Jim,
I am heartened to hear you mention a discussion of 'zinngeschrei' (G=
erman word for tin cries). It's something that I came to know about years =
ago that got me intensely interested in the problem of mesodynamics. While=
I wait to see just what Larry would have me do relative to our discussions=
, I will offer something for you, Brett, to think about.
About the time of the "Woodstock of Physics" (high temperature superco=
nductivity gathering in 1987), my brother Palmer was doing research on silv=
er doped cuprous oxide crystals given him by M. K. Wu. Wu is the one who m=
ade the first Hi-TC crystals (transition temperature above the boiling poin=
t of Nitrogen at 77 K, room pressure). With one of these crystals Palmer d=
iscovered the suspension effect, in his capacity as a research physicist wi=
th NASA at MSFC in Huntsville, AL. He also was the first to fly experiment=
s on the shuttle that demonstrated the dramatic importance of atomic oxyge=
n on low altitude satellites. The suspension effect astounded the physics =
world in 1988 (c.f. the New York Times article http://www.nytimes.com/1988/=
09/20/science/suspension-effect-astounds-scientists.html)
In my opinion the mesodynamics that I've researched, and the suspension eff=
ect discovered by my brother are part and parcel of similar defect structur=
e influences at the meso-scale. Let me now explain my thinking on the matt=
er.
When you try to suspend a ferrous material below a permanent magnet, m=
ost every child knows that the equilibrium being explored is an unstable on=
e. Get too close and a piece of iron is snapped up to the magnet. Get to=
o far away, on the other hand, and the iron falls to the ground. The first=
person to scientifically remove the challenges of hanging the iron, in see=
ming violation of Earnshaw's theorem, was Prof. Jesse Beams at the Universi=
ty of Virginia. Jesse was such a profoundly competent experimentalist, tha=
t he managed to do this with a steel ball bearing in vacuum, and with an ev=
er increasing frequency of external additional rotating (horizontal) magnet=
ic field, angularly accelerate the ball until the yield point was exceeded.=
In other words, get it spinning so fast that it ruptured. By this means =
he studied diffusion effects in solids, work that was sufficiently importan=
t for the lab he worked to be named in his honor. My first encounter with =
his experiments was when I was a freshman physics major at the University o=
f Tennessee in Knoxville, in 1961. Palmer's PhD advisor at the time was th=
e one who 'commissioned me to duplicate Beam's setup using a light source a=
s the means to provide an error signal for 'force balance'. By this means =
I could increase current to a solenoid when the ball started to fall, or de=
crease the current if it started rising-in a standard to EE feedback networ=
k. This worked very well, so you see that force balance was one of my earl=
iest exposures to physics. I certainly am not opposed to its use, since it=
was for me in this instance the means for converting the unstable potentia=
l well into one having a localized minimum superposed on the rascally one.
The silver doping in Wu's crystal did the same thing all by itself na=
turally in Palmer's case, because of flux pinning. There are actually seve=
ral stable points typically encountered, and one can feel the 'granularity'=
of them as the superconducting sample and the rare earth permanent magnet =
are pulled apart (similar to 'tin cries'). I see this process as a potenti=
al energy function that is very much like the vertical seismometer, except =
turned upside down. Extending the spring and then releasing, it does not r=
eturn to a perfectly defined equilibrium point; i.e., it finds a new very s=
lightly different places to come to rest because of the 'ratchety' nature o=
f the restoring force at the very low levels. Much of my experimental work=
is consistent with this 'heretical' viewpoint, and I think it is the very =
reason, Brett, you would do well to try and do some low level dithering of =
your instrument. Allan Coleman's approach seems to accomplish this by mean=
s of his passive leveling arrangement.
There is additional other evidence for the case I'm making. In earlier t=
imes, nearly every electrical engineering student was told about the Barkha=
usen effect. When a ferrous specimen is initially polarized with an extern=
al field in a coil, the B value does not rise smoothly, but does so in jerk=
y fashion. Richard Feynman was intrigued by this phenomenon, and wrote abo=
ut it in one of his famous three volume set of textbooks. He also was enth=
ralled with the Bragg brothers (x-ray giants) who had looked with fascinati=
on at bubble rafts. These bubbles are probably similar to dislocation latt=
ices that try to develop in crystals when you strain them, such as the copp=
er ones I studied as a PhD student.
Most everybody has a decent understanding of hysteresis (through stud=
ent training) when it comes to ferromagnetism. So very few have even a clu=
e about equally important to seismology, the hysteresis of mechanical type =
(that keeps Hooke's law from being obeyed).
