成人快手

However much we might try to resist its incessant march, time is central to almost everything we do, from knowing when to sleep or use the toilet, to timing our movements so that a kiss doesn't become a head butt.

Although biologists haven't been able to agree how they work, it seems clear that the body has a number of internal timing systems to help us judge the passage of time. Sometimes, however, our natural clocks seem to run fast or slow. Not because our internal clocks themselves are faulty, but because our perception of the passing of time seems to vary with circumstances.

When time seems to fly or drag, it's nothing to do with our internal clock speeding up or slowing down. It's how the brain processes time-related information that generates the illusion. When a person's life is in danger, a phenomenon known as 'time-dilation' can occur. This is when, during a car crash for example, time seems to slow down or become frozen.

In these cases the body's internal clock speeds up when facing a potential catastrophe, so that it can take in more information more quickly and function more effectively in an emergency.

This is also a phenomenon actively sought by elite sportspeople, when they get 'in the zone'. Some of the chemicals in the brain, such as dopamine, can affect our perception of time. Deficiencies in these chemicals can lead to brain disorders.

In today's technological age, the body's natural clocks are being hijacked by timetables, schedules and diaries. By paying more attention to our watches, rather than our internal clocks, could we be losing touch with time as it should be perceived?