[The Global Consciousness Project: Meaningful Correlations in Random Data]
TL;DR Pretty much scientists use a random number generator for a series of experiments. They use a machine to randomly spit out numbers, but their results are oddly structured during human tragedies. Before 9/11 they had a spike in their numbers at 4am EST. 4 hours before the first plane even struck. That was their highest spike in numbers to date, and this experiment has been on going for a couple decades.
[The Global Consciousness Project: Meaningful Correlations in Random Data]: http://noosphere.princeton.edu/