What time is it?

When I was in elementary school I remember a teacher having us put our heads down on our desks and then asking us to sit up when we thought one minute had passed. I can't remember the pedagological reason for this exercise, it probably was just a way to keep us quiet for a few minutes. Some of us used the "1 one hundred, 2 one hundred" method of counting off the sixty seconds, others relied on their gut instincts. A few were able to hit the minute mark directly, but most of us missed one side or the other.

I'm sure we have all had the experience of feeling like time was either moving very quickly or very slowly. Last night in my exercise class the one minute of wall sitting felt like an hour, but the one minute of time I have for playing Bejeweled whizzes by. Why is that? How can we perceive time so differently when it is an objective measure?

Turns out our brains are not very good time keepers at all. I just read an article by Annalee Newitz in the Dana Foundation's Brain newsletter. She talks at length about the research on our ability to "tell time." Our bodies use an internal biological clock that doesn't run as consistently as an external, digital clock. So, while crossing a street may take 60 seconds, our body may register this as 50 "pulses" or 100 "pulses" depending upon what drugs (legal or illegal) we have taken to what other things we are paying attention to at the time. Our brains register these events as two different times.

With enough experience, we build up a probability distribution of these internal times. On average, our estimation of time will be accurate based on the normal distribution of times we have stored. But, sometimes we will pull from the distribution an outlier, a time that is out of step with the external world. As Annalee says, "Your intuitive sense of how much time something will take is taken at random from many distorted memories of objective time."

It reminds me of a quote I think I wrote about here once before, "decisions that people make for teh future are sometimes guided by erroneous evaluations of the past."

You have to wonder to what extent our predictions about the world and all of its components, are based on underlying distortions of some objective reality.


http://io9.com/5646561/how-do-you-really-know-what-time-it-is