Impressive ancient construction does not require a forgotten advanced civilization. Technical knowledge does not accumulate in a straight line because societies can lose methods and parts of earlier foundations. Roman concrete provides the example: researchers have only recently recovered a better understanding of a material people long tried to reproduce. Gaps in technological transmission alone do not prove the existence of an otherwise unsupported civilization.
Notable Point · 1:11:27-1:12:25
Why lost technology does not prove a vanished advanced civilization
Roman concrete demonstrates that societies can lose effective methods and technological history need not advance continuously.