Picture of Christian Doppler
The University of St. Andrews, Scotland
Christian Doppler was an Austrian mathematician who lived between
1803-1853. He is
known for the principle he first proposed in Concerning the coloured
light of double stars
in 1842. This principle is now known as the
. He hypothesised that the pitch of a sound would change if
the source of the sound was moving.
Doppler's hypothesis was tested by Buys Ballot in 1845. He used two sets of trumpeters: one set
stationary at a train station and one set moving on an open train car.
Both sets of musicians had perfect pitch and held the same note. As the
train passed the station, it was obvious that the frequency of the two
notes didn't match, even though the musicians were playing the same
note. This proved Doppler's hypothesis.
Later, a scientist named Fizeau generalized Doppler's work by applying his
theory not only to sound but also to light.
You might also be interested in:
How did life evolve on Earth? The answer to this question can help us understand our past and prepare for our future. Although evolution provides credible and reliable answers, polls show that many people turn away from science, seeking other explanations with which they are more comfortable....more
The Doppler effect was named after Christian Doppler, who first came up with the idea in 1842. He learned that sound waves would have a higher frequency if the source was moving toward the observer and...more
Sound travels in waves. You hear sound because waves hit your ear. Sound waves are similar to ocean waves. They both have a certain frequency. The frequency is measured in hertz, which is one cycle per...more
Charles Darwin was an English Naturalist who lived between 1809-1882. He laid the foundations for the modern science of biology, and changed how other scientists understood the appearance of life on Earth....more
Christian Doppler was an Austrian mathematician who lived between 1803-1853. He is known for the principle he first proposed in Concerning the coloured light of double stars in 1842. This principle is...more
Ben Franklin was an American scientist and statesman who lived between 1706-1790. At a time when little was known about electricity, he carried out many experiments to learn of its dangers and possible...more
Edmond Halley was an English astronomer who lived between 1656-1742. Using historical records, his own observations, and Newton's universal law of gravitation, he reasoned that the comets which had appeared...more
William Herschel was born in Germany and lived in England as he worked as an astronomer. He lived between 1738-1822. He built high magnification telescopes that let him observe the heavens with greater...more