#18 Cable on the moon
It is the year 2100, and the Moon Colonisation Programme is well-advanced.
A power cable is being laid all the way around the moon鈥檚 equator. The original plan was to put the cable on the moon鈥檚 surface, but it has been suggested that instead it should be buried in a trench that is 1-metre deep. This will make it safer and will also save on the amount of cable needed.
How much shorter will the cable be if it is buried in this way?
Answer next week
#17 Which flipping year?
Solution
The date with the biggest flipping difference since the Romans conquered Britain was, fittingly, 1066, the year of another invasion.
9901 鈥� 1066 = 8835.
The digits that are flippable on an old-style calculator display are 0, 1, 2, 5, 6, 8 and 9.
Quick Quiz #17
1 With which cosmological discovery are the names of Vera Rubin and Fritz Zwicky particularly associated?
2 What is the name given to materials engineered to bend light waves in particular ways in their interior, leading to potential applications such as Harry Potter-style 鈥渋nvisibility cloaks鈥�?
3 What distinction does the volcanic peak Chimborazo in Ecuador hold, one that puts Mount Everest in the shade?
4 A complete or partial third copy of which chromosome is the cause of Down鈥檚 syndrome?
5 With a maximum air speed approaching 400 kilometres per hour when diving, what is the world鈥檚 fastest bird?
Answers below
Quick Quiz #17
1 Dark matter
2 Metamaterials
3 It is the highest point on Earth鈥檚 surface measured from its centre, thanks to our planet鈥檚 equatorial bulge
4 Chromosome 21
5 The peregrine falcon, Falco peregrinus
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