Communicating science

I recently read an article somewhere how versions of Pythagoras' Theorem were independently "discovered" in Egypt, India and China prior to its namesake. Why then do we associate it with a single Greek?

It is not uncommon for scientific and mathematical discoveries to occur multiple times. So who chooses the credit?

Communication plays no small part in this. The more widely a discovery is communicated, the more awareness there is of a result, the less chance that it will be repeated as if new. That means researchers can put their efforts into something new rather than wasting time on reinvention of the old.

Science communication shouldn't just be about promoting ideas for money and prestige, it should also be for ensuring that knowledge is accessible, not hidden away in some dark corner.