Du ignorerar det faktum att varje min innehåller en liten mängd handwavium . I Trek-universum är det uppenbarligen möjligt att extrahera rimliga mängder energi från vakuumet själv och massan tillhandahålls till den berörda gruvan av sina grannar (som sedan använder den energi som de har extraherat för att skapa mer massa):
The replicator system was designed to accommodate a swarm detonation of up to twenty mines and still maintain the total shell. The replicator was a kludge of Cardassian and Starfleet types and included a raw-matter supply container able to contribute enough mass to build one-sixty-fifth of a complete mine. Mass for any one new mine was transported through the replicator's subspace emitters from as many mines away as was necessary. In a bucket-brigade system. As distributed over the entire shell, enough mass was stored to replace over 2,500 mines.
In the event the mass supply dwindled below 85 percent, the replicator sections were designed to extract particles from the zero-point vacuum domain to replenish the system. The threshold was set deliberately high because of the long lead time required to produce small numbers of particle pairs. - DS9: Technical Manual
Teoretiskt kunde Cardassiansna ha överväldigat systemet genom att ständigt kasta saker på minfältet, men i praktiken kan gruvorna fungera obestämt, ersätta brutna gruvor och ladda upp sig själva.