If two things are correlated, there is causation.
I am confused, that doesn't seem to be true.
Consider a sine wave. It can be observed in a great number of phenomena, from the sound produced by a tuning fork to the plot of temperature in mid-latitudes throughout the year. All measurements which produce something resembling a sine wave are correlated. Remember that correlation (well, at least Pearson's correlation -- I assume that's what is meant here) is invariant to linear transformations so different scale is not a problem.
All measurements which produce something resembling a sine wave are correlated.
Only if the frequencies are identical. In that case, follow the improbability and ask how they come to be identical.
People want to tell everything instead of telling the best 15 words. They want to learn everything instead of the best 15 words. In this thread, instead post the best 15-words from a book you've read recently (or anything else). It has to stand on its own. It's not a summary, the whole value needs to be contained in those words.
I'll start in the comments below.
(Voted by the Schelling study group as the best exercise of the meeting.)