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The inner planets like Earth formed initially from the coalescence of solids in the protoplanetary disc. The disc itself would have a similar overall composition to the Sun itself, but close to the protosun, the composition of the solids would be quite different. The high condensation temperatures of solids containing iron, silicon and oxygen mean that they ...


The composition of the Sun is close to the composition of the universe as a whole. It's the Earth that's the outlier. If you look up the elemental composition of the universe as a whole, you'll see numbers for hydrogen and helium almost identical with the ones for the Sun. Theory can predict the elemental ratios. The universe started out as entirely hydrogen,...


thinkers!There was a massive CHANGE in the obliquity of the ecliptic around 2300 B.C.This caused much physical upheaval,which settled down in the middle ages .When there was a "renaissance"meaning "rebirth". From what?


Star formation requires a continuous energy loss of the material in the proto-stellar cloud. This can only happen through inelastic collisions of the atoms/ions (with the kinetic energy lost radiated away). Now, inelastic (as well as elastic) collisions are most effective with regard to energy loss for particles of equal or similar mass. So hydrogen and ...

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