Free-falling scientists seek to slow time

6 days ago

WASHINGTON (AFP) — US scientists lept off a 150-foot (45-meters) high platform in a hair-raising bid to test if time really does slow down in a crisis as film-makers like to show, a new study said Wednesday.

"People commonly report that time seemed to move in slow motion during a car accident," said David Eagleman, assistant professor of neuroscience and pyschology at Baylor College of Medicine in Houston, Texas.

"Does the experience of slow motion really happen, or does it only seem to have happened in retrospect? The answer is critical for understanding how time is represented in the brain."

When Eagleman and two graduate students found that roller coasters and amusement park rides did not provide enough thrills, they hit on the idea of using a controlled free-fall system.

"It was the scariest thing I have ever done," admitted Eagleman, after he dropped backwards off a 150-foot high platform, falling 100 foot (30 meters) in free-fall before landing in a suspended net.

Known as Suspended Catch Air Device diving, participants are not attached to ropes and fall at a rate of some 70 miles (112 kilometers) an hour in their three-second fall.

But unlike Neo, the hero of "The Matrix" movies who is able to dodge assailants blows and bullets by bending time in his computer-simulated world, Eagleman found that what happened was the volunteers only believed their fall was longer than it really was.

The experiment was divided into two parts. First the researchers asked volunteers to show on a stopwatch how long someone else's fall had taken, then how long their own fall took.

All the participants believed their own fall had taken some 36 percent longer, according to the study published in the Public Library of Science One.

Then participants were fitted with a special watch called a perceptual chronometer which showed flickering numbers. The idea was that if their perception of time really did slow down during their fall, then the participants would be able to decipher the digits.

But while the volunteers could read the numbers shown at normal speeds, they could not make out those which had been speeded up.

"We discovered that people are not like Neo in 'The Matrix', dodging bullets in slow-mo. The paradox is that it seemed to participants as though their fall took a long time," Eagleman said.

Researchers believe that during terrifying events a part of the brain called amygdala becomes more active, adding extra memories that accompany those normally dealt with by other parts of the brain.

"In this way, frightening events are associated with richer and denser memories. And the more memory you have of an event, the longer you believe it took," said Eagleman.

"It can seem as though an event has taken an unusually long time, but it doesn't mean your immediate experience of time actually expands. It simply means that when you look back on it you believe it to have taken longer."

The same phenomenon is true when children look back on their summer holidays and think they went on forever, while their parents who had seen it all before thought the time had flown, he added

עוד בנושא אפשר למצוא באתר של דייויד איגלמן:

http://neuro.bcm.edu/eagleman/