Blue

:For other uses, see Blue (disambiguation)

Math, science, and technology

"Big Blue" is a nickname for IBM. The company's chess computer (which defeated chess champion Garry Kasparov) was called Deep Blue. Users of Microsoft Windows often use the term "blue" to describe a computer that has encountered a "blue screen of death."

Related Topics:
IBM - Chess computer - Garry Kasparov - Deep Blue - Microsoft Windows - Blue screen of death

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A blue box is an electronic device with a tone pulsator that simulates a telephone operator's dialing console by replicating the tones used to switch long-distance calls and using them to route the user's own call, bypassing the normal switching mechanism. They were used to avoid charges for telephone calls.

Related Topics:
Blue box - Telephone operator

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A "blue chip" is the nickname for a stock that is thought to be safe and in excellent financial shape. In the United States, $1 bills are delivered by the Federal Reserve Bank in blue straps.

Related Topics:
Blue chip - Stock - $1 bill - Federal Reserve Bank

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In medical diagrams, blue is used to represent veins carrying deoxygenated blood back to the heart. Deoxygenated blood is actually reddish violet. When a medical patient is not getting enough oxygen or has stopped breathing, however, their skin often takes a blue tint, a condition called cyanosis.

Related Topics:
Vein - Blood - Heart - Cyanosis

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In astronomy, a blue moon is the second full moon in a calendar month, the third full moon in a season that has four, or a moon that appears blue because of particles in the atmosphere. All are uncommon enough that the expression "once in a blue moon" means "once in a great while" or "infrequently."

Related Topics:
Astronomy - Blue moon - Full moon

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