PSN-L Message - Subject: temperature effects

Mauro,

You may be a= n ‘amateur’, but your work is nevertheless influenced by the ki= nd of expertise that goes all the way back to Galileo! I first heard = about you from Chris Chapman, so we see then again an example of the signif= icance to networking of these our ‘amateur’ musings.=

I agree with = you that temperature change is one of the single-most important features wh= en it comes to instrument performance. I came to realize this while d= oing a study several years ago of a pendulum that folks would probably neve= r think about using, because of its ‘heretical’ nature; i.e., t= his instrument with a period close to the 4 s microseisms-- I o= perated purposely without external damping. With a Q of about 2= 00 there is considerable enhancement of the microseism activity, and I beli= eve that it could be an important part of the study of hurricanes. Th= e pro’s scoffed at my ideas when I tried to interact with them in thi= s way, telling me “congratulations that you have been finally able to= see the microseisms (that every seismologist knows about routinely) with y= our instrument that is little more than a toy”. Also, it = was the basis for the invited chapter that I wrote (in print by Nova = Publishing) titled “Building on old foundations with new technologies= ”-- the 2^nd chapter of the 2008 book titled “Science= education in the 21^st century”. T= his morning I found my chapter listed as the first item of several million = using Google, by typing in the title (without the tick marks for literal se= arch) Unfortunately I can’t provide you with details as I would= like, straight from the chapter, for reason of copyright issues. For= those interested, I can tell you about some of the ‘crazy’ tem= perature effects I saw with this instrument as I would first excite the pen= dulum into resonance and then watch its free decay. Depending on the = temperature (which varied diurnally through less than 10 degrees F in = my basement in Macon, GA) dramatically different things could happen. = ; My opinion is that what I saw was consistent with my years-ago hypothesis= that a phonon maser could be built on the basis of stimulation of the defe= ct structures of a solid. Lest you think my idea was preposterous, th= e legendary Charles Townes (Nobel Laureate inventor of the laser) not only = found it an interesting possibility—he even dug out of his files for = me an old 60’s era paper that he had written on a related concept.&nb= sp;

As al= l of you probably know, the introduction of external damping is usually con= sidered an absolute must when it comes to anything involving seismology.&nb= sp; Some of the legendary seismology figures scoffed at anybody who thought= of operating any pendulum otherwise. Their thinking was influenced b= y the desire to readily interpret earthquake waves, without the time-domain= complications of the transient response of the instrument. Well, I h= aven’t been interested in just looking at earthquake traces. I = want also, if possible, to provide better insight into the so-far-unattaina= ble goal of earthquake prediction. Like myself, Mauro, your web-pages= show that you’ve also been willing to go ‘where angels apparen= tly fear to tread’. I have been working with a team to see if t= here are precursors to earthquakes that might just ‘be the ticketR= 17; to reliable prediction. We’re largely a bunch of ‘old= guys’, less concerned with reputation than the younger folks w= ho for reason of career advancement probably need to stay more conventional= . We presented at last year’s AGU conference, and you can see = some of the details of our presentation at the following website:

http://www.agu.org/meetings/fm10/waisfm10.html

where you will want to search with the keyword = “dusel”. The ‘mover/shaker’ person for much o= f this work is the very capable ‘maverick’ Friedemann Freund.&n= bsp; On the basis of his considerable professional PhD expertise, he years = ago postulated one of the most remarkable ideas ever—that currents ca= n be made to flow in granite as the result of stress-change. He proba= bly would have been ‘laughed out of the room’ as a young scient= ist for mentioning the very thought of his ‘p-holes’. If = you want to see what scientific progress nevertheless has been made, just t= ype “p-holes Freund” into Google!

What Friedemann found most significant= in the output of my instruments is the ‘boxcar’ shaped pulse t= hat is frequently seen in some records. Some of the team members have= also seen these pulses in electric signals, in tantalizing fashion before = some earthquakes in California. You might ask—can you depend on= such sightings, since the pro’s haven’t seen and been talking = about them? The answer to your question is the following—when y= ou operate with a velocity sensor, the boxcar pulse degenerates to a pair o= f sharp pulses (positive and then negative, or vice versa depending o= n sign, at the leading and trailing edges of the pulse). These = correspond to the derivative of what I see with my instrument the VolksMete= r ( the VM uses a displacement sensor responding to tilt). With the c= onventional instrument, the differentiated boxcar pulse is most likely goin= g to be interpreted as noise.

&nbs= p; Randall

PSN-L Email List Message