Around 1200 BC, the Dorians, another Greek-speaking people, followed from Epirus. Traditionally, historians have believed that the Dorian invasion caused the collapse of the Mycenaean civilization, but it is likely the main attack was made by seafaring raiders (sea peoples) who sailed into the eastern Mediterranean around 1180 BC. The Dorian invasion was followed by a poorly attested period of migrations, appropriately called the Greek Dark Ages, but by 800 BC the landscape of Archaic and Classical Greece was discernible.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"):  Is it believed that they truly aren't responsible in full for the collapse?
Ah, so.. unanswerable

Hunting and gathering was humanity's first and most successful adaptation, occupying at least 90 percent of human history. Following the invention of agriculture, hunter-gatherers have been displaced or conquered by farming or pastoralist groups in most parts of the world.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What was the first way humans used to find food?
Ah, so.. Hunting and gathering

Another potential weapon system for anti-aircraft use is the laser. Although air planners have imagined lasers in combat since the late 1960s, only the most modern laser systems are currently reaching what could be considered "experimental usefulness". In particular the Tactical High Energy Laser can be used in the anti-aircraft and anti-missile role. If current developments continue, some[who?] believe it is reasonable to suggest that lasers will play a major role in air defence starting in the next ten years.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): When did personnel first start thinking about using lasers in combat?
Ah, so..
the late 1960s