even medical tools.

Other scientists also helped develop this idea:

• Auguste Arthur de la Rive showed Colladon's experiment using electric light.
• Jacques Babinet created a similar effect with candlelight and a glass bottle.
• John Tyndall showed in 1870 that light could follow a curved path using a water jet.

Measuring the Speed of Sound in Water

Colladon also did important work with sound. In 1841, he performed experiments on Lake Geneva. He found that sound travels more than four times faster in water than in air!

He was able to send sound waves from Nyon to Montreux, which is about 50 kilometers (31 miles) away. He even thought about using underwater sound signals to send messages between England and France across the English Channel.

Other Inventions and Contributions

Colladon won a major award for his research on how much liquids can be squeezed, or their compressibility. He also worked on many other things, including:

• Hydraulics: This is the study of how liquids move and how they can be used to create power.
• Steam engines: These powerful machines use steam to create movement.
• Air compressors: These devices make air more compact.

He even invented a special type of machine that could float on water and produce energy. In 1844, Colladon helped bring gas lights to Geneva, making it the first city to have a network of these lights.

See also

In Spanish: Jean-Daniel Colladon para niños