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Sonoluminescence
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The controlled probability of parallel streamed sonoluminescence within the core of a music string. (Copyright Attribution - also refers to UK Patent Application 8402696)
Steven R .M. Acworth 1984 and 2001.
First, you ought to know these simple facts about music strings.
© A wire-wound, carbon-cored, water-filled music string serves as the axle for a spoked rotor.
Mounted to spin freely at the octave node of a speaking length of the string, the four-spoke (aluminium) rotor is synchronously driven, magnetically and electrostatically, by a reciprocal system of coils and stators. Two sets of three stators are arranged either side of the rotor. These may be rotated out of mutual alignment, thus initialising harmonic multiplication in the string's vibration. Resonant feedback is supported within the system by piezoelectric transducer elements bearing the string's tension (which is slight). Voltages transduced are passed to induction coils, wound of the same type of string.
The machine is assembled upon a central chassis block.
A composite wire-wound music string constructed around a multifilament tow core of raw carbon fibres encloses a number of approximately 1 micron sq. section capillary spaces, each space bounded by three fibres.
There will be approximately twice as many capillary spaces as there will be fibres in the core.
Water vapour, permeating these capillaries by immersion of the music string in boiling water, upon cooling, draws liquid water into the string core. Unable to wet the carbon fibres' surfaces, the water forms spontaneously into surface-tension, meniscus-bounded and suspended strings (whose existence may be verified by measurement of the whole composite music string's internal light transmission capacity, each 'water-string' functioning as an efficient fibre-optic, centred in each capillary space).
An electrical insulation (P.T.F.E.) coated example of this type of composite string is used :
(a) as a 'speaking-length' of music string, supported in (variable) tension between two adjustable points of support and:
(b) to be wound as coils, coaxially around that (a) speaking-length, to apply synchronising feedback fields which are induced by current flow from voltages supplied via piezoelectric transducer elements mounted within the two speaking length tension-bearing supports, which are:
PTFE Piston Coil Formers protectively enclose and support the piezoelectric transducer elements.
In order to allow a multifilament carbon-fibre tow cored string ; (a) to work freely and (b) to have a reasonable working lifespan avoiding early fatigue and fracture, a special design of 'bridge' support is necessary:
For the case of a wire-wound string constructed around a multifilament carbon fibre core, a 'flared' design of 'bridge' is required to bring out the optimum harmonic performance and capability. For the test rig described in the following specification, I have designed the 'bridge' as exponentially flared collets.
These are multi-functional (parts 7a,7b,7c). The same interchangeable parts serve as capacitive stators for the purpose of synchronisation of vibrations in string (a) to the rotation of a four-spoked rotor, mounted at the octave node of the speaking length within the coil (b). The same collet design also serves for the coil terminals, in conjunction with the stators, adjacent to the innermost windings on the coil bobbin formers.
A carbon-cored, water-filled music string (1,2,3) serves as the axle for a spoked rotor (4). Mounted to spin freely at the octave node of a speaking length of the string, the four-spoke (aluminium) rotor is synchronously driven, magnetically and electrostatically, by a reciprocal system of coils and stators. Two sets of three stators (7a) are arranged either side of the rotor (4), and they may be rotated out of mutual alignment to produce high numbered harmonics in the string's vibration. Resonant feedback is amplified in the system by piezoelectric transducer elements (9) which support the string's tension; and the voltages so produced are passed to induction coils (16), wound of the same type of string.
In this context it is essential that the string should be allowed to perform at its optimum capability. This cannot be achieved using single-position points of support as the inevitable structural stiffness of the string's materials would in that case have the effect of damping out the potential higher numbered harmonic series close to the points of support at either end of the speaking length; and, in the case of a carbon fibre tow core, lead to early fatigue and fracture. (It is a commonly held belief that, for example, old guitars sound better but the truth is that the points of string support have had time to wear, or be cut purposefully, into rounded profiles.)
Thirty years' work as an electric guitar technician taught me how music strings behave; when a tensioned music string is supported on rounded (convex) suspension points, a far greater harmonic content is enabled than is the case for knife-edged bridge saddles. It's all about flexibility; the last few millimetres of a speaking length, closest to the supporting bridge (or fret) is the area where the stiffness of the string's construction media cause problems of timbre by limitation of harmonic potential.
The case for rounded points of string support is founded on a simple (but here, quintessential) principle: as a string, supported by curved surfaces at either end vibrates, it wraps and unwraps around those surfaces tangentially at each cyclic oscillation. This gives rise to the 'chasing' or 'bootstrapping' of harmonic shock waves or 'echoes' longitudinally within the string, producing a richness of tone. In this proposal it should be noted that the string anchorages are formed as split collets (7c) of exponentially flared bore design. The bore through the rotor (4) spindle is similarly flared for the above reasons.
Vibration in one plane only is very rare for music strings; the swing pattern is complex, as is the propagation of internal longitudinal shock waves.
