If it can’t be measured, surely it doesn’t exist?

Dr Melinda Duer

27th October 2013

Science can explain everything, can’t it?  If not now, then with a bit more work, surely it can.  Actually, I’m not so sure.  I think there are some things that Science as it is presently operates, will not be able to explain or indeed shed much light on at all.  Why do I think that?  Because Science explains phenomena by measuring or calculating things and before you can measure or calculate something, you have to know what it is, or at least what kind of thing it is.  So, we can measure electrical currents with an oscilloscope, because we know about electrical currents, we know that they are basically a stream of charged particles, and so we can design a piece of kit to measure things about a stream of charged particles, be it in an electrical circuit in a television, or down a nerve in an animal.  But until we know what substance something is made up of, or what kind of force causes a phenomenon, we can’t even begin to design an experiment to measure or calculate anything about it.

I work on the boundaries between chemistry, physics, materials science, biology and medicine.  I’m trained as a physical chemist.  When I first started to look at human medicine, what struck me was just how little we know about the human body.  Of course, medical and biological science has advanced hugely in the last two centuries.  We know now how to cure cancers that only ten years ago killed without fail and how to replace defective hearts and livers, all amazing things.  But although we know that our tissues are largely made up of a protein called collagen and although that same collagen protein is used to plump up wrinkles in ageing actresses, we don’t actually know what its structure is.  Imagine that, the most abundant protein in our bodies, the molecule that is key in the tissue which forms all our organs, our kidneys, our heart, our blood vessels, bones, teeth and skin, and we don’t know how its atoms are arranged.  And because we don’t know how its atoms are arranged, we don’t know really how it works.  In truth, there is more in our tissues than just collagen protein.  There is a whole host of interacting molecules, that change with time and age and a whole load of other factors we still don’t know about.  And that’s what I work on – trying to deduce the structure of all those molecules, including collagen, and understand how they interact with each other to produce the amazing biological and mechanical functions of a tissue.

The reason that Science does not yet know the atomic structure of our tissues is, quite simply, that they are just so complicated.  The techniques that can tell us what the atomic structure of a silicon chip or a man-made polymer is simply don’t work on a tissue.  But at least we know that a tissue is basically made up of arrangements of atoms, so we can design experiments to begin to glean information about them. With the clues given by a whole host of experiments and modelling what structures could fit in with the results from them, we can begin to uncover the molecular structures.  In time, I am confident we will understand the molecular structure of tissues, and how and why they are altered by disease, how the molecules in a tissue are altered to allow cancer cells to grow there, for instance, why tissues age and skin wrinkles.  In fact, we’re more than halfway there on some of those aspects already but what I have learnt most in the last ten years is that you have to be incredibly broad minded and prepared to overturn long-held beliefs when you are the first person to ever see something.  When what is in a tissue has only ever previously been examined indirectly, by pulling a tissue apart and analysing the fragments of molecules that you are able to extract from it, the chances are that things will have been missed, sometimes, even rather big things.  And remember, we can only measure what we know about.  So, scientists know there are proteins in tissues, so they analyse proteins.  Scientists haven’t analysed much at all for other polymers or other types of molecule in tissues.  No one has seriously analysed tissues for (extracellular) DNA, for instance.  Scientists only look for DNA inside cells because all the research that has been done tells us without any doubt that DNA is in cells and we understand its job there; it’s a job that can only be done inside a cell.  Over the years scientists have implicitly made the assumption that DNA has only one function, and that function being inside a cell means that DNA only exists in any functional role inside a cell. 

I tell you this because some years ago, we started looking for the molecule that makes tissues calcify.  Our bone tissues calcify, that is, they acquire crystals of calcium phosphate.  That’s what makes bones strong and structural – and why your mother made you drink milk and eat your greens when you were kids.  But arteries also calcify – that’s the so-called hardening of the arteries; kidneys calcify causing kidney stones and ultimately, chronic renal failure.  The main technique we use in my lab, something called solid-state nuclear magnetic resonance spectroscopy, sees everything that is in a tissue, providing it’s there in reasonable concentration – and providing you have the patience for the months of data analysis. So using this technique, we see the proteins in a tissue – and everything else.  So we worked out that the molecules that trigger calcification of tissues is the same in all cases – in bones, in arteries and in kidneys -  and that in contrast to popular hypothesis, they are not a proteins, but sugars.  Everyone thought it must be protein, because they had only ever looked at the proteins – they’d simply never measured anything else.  Why not?  Because they didn’t know what else was there.  Because the technology to look at anything else either didn’t exist or was too complicated or expensive to use.  So, using what is a pretty new technique for biology, our nuclear magnetic resonance spectroscopy, we worked out that sugars were the culprit in calcification, but we knew very little else about it.  We didn’t know what sorts of sugars they are, what their structures are or how they’re linked to the rest of the tissue.  All we knew was that there were others things bonded to the sugar moelcules.  That was seven years ago.  Finally, in the last six months, we have worked out the identity of the sugars.  And guess what?  They’re fragments of DNA and a sugar-based polymer that biochemists know to be a repairer of damaged DNA.  They are so not what we, or anyone else, was expecting.  Where do they come from?  From dead cells – ones programmed to die in the case of calcifying bone; ones killed because of chronic inflammation and fatty deposits in the case of arteries and kidneys.  And it makes sense.  Nature is rarely wasteful – that’s what several million years of evolution does for you.  So why would Nature go to all the trouble of evolving a whole new molecule when there’s already one there that can do the job?  But DNA can’t be in tissues, someone told me confidently, only in cells.  Really?  Why not?  Because we couldn’t detect it in tissues before now.  Just because we can’t measure it, doesn’t mean it doesn’t exist.

