Austrian Marcel Hirscher in the men's giant slalom event at the FIS Alpine Skiing World Cup on January 9, 2010 in Adelboden. Photo: FRANCK FIFE/AFP/Getty Images.

Frozen in time, or speeding down a mountain? (Franck Fife / AFP/Getty Images)

By Marcelo Gleiser

"A watched pot never boils." We all know what this means: if you wait for an anticipated event with focused attention, time seems to drag on forever. Better to go and do something else. The same happens when you are a kid in school waiting for the recess bell to ring. On the other hand, the bell announcing the end of recess always seems to ring too fast.

Our sense of time can be very subjective. If your focus is not on the passage of time, that is, if you are engaged in doing something other than watching the clock, time seems to go faster.

As with many things in the brain, the sense (or perception) of time is not a simple matter. We do know that neurotransmitters such as dopamine and adrenaline alter our perception of time. Oliver Sacks, in his book Awakenings (also a well-known movie with Robin Williams and Robert de Niro), tells how patients suffering from rigid paralysis with symptoms similar to advanced Parkinson's disease awoke temporarily after taking L-dopamine, as if their brains, like a rusty engine that was oiled, suddenly clicked into the right sense-of-time gear.

There is also a genetic component to the sense of time. Plants, animals, fungi and bacteria, starting with the earliest, the cyanobacteria, share a similar circadian rhythm, the near 24-hour-long periodic reset of our brain and bodily functions. Fruit flies with a pathological sense of time have the same gene affected as humans with a sleep disorder named FASPS. If you doubt evolution and our shared common ancestry, this is an excellent reason for you to rethink your position.

Of course, there is also the notion that time is relative.

As Dr. Warren Meck and collaborators have shown, drugs such as cocaine also affect the sense of timing. The flow of information, the rate at which the brain collects and processes sensorial data, has a direct impact on how we sense time. As Aldous Huxley noted in his famous book Doors of Perception, mescaline, LSD and other hallucinogenic drugs make the whole notion of a regular passing of time pointless.

The same Dr. Meck from Duke University suggests a very interesting relationship between the sense of time and Einstein's special theory of relativity. According to the theory, two observers in relative motion will perceive the timing of events differently. For example, what can be simultaneous for one will not be for the other. (See my related post on 13.7)

From what I could understand of Meck's experiments, the brain may have different clocks working together but independently. These clocks will sense timings in different ways and only the context will select the "winner," that is, how we perceive the passage of time. Here, it seems that the many observers in relative motion live inside a single brain.

Who said that understanding time was simple?

I wonder if the relations between these inner-brain clocks change as we age. Everyone knows that time seems to pass faster as we get older. An obvious "explanation" is to say that it all depends on the fraction of your total life: for a 2 year old, one year is 50% of her life, while for a 65 year-old, it's a very small fraction of hers.

Apparently, the only way to slow down the passage of time -- discounting drugs and relativistic effects -- is to keep your brain as engaged as possible, always learning, always creating new memories. No one said it better than the Welsh poet Dylan Thomas

Do not go gently into that good night. Rage, rage against the dying of the light.

categories: Science and Culture

6:14 - January 31, 2010