Emphasizing Historical and Human
Dimension of Scientific Discoveries.
Using the Example of Nuclear
Magnetic Resonance.
Mark I. Liff
Philadelphia University, Philadelphia, PA, 215-3214759, liffm@philau.edu
•Informal Science Education÷Teaching Science to
the Public
•attention from agencies interested in science
education, including the NSF
•a story of discovery and development of Nuclear
Magnetic Resonance(NMR)
•educational and entertaining product.
•includes a booklet and software
•The Many Faces of Nuclear Magnetic Resonance
Why NMR? What is remarkable
about it that it deserves to be brought to
the attention of the public?
A little more than 50 years ago NMR was
just an elegant, though not particular
important, experiment in the realm of
Nuclear Physics. It was not expected to
develop into an area of an exceptional
scientific significance, nor to have broad
practical applications.
Who is the public? Who are the people
that constitute the target audience?
Why does the public need to know about
NMR? What is so unusual, or special
about NMR to make it a topic of a
common interest?
What are the means to make a story
entertaining and, simultaneously, highly
educational?
NMR today
• huge area of science and engineering
•continues to develop rapidly in many directions
•unrivaled as a structural method
•no modern chemical lab without an NMR-spectrometer
•and no molecular biology dept or a drug company
•in the form of MRI revealed new horizons in diagnostics
•changed the way chemists do their work and doctors
diagnose their patients
•from physics of metals to precise measurements of Earth's
magnetic fields, from materials science to archeology
archeology
the scale of publishing activities involving
NMR:
•approximately ten books annually
•an order of 500 comprehensive reviews
•several journals dedicated exceptionally to
NMR
•thousands of papers in physical, chemical,
biological and medical journals containing
NMR-data and results obtained by NMR
techniques.
What is the necessity of bringing science of NMR
to the attention of the public? What is
remarkable in NMR from a broader point of
view, beyond the fact that chemists, biologists,
physicists, medical doctors use it extensively?
• a unique history of NMR, full of unexpected
turns and surprising discoveries
•lessons in creativity that can be learned from the
pioneers of NMR.
•history + prehistory ≈ 70 years.
•many happy endings, but it had its portion of
drama
•NMR in liquids and solids has been detected only
≈ 20 years after the theoretical prediction and
understanding of the phenomenon.
Due to accidental circumstances NMR was
not detected in the 30s, 10 years before Bloch and
Purcell
•Early experiments--only to verify theoretical
models. Nobody thought about applications,
especially in chemistry, biology, or medicine.
•In the fifties, discoveries of chemical shift and spin
coupling. Every type of a molecule has its easily
recognizable NMR-face. Chemical structure can be read
out almost directly from its NMR spectrum
•Till the middle 60s NMR was efficient for only one type of
nuclei, protons, and only for small molecules. No large
molecules. No nuclei like isotopes of carbon, phosphorus,
nitrogen, oxygen. No means to improve the situation
•Fast Fourier-spectroscopy and computers → NMR of
many elements of the Periodic Table
•Super-conducting magnets of high homogeneity → NMR
of complicated bio-molecules, fragments of proteins and
nucleic acids.
•1950s--NMR shifted towards chemistry away from
physics.
•NMR is dead--this was a prevalent diagnosis regarding
the physics
•1960s--high-resolution spectra in solid state in the absence
of displacement of nuclei with respect to each other.
•The train of discoveries continued on: Multidimensional
Spectroscopy and Magnetic Resonance Imaging
• NMR-industry adopted instantaneously all arriving
related technical and theoretical novelties: computer
technology, electronics, or cryo-technology, and the
concurrent theoretical developments
a variety of means to make the story entertaining and
educational
Historical dimension is emphasized
• Human creativity is another focus beyond history
Computer animations to demonstrate the NMRexperiments (absorption, saturation, etc.)
Computer-directed discoveries of Nuclear
Overhauser Effect, Chemical Shift, Spin Coupling,
etc.
1. Begin from the beginning.
•What do an atomic nucleus, a top, and a
compass needle have in common? Magnetism
and mechanical momentum.
•Head-over-heels in the magnetic field. NMR
through the eyes of a physicist from the prequantum era.
•Flip-flopping spins. The quantum-mechanical
approach.
2. Against all odds.
• Failure as a part of success. What kept Gorter
from discovering NMR in 1930s? The role of
spin-lattice relaxation.
•The roads the lonely spins choose. Resonance
experiments with beams of isolated spins by I.
Rabi, NY, 1938.
•Full speed ahead down the temperature scale.
Measurements of spin populations near absolute
zero in the late 1930s
3. At the ball of luck and triumph.
• From Russia with discovery. Zavoisky observes
electron spin resonance in 1944.
• Born in 1945. NMR is registered by Bloch in Stanford,
and Purcell in Harvard.
• The stone that started the avalanche: the discovery of
chemical shift in the 1950s.
• Know your neighbor. Spin-spin interactions
•4. On the way to maturity.
One resonance is fine, two is better. First experiments
in double resonance.
• The conductors of spin orchestras. Multiple pulses
• Slender lines and spin gymnastics. Three ways to
narrow NMR line-widths.
Traveling into new dimensions. 2D NMR, nD NMR.
Some lessons in creativity from the
discoveries in NMR. An attempt to relate the
creative strategies that are commonly discussed
by creativity experts and trainers with the
approaches from the NMR discoveries.
Find What You Are Not Looking For
•B. F. Skinner: if you find something unusual and
interesting, stop pursuing your original goal, and
study in detail the unusual events.
•Science classics--Fleming's discovery of
penicillin. He was not looking for penicillin.
•Back to NMR, a great example of finding of what
you are not looking for is the discovery of
chemical shift in the 1940s and also spin-spin
coupling in 1950s.
•The physicists tried increased the value of
permanent field B to accurately find the magnetogyric ratio g from a simple formula w = g B.
Upon increasing B and homogeneity of the
external field B they saw many lines instead of
one. Spin coupling was discovered in a similar
fashion.
Connect The Unconnected, or Look At The Other World.
•a classical example: Nicola Tesla's watched a sunset,
thinking about the Earth spinning around its axis and
originating the idea of an AC motor.
•application of the theory developed initially for spin
glasses in physics to brain neurons in biomedicine. An
approach developed or observed in one world is
transferred to another one.
•Magnetic Resonance Imaging received a huge
momentum after adopting some ideas of Computer
Tomography, namely Reconstruction by Projections.
•the idea came to MRI from the world of X-rays where
information about the image is gained through
examining its shadows.
•NMR/ MRI is totally different from X-rays, there are no
shadows in MRI. However application of field gradients in
different directions in combination with Reconstruction by
Projections.
•Looking for examples of successful application of this
strategy we can deviate from science
•the similar creative approach was used by W. Gordon to
develop Pringles potato chips. The question at issue was
denser packaging of chips inside the bag
•dry chips like dry leaves in the late fall do not pack very
closely
•wet leaves are rather elastic and can pack closely inside a
trash bag. When they dry inside the bag, they retain the
shape needed for close packing