The observer (receiver) starts moving towards the light source with constant speed v. The speed of the pulses as measured by the observer shifts from c to c'=c+v, and the frequency he measures shifts from f=c/d to f'=c'/d, where d is the distance between the pulses:

http://www.einstein-online.info/imag...ector_blue.gif

https://www.youtube.com/watch?v=bg7O4rtlwEE

Einsteinians accept the formula

f'=c'/d

but don't accept it presented in this way:

c'=df'

When they look at c'=df' they see c'=c and sing "Divine Einstein":

https://www.youtube.com/watch?v=9lE-I2I4i00

http://www.everythingimportant.org/E...neEinstein.jpg

The reason behind such a behavior was explained by Ignatius of Loyola, long time ago:

Ignatius of Loyola: We should always be prepared so as never to err to believe that what I see as white is black, if the hierarchical Church defines it thus.

https://pbs.twimg.com/media/DqAuyByXQAASu-Z.jpg

Pentcho Valev