The stators (7a), coil contacts (7b) and collets (7c) are of exactly the same design and are completely interchangeable. Capacitive spike discretion is maintained by the shape of the exponential cavity formed between these components (7a, 7b), when joined in assembly. Any rotor spoke ball-end, in passing the flat face of stator (7a), experiences this discrete spike. Maximum field compression occurs at the exact coaxial centre of the string (at the octave node within the spinning rotor) because the (diamagnetic) aluminium rotor repels alternating (rotating) fields within its central bore. The field compression spikes generate synchronised mechanical shockwaves in the water-strings. The shockwaves propagate longitudinally. Conventional standing-wave mechanics apply within each separate water-string.
Contact terminals (7b) convey charge and current between the stators (7a) and the coils (16), wound of the same string (1,2,3) that is used for the speaking length. In this arrangement, spare string is held 'in stock' in the outer windings of the coils ready for stripping down and re-assembly in the event of string speaking length failure/breakage. The string has a limited lifespan due to inevitable materials fatigue.
During assembly contact terminals (7b) break the PTFE insulation of innermost coil windings by insertion, using ring (11) to press all three home between stators (7a).
The coils (16) are wound upon two mutually opposed piston-coil formers (10) mounted in either end of a central pressure controlled cylinder (5,6). The stators (7a) and the coil contact terminals (7b) are mounted in the coil formers' piston faces (10a). P.T.F.E. tape interleaving renders the coils air-tight enabling their function as pressure-sensitive pistons.
The string (1,2.3) core is a tow bundle of clean, unetched carbon fibres (1). A manual pressure control assembly (12,13,14,17) enables mercury to be drawn into the central chamber for start-up. The wire winding (2,3) of P.T.F.E. (3) insulated aluminium forms a permeable membrane, allowing water molecules to pass into the core and serves (weakly) as a collimating solenoid to the string's internal eddy currents during operation, thus aiding a tight, axial focus. Ideally, the core (1) would be of coherently arranged fibres but, by default, considerable accidental coherence occurs over short lengths, given a randomly assembled bundle.
Piezoelectric transducer elements mounted within the piston coil formers are of an industrial standard design, flat plane polarised and silvered.
Terminal Crowns (8) receive collets (7c), thus applying string tension across the outer faces of piezo discs (9) and complete electric current circuit with string (1,2,3) and coils (10). The crowns are shaped with grooves to protectively accommodate the bent-around continuation of the string speaking length at the nominated 'male' end of the assembly. The 'female' end of the string speaking length is broken off at exit from collets (7c) and serves as a photon emitting 'window' for sonoluminescence activity.
Method for priming the string with water: Immersion of the assembled mechanism (with pressure controls removed) into boiling water and allowing to cool whilst submerged. When priming is complete the chamber is emptied, admitting air. The pressure control mechanism (12,13,14,) is then reassembled, allowing for adjustments to the chamber pressure, and hence to the string tension (which is not required to be great). Pin 14 is for fine adjustment.
The whole system, when assembled, is extremely sensitive: any subtle speaking length vibration being converted into electrical energy by the piezos (9). Voltages thus transduce to fields in the (very low impedance) coils (16), extending the natural decay of the string vibration, or cancelling it, depending on the system resonance as set by string tension and the rotor inertia. At crucial settings the system is on the verge of feedback but 'conservation of energy' naturally denies that possibility.
Energy required to spin the rotor is vanishingly small, as is the probability that any rotor spoke ball-end will come to rest exactly centred adjacent to any of the stators' exponential grooves. In that event, a catastrophic scenario exists and rotation will commence, stimulated by the string bowing action and the through-fields from the coils, according to the summation of the left-hand rule of electrodynamics within the system.
Seeding energy for initial rotation may come from manual stimulation. This is achieved by use of a rattling mechanism (23,24) or, conversely, by any externally applied electromagnetic alternating field from a separate power supply. In air, human vocal drone power will also serve this purpose. Providing a suitable resonance is adjusted for and set, the rotor is induced to spin and in the absence of any further stimulation, the rotation and vibration will decay over a period of several seconds.
Antipathy between the water and carbon causes 'water-strings' to spontaneously form centrally in each capillary. Over short distances these water-strings will behave as efficient fibre optics for any light introduced longitudinally at very shallow angles of incidence. Each water-string is bounded by three adjacent, touching carbon fibres, and thus three air-strings will also be present, linked to form a triple-lobed tube of air surrounding each water-string element. An electrostatic charge due to the materials' natural antipathy is maintained in each air-tube string., catalysing and seeding standing-wave regeneration.
As the solid string vibrates the water and air strings are forced to follow, initially at the low numbered harmonics generated. The solid string is required only to resonate within a spectrum of frequencies in the middle to upper range of human hearing - it is not required to physically vibrate at higher frequencies. Higher orders of frequency vibration than this are threatening to the carbon fibres' structural integrity. This is an area where care must be exercised in tuning / tension adjustment.
Use of rattling mechanism (23,24) allows step-detented adjustment of radial positioning for the stators (7a) and combined with the rotational velocity of the rotor (4), determines a synchronous pulse rate for precise and discrete field compression timing spikes within the rotor bore and hence also within the string. This frequency, when applied to the air-strings and water-strings causes constrictions in them, and the resultant shock waves travel away from the octave node in both directions, producing a symmetrical modulation of extant harmonic echoes longitudinally.
Dependent upon the speed of sound in the respective materials, symmetrically arranged shock waves (or 'echoes') propagate longitudinally throughout the speaking length of each type of string, generating high numbered standing waves as a multiplex of the solid string harmonics.
The forcing of synchronous longitudinal modulations within the water-strings renders a symmetrical set of values for positions of probability where sonoluminescence (S.L.) events may occur either side of the rotor, spinning at the octave node. (Maximum field compression is sharply defined at the exact coaxial and coincident centre of both the rotor and the composite string).
The summation of travelling and standing waves in the air-strings and water-strings, interacting at their interfaces, resolves to white / pink noise rendering a high degree of acoustic energy excitation within the water-strings, thereby promoting (predicted) chained spontaneous sonoluminescence en masse.
Any two synchronous S.L. bubble events that may occur will define, by their symmetrical spacing, one analogue precise new wavelength of electromagnetic radiation with its own implied longitudinal frequency, which passes to the coils, in turn becoming a reciprocal phase controlling force. An 'infinite squaring' function is thus applied to the feedback loop modulus and potential node separation is immediately limited only by fundamental particle spacing.
(The static mid-point of that precise new wavelength will be the central node of the music string).
Manual pressure control assembly (12,13,14,17) enables mercury to be drawn into the central chamber for start-up. When priming is complete the chamber is emptied, admitting air. Parts (17) are copper rings, set in the plastic handle to provide (a) a manual protective short-turn screen and (b) together with Pin (14) an attempt to directionally focus any fields of unknown provenance (the best I could do in the face of the uncertain). Pin (14) is for fine adjustment of chamber pressure and, slightly flexible, is of magnetostrictive alloy to aid system resonance.
Photon emission from any S.L. event will be absorbed laterally by the black carbon fibres but at shallow angles of incidence longitudinally, light will be conducted along each capillary axis by the water-strings' fibre optic properties. The synchronous nature of such streamed photon emissions will thus generate multiple and parallel lasers from the capillaries.
A flexible tubing loop (18), is connected by means of finger-nuts (19) to the chamber (5) via two ducts (20, 21) and , filled with mercury, is required at start-up to complete the circuit between opposing stators. Functioning also as a massive flexible short turn, the looped handle may be used to control vectors of electromagnetic radiation locally generated by the assembled rig (unquantified at time of writing). Once the rotor is up to speed (100,000+ rpm being easily achievable), the mercury can be pumped out of the central chamber or drawn back in by increment as required, by pressure setting mechanism (12,13,14). The loop (18) is large enough to allow for a sufficiently substantial reservoir of mercury in an elastic container which can be easily serviced (without tools) and manually distorted. A much broader range of preset coarse control may also be set instantly, by rotation-detented (23,24) adjustment of the piston-coil formers (10) in either end of the cylinder bore.
At the cut string end a short length of each water-string will be expelled after priming. The properties of electrostatic antipathy, surface tension and extant electromagnetic forces all bear upon the water to exit via the cut string end but the end-meniscus formed at the break will be unable to advance over the last few millimetres, where longitudinal antipathy becomes massive relative to lateral pressure and a balance point occurs, keeping the remainder of the water in each capillary.
With the exception of waves or particles leaving the cut end of the string (1,2,3), all other electro-photonic energies are recaptured by the system and recycled as feedback. As sonoluminescence events occur, only photons vectored in a narrow cone towards the cut end will escape. For a one millimetre diameter core there will be approximately 5,000 capillaries and most of the water-strings contained therein will experience extremely similar conditions at any given distance symmetrically from the octave node. Within the entire core, many millions of the S.L. events will be completely synchronous.
The author finds it ironic, in consideration of quantum theory, that under no circumstances can sonoluminescence events generated in this way be observed except by the summation of their cumulative by-products exterior to the machine. If sonoluminescence events occur en masse at every triggered position of probability throughout the speaking length subject to specifically localised high energy noise then external power supplies may be turned off or withdrawn, the process being temporarily self-sustaining due to (predicted) chained sonoluminescence whilst reserves of water remain within the string core.
The machine has been designed to be manufactured using the absolute minimum number of working parts, for easy, unskilled assembly, adjustment of operation and manual servicing without tools and with operator safety in mind. The parts have been designed to be robust, impossible to wrongly assemble, and to snap-connect together. Power source: Manual agitation to start-up. Fuel: Water with trace mineral elements or compounds. Catalyst: Mercury.
