What is "span"

Span \Span\, v. i. To be matched, as horses. [U. S.]

Span \Span\, archaic imp. & p. p. of Spin.

Span \Span\, n. [AS. spann; akin to D. span, OHG. spanna, G. spanne, Icel. sp["o]nn. [root]170. See Span, v. t. ]

1. The space from the thumb to the end of the little finger when extended; nine inches; eighth of a fathom.

2. Hence, a small space or a brief portion of time.

   Yet not to earth's contracted span Thy goodness let me bound.
   --Pope.

   Life's but a span; I'll every inch enjoy.
   --Farquhar.

3. The spread or extent of an arch between its abutments, or of a beam, girder, truss, roof, bridge, or the like, between its supports.

4. (Naut.) A rope having its ends made fast so that a purchase can be hooked to the bight; also, a rope made fast in the center so that both ends can be used.

5. [Cf. D. span, Sw. spann, Dan. sp[ae]nd, G. gespann. See Span, v. t. ] A pair of horses or other animals driven together; usually, such a pair of horses when similar in color, form, and action.

   Span blocks (Naut.), blocks at the topmast and topgallant-mast heads, for the studding-sail halyards.

   Span counter, an old English child's game, in which one throws a counter on the ground, and another tries to hit it with his counter, or to get his counter so near it that he can span the space between them, and touch both the counters.
   --Halliwell. ``Henry V., in whose time boys went to span counter for French crowns.''
   --Shak.

   Span iron (Naut.), a special kind of harpoon, usually secured just below the gunwale of a whaleboat.

   Span roof, a common roof, having two slopes and one ridge, with eaves on both sides.
   --Gwilt.

   Span shackle (Naut.), a large bolt driven through the forecastle deck, with a triangular shackle in the head to receive the heel of the old-fashioned fish davit.
   --Ham. Nav. Encyc.

Span \Span\, v. t. [imp. & p. p. Spanned; p. pr. & vb. n. Spanning.] [AS. pannan; akin to D. & G. spannen, OHG. spannan, Sw. sp["a]nna, Dan. sp[ae]nde, Icel. spenna, and perh. to Gr. ? to draw, to drag, L. spatium space. [root]170. Cf. Spin, v. t., Space, Spasm.]

1. To measure by the span of the hand with the fingers extended, or with the fingers encompassing the object; as, to span a space or distance; to span a cylinder.

   My right hand hath spanned the heavens.
   --Isa. xiviii. 13.

2. To reach from one side of to the order; to stretch over as an arch.

   The rivers were spanned by arches of solid masonry.
   --prescott.

3. To fetter, as a horse; to hobble.

Spin \Spin\ (sp[i^]n), v. t. [imp. & p. p. Spun(Archaic imp. Span); p. pr. & vb. n. Spinning.] [AS. spinnan; akin to D. & G. spinnen, Icel. & Sw. spinna, Dan. spinde, Goth. spinnan, and probably to E. span. [root]170. Cf. Span, v. t., Spider.]

1. To draw out, and twist into threads, either by the hand or machinery; as, to spin wool, cotton, or flax; to spin goat's hair; to produce by drawing out and twisting a fibrous material.

   All the yarn she [Penelope] spun in Ulysses' absence did but fill Ithaca full of moths.
   --Shak.

2. To draw out tediously; to form by a slow process, or by degrees; to extend to a great length; -- with out; as, to spin out large volumes on a subject.

   Do you mean that story is tediously spun out?
   --Sheridan.

3. To protract; to spend by delays; as, to spin out the day in idleness.

   By one delay after another they spin out their whole lives.
   --L'Estrange.

4. To cause to turn round rapidly; to whirl; to twirl; as, to spin a top.

5. To form (a web, a cocoon, silk, or the like) from threads produced by the extrusion of a viscid, transparent liquid, which hardens on coming into contact with the air; -- said of the spider, the silkworm, etc.

6. (Mech.) To shape, as malleable sheet metal, into a hollow form, by bending or buckling it by pressing against it with a smooth hand tool or roller while the metal revolves, as in a lathe.

   To spin a yarn (Naut.), to tell a story, esp. a long or fabulous tale.

   To spin hay (Mil.), to twist it into ropes for convenient carriage on an expedition.

   To spin street yarn, to gad about gossiping. [Collog.]

"distance between two objects," from Old English span "distance between the thumb and little finger of an extended hand" (as a measure of length, roughly nine inches), probably related to Middle Dutch spannen "to join, fasten" (see span (v.)).\n

\nThe Germanic word was borrowed into Medieval Latin as spannus, hence Italian spanna, Old French espan "hand's width, span as a unit of measure," French empan. As a measure of volume (early 14c.), "what can be held in two cupped hands." Meaning "length of time" first attested 1590s; that of "space between abutments of an arch, etc." is from 1725. Meaning "maximum lateral dimension of an aircraft" is first recorded 1909.

"two animals driven together," 1769, American English, from Dutch span, from spannen "to stretch or yoke," from Middle Dutch spannan, cognate with Old English spannan "to join" (see span (v.)). Also used in South African English.

