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zutnoq t1_j656wje wrote

Reply to comment by VainVeinyVane in [Electricity and magnetism] For a half-wavelength dipole antenna, why is the voltage distribution a quarter wavelength out of phase with the current? by VainVeinyVane

If you want a more hand wavy explanation I think the antenna is essentially acting as a giant capacitor (or rather one side of a capacitor) which would certainly explain the 90° phase difference between voltage and current as that is exactly what happens with a regular capacitor driven with AC (the exact opposite phase shift happens for an ideal inductor driven with AC).

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VainVeinyVane OP t1_j65y9rc wrote

can you explain how it acts like a capacitor lol I'm having a hard time wrapping my head around it.

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zutnoq t1_j67q8kj wrote

A capacitor is essentially two plates of metal separated by a layer of insulator. The antenna is acting like one of those plates of metal, the air is the insulator and (the) ground is acting as the other plate.

Edit: in this specific case the other arm of the antenna is the other plate, if that wasn't obvious.

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