Life of Pi
A group of mathematicians is campaigning for the mathematical constant pi to be replaced by tau, the latter being the ratio of the circumference to the radius as opposed to that of the circumference to the diameter. As tau is simply twice the value of pi (approximately 6.28) it won’t consume so many centuries to establish its value as pi.
— A value for pi is mentioned in the Old Testament relating to the construction of the Temple of Solomon around 450 bc. It sets a value of three, suggesting that the temple may have been very shoddily built. — In the 3rd century bc, Archimedes
calculated the value of pi to lie somewhere between 223/71 and 22/7, which is correct to three decimal places.
— The 5th-century Chinese mathematician Zu Chongzhi estimated pi at 355/113, correct to six decimal places.
— The real breakthrough came with a formula devised by a 17th-century British mathematician, which has enabled pi to be calculated by many thousands of places.
Power in a union
Public-sector union leaders are threatening strike action over their members’ pay and pensions. How much are they paid?
Derek Simpson, Unite £186,626
Dave Prentis, Unison £130,109
Matt Wrack, FBU £117,230
Bob Crow, RMT £113,011
Mark Serwotka, PCSU £112,634
Provincial wealth
China, per capita, is poorer than anywhere in the West. How do Chinese regions compare to other countries, on that basis?
GDP per head
Macau $72,110
United States $47,284
Hong Kong $45,580
United Kingdom $34,920
Shanghai $22,983
Poland $18,936
Brazil $11,239
Shandong $10,914
Sources: CEIC, IMF
On the runways
It was revealed that planes spend a total of 55 hours every day circling Heathrow waiting to land. How many runways do other large airports have?
Annual passengers………….. Runways
88m……………Atlanta………………..5
66m………….Heathrow………………2
65m………….Beijing Int……………. 3
64m……..O’Hare, Chicago………..7
62m…………….Tokyo………………..4
58m…………Paris CdG……………..4
Source: Airports Council International
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