2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/45701We consider versions of the Casimir effect where the force can be controlled by changing the angle between two Casimir ``plates'' or the temperature of two nearby rings. We also present simple arguments for the sign of Casimir forces.3 pages of double column revtex, + 4 figures. For correspondence use Tel Aviv address, or nussinov@ccsg.tau.ac.ilHigh Energy Physics - Phenomenologytext