When Logic Says It Is Impossible

“You could write the entire history of science in the last 50 years in terms of papers rejected….”  –Paul Lauterbur, inventor of the MRI, about being told his idea could not work

Lauterbur always comes to my mind whenever the question becomes, “Do all scientists understand their subject matter in the same way?” That question arises because it is relevant to Thomas Kuhn’s arguments about paradigm shifts and to how science changes its mind. Also, it arises in conjunction with discussions of the differences between physics and mathematics (as when an old physics prof of mine told us, “Beware of mathematicians. They will rot your mind”). Math is a formal system where there is just one logic that applies to everything, but nature is full of gray areas. For instance, in math it works to say, “Either it is this way, or it is not.” But in the real world, that assertion creates the problem of double negatives. Regarding nature, to say, “It’s not ‘not that way’” only opens the door to many possibilities.

Lauterbur was a chemist who did research in nuclear magnetic spectroscopy, which is a method in analytical chemistry for identifying unknown chemicals. He had the idea that that could be turned into an imagining technique. But when he submitted it for publication, he was told that his idea would not work and, moreover, the consensus was that it was thought to be impossible. And even Lauterbur later admitted that the reason it had not been already done was that, in his words, “If it doesn’t seem possible, nothing much gets done.”

But Lauterbur had his own way of understanding nuclear magnetic resonance, based on his own years of research. He brought to the subject his own intuition of what was going together to make it work. And in his way of making sense of NMR, it ought to be possible to turn it into MRI (magnetic resonance imaging).

Of course, needless to say, he did it. And further, after he won the Nobel prize, he talked with reporters about how science learns to change its mind.

So first, let’s look at how his experience speaks to Kuhn’s famous description of the way science is said to change its mind. Kuhn argued that science displays long periods of everyone thinking the same way (Kuhn called it “normal science”), interspersed with dramatic new ideas which come along and cause a “paradigm shift” after which everyone thinks the same in the new way.

But an alternative to Kuhn’s explanation is to see that any single scientific notion can be understood with slightly different suppositions by different people, and then advances can be made as one slightly different way proves more fruitful than the others. And as time goes along, the fruitful way becomes more and more utilized in what people do next, which could eventually lead to breakthrough kinds of developments because having more people using it means having still more slightly different suppositions and backgrounds coming to bear on it. (At least that is how I would answer Kuhn. I think Lauterbur exemplifies that approach and would agree). As it turns out, even Kuhn himself, in his later years (at least according to the editors of his posthumous papers), came to worry that paradigm shifts were contrary to how changes occur in Darwinism, where changes are all about gradualism. In biology, sudden shifts—called “saltation”—are vehemently argued to be impossible (although once it was discovered that viruses can incorporate themselves into the genes of hosts, that is being rethought).

But an interesting aside is that, yes, Lauterbur had his idea while at a restaurant, and true to the proverbial manner of physical scientists, he jotted down on a napkin how to make MRI’s (and the napkin—actually, it was an envelope—is supposedly on display somewhere). I once was at a restaurant where I saw a table of eight people wildly scribbling down notes on napkins, calling for more napkins, and all of them greatly excited. I wanted to go up to them and ask, “Pardon me, but would you people happen to be physicists?” But of course I didn’t because I didn’t want to disturb their inspiration.

Anyway, back to Lauterbur because there is a second major point that can be made about his experience. It is often held philosophically that objects have a distinct set of qualities to them, and that that is that. Those qualities make what the objects are. But nuclear magnetic resonance does not work that way. In NMR, the amount of resonance depends on what else is present. A methyl group resonates with a different range of frequency depending on what atoms are next to it, a difference which is what enables the identification of the rest of the molecule. (We say, “The methyl group is acting this way, so that indicates that what else is there must be such-and-such”). Since the methyl group is measured to have different qualities depending on its neighbors, it seems not to exist in the absolute sense of having a fixed set of qualities that is always the same.

If by “absolute” we mean “not dependent on anything else to be what it is,” then NMR is an example of the contrary. It shows that the qualities of a thing can be different depending on the setup of its situation.