Randall
Jim,
I am heartened=
to hear you mention a discussion of ‘zinngeschrei’ (German wor=
d for tin cries). It’s something that I came to know about year=
s ago that got me intensely interested in the problem of mesodynamics. =
; While I wait to see just what Larry would have me do relative to our disc=
ussions, I will offer something for you, Brett, to think about.
About the time of the R=
20;Woodstock of Physics” (high temperature superconductivity gatherin=
g in 1987), my brother Palmer was doing research on silver doped cuprous ox=
ide crystals given him by M. K. Wu. Wu is the one who made the first =
Hi-TC crystals (transition temperature above the boiling point of Nitrogen =
at 77 K, room pressure). With one of these crystals Palmer discovered=
the suspension effect, in his capacity as a research physicist with NASA a=
t MSFC in Huntsville, AL. He also was the first to fly experiments on=
the shuttle that demonstrated the dramatic importance of atomic oxyg=
en on low altitude satellites. The suspension effect astounded the ph=
ysics world in 1988 (c.f. the New York Times article =
http://www.nytimes.com/1988/09/20/science/suspension-effect-astounds-scient=
ists.html)
In my opinion the mesodyn=
amics that I’ve researched, and the suspension effect discovered by m=
y brother are part and parcel of similar defect structure influences at the=
meso-scale. Let me now explain my thinking on the matter.
When you try to suspend a=
ferrous material below a permanent magnet, most every child knows that the=
equilibrium being explored is an unstable one. Get too close a=
nd a piece of iron is snapped up to the magnet. Get too far away, on =
the other hand, and the iron falls to the ground. The first person to=
scientifically remove the challenges of hanging the iron, in seeming viola=
tion of Earnshaw’s theorem, was Prof. Jesse Beams at the University o=
f Virginia. Jesse was such a profoundly competent experimentalist, th=
at he managed to do this with a steel ball bearing in vacuum, and with an e=
ver increasing frequency of external additional rotating (horizontal) magne=
tic field, angularly accelerate the ball until the yield point was exceeded=
.. In other words, get it spinning so fast that it ruptured. By =
this means he studied diffusion effects in solids, work that was sufficient=
ly important for the lab he worked to be named in his honor. My first=
encounter with his experiments was when I was a freshman physics major at =
the University of Tennessee in Knoxville, in 1961. Palmer’s PhD=
advisor at the time was the one who ‘commissioned me to duplicate Be=
am’s setup using a light source as the means to provide an error sign=
al for ‘force balance’. By this means I could increase cu=
rrent to a solenoid when the ball started to fall, or decrease the current =
if it started rising—in a standard to EE feedback network. This=
worked very well, so you see that force balance was one of my earliest exp=
osures to physics. I certainly am not opposed to its use, since it wa=
s for me in this instance the means for converting the unstable potential w=
ell into one having a localized minimum superposed on the rascally one.&nbs=
p;
=
The silver doping in Wu’s crystal did the same thing all by itself na=
turally in Palmer’s case, because of flux pinning. There are ac=
tually several stable points typically encountered, and one can feel the &#=
8216;granularity’ of them as the superconducting sample and the rare =
earth permanent magnet are pulled apart (similar to ‘tin cries’=
). I see this process as a potential energy function that is very muc=
h like the vertical seismometer, except turned upside down. Extending=
the spring and then releasing, it does not return to a perfectly defined e=
quilibrium point; i.e., it finds a new very slightly different places to co=
me to rest because of the ‘ratchety’ nature of the restoring fo=
rce at the very low levels. Much of my experimental work is consisten=
t with this ‘heretical’ viewpoint, and I think it is the very r=
eason, Brett, you would do well to try and do some low level dithering of y=
our instrument. Allan Coleman’s approach seems to accomplish th=
is by means of his passive leveling arrangement.
There is additional other evidence for the case IR=
17;m making. In earlier times, nearly every electrical engineering student =
was told about the Barkhausen effect. When a ferrous specimen is init=
ially polarized with an external field in a coil, the B value does not rise=
smoothly, but does so in jerky fashion. Richard Feynman was intrigue=
d by this phenomenon, and wrote about it in one of his famous three volume =
set of textbooks. He also was enthralled with the Bragg brothers (x-r=
ay giants) who had looked with fascination at bubble rafts. These bub=
bles are probably similar to dislocation lattices that try to develop in cr=
ystals when you strain them, such as the copper ones I studied as a PhD stu=
dent.
&nb=
sp; Most everybody has a decent understanding of hysteresis (through s=
tudent training) when it comes to ferromagnetism. So very few have ev=
en a clue about equally important to seismology, the hysteresis of mechanic=
al type (that keeps Hooke’s law from being obeyed).
Randall
=