Why is the waiting room at a radio or television studio usually referred to as the green room?

The term green room comes from the theatre and has been used to describe the actors’ waiting room. There have been various suggestions as to why it is used; it’s certainly not because the walls are painted a restful shade of green. The most likely explanation is that in the Middle Ages the stage (for strolling players) was the green. The green room was at the side for actors waiting to make their entrance.

Charles Hope, West Horsley, Surrey

I understand that the Japanese language uses a large proportion of Chineses ideograms in writing. Is there a foolproof way or some shortcut to help one to distinguish which language one is faced with?

Japanese does use Chinese characters, but, like Korean, it has its own script as well. The differences between them are immediately apparent to people who have learnt any one of the three, but almost impossible to describe in words. Perhaps the best way to distinguish between them quickly, without learning one of the languages, is to look at articles on kana and hangul. A text that could be Chinese or Japanese or Korean but contains a large number of kana is Japanese and one with hangul is Korean; if it has neither it is Chinese.

Christopher Evans, Shipley, W Yorks

In print, modern Chinese, Japanese, and Korean are easy to distinguish at sight. In Korean, ideograms are lacking; in Japanese, they are interspersed with kana, modified ideograms consisting of at most a few elements, and those simple ones; and in Chinese only punctuation (the same symbols as those used in English) interrupts the columns of ideograms.

Alex Knisely, London SE5

How close to the Earth was the Moon when it came into being and what was the effect?

When it was formed, apparently after a collision between the proto-Earth and a body the size of Mars, the Moon must have been very close. But it must have been outside the Roche limit, which is about 41 times closer than the Moon is now (9,495 km). The Earth would have been rotating much faster, with a shorter day and huge ocean tides. The Moon itself would have orbited in a period of only about five hours.

Steuart Campbell, Edinburgh

The Bible refers many times to 40-day periods, and to the Israelites’ 40 years in the wilderness. Could this be linked to early Babylonian knowledge of the planet Venus moving in regular 40-year cycles, and of the Pleiades star cluster disappearing for 40 days a year?

In the Middle East 40 means not only four times ten but an indeterminate, but pretty large, number. Thus Ali Baba, hiding in his huge jar, probably could not count the thieves, but there were an awful lot of them. Similarly, in Isfahan, Iran, in the open hall known as Chihill Sotun — meaning Forty Columns — there are only 20 columns, but it looks a lot. So one may doubt whether in Noah’s time exactly 40 days of rain was enough to inundate “all the high hills that were under the whole heaven”. And, dare one ask, did Jesus really fast in the wilderness for 40 days and nights or just a very long time?

Nigel Hawkins, Warminster, Wilts

I was amazed to read Joan Langrognat’s reply (July 19). I have no knowledge of Turkish, but I can confirm that kirkek is not the Hebrew word for “a great many”, nor does it in any way resemble any Hebrew word.

Meirav Micklem, Worthing, W Sussex

Why is St Pancras always portrayed with parsley in a phial, particularly in Spain?

Stephen McClarence, Bristol

Why does our national sea area shipping forecast extend down to southern Spain, and do other countries’ shipping forecasts stray out of their home waters?

Chris Irwin, Dorchester, Dorset

Has anyone ever tamed and ridden a zebra?

Ida Staples, Huntingdon, Cambs