Encyclopedia > 20th century BC

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20th century BC

(21st century BC - 20th century BC - 19th century BC - other centuries)

(3rd millennium BC - 2nd millennium BC - 1st millennium BC)


Significant persons:

Inventions, Discoveries, Introductions:

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Talk:Gravitational constant

... known as well as, say, the speed of light or Planck's constant, but surely it's known to better than two places? Cite? (And if so, please clarify whether that means the ...