What is armchair anthropology? Problems that arise?

Also it was an American anthropologist that brought this to mind in the person of Franz Boas and this gradually helped to curb the problems of "arm-chair" anthropology such as being subjective/bias,ethnocentric and making value judgement amongst many others.

Explanation:

giant impact theory - the moon was formed from the collision between earth and another mars-sized body.

colliding planetesimals hypothesis - the moon was formed from the same cloud of material as earth.

capture hypothesis - the moon was locked into orbit by earths gravity as it was passing by it.

accretion hypothesis - the moon was formed from collisions and combining of planetesimals.

i think this is right, if not and you know better let me know.

the answer to your question is,

old stone age.

-mabel < 3