13/07/2026
How Many Seconds in a Day? A Year? And, thinking about it, What exactly is a year?
Matt Parker, talking about eclipses, gives some insight into why a year is much more complicated than it appears. A year is 365 days, surely? Or 365¼ days? “Unfortunately it’s not that simple”.
Solar Eclipse Maths and the Cosmic Coincidence of the Saros Cycle
There was a solar eclipse on the 20 March 2015 and so I thought I'd...
13/07/2026
What’s the next term in the sequence?
a) Possibly the most famous sequence in the history of maths. This is how it begins
1, 1, 2, 3, 5, 8, 13, 21, …
What number is next? And why?
b) Letters can be in sequence too. What is the next letter in this sequence and why? Incredibly simple when you see it. Seemingly impossible when you don’t.
O, T, T, F, F, S, S, …
What letter is next? And why?
c) And one of my favourites, because in many ways a small child has more chance of getting this right than a Professor of Mathematics. What is the next number in this sequence?
1, 11, 21, 1211, 111221, 312211, …
What number is next? And why?
Why the sunflower? It’s all to do with the first sequence.
