John Turton Randall was trying hard, real hard. For some time now, the University of Birmingham physicist was focusing on trying to improve the features of a machine which transmitted and received electromagnetic waves. A few years back this would have been just another intriguing academic problem for a physicist to crack, but this time it was a matter of life and death for thousands. Literally. It was 1939, and an ominous menace loomed large over Europe in the person of Adolf Hitler. The machine Randall was working on was designed to thwart Hitler's attempts to invade the British mainland. It sent out electromagnetic waves of meter wavelength and tried to deduce the position of an object based on its reflection of these waves. The operating principle of this humble machine later turned into a household name- Radar.
Unfortunately, Radar as it stood in 1939 was
extremely poor at thwarting an enemy invasion. Britain's Radar defenses all
relied on meter-wave radio detection. They were plagued by poor resolution and
low power and could detect enemy aircraft only to a range of about 100 miles.
They were fairly good at detecting distance, but not angle. And they were
abysmal at detecting low-flying aircraft. The trick was to somehow design
microwave transmitters, which could significantly ameliorate all these problems.
The amelioration turned out to be quite a scientific and engineering feat, but
it won the British the Battle of Britain and The War. Even more than the atomic
bomb, it was Radar that saved Queen and Country.
A few years before, two other Britons had
investigated how to determine the structure of molecules using beams of x-rays.
The father and son duo of William and Lawrence Bragg found out that they could
finely interrogate molecular crystals with x-rays, the way a handsome movie star
would obsess over combing his hair with a fine-toothed comb to plough through
every single fiber. By knowing the wavelength of the x-rays and the angle at
which the x-rays were scattered, the two could determine the location of atoms
in the crystal, an amazing achievement considering how small atoms
are.
Half a world away on the other side of the
pond, another physicist named Isidor Rabi was experimenting with a different
kind of beam- a molecular beam of magnetic particles. A supremely confident
physicist without a hint of arrogance, Rabi had been educated in the best center
of physics in Europe during the 1920s. Now at Columbia University in New York
City, Rabi was observing something startling. A beam of ions passing through a
magnetic field could be manipulated by another magnetic field perpendicular to
the first one. Rabi noticed that at certain frequencies of the second magnetic
field, there was a sudden dip in intensity of the beam, indicating a sharp
absorption of energy. Rabi had been intrigued by this phenomenon which had
turned out to be very general. The absorption of energy seemed very similar to
the phenomenon of resonance in physics that can lead to glasses being shattered
by unbearably shrill opera singers and bridges being shattered when soldiers
march in lockstep on them. Rabi saw an analogy in his experiments and named the
phenomenon "nuclear magnetic resonance".
If modern molecular biologists can be
grateful to a handful of founding physicists for bequeathing them an enormous
legacy, Randall, Rabi and the two Braggs should be on top of their list. Rabi's
experiments were enhanced and finessed to perfection. They were turned into one
of the two most important methods in chemistry- Nuclear Magnetic Resonance
spectroscopy. Randall's microwaves became valuable tools in determining
molecular structure (it was microwave spectrosopy for instance that has brought
Harry Kroto to Lindau for his discovery of fullerenes) and in astronomy. More
importantly, after the war, Randall switched fields and turned to the
fledgling science of molecular biology. He pioneered study in this field when it
was just getting jump started. He was the person who brought Maurice Wilkins and
Rosalind Franklin to King's College, London. They in turn collaborated with
James Watson and Francis Crick- recruited by Lawrence Bragg- at Cambridge
University to make the epochal discovery of the structure of DNA. Others under
the guidance of Bragg such as Max Perutz and John Kendrew pioneered the study of
protein structure.
I narrate the story of these physicists
because they illustrate two of the best examples of what we can call
'tool-driven scientific revolutions'. Today, NMR spectrcopy and x-ray
crystallography are at the heart of molecular biology. X-ray diffraction
especially is the single-most important tool in the field. It is as close as one
can get to taking a direct photograph of a molecule. Molecular biology today
would be unthinkable without it. In fact all of chemistry and biology would
still be struggling to get its feet off the ground without these two techniques.
Not only have the techniques given us the structure of DNA and proteins, but
they conitnue to supply us with insights that lead to better drugs to combat
disease. It should not surprise us at all that a few dozen Nobel Prizes have
been awarded to pioneers and users of these techniques.