In other words, context counts. And that might seem obvious enough, but it is one of those ideas that has been taboo in philosophy because historically philosophy prefers to talk of “things in themselves” that follow laws absolutely (regardless of anything else).

NMR was one of those 20th Century advances (along with relativity) which cast doubts on the notion of absolutes. But unlike relativity, which only applies at velocities near the speed of light (and so could be ignored in daily life) NMR works at any speed.

And all of that was well-understood by Lauterbur’s time. It was part of the new belief in what was now logical.

But then look at what Lauterbur did. To make an image would seem to entail making a lot of dots, or pixels, which altogether constitute the image. To aa viewer, each pixel would seem to be what it is regardless of anything else. It would seem to reflect what was really there absolutely in the thing being imaged. How could Lauterbur make such an image (with each pixel unique) using a technology where demonstrably the value of each pixel is going to be varied depending on its neighbors? There could be no direct correspondence between a spot in the thing being imaged and the pixel that was representing it because the measurements would be blurred by the myriad neighbors. How could all that neighbor effect be eliminated to see what was “really” there in the thing itself?

It seemed logically impossible.

But then again, maybe not if looked at slightly differently. Perhaps all of that neighbor effect would combine to create unique differences from place to place in a way that would show up under certain background conditions,

If what a thing is measured to be depends on the setup of what else is there, then change the setup to get what you want.

That is how to handle knowing things relatively (knowing them compared to something else) rather than knowing them absolutely (regardless of anything else). We can look to the entire setup of how things are fitting together.

It is actually very common to deal with a relative world in that manner. If the atoms in a piece of metal vibrate with a frequency that is different depending on the temperature of the air, and if that vibration further depends on the type of metal, and if that creates different amounts of expansion and conductivities, then all those differences and dependencies do not create a mess of confusion. Just the opposite, the differences and dependencies are what enable us to be creative about the setup, in this case to build a thermostat where two metals coupled together can switch a furnace on and off by their relative expansions in an electric circuit.

The utility lies in how it all fits together (not in seeing things in isolation, regardless of anything else). And again, that is how to deal more generally with relative knowledge rather than absolute knowledge. Look to see what can happen under different arrangements of setups.

Regarding using NMR for imaging, in Lauterbur’s way of understanding it, it could work if we concentrate on measuring hydrogen atoms (whereas in spectroscopy we concentrate on carbon atoms). There are plenty of hydrogen atoms in the water in our cells, and the neighbor effects of other hydrogens could be thought of as creating a density of hydrogen that is different from place to place.

I won’t go into the details, but the point is that seeing an image where each pixel appears to be a “thing in itself” got that way by going through a process wherein what a thing even “is” depends upon its neighbors. It is not a direct process like an x-ray being able to pass through an object, or not, in going from here to there.

And ahem, could the rest of the world work in a similar manner? What our minds make for us to observe is a processed result, and it seems wrong to assume that the logic of how the processing works has to be the same as the logic that we see in the finished product. Yet it is often assumed that there is just one logic that applies to everything. For instance, I see that assumption made all the time in the theories of how minds arise from brains (as if brains have to work via the logic of Newtonian mechanics). Or when we say that quantum mechanics is paradoxical, that just means that the logic of macro-scale actions is a finished product and not the same logic as what made that finished product.

I am perplexed that the philosophy of science seems to have bifurcated itself into the philosophy of physics and the philosophy of biology (and even of mathematics and of mind), but it has left out a philosophy of chemistry. Chemistry is the study of how matter fits together to make setups, and, as I have been arguing, different setups have different logics to them. Chemists have discovered a lot of little tricks which nature uses to put together more complex entities. And these little tricks might apply to knowledge and to how it is put together and so to what is logical to believe. But that is being left out of the discussion.

Lauterbur is just one example of what a philosophy of chemistry might study.

He also exemplifies expanding knowledge by, as he put it, “continuing my habit of doing things a little differently than expected….”

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