# Gravititonal fields compared to electromagnetic fields - are they infinite in range?

me and my friend has a discussion last night, and he argued that both an electromagnetic field and gravititonal field are infinite in their area of effect, but with diminishing effects as you get farther away from the object.

I argued that only gravity field is infinite in range.

So which one of us is correct, and please explain in laymen's terms, as we're not physicists :)

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Actually, your friend is right! The electromagnetic field has an infinite range, for example for a charged point particle the electric field is proportional to $\frac 1{r^2}$, where $r$ is the distance to the particle. However in very special circumstances, like inside a superconductor, the electromagnetic field will be short-range because the photons will effectively be massive.
You've got a typo here: the electric field is proportional to $1/r^2$, not to $1/r$. Alternatively, the electric potential is proportional to $1/r$. –  Ted Bunn Jul 3 '11 at 15:45