Top: Working on the Manhattan Project; Ernest Lawrence, Enrico Fermi and Isidor Rabi. Bottom: John Randall
X-ray crystallography and NMR spectrocopy
seem to fly in the face of those who commonly believe that science is idea and
concept-driven. The whole business of grand ideas driving scientific revolutions
got a tremendous boost when Thomas Kuhn's "The Structure of Scientific
Revolutions" was published in 1962. The story goes that Kuhn got the idea for
his book when he had been asked to teach a course on Aristotlean science at
Harvard. Going over Aristotle's works, Kuhn was astonished how someone who was
of such a supreme intellectual caliber could get his basic physics so woefully
wrong. Pondering over this paradox, Kuhn's eyes were opened when he realized
that he was looking at the subject all wrong; look at the subject through Aristotle's eyes and the world of five elements and
four causes seems to make sense. Aristotle had the right mind, but he was
working with the wrong paradigm. What he needed was a paradigm
shift.
Since then, the term "paradigm shift" has
become part of everyday language, and it has been misused outside its context of
science much more than it has been used inside it. Kuhn himself toward the end
of his life was furious at its misuse and used to ferociously insist that he was
"not a Kuhnian". But the basic idea that science is essentially concept-driven
has stuck. However, the history of crystallography and NMR spectroscopy seem to
indicate that scientific revolutions can also be engendered by more mundane
developments of machines and practical tools; what physicist Freeman Dyson calls
the "craft of science". What would medicine and
biology look like for example without the invention of the microscope? As
Dyson says, the tool-inspired paradigm has been best explained by Harvard
University philosopher Peter Galison, especially in his 1997 book "Image and
Logic". The book is full of diagrams of scientific instruments, circuits and
schematics, unlike Kuhn's book which is full of words. Everyone remembers Kuhn's
book; few seem to recognize Galison's name.
Galison even points us to the most popular
twentieth century example of an apparently idea-driven scientific revolution and
demonstrates how tools played a crucial role in it. He is talking about
Einstein's theory of relativity, whose formulation crucially depended on thought
experiments on clocks and moving rods which the young patent clerk obsessed
over. In fact Einstein was fascinated by clocks, and he happened to be in Bern
which at the time was a world leader when it came to clock manufacture and
design. As he got on the train everyday, he undoubtedly would have wondered
how the clocks on different train stations were so precisely synchronised.
Einstein's Clocks became an integral part of Einstein's Theory.
As another example of tool-driven science,
consider another supremely accomplished scientist of the twentieth century-
Ernest Rutherford. An experimentalist who often scorned theorists, Rutherford
was nonetheless responsible for a paradigm shift in our view of the structure of
the atom. But one would be hard-pressed to find anyone else who reveled so much
in the joys of machine oil, sealing wax and duct tape. Rutherford undoubtedly
liked to roll his sleeves up and get his hands dirty. He hardly fits our
conception of the philosopher-scientist who heralds revolutions by power of
thought alone. And yet Rutherford without a doubt led a scientific revolution in
a laboratory which has produced no less than 29 Nobel Prize winners. Yet another
example of a brilliant tool wielder was the American physicist Ernest Lawrence,
whose invention of the cyclotron opened the curtain on a new era of research in
atomic and nuclear physics.
The list can be endless if you look in the
right places. The fact is that tool-driven science has been as responsible for
scientific revolutions as have grand ideas. Let us appreciate the laboratory
toilers covered with sweat as much as we appreciate the deep thinkers. Science
needs both to progress. And it is only fitting that tool-driven science has
culminated in in the 2010 Nobel Prize in chemistry. We will look at this in the
next post.
"Science needs both to progress. And it is only fitting that tool-driven science has culminated in in the 2010 Nobel Prize in chemistry"
I guess you meant 2009.
or is it 2011 already? sometimes I forget which year we are in.
That happens to me too! Thanks for pointing it out.
I agree. Science has always been tool-driven, in my opinion. Knowledge of the world really took off when people seriously started toying around with it instead of only using logic and reason (which are overrated anyway). Everything that came before experimenting was, in my opinion, hapless guesswork.
Akshat Rathi 23.06.2010 | 20:04
I agree that the scientific method and the wide use of experimentation has done a lot for science but I won't go so far to say that what came before was 'hapless guesswork'. It was the body of thought, the act of contemplation that conceived the idea of experimentation. For realisation of those ideas you needed tools.
What Ashutosh is arguing here is that these tools did not just help realise or prove wrong the ideas that were thought before the tool was made but it also allowed people to come up with ideas because there existed a tool to achieve it.
Ashutosh's argument, as I understand, is that one should not underestimate the power of tool-driven science but it is not trying to down play the importance of idea-driven science.
Ashutosh 28.06.2010 | 14:05
Indeed! Ideas and logic are supremely important in science. As Akshat says, my post was only meant to suggest that tools are sometimes undervalued and they too can often bring about scientific revolutions.