Khayyam measured the length of the year as 365.24219858156 days. Two comments on this result. Firstly it shows an incredible confidence to attempt to give the result to this degree of accuracy. We know now that the length of the year is changing in the sixth decimal place over a person's lifetime. Secondly it is outstandingly accurate. For comparison the length of the year at the end of the 19th century was 365.242196 days, while today it is 365.242190 days.

And when like her, oh, Saki, you shall pass Among the Guests Star-scatter'd on the Grass, And in your joyous errand reach the spot Where I made One - turn down…

Yon rising Moon that looks for us again - How oft hereafter will she wax and wane; How oft hereafter rising look for us Through this same Garden - and for one …

Ah, Love! could you and I with Him conspire To grasp this sorry Scheme of Things entire, Would not we shatter it to bits - and then Re-mould it nearer to the H…