Old English spannan "to join, link, clasp, fasten, bind, connect; stretch, span," from Proto-Germanic *spannan (cognates: Old Norse spenna, Old Frisian spanna, Middle Dutch spannen, Dutch spannan "stretch, bend, hoist, hitch," Old High German spannan, German spannen "to join, fasten, extend, connect"), from PIE root *(s)pen- "to draw, stretch, spin" (cognates: Latin pendere "to hang, to cause to hang," pondus "weight" (perhaps the notion is the weight of a thing measured by how much it stretches a cord), pensare "to weigh, consider;" Greek ponos "toil," ponein "to toil;" Lithuanian spendziu "lay a snare;" Old Church Slavonic peti "stretch, strain," pato "fetter," pina "I span;" Old English spinnan "to spin;" for other cognates, see spin (v.)).\n

\nThe meaning "to encircle with the hand(s)" is from 1781; in the sense of "to form an arch over (something)" it is first recorded 1630s. Related: Spanned; spanning.

Etymology 1 n. 1 The space from the thumb to the end of the little finger when extended; nine inches; eighth of a fathom. 2 Hence, a small space or a brief portion of time. 3 The spread or extent of an arch or between its abutments, or of a beam, girder, truss, roof, bridge, or the like, between supports. 4 The length of a cable, wire, rope, chain between two consecutive supports. 5 (context nautical English) A rope having its ends made fast so that a purchase can be hooked to the bight; also, a rope made fast in the center so that both ends can be used. 6 (context obsolete English) A pair of horses or other animals driven together; usually, such a pair of horses when similar in color, form, and action. 7 (context mathematics English) the space of all linear combinations of something Etymology 2

vb. 1 To traverse the distance between. 2 To cover or extend over an area or time period. 3 To measure by the span of the hand with the fingers extended, or with the fingers encompassing the object. 4 (context mathematics English) to generate an entire space by means of linear combinations 5 (context intransitive US dated English) To be matched, as horses. 6 To fetter, as a horse; to hobble. Etymology 3

vb. (context archaic nonstandard English) (en-simple past of: spin)

1. v. to cover or extend over an area or time period; "Rivers traverse the valley floor", "The parking lot spans 3 acres"; "The novel spans three centuries" [syn: cross, traverse, sweep]

2. [also: spanning, spanned]

1. n. the complete duration of something; "the job was finished in the span of an hour"

2. the distance or interval between two points

3. two items of the same kind [syn: couple, pair, twosome, twain, brace, yoke, couplet, distich, duo, duet, dyad, duad]

4. a unit of length based on the width of the expanded human hand (usually taken as 9 inches)

5. a structure that allows people or vehicles to cross an obstacle such as a river or canal or railway etc. [syn: bridge]

6. the act of sitting or standing astride [syn: straddle]

7. [also: spanning, spanned]

A span is the distance measured by a human hand, from the tip of the thumb to the tip of the little finger. In ancient times, a span was considered to be half a cubit. Sometimes the distinction is made between the great span (thumb to little finger) and little span (index finger to little finger).

In category theory, a span, roof or correspondence is a generalization of the notion of relation between two objects of a category. When the category has all pullbacks (and satisfies a small number of other conditions), spans can be considered as morphisms in a category of fractions.

Span is a programming language targeting the Parrot virtual machine. Its syntax is meant to be very similar to C, but its philosophy is Smalltalk-like, and it uses Smalltalk-style message syntax. Almost all of Span's library visible to the user is written in Span itself. Span is dynamically typed. The hello world program in Span is

class Hello {
static public main: args {
Console << "Hello World!\n";
}
}

Span uses blocks ala Smalltalk for all flow control constructs except definition. For example, for this pseudocode fragment:

if x > y
print "yes"
else
print "no"

Span would write

(x > y)
ifTrue: { Console << "yes" }
ifFalse: { Console << "no" };

Span is currently in very early stages of development.

SPAN was a Norwegian rock band that formed in 2000 from the ashes of two other outfits; Explicit Lyrics and Squid. Self-proclaimed as "Norwegian Turbo-Rock 'n' Roll Commandos", the band was made of Jarle Bernhoft on lead vocals and guitar, Fridtjof Nilsen on guitar, Vemund Stavnes on bass and Fredrik Wallumrød on drums. When Vemund Stavnes left in 2003, he was replaced by Kim Nordbæk.

SPAN spent much of the years between 2002 and 2004 touring the UK and Norway as well as spending a brief time in the U.S.. To date they have sold over 55,000 albums world wide.

In August 2005, much to their loyal fans' disappointment, SPAN announced that they were to take a break. Unfortunately there are no plans to return since a post on their website stated that the band "no longer share a common dream and ambition" and that they have "decided to end this while we are still the best of friends".

Span is the distance between two intermediate supports for a structure, e.g. a beam or a bridge. A span can be closed by a solid beam or by a rope. The first kind is used for bridges, the second one for power lines, overhead telecommunication lines, some type of antennas or for aerial tramways.

The span is a significant factor in finding the strength and size of a beam as it determines the maximum bending moment and deflection. The maximum bending moment M and deflection δin the pictured beam is found using:

$$M_{max} = \frac {q L^2} {8}$$

$$\delta_{max} = \frac {5 M_{max} L^2} {48 E I} = \frac {5 q L^4} {384 E I}$$

where

q
= Uniformly distributed load

L
= Length of the beam between two supports (span)

E
= Modulus of elasticity

I
= Area moment of inertia

Note that the maximum bending moment and deflection occur midway between the two supports. From this it follows that if the span is doubled, the maximum moment (and with it the stress) will quadruple, and deflection will increase by a factor of sixteen.

For long-distance rope spans, used as power line, antenna or for aerial tramways, see list of spans.