The Top 10: Things we don’t know we know

Amazing human abilities of which most of us are unaware

Never forget: to turn a bicycle to the left, you steer right first to stay balanced (Getty Images)

This list started with Ian Leslie (I recommend his newsletter), who cited a study that showed people can tell hot water from cold from the sound of it pouring. Tom Stafford confirmed it with an experiment with his family, and commented that it was like the order of adjectives.

1. We can hear the difference between hot and cold water. “The Archers uses hot water to make hot drinks because listeners can tell the difference between the sounds,” said Martin McDonald.

2. The order of adjectives. Mark Forsyth said in The Elements of Eloquence that JRR Tolkien’s first story, written at the age of seven, featured a “green great dragon”; he was discouraged when his mother told him it had to be a “great green” one. Thanks also to Stewart Slater and Paul A Davies.

3. The order of vowel sounds in repeated similar words. Always I-A-O. Bish bash bosh; ping pong; tick tock; dilly dally. It is called ablaut reduplication. Thanks to James of Nazareth and Akash Paun.

4. Rules of grammar. Most people wouldn’t know how to conjugate a verb, but they’d have no problem using the word in context. Thanks to Jonn Elledge and Martin McDonald.

5. Proprioception. We know the position of our limbs without seeing them, moving them or touching anything. Nominated by Dan Dennis.

6. Logarithms. The relative difference between 1 and 2 is equivalent to that between 5 and 10. Young children and even animals can intuit these differences, said Peter Sigrist.

7. Musical scales are ratios of frequencies. If you change key the ratios stay the same. Our brains can effortlessly process that and make it sound the same, said Dan Tench.

8. To turn a bicycle to the left, you steer right first to stay balanced. Another from James of Nazareth, with video.

9. When to wake up. Lots of people set an alarm but wake up before it goes off.

10. Finding water. Human noses are sensitive to geosmin, detectable at concentrations as low as 400 parts per trillion. It is a chemical given off by damp ground which explains the intense smell after a rainstorm. Possibly an evolutionary hangover from when finding sources of water was essential, said Stewart Slater.

Next week: MPs better known for other things, starting with Geoffrey Chaucer.

Coming soon: I’ll have another go at “feasts left untouched for enemies to enjoy”, such as President James Madison’s dinner in 1814, enjoyed by British troops before they set fire to the White House.

Your suggestions please, and ideas for future Top 10s, to me on Twitter, or by email to top10@independent.co.uk