Here it is in a nut shell:
Lets say you are receiving some radio signal with you equipment.
You read the frequency and the wave length.
If you increase your speed toward the signal the frequency will increase
and the wave length will decrease so that any time you multiply
the frequency times the wave length you will get the speed of light.
186000 miles per second in a vacuum.
The frequency change makes logical sense the wave length change is magic.
Welcome to the illusion.
We are looking for the how and why but all we get is a riddle, wrapped in a mystery, inside an enigma.