Vazdesky engines

Vazdesky energy is certainly one of the greatest inventions of all time. It is, in fact, the first truly clean form of energy used by man. Accidentaly discovered by Professor Vazdesky, it can be stored in batteries of any material (as long as it is sufficiently resistant) and of any size. The energy thus stored and released is not polluting in any way whatsoever. With Vazdesky batteries you can feed any device, from a watch to a huge spaceship, at virtually no cost.
What you can see in the picture below is the usual enormous double-battery Vazdesky engine installed on spaceships. The batteries are the two green luminescent tubes, which look exactly like that also when they're built in smaller sizes. There's a difference between batteries above three meters in length and the smaller ones, however, as you can read further below.
The green creatures you can see on the left develop spontaneously in the liquid that generates the Valdesky energy. However, this only happens in batteries three meters in length and above (those normally used in trains, spaceships, factories etc). Nobody knows how or why this happens, it just does.
But there's more: these creatures seem to have a soothing effect on the human soul, al you have to do is sit or lie down near a big battery, and you will just feel relaxed and positive. We use the term "soul" as no physical effect has ever been detected - the body's and the brain's chemical or electrical functions show no alteration at all. Therefore, don't think of this as a kind of drug, as it is not. It is closer to a sort of "cosmic comfort" that these creatures donate.
This energy and the creatures that live in it may actually be one of the most marvellous gift from the universe humanity ever received.