Όχι, δεν γνωρίζω δόκιμη μετάφραση, αλλά είναι η πρότασή μου, βασισμένη σε κείμενο της Thomas και προτιμώ, από μια γεωλογική μάλλον παρά ιστοριολογική προσέγγιση, το μετατοπιζόμενο χάσμα από το μετατοπιζόμενο κενό.

Ενδιαφέρον ερμηνευτικό κείμενο:
Anthropological work on oral tradition provides eloquent testimony to the existence of that is called the ‘floating gap’ and to the ‘hourglass effect’ which is closely associated with it. In societies where knowledge of the past is dependent upon memory and oral tradition, there tends to be a clustering of traditions and memories around the very distant past and the very recent. This seems to be the case in whatever way the oral traditions are preserved, and whether or not those societies have some knowledge of writing. Many traditions may exist, for instance, about the first origins, and about the most recent two or three generations. The very recent past may be remembered simply because it was recent, within living memory: there are numerous examples where knowledge of the past peters out after three or four generations, unless there is some particular incentive to go back further. Yet at the same time the same society’s traditions may have much to say about very remote times, times of origin, which have an important explanatory role–and there is a 'gap' in between. This gives a curious effect to the external observer, though to the people concerned it may be unremarked: a clustering of traditions at distant ends of a supposed chronological line with little information of any kind in between. Hence a couple of bulges at top and bottom with a tiny waist in the form of an hourglass. The periods in between become forgotten if they are not thought important in some way, and tend to fall out of the traditions, and the effect is to telescope the early and recent periods together. The intervening period ‘contracts’, or rather, since it is not perceived as missing, the early and recent past grow closer. The gap *moves* because as time progresses, the recent past that is remembered obviously moves forward in time too. Therefore the gap between recent and remote past can be said to ‘float’.
[Rosalind Thomas, Herodotus' Histories and the Floating Gap, in Nino Luraghi’s The Historian’s Craft in the Age of Herodotus, OUP USA, 2002]

ιστορικό χάσμα (historical gap):
Η ιστορική συνέχεια του "Ελληνισμού" αποτελεί ανυπόστατο ψέμα. Στο αποκαλούμενο "Βυζάντιο", που επίσημα ονομαζόταν Ρωμαϊκή αυτοκρατορία, υπάρχει *ιστορικό χάσμα* 11 αιώνων στην διάρκεια του οποίου αναδείχθηκε ένας εκβαρβαρισμένος Ρωμαϊκός και όχι Ελληνικός πολιτισμός, με χριστιανικό επίχρισμα
Στη σύντομη αναδρομή του στην ιστορία της βρετανικής επικυριαρχίας στην Κύπρο ο Ρόμπερτ Φισκ παραλείπει τον ρόλο των βάσεων στην τουρκική απόβαση του 1974 και με ένα *ιστορικό χάσμα* πετάγεται στο 1991.
... συνηθισμένο *ιστορικό χάσμα* ανάμεσα στα προϊστορικά και ιστορικά χρόνια...