#44 Elevator pitch
On the way back from a party the other day, my daughter and I got into an elevator. I was holding a cup of water with an ice cube floating in it, while my daughter was admiring her helium-filled balloon as it floated above her on a slack string. Our only company in the elevator was a spider, dangling from the lift鈥檚 ceiling on a thin thread of silk. As the lift accelerated upwards, what did we see happening to the balloon, the ice cube and the spider?
Answer next week
#43 Dividing Grandma鈥檚 field
Solution
A fence passing through points A and B divides the area precisely in half and ensures two oak trees (green dots) are in each plot.
Any line that passes through point A (the centre of the rectangle that is formed by the top three squares) will divide that rectangle in half. The same is true of any line that passes through point B (the centre of the lower rectangle).
Points A and B can be found by folding or by drawing diagonals, so no measurement is required.
Quick quiz #36
1 What word, from ancient Greek for 鈥渁 changing鈥�, is used to describe when a cancer spreads from its original site?
2 How many officially recognised dwarf planets does the solar system have?
3 Thanks to the 鈥渕agic鈥� number of 50 protons in its nucleus, which chemical element has the greatest number of stable isotopes?
4 The dormant volcano Emi Koussi is the highest point in the Tibesti mountains, and also therefore in which unforgiving place on Earth?
5 The name of the warbler Sylvia undata means 鈥渨ave-patterned woodland sprite鈥�; what is its rather more prosaic English name?
Answers below
Quick Quiz #36
Answers
1 Metastasis
2 Five: Ceres in the main asteroid belt; Pluto, Makemake and Haumea in the Kuiper belt; and Eris, the most distant of all
3 Tin
4 The Sahara desert; the peak lies in northern Chad
5 The Dartford warbler, after two specimens found by ornithologist John Latham near Dartford in Kent