string theory. Three scenarios are in our view in principle possible. Either, both approaches adress the same phenomena in different languages, or they deal with them on different scales of resolution of space-time. Be that as it may, we think that our observation that the true ground state of our quantum vacuum seems to be what we call a wormhole space (see section \[worm\]) is an aspect which is not apparent in the original string theory approach and may be helpful to fix the proper ground state in string theory.

In [@Bekenstein2] Bekenstein remarked that the deeper meaning of black-hole entropy (BH-entropy) remains mysterious. He asks, is it similar to that of ordinary entropy, i.e. the log of a counting of internal BH-states, associated with a single BH-exterior? ([@Bekenstein1],[@Bekenstein3] or [@Hawking1]). Or, similarly, is it the log of the number of ways, in which the BH might be formed. Or is it the log of the number of horizon quantum states? ([@Hooft1],[@Susskind1]). Does it stand for information, lost in the transcendence of the hallowed principle of unitary evolution? ([@Hawking2],[@Giddings]). He then claims that the usefulness of any proposed interpretation of BH-entropy depends on how well it relates to the original 