Editing Spanreed

{{fabrial
|type=Conjoiner
|gem=Ruby
}}
{{update|sa3|sa4}}
A '''spanreed''' is a type of [[Fabrial#Conjoiner| conjoiner fabrial]] developed sometime before the [[War of Reckoning]] that enabled long distance communication on the world of [[Roshar]].{{book ref|sa1|28}}{{book ref|sa1|part=ars}}

== Function and Mechanics ==
Spanreeds, like all conjoiner fabrials, are made by capturing a spren inside a ruby and splitting it in half.{{book ref|sa3|100}}  The two halves are then embedded in reed pens.  The two pens can then mimic the movements of the other, exactly. The energy required for the second pen to move is provided by the holder of the first pen, which feels twice as heavy as an ordinary pen would.{{book ref|sa1|part=ars}} The farther apart spanreeds are, the heavier the pens became after activation. This can be used to triangulate the position of the opposite spanreed.{{book ref|sa4|28}}  Furthermore, they cannot communicate faster-than-light, due to a mixture of the fact they grow heavier the further apart they are, and a lag between the communication of two spanreeds, presumably proportional to the distance between them.{{url ref|url=https://www.tiktok.com/@authorbrandonsanderson/video/7153480408280255790|text=Discussion on quantum entanglement|site=Brandon's TikTok|date=2022-10-12}}

The setting of the ruby can be rotated to switch between different "modes." One is to alert the possessor of the spanreed's twin that a conversation is desired.  Another to alert the first that the message was received.  The third and fourth notches sync the movements of the two pens, each notch makes one pen the transmitter and the other the receiver.{{book ref|sa1|28}} Vorin men who do not write can communicate with a spanreed by turning the gem on and off to indicate that they are still alive.{{book ref|sa3|64}}

Spanreeds cannot be used effectively whilst moving when its pair is stable.{{book ref|sa2|88}} Since the function of fabrials is dependent on the user's frame of reference, a spanreed in motion would be incapable of relaying a clear message to its stationary pair. If both spanreeds are on the same ship, for example, then the spanreed would function properly because both users have the same frame of reference. This is also why spanreeds are unaffected by the planet's motion and curvature.{{book ref|sa3.5|5}} 

It is possible to create three or more linked spanreeds by breaking a ruby into more than two parts. However, all attempts have currently been unsuccessful.{{wob ref|10750}}

Spanreeds are incapable of interrealmatic communication between the [[Physical Realm|Physical]] and [[Cognitive Realm]]s.{{book ref|sa4|20}}

== History ==
As of {{rosharan date|1168}}, shortly after the [[War of Reckoning]] began, spanreeds were still regarded as a recent innovation.{{book ref|sa1|44}}

By the sixth year of the war, spanreeds have achieved widespread use, at least among the [[Vorin]] nations, from the [[Shattered Plains]], to [[Kharbranth]], and even to the isolated estates of [[House Davar]].{{book ref|sa1|28}}{{book ref|sa1|39}}

As of {{rosharan date|1173}}, [[Tashikk]] is beginning to become a spanreed hub, with several people and places having reeds connected to various businesses in Tashikk. The Tashikk operator is hired by the remote user to exchange messages, to research on your behalf, and to make other enquiries.{{book ref|sa2|24}}

== Known Pairs ==
* [[Shallan Davar]] was in possession of a spanreed paired with one located at her family's estate which she uses to communicate with her brothers.{{book ref|sa1|39}} It is lost after the sinking of the ''[[Wind's Pleasure]]''.{{book ref|sa2|7}}{{book ref|sa2|21}} She is attempting to replace the lost one by sending another to her family.{{book ref|sa2|47}}
* [[Dalinar Kholin]] is in possession of a number of spanreeds, including one paired with one possessed by [[Jasnah Kholin]]{{book ref|sa1|28}}{{book ref|sa2|1}}
* The relay station at [[Tashikk]] has at least one pair for each Alethi warcamp{{book ref|sa2|47}}{{book ref|sa2|67}}
* [[Tyn]] also has a Tashikk-paired reed.{{book ref|sa2|42}} It is used by Tyn, and later Shallan, to contact the [[Ghostbloods]].
* Presumably Tashikk is also paired with [[Kharbranth]]{{book ref|sa2|67}}
* [[Meridas Amaram]] possesses a connection to [[Restares]]{{book ref|sa2|88}}

== Notes ==
<references /><!-- sa1 22, 28, 29, 39, 45, 60, 74, I-2, ars, sa2 1, 2, 24, 31, 34-36, 42, 43, 46, 47, 51, 54, 62-64, 80, 87-89 -->
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