Perceptual Chronometer
From BBC News "Time Out of Mind"
By Annabel Gillings
"...people also speak of "time flying" when they're enjoying themselves, or slowing right down in perilous situations such as car crash.
But is there any real distortion of perceived time here, or are people re-inventing their experiences after the event?
Psychologist Dr David Eagleman, of the University of Texas, recently set out to nail this assumption, and a BBC film crew was there to record it. He asked volunteer Jesse Kallus to perform a terrifying backwards free-fall of 33 metres.
If the anecdotes are correct, Jesse's perception of time would be slowed by the terrifying experience. But how could one monitor such a thing?
Mr Eagleman came up with a cunning device: the "perceptual chronometer", a wristwatch-like device which flicked blindingly fast between two LED screens.
Normally the flicker would be so fast Jesse could only see a blur. But if time slowed down for him, he might be able to discern the two different screens and read a random number on one of them.
"There's no way to fake this test," says Dr Eagleman, "because if time is not running more slowly, they can't see the sequence."
All Jesse had to do was jump, and read. As he ascended the 33ft metal cage no-one seemed to believe this curious experiment might work.
When Jesse landed, he noted he had seen "98". Dr Eagleman checked. In fact the number was 96. Not quite spot-on, but the two numbers look very similar on a digital screen.
"I would have loved it if he had seen the numbers exactly," says Dr Eagleman. "But this at least suggests to me that he's able to take in information faster than he was before".
Further jumps got similar results - all suggesting that time did seem to slow down for Jesse during the jump.
So while time on the clock may be constant, the time in one's brain is elastic and personal - something to remember in a boring meeting when time seems to grind to a halt. Time is not simply a fourth dimension in which we exist. It's something we, at least partly, create in our minds."
By Annabel Gillings
"...people also speak of "time flying" when they're enjoying themselves, or slowing right down in perilous situations such as car crash.
But is there any real distortion of perceived time here, or are people re-inventing their experiences after the event?
Psychologist Dr David Eagleman, of the University of Texas, recently set out to nail this assumption, and a BBC film crew was there to record it. He asked volunteer Jesse Kallus to perform a terrifying backwards free-fall of 33 metres.
If the anecdotes are correct, Jesse's perception of time would be slowed by the terrifying experience. But how could one monitor such a thing?
Mr Eagleman came up with a cunning device: the "perceptual chronometer", a wristwatch-like device which flicked blindingly fast between two LED screens.
Normally the flicker would be so fast Jesse could only see a blur. But if time slowed down for him, he might be able to discern the two different screens and read a random number on one of them.
"There's no way to fake this test," says Dr Eagleman, "because if time is not running more slowly, they can't see the sequence."
All Jesse had to do was jump, and read. As he ascended the 33ft metal cage no-one seemed to believe this curious experiment might work.
When Jesse landed, he noted he had seen "98". Dr Eagleman checked. In fact the number was 96. Not quite spot-on, but the two numbers look very similar on a digital screen.
"I would have loved it if he had seen the numbers exactly," says Dr Eagleman. "But this at least suggests to me that he's able to take in information faster than he was before".
Further jumps got similar results - all suggesting that time did seem to slow down for Jesse during the jump.
So while time on the clock may be constant, the time in one's brain is elastic and personal - something to remember in a boring meeting when time seems to grind to a halt. Time is not simply a fourth dimension in which we exist. It's something we, at least partly, create in our minds."