GIGO

Stretching Time

It's not just physicists who understand the relativity of time -- anyone who has sat in a dentist's chair or waited for a child's birthday guests to turn up knows that time can stretch or compress in a startling fashion. It possibly tells us more about how we view the world than how it actually is.

My five-year-old's time-line is somewhat logarithmic with the three main dating points being "now", "when Queen Elizabeth (the First) was alive" and "when the dinosaurs were around". Trying to give him a sense of the increase in distances between those points is a challenging task. Few of us ever really appreciate the vastness contained within a million, whatever unit we care to attach to it.

While a sense of history has helped develop our time sense, it is science and, as a consequence, technology, which constantly reminds us of the relative nature of time. To a software engineer, seconds are vast expanses to be filled with ever-faster routines; to a geologist, millennia can offer a time-scale too swift to be useful. Beech forests grew in Antarctica a breathtakingly short three million years ago; follow the swift flight of a dragonfly across a river and you're watching a dance that has remained essentially unchanged over the last 300 million years.

We sit through the sweltering heat of an El Niño summer and talk about how the weather is changing, but we need to think about whether the time-scale of a couple of years, a couple of decades or even a couple of centuries is an appropriate one, and what implications that has for what actions -- if any -- we can and should undertake.

We need to strike a balance between an awareness of our relative insignificance in the Earth's time-line, with the consequent fatalism that can engender, and the sense that we are somehow responsible for all the environmental woes that befall us.

We do well to become familiar with the range of time-scales and to appreciate the sort of impacts we are responsible for in our own extremely brief time on this planet, both in a personal, individual sense and as part of the broader society of humankind.

Vicki Hyde is the editor of New Zealand Science Monthly.