ARRHENIUS, WORLDS IN THE MAKING

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Re: ARRHENIUS, WORLDS IN THE MAKING

Post by thelivyjr » Tue Feb 11, 2020 1:40 p

VII - THE NEBULAR AND THE SOLAR STATES, continued ...

Chamberlin and Moulton have attempted to show that the difficulties of the hypothesis of Laplace may be obviated (removed) by the assumption that the solar system has evolved from a spiral nebula, into which strange bodies intruded which condensed the nebular mass of their surroundings upon themselves.

We have pointed out examples of how the nebula seems to vanish in the vicinity of the stars, which would correspond to growing planets, located in nebulae.

In concluding this consideration, we may draw a comparison between the views which were still entertained a short time ago and the views and prospects which the discoveries of modern days open to our eyes.

Up to the beginning of this century the gravitation of Newton seemed to rule supreme over the motions and over the development of the material universe.

By virtue of this gravitation the celestial bodies should tend to draw together, to unite in ever-growing masses.

In the infinite space of past time the evolution should have proceeded so far that some large suns, bright or extinct, could alone persist.


All life would be impossible under such conditions.

And yet we discern in the neighborhood of the sun quite a number of dark bodies, our planets, and we may surmise that similar dark companions or satellites exist in the vicinity of other suns and stars; for we could not understand the peculiar to-and-fro motions of those stars on any other view.

We further observe that quite a number of small celestial bodies rush through space in the shapes of meteorites or shooting-stars which must have come to us from the most remote portions of the universe.

The explanation of these apparent deviations from what we may regard as a necessary consequence of the exclusive action of gravity will be found under two heads in the action of the mechanical radiation pressure of light, and in the collisions between celestial bodies.

The latter produce enormous vortices of gases about nebular structures in the gaseous condition; the radiation pressure carries cosmical dust into the vortices, and the dust collects into meteorites and comets and forms, together with the condensation products of the gaseous envelope, the planets and the moons accompanying them.

TO BE CONTINUED ...

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Re: ARRHENIUS, WORLDS IN THE MAKING

Post by thelivyjr » Wed Feb 12, 2020 1:40 p

VII - THE NEBULAR AND THE SOLAR STATES, continued ...

The scattering influence of the radiation pressure therefore balances the tendency of gravitation to concentrate matter.

The vortices of gases in the nebula only serve to fix the position of the dust, which is ejected from the suns through the action of the radiation pressure.

The masses of gas within the nebulae form the most important centres of concentration of the dust which is ejected from the sun and stars.

If the world were limited, as people used to fancy that is to say, if the stars were crowded together in a huge heap, and only infinite, empty space outside of this heap, the dust particles ejected from the suns during past ages by the action of the radiating pressure would have been lost in infinite space, just as we imagined that the radiated energy of the sun was lost.

If that were so, the development of the universe would long since have come to an end, to an annihilation of all matter and of all energy.


Herbert Spencer, among others, has explained how thoroughly unsatisfactory this view is.

There must be cycles in the evolution of the universe, he has emphasized.

That is manifestly indispensable if the system is to last.

In the more rarefied, gaseous, cold portions of the nebulse we find that part of the machinery of the universe which checks the waste of matter and, still more, the waste of force from the suns.

The immigrating dust particles have absorbed the radiation of the sun and impart their heat to the separate particles of the gases with which they collide.

The total mass of gas expands, owing to this absorption of heat, and cools in consequence.

The most energetic molecules travel away, and are replaced by new particles coming from the inner portions of the nebulse, which are in their turn cooled by expansion.

Thus every ray emitted by a sun is absorbed, and its energy is transferred, through the gaseous particles of the nebulse, to suns that are being formed and which are in the neighborhood of the nebula or in its interior portions.

The heat is hence concentrated about centres of attraction that have drifted into the nebula or about the remnants of the celestial bodies which once collided there.


Thanks to the low temperature of the nebula, the matter can again accumulate, while the radiation pressure, as Poynting has shown, will suffice to keep bodies apart if their temperature is 15 C., their diameter 3.4 cm., and their specific gravity as large as that of the earth, 5.5.

At the distance of the orbit of Neptune, where the temperature is about 50 absolute and approximates, therefore, that of a nebula, this limit of size is reduced to nearly one millimetre.

It has already been suggested (compare page 153) that capillary forces, which would prevail under the co-operation of the gases condensed upon the dust grains, rather than gravity, play a chief part in the accumulation and coalescence of the small particles.

In the same manner as matter is concentrated about centres of attraction energy may be accumulated there in contradiction to the law of the constant increase of entropy.

TO BE CONTINUED ...

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Re: ARRHENIUS, WORLDS IN THE MAKING

Post by thelivyjr » Thu Feb 13, 2020 1:40 p

VII - THE NEBULAR AND THE SOLAR STATES, concluded ...

During this conservational activity the layers of gas are rapidly rarefied, to be replaced by new masses from the inner parts of the nebula, until this centre is depleted, and the nebula has been converted into a star cluster or a planetary system which circulates about one or several suns.

