show more 26wks1dy pregnant. Why is it that in a singleton pregnancy, full term is considered 37wks, however in a twin pregnancy, full term is considered 35wks, & in a triplet pregnancy, full term is considered 31wks? Don't the babies in all pregnancies grow/develop at the same rate?hy is it that in a singleton pregnancy, full term is considered 37wks, however in a twin pregnancy, full term is considered 35wks, & in a triplet pregnancy, full term is considered 31wks?
For orbits around the Earth, see Geocentric orbit. In astronomy, the geocentric model (also known as geocentrism, or the Ptolemaic system) is a superseded description of the universe with the Earth at the center. Under the geocentric model, the Sun, Moon, stars, and planets all circled Earth.
And by classical antiquity, scientists had formulated ideas on how the motion of the planets occurred, and how all the heavenly orbs fit together. This gave rise to the Geocentric model of the universe, a now-defunct model that explained how the Sun, Moon, and firmament circled around our planet. The notion that the Earth was the center of the Universe is certainly an understandable one.