Which spice is the "spice of life"? Sarah Andrew, London
The spice of life is actually a little known spice from Madagascar called pirisipion. It was known by early sailors as the "spice of life" because of the local belief that it granted, if not immortality, then a greatly extended lifespan.
The highly unusual appearance of the ground spice -- iridescent red and blue -- increased its mystique. Though later investigated and found to be of no more medical use than garlic, the expression lived on.
Lynne Martin, London
As mice is the plural of mouse, so spice is the plural of spouse, Need I say more?
Miggy Scott, Winchester
Who decided and how, that Greenwich Mean Time would be where it is, and what year was it instigated?
Until Greenwich Mean Time (GMT) was established at the International Meridian Conference in Washington DC in 1884, every country in the world kept to its own meridian.
Twenty-five countries were represented at the conference. Following a month of meetings, seven resolutions were passed. It was agreed that the governments represented would adopt the Prime Meridian at Greenwich.
This meant that zero longitude was placed at Greenwich -- the meridian being defined by an imaginary circle which passes through the North and South Poles. The Prime Meridian of the World was defined by "The Centre of the Transit Instrument at the Observatory, Greenwich". This legally established that every new day begins at mean midnight at the "cross-hairs of the Airy Transit Circle telescope", which was built by the seventh Astronomer Royal, George Airy in 1848 and to this day is housed in the Royal Observatory.
Most importantly, the Conference proposed the formulation of a universal day, which would be calculated in terms of mean solar time, or the average measurement of a year's worth of days. This universal day "is to begin for all the world at the moment of mean midnight of the initial meridian, coinciding with the beginning of the civil day and date of that meridian; and is to be counted from zero up to 24 hours". Therefore all time for all the world begins at Greenwich. Interestingly, this means that Greenwich will be at the centre of the millennium celebrations as the Prime Meridian will be the point at which the new Millennium begins. Press Office, the Royal Observatory, Greenwich, London (prize donated to local school)
What is the origin of the baobab, Africa's upside-down tree? …