Time is of the essence. Time heals all wounds. Time flies when you're having fun... Such time-based platitudes are neverending. In fact, time is the most-used noun in the English language, so concerned are we by our position in it, our grasp of it — and its power over us.

The platitudes exist because they represent broad, if scientifically unproven, notions that time is elastic. Time does seem to fly by when we're having fun. Likewise, it stretches out ad infinitum when we're willing it to zip past and deliver us with birthdays, Christmas Day or that longed-for holiday.

Claudia Hammond, the psychology lecturer, broadcaster, and writer, has a better understanding than most of the ways that our perspectives on time can be morphed, manipulated and played with. Her new book, Time Warped, examines the myriad ways that time seems to change gear. Here, she explains (or disproves) some of the mysteries of time.

Time is determined by the body's circadian rhythms | FALSE

The circadian rhythms affect only our 24-hour day/night cycle. They have nothing else to do with our perception of time from moment to moment. It's a myth that they affect time. We do, however, run an automatic body clock. This can go out of sync, which is known as "free running" . This is common particularly in blind people, who are isolated from environmental time cues. In most of us, however , the circadian oscillations correct themselves using daylight.

Time speeds up as we get older | FALSE

People think that time speeds up when we get older. But it's not true that time at any one moment (ie second by second) gets faster. It's our experiences over days, weeks, months and years that seem to condense. There's no biological basis for the sensation that it speeds up. It's simply to do with our judgements on time retrospectively .

Time is money | TRUE

Social psychologist Robert Levine measured three things in 31 countries around the world to determine the tempo of life: the time taken to buy a stamp, average walking speed of pedestrians during rush hour, and the accuracy of clocks on the walls of banks. It followed that places such as New York and London had the fastest times. This suggests a connection between time and money, though it isn't known which came first — the culture of rushing around or the buoyant economy.

We can mentally time-travel | TRUE

We are the one animal able completely, at will, to throw ourselves backwards into the past or forwards into the future. The ability to conceive events that haven't happened yet is a crucial basis for our imagination. Amnesia sufferers lose the ability to imagine the future, as well as their ability to recall who they are or what's happened to them.

Time feels slower when you want something done fast | TRUE

Psychologists Chen-Bo Zhong and Sanford DeVoe conducted experiments that revealed that exposure to fast food, both visual symbols and actual food, increases feelings of impatience. We associate fast food with being in a hurry or a rush. This anxiety makes us feel time is going more slowly.

Our sense of time can be affected by biological conditions | TRUE

A high temperature (a fever) makes our perception of time change so it feels slower. American psychologist Hudson Hoagland's wife was lying in bed with bad flu and she allowed him to conduct time tests on her. Hoagland asked her to say when a minute had passed 30 times over a day. When her temperature reached 103F, she felt a minute was up after just 34 seconds.

--THE INDEPENDENT