Christian doppler

1. Christian Doppler
(1803-1853)
Ayoub Fahad M Almughamisi
3547505
Studied the apparent change in wave frequency du
e to relative motion between observer and source

2. Christian Doppler (1803-1853)
His life
• Christian Doppler was born in Salzburg in Austria in November 2918
03.
• His father works in construction. Christian could not work in
his father's profession because of his weak structure.
• After completing high school, Doppler studied philosophy in Salzburg a
nd mathematics and physics at the Imperial–Royal Polytechnic Institute
(now Vienna University of Technology) where he began work as an assis
tant in 1829.
• He was appointed to a temporary position of assistant to the profe
ssor of higher mathematics and mechanics at the University.
• In 1835 he began work at a professor of mathematics and physics at t
he Prague Polytechnic (now Czech Technical University), where he recei
ved an appointment in 1841.
• One year later, at the age of 39, Doppler gave a lecture to the Royal
Bohemian Society of Sciences and subsequently published his most
notable work, which was on that would become know as the Doppl
er effect.

3. We notice the Doppler effect (video) today as the change of sound as an am
bulance with it’s siren going approaches us and then quickly passes and move
on. The pitch is higher as it approaches and lower as it moves away from us.
Christian Doppler (1803-1853)
Doppler effect.
The Doppler effect as Doppler stated it, deals with apparent change in wavele
ngth of sound caused by the motion of the source, observer, or both.
where the speeds of source and the receiver r
elative to the medium are lower than the vel
ocity of waves in the medium, the relationshi
p between observed frequency ƒ and emitte
d frequency ƒ0 is given by:
ƒ=(c+νr ⁄c+νs )
ƒ0
Where:
c is the velocity of waves in the medium.
vr is the velocity of the receiver relative to the medium; positive if the receiver is moving t
owards the source (and negative in the other direction).
vs is the velocity of the source relative to the medium; positive if the source is moving awa
y from the receiver (and negative in the other direction).

4. Christian Doppler (1803-1853)
If the speeds vs and vr are small compared to the speed of the wave, the relati
onship between observed frequency ƒ and emitted frequency ƒ0 is approximate
ly.
Observed frequency
ƒ= (1+ Δν/c)ƒ0
Change in frequency
Δƒ=Δν/c ׃0
• Doppler’s work dealing with sound was verified by John Russell ( 1802-18
82) in 1848, and Armand Fizeau (1819-1896) showed that the Doppler eff
ect also applies to light.
• Doppler’s research career in Prague was interrupted by revolutionary incide
nts, so in March 1848 he fled to Vienna There, in 1850 he was appointed he
ad of th Institute for Experimental Physics at University of Vienna.
• He played an influential role in the development of young Gregor Mendel
(1822-1884), who later become the founding father of genetics.
• Doppler died on 17 March 1853 at age 50 from a pulmonary disease in Ve
nice (at that time part of the Austrian Empire).His tomb is located just insid
e the entrance of the Venetian is island cemetery of san Michele.

5. References:
history of physics h.thomas.
The Physics class room.
Christian Doppler (wikipedia).
Doppler effect (wikipedia).
Science wonders.
Completed by:
Ayoub Fahad M Almughamisi.
3547505
Twitter: iAyoubFahad
Email: Ayoub.Fahad@Gmail.com