By Patrick J. Kiger

Chances are, you probably remember exactly what you were doing on the morning of September 11, 2001, at the moment when you first learned about the attack on the World Trade Center. And if you were one of the millions who stared in horror at the television images of smoke billowing from the crippled towers, you undoubtedly can recall the intense, excruciatingly painful surge of grief and anger and sadness that you felt.

You may be surprised, however, to learn that Princeton University researchers believe that so many people around the world were affected in the same way that their collective mental energy actually altered the operation of computers.

Those findings, which have aroused some controversy in the scientific world, were produced by Princeton’s Global Consciousness Project, whose goal is to determine whether, and if so to what extent, human consciousness—that is, our minds’ awareness of the world in which we exist—can synchronize and act coherently.

“I think the data are pretty much indisputably in support of that we do interconnect, we interact, we’re not isolated,” the project’s director, Roger Nelson, explains in this video on the organization’s website. “My consciousness, inside my skull, and yours, extend out into the world, and they intermix. We’re a little like neurons, in a giant brain, that we know nothing about.”

Since the 1990s, the Princeton researchers have been trying to measure this hypothetical giant, humanity-encompassing hive mind, by tracking the effect of events on a network of computers around the world that are set to churn out random strings of numbers. But the world paid relatively little attention to their efforts, until Nelson published this paper, “Coherent Consciousness and Reduced Randomness: Correlations on September 11, 2001,” in the Journal of Scientific Exploration in 2002. It reported that the traumatic terrorist attack, which caused a powerful outpouring of emotions across the planet, had a measurable effect upon the network’s computers that was extremely unlikely to have been caused by chance.

“The September 11 event is widely known as one of the things that is kind of emblematic of the global consciousness project,” Nelson explains in the video. “It’s in some respects, the biggest event that we’ve looked at. It turns out, in fact, it manifested the potential to change the world. We did an awful lot of analysis on that. Some of that analysis is just striking in how the data looks. There are some odd features.”

The REG data gathered on September 11 is an example of this effect. The researchers looked at a period beginning 10 minutes after American Airlines Flight 11 crashed into the North Tower at 8:46 a.m., and ending four hours afterward. To visualize the data, they plotted the cumulative deviation of a Chi-square test from chance expectations. If the data collected in such an experiment doesn’t show an effect, it will draw a random path around the horizontal line of expectation, with no clear trend. (In probability and statistics lingo, this is called a “drunkard’s walk.”)

Instead, according to Nelson’s paper, researchers found “a fluctuating deviation throughout the moments of the five major events, during which ever-increasing numbers of people around the world are hearing the news and watching in stunned disbelief.” He calculated that the odds against happening by chance 35 to one.

To validate their results, the researchers compared their findings to pseudo-data that they generated for September 11, and plotted in the same format. The simulated results, in contrast to the real ones, showed no long sustained periods of strong deviation from the expectation.

The researchers found an even more unsettling peculiarity in the data. “One of those measures started changing four or five hours before the first plane hit,” Nelson explains in the video.

That might seem to suggest the possibility that humans possess not just a collective consciousness, but also some degree of precognition–an even more controversial hypothesis, if that is possible. (From the National Geographic Channel’s Mysterious Science blog, here’s a post from earlier this year on the work of retired Cornell University psychologist Darryl J. Bem, who published this provocative scientific journal article on his experimental findings that humans have some ability to predict events before they occur.)

Just as Bem’s work came under withering attack, some also have dismissed the Princeton researchers’ findings about collective consciousness and the September 11 attacks. Here, for example, is a critique:

“Was There Evidence of Global Consciousness on September 11, 2001?” written by Jeffrey D. Scargle, a scientist at NASA’s Ames Research Center in California. “I personally disagree with the [Princeton scientists’] conclusion that anomalous effects have been unequivocally established,” he writes.

But the Princeton researchers’ case is bolstered by the data that they’ve amassed on other traumatic events in the decade that followed the September 11 attacks, including the July 22, 2011 terror bombing and shooting spree in Norway that killed 87 people, and the July 23 high speed train crash in Wenzhou, China, that took 40 lives and evoked widespread sorrow and outrage after allegations of railroad corruption and unsafe equipment surfaced. In both of those events, researchers found a slight but verifiable statistical effect that they could attribute to consciousness synchronization.