Is Life Based on the Laws of Physics?

New Laws in the Organism

The structure of living matter is not based on the ordinary laws of physics.

But there is no ’new force’ directing the behaviour of the single atoms within a living organism.

Rather, the construction is different from anything in the physical laboratory.

An engineer who only knows heat engines only will find that an electric motor works along principles he does not yet understand.

The events in the lifecycle of an organism has an admirable regularity and orderliness.

It is unrivalled by anything in inanimate matter.

It is controlled by a supremely well-ordered group of atoms, which represent only a very small fraction of the sum total in every cell.

From the mechanism of mutation, I conclude that the dislocation of just a few atoms within the group of ‘governing atoms’ of the germ cell can create a well-defined change in the large-scale hereditary characteristics of the organism.

These facts are easily the most interesting that science has revealed in our day.

We may be inclined to find them, after all, not wholly unacceptable.

An organism’s astonishing gift of concentrating a ‘stream of order’ on itself and thus escaping the decay into atomic chaos - of ‘drinking orderliness’ from a suitable environment - seems to be connected with the presence of the ‘aperiodic solids’, the chromosome molecules, which doubtless represent the highest degree of well-ordered atomic association we know of - much higher than the ordinary periodic crystal - in virtue of the individ ual role every atom and every radical is playing here.

To put it briefly, we witness the event that existing order displays the power of maintaining itself and of producing orderly events. That sounds plausible enough, though in finding it plausible we, no doubt, draw on experience con- cerning social organization and other events which involve the activity of organisms. And so it might seem that something like a vicious circle is implied.

Summarizing The Physical Situation

The regular course of physical events is never the consequence of the well-ordered configuration of atoms unless it was in a liquid or a gas.

Even when the chemist handles a very complicated molecule in vitro he is always faced with an enormous number of like molecules. To them his laws apply.

He might tell you, for example, that one minute after he has started some particular reaction half of the molecules will have reacted, and after a second minute three-quarters of them will have done so. But whether any particular molecule, supposing you could follow its course, will be among those which have reacted or among those which are still untouched, he could not predict. That is a matter of pure chance.

This is not a purely theoretical conjecture. I t is not that we can never observe the fate of a single small group of atoms or even of a single atom.

We can, occasionally. But whenever we do, we find complete irregularity, co-operating to produce regularity only on the average. We have dealt with an example in chapter I.

The Brownian movement of a small particle suspended in a liquid is completely irregu- lar. But if there are many similar particles, they will by their irregular movement give rise to the regular phenom- enon of diffusion.

The disintegration of a single radioactive atom is observable (it emits a projectile which causes a visible scintillation on a fluorescent screen). But if you are given a single radioactive atom, its probable lifetime is much less certain than that of a healthy sparrow. Indeed, nothing more can be said about it than this: as long as it lives (and that may be for thousands of years) the chance of its blowing up within the next second, whether large or small, remains the same. This patent lack of individual determination never- theless results in the exact exponential law of decay of a large number of radioactive atoms of the same kind.

The Striking Contrast

In biology, a single group of atoms existing only in one copy produces orderly events, marvellously tuned in with each other and with the environment according to most subtle laws.

I said, existing only in one copy, for after all we have the example of the egg and of the unicellular organism. In the following stages of a higher organism the copies are multiplied, that is true. But to what extent?

Something like 10 14 in a grown mammal, I understand. What is that! Only a millionth of the number of molecules in one cubic inch of air. Though comparatively bulky, by coalescing they would form but a tiny drop of liquid. And look at the way they are actually distributed. Every cell harbours just one of them (or two, if we bear in mind diploidy). Since we know the power this tiny central office has in the isolated cell, do they not resemble stations of local government dispersed through the body, communicating with each other with great ease, thanks to the code that is common to all of them?

Well, this is a fantastic description, perhaps less becoming a scientist than a poet.

However, it needs no poetical imagination but only clear and sober scientific reflection to recognize that we are here obviously faced with events whose regular and lawful unfolding is guided by a ‘mechanism’ entirely different from the ‘probability mechanism’ of physics.

For it is simply a fact of observation that the guiding principle in every cell is embodied in a single atomic association existing only in one copy (or sometimes two) - and a fact of observation that it results in producing events which are a paragon of orderliness. Whether we find it astonishing or whether we find it quite plausible that a small but highly organized group of atoms be capable of acting in this manner, the situation is unprecedented, it is unknown anywhere else except in living matter.

The physicist and the chemist, investigating inanimate matter, have never witnessed phenomena which they had to interpret in this way. The case did not arise and so our theory does not cover it - our beautiful statistical theory of which we were so justly proud because it allowed us to look behind the curtain, to watch the magnificent order of exact physical law coming forth from atomic and molecular disorder; because it revealed that the most important, the most general, the all-embracing law of entropy increase could be understood without a special assumption ad hoc, for it is nothing but molecular disorder itself.