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1. Time passes faster for your face than for your feet (assuming you're standing up). Einstein's theory of relativity dictates that the closer you are to the centre of the Earth, the slower time goes – and this has been measured. At the top of Mount Everest, a year would be about 15 microseconds shorter than at sea level.


2. A second isn't what you think it is. Scientifically, it's not defined as 1/60th of a minute, but as "the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom".

3. What you think of as a day – how long it takes the Earth to rotate – isn't 24 hours. It's 23 hours, 56 minutes and 4.2 seconds. The reason it's 24 hours from sunrise to sunrise is because every day the Earth moves further in its orbit round the sun – and the change in its position lengthens the day slightly.

4. When the dinosaurs were alive, there were 370 days in a year. The Earth's spin is getting slower because the moon's gravity is acting as a drag, so days are getting longer, by about 1.7 milliseconds per century.

5. The smallest standard scientific measure of time is the "Planck time". It takes you about five hundred and fifty thousand trillion trillion trillion Planck times to blink once, quickly.

6. On Mercury, a day is two years long.

7. There's no such thing as "now" as far as physics is concerned. Space and time are fluid, affected by gravity and your speed. Einstein put it like this: "For us physicists, the distinction between past, present and future is only an illusion, however persistent."

8. Because light takes time to reach us, everything we see is in the past. The sun you can see out of the window is 8 minutes and 20 seconds old. The light from our nearest star, Proxima Centauri, is 4 years old.

9. New experiences really do seem to be longer in the memory than familiar ones. It's called the "oddball effect", and it seems to be why time feels like it's going faster as you get older – because more stuff is familiar to you.

10. Time passes slower the faster you move. If you flew to the star Sirius at 99% of the speed of light, then flew back again, the people you left behind on Earth would have aged more than 17 years. But you would have aged less than two and a half years.