Envelope (disambiguation)

From Wikipedia, the free encyclopedia

Envelope comes from the French word envelopper, meaning to wrap in. All uses of the word envelope are related to this root meaning, but may have a more specific meaning in different contexts:

• An envelope is a thin paper container formed by folding a sheet of paper and securing the edges, and is the major staple consumable of a letterpost service.
• The envelope of an e-mail contains the information used for routing and is passed along the e-mail without being part of the actual message.

In science:

• envelope (mathematics) -- a curve, surface, or higher dimensional object defined as being tangent to a given family of lines or curves (or surfaces, or higher dimensional objects, respectively).
• In music theory, the envelope of a sound is its variation in amplitude over time; in Sound synthesis, envelopes are characterised by the attack, decay, sustain, and release times of the sound.
• In philosophy of probability, the two envelope problem is a paradox.
• In biology, the viral envelope is a membranal covering surrounding the capsid.
• In chemistry, the three-dimensional conformation of cyclopentane is commonly referred to as the "envelope" structure.

In applied science:

• envelope (mechanical engineering) -- a solid representing all positions that an object may occupy during its normal range of motion.
• building envelope -- the exterior layer of a building that protect it from the elements.
• In electronics, an envelope is a curve that bounds another curve or set of curves, as the modulation envelope of an amplitude-modulated carrier wave. See envelope detector.
• envelope (aerospace) -- the limits within which an aircraft can operate.
• envelope (lighter-than-air-craft) -- the airtight covering that holds buoyant gas, in a blimp, airship, gas balloon or hot air balloon.
• an envelope of glass separates the inner workings of incandescent or fluorescent light bulbs from their environment.

In the military:

• double envelopment or Pincer movement.

In entertainment:

• Envelope (band) -- a pop/rock band from Denmark.
• Envelopes (band) -- an indie/pop band from Sweden and France, based in the UK.