Thursday, 3 June 2010
How, Notwithstanding Its Stability, Matter Can Dissociate
Causes Capable of Modifying Molecular and Atomic Structures ~
The first objection which occurs to the mind of the chemist to whom one sets forth the theory of the dissociation of matter, is the following: How can bodies so stable as atoms --- which appear to withstand the most violent reactions, since their weight is always recognized as invariable --- dissociate either spontaneously or under such slight causes as rays of light hardly capable of influencing a thermometer?
To say, as I maintain, that matter is a large reservoir of forces, simply means that there is no need to look outside it for the origin of the energy expended during dissociation, but this in no way explains how intra-atomic energy condensed under an evidently very stable form can free itself from the bonds which hold it. The doctrine of intra-atomic energy therefore supplies no solution to the question just put. It is unable to say why the atom, which is to all appearance the most stable of all things in the universe, can, under certain conditions, lose its stability to the extent of easily disaggregating
If we wish to discover the solution of this problem, it will first be necessary to show, by various examples, that in order to produce in matter very great changes of equilibrium, it is not always the magnitude of the effort which counts, but rather the quality of that effort. Every equilibrium in Nature is only sensitive to the appropriate excitant, and it is this excitant which must be discovered in order to obtain the effect sought. Once discovered, it can be seen that very slight causes can easily modify the equilibrium of atoms and bring about, like a spark in a mass of gunpowder, effects whose intensity greatly exceeds that of the exciting cause.
A well-known acoustic analogy allows this difference between the intensity and the quality of the effort to be clearly shown from the point of view of the effects produced. The most violent thunderclap or the most deafening explosion may be powerless to cause the vibration of a tuning fork, while a sound, very slight but of suitable period, will suffice to set it in motion. When a tuning fork starts vibrating by reason of the production near it of a sound identical with its own, it is said to vibrate by resonance. The part played by resonance in acoustics as well as in optics is now well known; it gives the best explanation of the phenomena of opacity and transparency. It can help to explain, with all sthe facts I am about to state, that insignificant causes can cause great transformations in matter.
Causes Capable of Producing the Dissociation of Very Radioactive Substances ~
...Though the amount of energy radiated by atoms during their disaggregation is very large, the loss of material substance which occurs is extremely slight, by reason of the enormous condensation of energy contained in the atom. M. Becquerel estimates the duration of one gram of radium at a billion years. M. Curie contents himself with a million years. More modest still, Mr. Rutherford speaks only of a thousand years, and Sir William Crookes of a hundred years, for the dissociation of a gram of radium.
...But even if we accepted the figures of a thousand years given by Mr Rutherford for the duration of the existence of one gram of radium, it would be sufficient to prove that if spontaneously radioactive bodies, such as radium, existed in the geological epochs, they would have vanished long since, and would consequently no longer exist. And this again goes to support my theory, according to which rapid and spontaneous radioactivity only made its appearance since the bodies in question have been engaged in certain peculiar chemical combinations capable of affecting the stability of their atoms, which combinations we may perhaps some day succeed in reproducing.
Can the Existence of Radium be Affirmed With Certainty?
If radioactivity be the consequence of certain chemical reactions, it would appear that an absolutely pure body cannot be radioactive. It was on this reasoning, supported by various experiments, that I based by assertion a few years ago that the existence of the metal radium was very problematic. In fact, although the operation of separating a metal from its combinations is very easy, it has never been possible to separate radium.
...Without being able to pronounce positively, I repeat that I believe the existence of radium to be very disputable. It is, at any rate, certain that it has not been possible to isolate it. I should much more willingly admit the existence of an unknown compound of barium capable of giving this metal radioactive properties.
~~Gustave Le Bon