Are there any curiosities about time that few know about?

1. The oldest known object in the universe is a galaxy called z8 GND 5296. It's 13.1 billion years old – only about 700 million years younger than the universe.

Galaxy z8 GND 5296

2. The oldest known object on Earth is a 4.4-billion-year-old crystal, a zircon, that was found in Jack Hills in Western Australia. It's only 160 million years younger than the Earth itself.

3. Next week, your watch will be one second slow. The fact that the Earth's rotation is slowing, and therefore the days are getting longer, means that our 24-hour day is very slightly off. Every so often, the International Earth Rotation Service, the body which regulates astronomical time, has to add a second – called a "leap second" – to the clock to keep things regular. The next one is on June 30, 2015.

4. Time might be grinding to a halt. Distant galaxies appear to be moving faster than nearby ones, suggesting that the universe is accelerating as it expands. The usual theory to explain that is a mysterious force in the universe known as "dark energy". But a Spanish physicist has proposed an alternative possibility, that the further-away, older galaxies only seem to be moving faster because in the past, time was faster. If he's right, in a few billion years, "everything will be frozen, like a snapshot of one instant, forever".

5. The reason clocks show the same time across whole countries is that it makes train timetables easier to run. Until the 19th century, towns set their clocks by the local noon, so clocks in Bristol would be 11 minutes behind London. That meant people kept missing their trains, so railway companies began using standard, London-based UK time, starting with the Great Western Railway in 1840.

6. 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.

7. 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.