1. A FAST ACTING ELECTRIC SWITCH FOR CONDUCTING LARGE AMOUNTS OF ELECTRICAL ENERGY, COMPRISING FIRST CLOSELY SPACED ELECTRODES FORMING A SMALL GAP, AND MEANS FOR PROVIDING A METAL CONDUCTOR IN SAID GAP WHICH CONNECTS SAID FIRST ELECTRODES, COMPRISING A FLAT INSULATOR HAVING AN UNRESTRICTIVE PORTION BETWEEN SAID FIRST ELECTRODES FORMING SMALL, REACTION CHAMBERS THEREWITH SPACED METALLIC FOILS IN SAID INSULATOR HAVING THEREBETWEEN, AND ALUMINUM WIRE IN SAID UNRESTRICTED PORTION OF SAID INSULATOR, A CAPACITOR HAVING AN ELECTRICAL ENERGY SOURCE FOR SELECTIVELY CHARGING SAID CAPACITOR, AND A SPARK GAP HAVING A TRIGGER FOR SPARKING SAID SPARK GAP TO CONNECT SAID CAPACITOR SUDDENLY WITH SAID METALLIC MEANS ACROSS SAID SPARK GAP, SAID WIRE HAVING A THIN CROSS-SECTION IN SAID INSULATOR BETWEEN SAID FIRST ELECTRODES WITH ELECTRICALLY HEATS AND EXPLODES INTO SAID CHAMBERS IN THE FORM OF A DENSE, RAPIDLY EXPANDING, CURRENT CARRYING, CONDUCTING METAL WHICH PENETRATES SAID INSULATOR, FORMS A HOLE THEREIN, IS CONFINED THEREBY SUDDENLY TO FILL SAID REACTION CHAMBERS BETWEEN SAID FIRST ELECTRODES WITH A THICK ARC AND WHICH