Answer:
The quasar's red shift
Explanation:
When there is a change in the wavalength of a wave due to the relative motion of the reciever and the transmitter this is known as Doppler effect.
When the observer and the object are moving towards one another then the wavelength shortens. This is called blue shift.
When the observer and the object are moving away from one another then the wavelength lengthens. This is called red shift.
Here, Maarten Schmidt observed the wavelength increasing i.e., red shift. Hence, from this he calculated the speed of the quasar.
