There was a really good half-hour programme on Radio 4 today (you can hear it here). Tempus Fugit was an exploration of human perception of the passage of time. Not only did I find the subject absorbing but I also found the way scientists have tackled the subject remarkably inventive. For example, when we are intensely frightened (during a car accident, for example) we seem to percieve time going by more slowly than usual (a phenomenon known as "time dilation").. One researcher, Dr David Eagleman, devised an unforgettable experiment to see if it in fact we actually do.
Scary fairground rides turned out not to be scary enough to provoke the effect, so Eagleman took to dropping human guinea-pigs from a 150 foot tower and catching them in a net: three seconds of free-fall terror. Strapped to their wrist they had a device with lights on which flashed so fast they couldn't be seen to be flashing unless the person looking at them really was percieving time to be passing more slowly than usual. It made for great radio: they always say the difference between radio and television is that on the radio the pictures are better. It left me feeling quite dizzy.
The upshot of the experiment was that although subjects thought their perception of time had slowed down during the fall, the lights had not been seen to flash. Their minds were playing tricks on them. The latest theory is that time appears to slow down because of the way we lay down memories of frightening events. It's a shame, really. The idea that we really could slow down our experience of a passing moment was a very attractive one.
4 years ago