Dr dear Dr: Is there a reason why the Old Testament Bible fixes the length of an average life span at 70 or 80 for those who are strong?

True, the Old Testament Bible makes this remark and today it now seems remarkable and optimistic at the best of times. Also, in the High Middle Ages, the average life expectantcy was hovering around 40 to 45 at the best of estimates, and this was coloured largely by poor hygiene and the omnipresence of the dust-mites on rats that caused the Black Death in 1347, this reality in that timeframe caused life expectantcy to reduce to 40 for many, many years, as more and more villages and towns grappled with the disadvantages of the health issues of ordinary life. Since the pandemic that optimistic figure from the Bible seems so different now. Wisdom chapter 3 reminds us that “in the eyes of the unwise, they did only appear to die, their going looked like a disaster, but their hope was rich with immortality” so not every text of the Old Testament was pessimistic about the average life spans of the peoples in those times. It was clear that in the very hygienic and ablution conscious conditions of life among the Israelis with their exaggerated traditions of the washing of pots and pans and ablutions right up to the elbows on re-entering the privacy of house every time one had been out to town or city, that the terms of the Bible were regarded as an average, “70 or 80 for those who are strong.” Nowadays in the west what with the pandemic striking down those averages since 2019 and 2020 and 2021, we can be happy to reach 60 if we are lucky, especially as the pandemic bites into those optimistic assessments of the past. Such is life, such is the passing into life, such is pandemica. That is the science of the issue. The rest is history.