If the discharge is alone, without lateral and parallel secondary discharges (very rarely) and sufficiently precisely perpendicular, compressive forces spread from it in the first moments rather accurately in a circle shape (electromagnetic in absolute precise circle shape at any time).
Kung ang naglalabas ang nag-iisa, walang lateral at parallel pangalawang discharges (napaka Bihirang) at sapat tiyak patayo, kumalat compressive pwersa mula ito sa unang sandali halip tumpak sa isang bilog na hugis (sa ganap electromagnetic tumpak na hugis bilog sa anumang oras).