It's about a minute

Editors note: Those of us who were lucky enough to stick around this summer were treated to 60-second lectures presented at lunchtime by members of the Penn faculty and one University president. While not every speaker made it under the one-minute mark, all nine of them dealt with their chosen subjects with wit and erudition. Since time is of the essence, we decided to run two of these lectures, both of which dealt with...well, you get the picture.

We know the Earth is 4.5 billion years old. We seek a metaphor to help us grasp the immensity of that sweep of time.

[Unwrapping roll of toilet paper] Consider a standard roll of toilet paper 1,000 sheets, each 4.5 by 4.5 inches. Let each inch represent one million years of Earth history.

Since we dont have time to unroll it, imagine we have rolled up the toilet paper, and we are looking at the last square, the last 4.5 million years, the time of our bipedal primate ancestors...

The last 50,000 years, or 1/20th inch, represents the history of our species, Homo sapiens, and [snipping off 1/100 inch with giant scissors] the last 10,000 years, or 1/100th inch, is the span of recorded human history.

We know that our behavior today is influenced as much by our biological heritage as by our cultural legacy...

If we hope to make sense out of these troubled times... if we hope to project present trends into an uncertain future... if we hope to understand the last 10,000 years of human history, we must study the 4,499,990,000 years that came before.

This [holding up the 1/100th inch] may indeed become the best of times. To make it so, [holding up the rest of the roll of toilet paper] we must learn what we can about the rest of time.

Robert Giegengack is a professor of earth and environmental science and the director of the Center for Environmental Studies. This lecture was presented June 16.


Associate Professor of Classical Studies Joseph Farrell made it snappy during his 60-second lecture on July 21.

Photo by Daniel R. Burke

I only have a minute; and we all know just how long that is. But it wasnt always so. The Romans had no minute, only an hour that was longer in the summer and shorter in the winter. Not till the Middle Ages did people develop hours, minutes and seconds of fixed length. But as time measurement got more accurate and more precise, scientists came to recognize many minutes, including the solar minute, the sidereal minute and finally the atomic minute. Of course, none of these minutes is exactly the same length as any of the others, and relativity complicates the very idea that units of time can be fixed.

More important is perceptual time: Children perceive time as passing more slowly than adults. In perceptual terms, we live as much as half our lives before reaching adolescence. We need a minute that can account for differences in perception just as much as we need the standard minutes that we use to measure out our days.

Id like to say lots more about this and other kinds of flexible minutes, but I have to stop: My minutes up.

Joseph Farrell is an associate professor of classical studies and chairman of the Graduate Group in Classical Studies. This lecture was presented July 21.

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Originally published on September 2, 1999