Billion: Encyclopedia - Billion

Billion

The word "billion" and its equivalents in other languages refer to one of two different numbers, depending on whether the writer is using the long or short scale.

Billion - 10^¹²

The original meaning, established in the 15th century, was "a million of a million" (1,000,000², hence the name billion), or 10¹² = 1 000 000 000 000. This system, known in French as the échelle longue ("long scale"), was used until recently in the United Kingdom, and is used in most countries where English is not the primary language. 10¹² is referred to as a trillion in the "short scale" system.

Billion - 10^⁹

In the late 17th century a change was made in the way of writing large numbers. Numbers had been separated into groups of six digits, but at this time the modern grouping of three digits came into use. As a result, a minority of Italian and French scientists began using the word "billion" to mean 10⁹ (one thousand million, or 1 000 000 000), and correspondingly redefined trillion and higher numbers to mean powers of one thousand rather than one million. This is known in French as the échelle courte ("short scale") and is now officially used by English-speaking countries, as well as Brazil, Puerto Rico, Turkey and Greece.

Billion - Synonyms

Use of "thousand million" for 10⁹ and "million million" for 10¹² can avoid ambiguity; however, British media, including the BBC, which long used "thousand million" for this reason, use "billion" to mean 10⁹. The old word "milliard", also found in many other languages, can be used for 10⁹ but is unfamiliar even to many native English speakers. See long and short scales for a more detailed discussion and usage advice.

Billion - Trivia

The facts below give a sense of how large one billion (taken as 10⁹) is in the context of passage of time.

• About a billion seconds ago, the parents of middle school children were themselves in elementary school. (One billion seconds is roughly 31.7 years.)

• About a billion minutes ago, the Roman Empire was flourishing. (One billion minutes is roughly 1,900 years.)

• About a billion hours ago, modern men and their ancestors were living in the Stone Age (more precisely, the Middle Paleolithic). (One billion hours is roughly 114,000 years.)

• About a billion days ago, Australopithecus, an ape-like creature related to an ancestor of modern humans, roamed the African savannas. (One billion days is roughly 2.7 million years.)

• About a billion months ago, dinosaurs walked the earth during the late Cretaceous. (One billion months is roughly 82 million years.)

• About a billion years ago, the first multicellular organisms appeared on Earth. (The universe is now thought to be about 13.7 billion years old.)

In terms of distance:

• A billion centimeters is about the distance from Chicago, Illinois, USA to Tokyo, Japan.

• A billion inches is 15,783 miles, more than halfway around the world and sufficient to reach any point on the globe from any other point.

• A billion meters is almost three times the distance from the Earth to the Moon.

See also

• Long and short scales
• American and British English differences
• Millionaire
• False friends
• Large numbers
• Number names
• 1 E9 and giga (or 1 E12 and tera) for a list of occurrences of numbers of this magnitude
• 1000000000 (number)

Adapted from the Wikipedia article "Billion", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki