I was glad to see here a recent statement with which I heartily agree, "onl=
y so much can be done with electronics".  From decades-old studies which we=
re the main concentration of my career--mechanical oscillators (the heart o=
f every seismometer)--I am convinced that the place where amateurs could ma=
ke the most significant future contributions to seismology is by 'playing a=
round' with ('radical' to the professional world) new ideas focused on mech=
anical rather than electronic properties.
   I want to repeat, but with different words, something that I wrote to th=
is list-serve back in the summer.  The objective that I view, and which sho=
uld always be sought (as many of you realize, at least in part), is the 'sm=
oothest', most 'shallow' potential energy well that can be achieved within =
the constraints of material (mechanical) limitations.  Ideally, there is no=
 limit to how far we might go toward the realization of a really 'low and s=
low' oscillator. But mother nature never agrees with our definition of idea=
l, and I will speak shortly to why we will always bump up against frustrati=
ng limits. When we resort to assumptions like the proverbial "let us assume=
 a spherical egg', there is always, at some level, a measure of foolishness=
.
     The essence of our quest is what I call 'low and slow' periodic motion=
, in which really long-duration, long-period free oscillation is sought, fo=
r the instrument that is made to move without an external damping force.  W=
hy?, because its sensitivity to earth accelerations (the only thing that an=
y seismic instrument (or accelerometer) ever responds to) is proportional t=
o the square of the instrument's natural period.  If anybody wants to know =
still more than this too-long discourse on my thinking about the matter, I =
will expand the discussion on why our objective should always be focused fi=
rst and foremost on the mechanical features of the instrument and not on th=
e electronics used to monitor its motion.
      Concerning the physics of the matter:  I described in a previous list=
-serve email how the simple pendulum is an ideal system with which to easil=
y understand the above-mentioned comment concerning sensitivity, that can b=
e shown generally true. Every seismometer can be described from first princ=
iples (for small amplitudes of the motion) using a harmonic oscillator (par=
abolic) fit to its potential well.  This is done by solid state physics typ=
es (my graduate student training) even for the description of vibratory mot=
ions of atoms in a solid.  When the vibrations of the atoms get large enoug=
h through thermal excitation to depart from the harmonic oscillator approxi=
mation, we find then a natural means for understanding even thermal expansi=
on.
   So the simple harmonic oscillator (SHO) potential well is the natural ob=
jective toward which we should direct efforts in our quest for the elusive =
ideal seismometer.  That quest will never actually be realized for two reas=
ons.  First, no real oscillator is capable of an unbounded parabolic shape.=
  As amplitude of motion increases, there will always be distortions due to=
 inherent anharmonicity, due to the ever increasing departure from our (app=
roximate) parabolic first-order fit to the actual potential well.
    The second limiting factor involves defect structures that are part of =
all real solids.  Unfortunately, way too little exposure to defects is ever=
 provided to students, no matter whether their training is in engineering o=
r in physics.  For a variety of reasons, teachers (myself included) have co=
ncentrated on theories of ideal type as we exposed students to the fundamen=
tal physics of solids.  In actuality, at room temperature there is no solid=
 that can be free of defects (departure from complete perfect filling witho=
ut vacancies, of atoms on a three dimensional lattice).  There will always =
be Schottky defects where an atom is thermally excited out of its zero-temp=
erature lattice position where it is supposed to reside, so as to wind up o=
n the surface of the solid.  Additionally, consider what happens when a sol=
id is strained (the essence of what happens in the materials with which we =
choose to make an 'axis' for our seismometer).  Defect structures of synerg=
etic type, called dislocations begin to move throughout the material (typic=
ally starting at a surface, such as an 'edge' dislocation).  The stress for=
ced motion of these dislocations (more complex than described by a single B=
urgers vector, involving even 'defect lattice' types) results in thermoelas=
tic damping (energy loss of internal friction type).  But these structures =
are also responsible for something else, that I have 'bumped against' conti=
nually for the last two to three decades.  Because dislocations operate at =
the mesoscale, they are cause for the ideal SHO potential to be ever more e=
lusive, as we move ever closer to our 'low and slow' objective. In particul=
ar, they are responsible for 'fine structure' features that cause the actua=
l potential well to be more 'ragged' at low levels than the idealized harmo=
nic oscillator potential of our approximation.
     At the 'broadband conference' in Lake Tahoe a number of years ago, a w=
orld famous seismologist told me that he once thought "I was crazy", after =
I mentioned to him my opinion concerning the importance of these mesoscale =
defect structures to the performance of a seismograph.  He would not have t=
old me this, had he not eventually delved into my claims and come to recogn=
ize, at least in part, some of what I was saying to be true.  His initial r=
eaction was typical of what I have faced from individuals in a variety of d=
isciplines, in coming finally to my present place as a (retired) Professor =
Emeritus of Physics.  One 'satisfying' experience of opposite type actually=
 resulted directly from a recommendation made to me several years ago by Ch=
ris Chapman --that I get in touch with a British scientist heading up one o=
f the several 'big science' programs dedicated to the elusive goal of tryin=
g to directly observe 'gravitational waves' that were theoretically predict=
ed long ago by Einstein. A very special 'highlight' of the lecture that I g=
ave to (Fellow of the Royal Society) Jim Hough's group at the University of=
 Glasgow was the following.  He had invited one of his years earlier (highl=
y respected physics) 'mentors' to come and hear (and evaluate) my presentat=
ion. For this wise elderly gentleman to seek me out afterwards and complime=
nt my talk is an event I will always fondly remember with great appreciatio=
n.  Increasingly in the U.S. it is more likely that we label elders as irre=
levant 'old fogies'.
     I want also to point out that I have had some influence on the folks a=
t LIGO (the U.S. program given basically to the same goal as Hough's group)=
..  In the mid-1990's I tried unsuccessfully to get a well known leader of L=
IGO to take early interest in mechanical system 'mesodynamics', which at th=
at time I felt would become for them a critical issue. Only after the broad=
band conference which was also attended by a LIGO scientist, did there deve=
lop a keen awareness of the importance of dislocations to the performance o=
f their isolation springs. Not long after that conference I refereed a LIGO=
-generated article dealing with the matter, that did get published (concern=
ed with 'hysteresis associated with system isolation'; the editor's secreta=
ry told me that I had been selected to review the article 'because of my in=
ternet publications').  Ligo's quest is just the opposite to that of seismo=
logists.  They want to see nothing of earth's vibrations, whereas we would =
like to see everything.  In both cases, the 'achilles heel' has been the no=
n-ideal properties of real springs.
     I have some ideas, the nature of which are suggested in the specific s=
election of words that I chose as the topic for the present message. If suf=
ficient interest should develop and be expressed, I will gladly share some =
of my thoughts with you.  But I respectfully request that you will have fir=
st read in detail the things that I have written above (already made longer=
 than I wanted). In the event of minimal interest, it would be better if yo=
u contact me by way of my Mercer University email address.
  Randall
I was glad to se=
e here a recent statement with which I heartily agree, "only so much c=
an be done with electronics".  From decades-old studies which wer=
e the main concentration of my career--mechanical oscillators (the heart of=
 every seismometer)--I am convinced that the place where amateurs could mak=
e the most significant future contributions to seismology is by 'playing ar=
ound' with (‘radical’ to the professional world) new ideas focu=
sed on mechanical rather than electronic properties. 
   I want to repeat, but with different words,=
 something that I wrote to this list-serve back in the summer.  The ob=
jective that I view, and which should always be sought (as many of you real=
ize, at least in part), is the 'smoothest', most 'shallow' potential energy=
 well that can be achieved within the constraints of material (mechanical) =
limitations.  Ideally, there is no limit to how far we might go toward=
 the realization of a really 'low and slow' oscillator. But mother nature n=
ever agrees with our definition of ideal, and I will speak shortly to why w=
e will always bump up against frustrating limits. When we resort to assumpt=
ions like the proverbial "let us assume a spherical egg', there is alw=
ays, at some level, a measure of foolishness.   
     The essence of our quest i=
s what I call 'low and slow' periodic motion, in which really long-duration=
, long-period free oscillation is sought, for the instrument that is made t=
o move without an external damping force.  Why?, because its sensitivi=
ty to earth accelerations (the only thing that any seismic instrument (or a=
ccelerometer) ever responds to) is proportional to the square of the instru=
ment's natural period.  If anybody wants to know still more than this =
too-long discourse on my thinking about the matter, I will expand the discu=
ssion on why our objective should always be focused first and foremost on t=
he mechanical features of the instrument and not on the electronics used to=
 monitor its motion.   
 =
     Concerning the physics of the matter:  I=
 described in a previous list-serve email how the simple pendulum is an ide=
al system with which to easily understand the above-mentioned comment conce=
rning sensitivity, that can be shown generally true. Every seismometer can =
be described from first principles (for small amplitudes of the motion) usi=
ng a harmonic oscillator (parabolic) fit to its potential well.  This =
is done by solid state physics types (my graduate student training) even fo=
r the description of vibratory motions of atoms in a solid.  When the =
vibrations of the atoms get large enough through thermal excitation to depa=
rt from the harmonic oscillator approximation, we find then a natural means=
 for understanding even thermal expansion. 
   So the simple harmonic oscillator (SHO) potential wel=
l is the natural objective toward which we should direct efforts in our que=
st for the elusive ideal seismometer.  That quest will never actually =
be realized for two reasons.  First, no real oscillator is capable of =
an unbounded parabolic shape.  As amplitude of motion increases, there=
 will always be distortions due to inherent anharmonicity, due to the ever =
increasing departure from our (approximate) parabolic first-order fit to th=
e actual potential well. 
  &n=
bsp; The second limiting factor involves defect structures that are pa=
rt of all real solids.  Unfortunately, way too little exposure to defe=
cts is ever provided to students, no matter whether their training is in en=
gineering or in physics.  For a variety of reasons, teachers (myself i=
ncluded) have concentrated on theories of ideal type as we exposed students=
 to the fundamental physics of solids.  In actuality, at room temperat=
ure there is no solid that can be free of defects (departure from complete =
perfect filling without vacancies, of atoms on a three dimensional lattice)=
..  There will always be Schottky defects where an atom is thermally ex=
cited out of its zero-temperature lattice position where it is supposed to =
reside, so as to wind up on the surface of the solid.  Additionally, c=
onsider what happens when a solid is strained (the essence of what happens =
in the materials with which we choose to make an 'axis' for our seismometer=
).  Defect structures of synergetic type, called dislocations begin to=
 move throughout the material (typically starting at a surface, such as an =
‘edge’ dislocation).  The stress forced motion of these di=
slocations (more complex than described by a single Burgers vector, involvi=
ng even 'defect lattice' types) results in thermoelastic damping (energy lo=
ss of internal friction type).  But these structures are also responsi=
ble for something else, that I have 'bumped against' continually for the la=
st two to three decades.  Because dislocations operate at the mesoscal=
e, they are cause for the ideal SHO potential to be ever more elusive, as w=
e move ever closer to our 'low and slow' objective. In particular, they are=
 responsible for 'fine structure' features that cause the actual potential =
well to be more 'ragged' at low levels than the idealized harmonic oscillat=
or potential of our approximation.   
     At the 'broadband conference' in Lake=
 Tahoe a number of years ago, a world famous seismologist told me that he o=
nce thought "I was crazy", after I mentioned to him my opinion co=
ncerning the importance of these mesoscale defect structures to the perform=
ance of a seismograph.  He would not have told me this, had he not eve=
ntually delved into my claims and come to recognize, at least in part, some=
 of what I was saying to be true.  His initial reaction was typical of=
 what I have faced from individuals in a variety of disciplines, in coming =
finally to my present place as a (retired) Professor Emeritus of Physics.&n=
bsp; One 'satisfying' experience of opposite type actually resulted directl=
y from a recommendation made to me several years ago by Chris Chapman --tha=
t I get in touch with a British scientist heading up one of the several 'bi=
g science' programs dedicated to the elusive goal of trying to directly obs=
erve 'gravitational waves' that were theoretically predicted long ago by Ei=
nstein. A very special 'highlight' of the lecture that I gave to (Fellow of=
 the Royal Society) Jim Hough's group at the University of Glasgow was the =
following.  He had invited one of his years earlier (highly respected =
physics) 'mentors' to come and hear (and evaluate) my presentation. For thi=
s wise elderly gentleman to seek me out afterwards and compliment my talk i=
s an event I will always fondly remember with great appreciation.  Inc=
reasingly in the U.S. it is more likely that we label elders as irrelevant =
‘old fogies’.
   &=
nbsp;  I want also to point out that I have had some influence on=
 the folks at LIGO (the U.S. program given basically to the same goal as Ho=
ugh's group).  In the mid-1990's I tried unsuccessfully to get a well =
known leader of LIGO to take early interest in mechanical system ‘mes=
odynamics’, which at that time I felt would become for them a critica=
l issue. Only after the broadband conference which was also attended by a L=
IGO scientist, did there develop a keen awareness of the importance of disl=
ocations to the performance of their isolation springs. Not long after that=
 conference I refereed a LIGO-generated article dealing with the matter, th=
at did get published (concerned with 'hysteresis associated with system iso=
lation'; the editor's secretary told me that I had been selected to review =
the article 'because of my internet publications').  Ligo's quest is j=
ust the opposite to that of seismologists.  They want to see nothing o=
f earth's vibrations, whereas we would like to see everything.  In bot=
h cases, the 'achilles heel' has been the non-ideal properties of real spri=
ngs. 
     I ha=
ve some ideas, the nature of which are suggested in the specific selection =
of words that I chose as the topic for the present message. If sufficient i=
nterest should develop and be expressed, I will gladly share some of my tho=
ughts with you.  But I respectfully request that you will have first r=
ead in detail the things that I have written above (already made longer tha=
n I wanted). In the event of minimal interest, it would be better if you co=
ntact me by way of my Mercer University email address.
 
  Randall&nbs=
p; 
=