[DigitalDark] [StarSmoke] [NanoBump] [FringePatterns] [Surprisal] [NanoSleuth] [AnySpeed]
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Digital
darkfield detective work (blurb started here
May 2003) Visualizations: simulated experimental ico-twin butterfly reciprocal nanocone Papers on tableaus and picometer differences for Microscopy and Microanalysis 2006 in Chicago IL. Digital darkfield decompositions: Manfred Rühle Interfaces Symposium, August 2004 Microscopy and Microanalysis, Savannah GA. [slides] More detailed eprint. |
![]() This digital darkfield detective work helps researchers at industries and universities across the region to find and identify hidden structures in images (e.g. twinning in metal nanocrystals, or reaction rims on catalysts), as well as to map atom position deviations as small as a hundreth of an atom across. These deviation maps in turn allow "strain-mapping" as illustrated here, below an image of white tunnels between atom columns in a cross-section of wafer silicon on silicon-germanium under development by industry for the next generation of smaller and faster computer chips. |
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Starsmoke nano-cones photographed at UM-StL (Ap J Lett 578 L153-156, 2002) as continuation of the long-standing role of St. Louis researchers in the laboratory study of dust from around our star and other stars Paper on presolar atom-sheet bending for Microscopy and Microanalysis 2006. Slides on materials astronomy |
![]() Now researchers only 15 minutes away at the
University of Missouri-StL
have obtained pictures of carbon atom sheets whose arrival in our solar
system was concurrent with the carbon atoms in you, but which remain
bonded to sibling atoms that made the trip across the galaxy with them
from the star in which they were born. In other words, we now have
pictures of molecules like those in which your carbon atoms made their
interstellar voyage to earth. |
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Spontaneously-formed nano-pits in air-exposed silicon for gigascale integrated-circuits (ESSL v5 n9 G83-G85, 2002), as continuation of the long-standing role of Missouri researchers in silicon science and technology | A breakthrough came when Iris Mack, an exchange student from Stuttgart, discovered that "running down the hall after thinning a specimen" to put it into the electron microscope not only suppressed defect formation, but allowed microscopists to thereafter observe the spontaneous formation of these defects in real time. The results were reported in ESSL, the rapid publication journal of The Electrochemical Society. Researchers here suspect that these defects in effect harden the surface of air-exposed silicon much like the formation of a film on cooling but unstirred soup, and hence may prove to be worthy allies or adversaries as computer chip line-widths move into the nanometer range. Current work is focussing on the possible role of transition metals in their formation. |
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Fingerprinting nanocrystals from lattice images at two tilts (Ultramicroscopy v94 n3-4 245-262, 2003) More on visibility maps and making sense of lattice fringes now available in: J. Appl. Phys. 98 (2005) 114308 and the vJournal of Nanoscale Sci & Tech 12 (2005). Some interactive fringe visibility and Kikuchi maps. Additional papers for aberration-corrected microscopy meetings, and other stuff on digital interferometry, are linked here. Notes on covariance profiling. |
This paper considers how nano-humans might determine the 3D structure of crystals, if they were able to re-orient the crystal in their hand while trying to peer down along tunnels between the columns of atoms which run in various directions. If you could see these tunnels, you could formulate rules for folks to use in recognizing a face-centered cubic crystal, a body-centered cubic crystal, etc. Precisely this type of manipulation (imagine a hand which can only tilt the crystal through a limited angle, over one or two fixed axes) is becoming possible with modern day million-dollar atomic resolution transmission electron microscopes.
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Thermal
roots of correlation-based complexity (blurb started here
May 2003) Tales of a cool device, bogeyman code, plus multiscale time and values. Notes on layered niche-networks for the May 2006 Understanding Complexity meeting at UIUC. Notes and paper from a talk at the 2005 meeting. "Net surprisals ala Tribus: correlations from reversible thermalization" (poster/MS for ICCS 2004 in Quincy MA, May 2004). "Heat capacity in bits" in Amer J Phys 71, 11 (2003) 1142-1151 in the long-standing tradition of Missouri researchers (including E. T. Jaynes) applying gambling theory to physical systems. AAPT summer 2003 talk notes. How about courses with few prereqs on everyday inventions, or informatics? |
The physical role of uncertainty
about the state of a system in
its environment has become increasingly
apparent since work by Claude Shannon on noise in
communication lines in the late 1940's. It has
guided error-correction in phone communications,
the development of data-compression methods (e.g.
ZIP and GIF files on your computer), and
the development of tools for tracking the evolution
of information in genetic codes (e.g. mitochondrial
DNA) as well as ideas (see the article on
chain
letters in the June 2003 issue of Scientific American).
Now it's moving into areas relevant to
the future of computers, and provides a
common physical framework for considering such
disparate issues as energy conservation, maintenance
of genetic diversity within and between species,
idea dynamics,
and the future of cultural diversity in the face
of increasingly rapid means
for communication and transportation. In a paper for AJP, the most prestigous but also least understandable physics education journal, researchers at UM-StL examined how these developments impact our understanding of simpler things e.g. why temperature is a useful concept, or how the heat capacity of water changes as it cools from gas to liquid to solid form. In the process, one discovers that temperature is a measure of the energy needed to decrease the mutual information about a system of molecules by one bit, and heat capacity measures the number of bits of information lost per two-fold increase in temperature. Although these insights are unlikely to affect the way weather is reported on the morning news anytime soon, they are already providing insight for students into the physical laws that underlie complex systems ranging from lasers, through computers, to human communities. One set of connections in this regard is illustrated below... ![]() |
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Nano-detective challenges for students in
web-connected classes (blurb started here Aug 2004) .
St. Louis Science Cyberville splash screen for our Oct 2005 nanoday, links for a 2006 book chapter on nanoed, an intro-chem nanochallenge, and a web journal for peer reviewing empirical observation reports. Some interactive... A web/lab course in nanoscale science practicals Savannah 2004 poster Recent NSF proposal summary Some variable size scale adventure links. AAPT crackerbarrel on deep simplifications |
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Metric-based
approaches to anyspeed motion
empower students and explode myths "Live remote" spacetime explorer and artificial gravity laboratories for data acquisition by students in web-connected classrooms. Note on introducing mechanics metric-smart from day one. An anyspeed acceleration applet. Storylines for use of these tools in existing courses. Many of our notes for teachers are archived in citable form. The collection single-frame views of spacetime is an exception. Roadmap to content modernization on this site. |
![]() Allpaths/Action/Aging approaches to introducing the quantum-mechanical causes of motion (even in curved spacetime) under development for introductory classes, e.g. by E. F. Taylor at MIT, are complemented by map-based (single-frame metric-based) "anyspeed" descriptions of motion being refined at UM-StL. One element of these approaches is to "maximize insight while minimizing misconceptions" from the beginning. The work at UM-StL, using Minkowski's spacetime version of Pythagoras' theorem to define anyspeed variables and rules (referenced to a coordinate-grid and clocks co-moving with a selected "map-frame"), shows students with few to no prerequisites how:
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