1. The problem statement, all variables and given/known data When an initially charged capacitor is connected in a circuit with an uncharged capacitor, why would the total energy of both capacitors be less than the initial energy of the charged capacitor? 2. Relevant equations This was a question asking for an explanation, so I'm not sure if any equations are relevant here. 1/C = 1/C1 + 1/C2 3. The attempt at a solution Would it be due to heat dissipated in the circuit when the charge (or current?) flows in the circuit? Also, the suggested explanation was that a spark was produced - why and where this happens, I don't really know. Thanks for your help!