Changes

== Scientific basis ==

== Scientific basis ==

The Xylophone is aptly named, because its purpose is to destroy things by using ultrasonic sound. This is an extreme application of a technique, often called ''sonication'', that is used in dentistry to remove [[tartar]] from teeth and occasionally to remove [[calcium]] deposits from [[denture]]s.

The Xylophone is aptly named, because its purpose is to destroy things by using ultrasonic sound. The novel makes no effort to describe the actual technique involved. Basically, using sound to pulverize an object is an extreme application of a technique, often called ''sonication'', that is used in dentistry to remove [[tartar]] from teeth and occasionally to remove [[calcium]] deposits from [[denture]]s. But this technique typically requires a heavier-than-[[air]] intermediary substance, typically [[water]].

No real-life investigator has ever attempted to duplicate the Xylophone or to build anything like it. The most recent use of sound as a weapon occurred in the [[Iraq]] theater, where soldiers often used Long Range Acoustical Devices, or LRADs, to direct an ear-splitting sound at an unruly crowd or an approaching attacker.<ref name=lrad>"Troops in Iraq Get High-tech Noisemaker," [[Associated Press]], March 3, 2004. <http://www.military.com/NewsContent/0,13319,FL_noise_030304,00.html?ESRC=eb.nl></ref> About a year later, a cruise ship used an LRAD-like device to repel [[pirates]].<ref name=usatoday>Pain, John, "Cruise ship attacked by pirates used sonic weapon," ''USA Today'', November 7, 2005.<http://www.usatoday.com/tech/news/techinnovations/2005-11-07-cruise-blast_x.htm></ref>

No real-life investigator has ever attempted to duplicate the Xylophone or to build anything like it. However, scientists at the [[University of Nottingham]] have built a device capable of producing a beam of coherent sound in the range of terahertz (trillions of vibrations per second).<ref name=Nottingham/> The project scientists call their device a "saser," a play on [[laser]], a device for producing coherent [[light]]. The Nottingham group hopes to use their device as an instrument of harmless imaging, for [[medicine|medical]] or security purposes (i.e., anti-[[terorrism|terrorist]] screening in public venues). They also talk hopefully of using their device to produce [[computer]]s with ''very'' high-speed internal clocks. But just as lasers have always been theoretically capable of burning or cutting if the light is powerful enough, the "saser" could deliver an ultrasonic beam capable of pulverizing an object, just as a dentist's sonicator pulverizes calcium deposits on teeth or dentures.

 

The most recent use of sound as a weapon occurred in the [[Iraq]] theater, where soldiers often used Long Range Acoustical Devices, or LRADs, to direct an ear-splitting sound at an unruly crowd or an approaching attacker.<ref name=lrad>"Troops in Iraq Get High-tech Noisemaker," [[Associated Press]], March 3, 2004. <http://www.military.com/NewsContent/0,13319,FL_noise_030304,00.html?ESRC=eb.nl></ref> About a year later, a cruise ship used an LRAD-like device to repel [[pirates]].<ref name=usatoday>Pain, John, "Cruise ship attacked by pirates used sonic weapon," ''USA Today'', November 7, 2005.<http://www.usatoday.com/tech/news/techinnovations/2005-11-07-cruise-blast_x.htm></ref>

This is not the same as using sound to pulverize an object. The worst hazard that the LRAD could present to an overexposed subject is permanent hearing loss.

This is not the same as using sound to pulverize an object. The worst hazard that the LRAD could present to an overexposed subject is permanent hearing loss.

The use of sound, especially in the ultrasonic range, as a weapon is a common theme in [[science fiction]]. For example, in the ''[[Star Trek]]'' episode "The Way to Eden," a group of galactic drop-outs gerry-rig an ultrasonic broadcaster to incapacitate the crew of ''USS Enterprise'' (NCC-1701) long enough to allow the drop-outs to disembark, and then to reactivate at a level that could kill. No contemporary acoustical expert has ever suggested that a man could die from overexposure to sound or ultrasound at any given pitch.

The use of sound, especially in the ultrasonic range, as a weapon is a common theme in [[science fiction]]. For example, in the ''[[Star Trek]]'' episode "The Way to Eden," a group of galactic drop-outs gerry-rig an ultrasonic broadcaster to incapacitate the crew of ''USS Enterprise'' (NCC-1701) long enough to allow the drop-outs to disembark, and then to reactivate at a level that could kill. No contemporary acoustical expert has ever suggested that a man could die from overexposure to sound or ultrasound at any given pitch. However, that was before the invention of the "saser" at the University of Nottingham.

== Typology ==

== Typology ==