In your opinion, what is the greatest invention/discovery for ALL mankind and why?
My vote goes to sterilizing canned food. The first was steam or heat but the reason it gets my vote is thise living in arid climates can live at an oasis or dig a well. This gets them water but their soil provides no crops or grazing for cattle (on a large scale.) Once the need for water is resolve, the second need is food. No refrigeration means the only other source od preservation was huge amounts of salt. this causes a greater need for water and limits food supply. Along comes sterilizing canned food and no fridge needed, a greater variety of food and limited spoilage was a great assist to the impoverished even in temperate climates.
Your turn!!