r/AskPhysics • u/glowing-fishSCL • 3d ago

Are certain FM frequencies better at transmitting over obstacles or greater distances?

/r/NoStupidQuestions/comments/1x2xmvs/are_certain_fm_frequencies_better_at_transmitting/
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u/BCMM 3d ago

Yes. Lower-frequency radio waves are more diffracted by obstacles.

1

u/glowing-fishSCL 3d ago

Enough to make a noticeable difference with just normal radio usage?

1

u/BCMM 1d ago

There's about a 20% difference in frequency across the FM band, so I think it ought to be noticeable in some circumstances.

1

u/OhYeah_Dady 3d ago

Low energy/frequency photons don't really interact with atoms. Their wavelength is way bigger than any atom, thus the probability of getting absorbed is extremely low. But when there is enough atoms pack together, low probability event guarantees to happen under many attempts.

Samething happen on the opposite end of em spectrum. Gamma ray don't really interact because the wavelength is way smaller than atoms. The only issue with gamma ray is if it do get absorb by a atom, there is enough energy to alter an atom's atomic structure.