# Do we need infinite energy to make 2 similar charges touch only in theory?

By Coulomb's law, say if we have 2 point particles each having a charge of +1C then by the formula, F = k/(d)^2

if we need to make the distance between them zero, clearly y the formula, we need to have an infinite amount of force.

However, in a real life scenario, we see that if we rub two balloons with our head, they acquire the same charge. However, it is still possible to make them touch.

Is this because the two balloons are not point objects? OR is the definition d=0 actually mean "to occupy the same space".

for d to be 0, do the objects only need to touch or do their centers need to be together?

• You might wanna see this:physics.stackexchange.com/questions/23797/… very simply, two objects can never touch, only come pretty close apart. – udiboy1209 Aug 11 '13 at 16:10
• Note that Coulomb's law applies to point charges. Also, it happens to work for uniform perfect spheres of charge (why? good exercise to work it out). In that case $d$ is the distance between the centres, not the surfaces. – Michael Brown Aug 11 '13 at 16:33
• Please read my answer to a similar question physics.stackexchange.com/questions/72927/… . When infinities appear of any sort in extrapolation of theories, it means a new theoretical framework is necessary, usually provided by quantum mechanics. Electrons are point charges, but the heisenberg uncertainty principle ( look it up in wiki) eliminates infinities. – anna v Aug 13 '13 at 19:54

• This is not quite correct. The charges inside the balloons will redistribute, but they will leave the extremes positively charged and the middle sections neutral: not $+,-,+,-$ but $+$, neutral, neutral, $+$. – Emilio Pisanty Aug 13 '13 at 16:11