Say Im approaching a radio station with my car at near lightspeed whilst listening to some AM broadcast, say Miley Cirus' party in the usa
What will I hear? will the song be faster? will the pitch go up as I go faster?
you'll hear nothing, the radiation will be so blueshifted or redshifted that you won't recieve anything because your radio won't be able to lock on anything meaningful.
>>8101743
okay. Say Im standing still and listening to some AM signal of hannah montana's hoedown throwdown (broadcasted from some fixed radio station at infinity) and during the first refrain start to accelerate such that by the third refrain I am close to lightspeed.
really? doppler shift is too hard for /sci/?
Obviously we can assume the signal to be a sinewave with frequency [math]f_c[/math] modulated by some sinewave with frequency [math]f_m[/math].
So, simplified, our K-pop song looks like this mathematically (as an EM-signal)
[math]y(t)=(1+M \cdot \sin(f_m t)) \cdot \sin(f_c t)[/math]
where 0<M<1 is some constant.
Now this, as every child knows, is equivalent to
[math]y(t) = \sin(f_c t) + \frac{M}{2} \left[\sin((f_c + f_m) t ) + \sin((f_c - f_m) t )\right][/math]
Now someone apply the doppler shift formula to that and tell me what happens to [math]f_c[/math]
you will have to retune your radio station to a different frequency. once you do that, your radio signal will be both faster and higher pitched. simple.
>>8101773
>really? doppler shift is too hard for /sci/?
no, you just don't know how a radio works so you can keep asking, the answer will always be the same: you won't hear shit.
>>8101743
let's say it's a magic radio.
>>8101863
thats stupid. your stupid.
>>8101921
let's not
>>8101950
whats your actual problem here, you dense turbonigger?
is it that one would have to tune the receiver up to compensate for the frequency shift?
you may assume that my trustworthy minion niggles is manning the radio tuning knob and compensating for anything that your childhood makes you feel should be compensated for
>>8101973
>you dense turbonigger
Commercial AM uses large carrier signals, so demodulators typically just use a rectifier and peak follower rather than the proper mix->lowpass technique. Even if you could tune the resonator to the new carrier frequency, the peak follower time constant would be too long for the new signal and you'd constantly see the largest peak. If you had a properly tuned peak follower or a PLL demodulator the resultant signal would have it's band stretched significantly.