All in all, I’m pretty confident that given time and a substantial amount of effort from me and many others the world over, we, the scientific community, can explain a huge amount about the atomic structure of tissues and how they work.  But there is one thing in my research that I am equally confident that I will not be able to explain, no matter how much effort I put in.

Let me give you a little background here before I tell you what it is.  I work with biologists, physicists, medics, even engineers, a very interdisciplinary team.  The best days I have,  without the shadow of a doubt, are those when we all meet up and chew over the latest results, because when that team gets together, something that I can only describe as magic happens.  Ideas come out that none of us alone would have dreamt of.  We as a team become more than the sum of our parts.  Something very special happens when human beings interact and that is what I cannot explain.  Sometimes in our research group, the ideas start to flow before any of my colleagues have even opened their mouths, so it’s not the verbal exchange of ideas.  There is, I am quite certain, some sort of communication or link between human beings that doesn’t use sight or sound or smell or even touch.  I call it our humanness. 

It’s the same sense, I think, that allows us to know when a loved one is in trouble.  For some part of my childhood, I was the main carer for my little brother (I still call him my little brother even though he’s now 43 and a good 6’6’’ tall) .  As a child, I always knew when he’d fallen down and cut himself, long before I heard the screams or saw the blood.  I suspect it’s something of the same humanness that makes a complete stranger stop to help someone in distress.  When you think about it, stopping to help a spiritually or physically injured person defies logic.  At the very least, it makes you late for work.  In evolutionary terms, it ensures there is another mouth to feed and one we surely can’t imagine will help us.  Yet we all know that feeling that sometimes there is something that is so much more important than being on time for work or even than our own wellbeing, that we just have to stop and help whatever the consequences.  We might call it empathy or sympathy, but what are those things?  Science can do experiments that show which part of the brain lights up when we help someone.  It can measure all sorts of responses that demonstrate the existence of something, but none of those experiments explain what this humanness is.  They can’t.  We don’t fundamentally know what it is, what it consists of, so we don’t know how to measure it.  We can guess at what it might be and set up experiments on that basis.  But if those experiments show nothing, it does not mean that our humanness does not exist, only that we don’t know how to measure it.

There’s one other aspect of our humanness that I want to mention, because it’s relevant here: that part which gives us an innate sense of right and wrong.  I’m not talking of our conscious debate about moral rectitude – as adults we are aware of a huge grey area that is the stuff of debates and politicians’ careers.  I’m talking about that deep down feeling when we just know, without being able to explain, that something is right or wrong.  In the recent Westgate Shopping Mall massacre in Kenya, it was a four-year old boy, a four year old, who saved his mother from a gunman by shouting at him,

            “You’re a very bad man!  Leave us!”  Because a four year old boy knew what somehow that grown man had managed to eradicate – that killing a mother in cold blood is wrong.

That massacre, like others before it and others inevitably to come, was ostensibly done in the name of religion.  You don’t need me to tell you that no true religion, including Islam, advocates murder.  Rather, it seems to me that religions like Islam and Christianity are, at least at some level, doing for our humanness what science seeks to do for our physical world: provide a framework on which we can understand it.  And like science, there is a very honourable intention behind the endeavour which I can best describe as trying to make our lives better in some shape or form – healthier, perhaps.  Because as soon as we begin to understand something, we accept it.  If we have some sense of understanding our humanness, we will accept it, we will honour it, not try to fly against it as the gunmen in Kenya and murders everywhere have. 

There are other aspects similar in both science and religion.  Terrible things are done in the name of religion. Terrible things are done in the name of science too.  It seems to me that we cannot go against our basic humanness, against what we know is fundamentally right and wrong, without ascribing our motive to some higher force.  In that context, both science and religion all too easily become the culprits.  But at their best, both science and religion give us confidence, confidence that we can understand the world around us in all the aspects that matter to us right now.  If they are to serve us well though, we must keep questioning and both science and religion must allow us to question, because we don’t know, we cannot yet know, how we will need to understand our world next year or in the next century. 

But always remember, just because you can’t measure it, see it, smell it , hear it or touch it, doesn’t mean it doesn’t exist.