When the suns collide once more new nebulae are created.

The explosive substances, consisting probably of hydrogen and helium (and possibly of nebulium), in combination with carbon and metals, play a chief part in the evolution from the nebular to the stellar state, and in the formation of new nebulae after collisions between two dark or bright celestial bodies.

The chief laws of thermodynamics lead to the assumption that these explosive substances are formed during the evolution of the suns and are destroyed during their collisions.

The enormous stores of energy concentrated in these bodies perform, in a certain sense, the duty of powerfully acting fly-wheels interposed in the machinery of the universe in order to regulate its movements and to make certain that the cyclic transition from the nebular to the star stage, and vice versa, will occur in a regular rhythm during the immeasurable epochs which we must concede for the evolution of the universe.

By virtue of this compensating co-operation of gravity and of the radiation pressure of light, as well as of temperature equalization and heat concentration, the evolution of the world can continue in an eternal cycle, in which there is neither beginning nor end, and in which life may exist and continue forever and undiminished.

TO BE CONTINUED ...

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Re: ARRHENIUS, WORLDS IN THE MAKING

Post by thelivyjr » Fri Feb 14, 2020 1:40 p

VIII

THE SPREADING OF LIFE THROUGH THE UNIVERSE


WE have just recognized the probability of the assumption that solar systems have been evolved from nebulae, and that nebulae are produced by the collision of suns.

We likewise consider it probable that there circulate about the newly formed suns smaller celestial bodies which cool more rapidly than the central sun.

When these satellites have provided themselves with a solid crust, which will partly be covered by water, they may, under favorable conditions, harbor organic life, as the earth and probably also Venus and Mars do.

The satellites would thereby gain a greater interest for us than if we had to imagine them as consisting entirely of lifeless matter.

The question naturally arises whether we may believe that life can really originate on a celestial body as soon as circumstances are favorable for its evolution and propagation.

This question will occupy us in this last chapter.


Men have been pondering over these problems since the remotest ages.

All living beings, past ages recognized, must have been generated and they had to die after a certain shorter or longer life.

Somewhat later, and yet still in a very early epoch, experience must have taught men that organisms of one kind can only generate other organisms of the same kind; that the species are invariable, as we now express it.

The idea was that all species originally came from the hands of the Creator endowed with their present qualities.

This view may still be said to represent the general or "orthodox" doctrine.

This view has also been called the Linnsean thesis, because Linne, in the fifth edition of his Genera Plantarum, adheres to it strictly: "Species tot sunt, quot diversas formas ab initio produxit Infinitum Ens, quae deinde formae secundum generationis inditas leges produxere plures, at sibi semper similes, ut species nunc nobis non sint plures quam fuerunt ab initio."

Which we may render: "There are as many different kind of species as the Infinite Being has created different forms in the beginning."

"These forms have later engendered other beings according to the laws of inheritance, always resembling them, so that we have at the present time not any more species than there were from the beginning."

Time was ripe, however, even then for a less rigid conception of nature, more in accordance with our present views.

The first foundations of the theory of evolution in the biological sciences were laid by Lamarck (in 1794), Treviranus (in 1809), Goethe and Oken (in 1820).

But a reaction set in.

Cuvier and his authority forced public opinion back to the ancient stand-point.

In his view the now extinct species of past geological epochs had been destroyed by natural revolutions, and new species had again been generated by a new act of the Creator.


TO BE CONTINUED ...

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Re: ARRHENIUS, WORLDS IN THE MAKING

Post by thelivyjr » Fri Feb 14, 2020 1:40 p

VIII

THE SPREADING OF LIFE THROUGH THE UNIVERSE
, continued ...

Within the last few decades, however, the general belief has rapidly been revolutionized, and the theory of evolution, especially since the immortal Charles Darwin came forth with his epoch-making researches, now meets with universal acceptance.

According to this theory the species adapt themselves in the course of time to their surroundings, and the changes may become so great that a new species may be considered to have originated from an old species.

The researches of De Vries have, within quite recent times, further accentuated this view, so that we now concede cases to be extant where new species spring forth from old ones under our very eyes.

This thesis has become known as the theory of mutation.


At the present time we accordingly imagine that living organisms, such as we see around us, have all descended from older organisms, rather unlike them, of which we still find traces and remnants in the geological strata which have been deposited during past ages.

From this stand-point all living organisms might possibly have originated from one single, most simple organism.

How that was generated still remains to be explained.

The common view, to which the ancients inclined, is that the lower organisms need not necessarily have originated from seeds.

It was noticed that some low-type organisms, larvae, etc., took rise in putrid meat; Vergil describes this in his Georgicas.


It was not until the seventeenth century that this belief was disproved by many experiments, among others by those of Swammerdam and Leuwenhoek.

The thesis of the so-called "Generatio spontanea" once more blossomed into new life upon the discovery of the so-called infusoria, the small animal organisms which seem to arise spontaneously in infusions and concoctions.

Spallanzani, however, demonstrated in 1777 that when the infusions, and the vessel containing them, as well as the air above them, were heated to a sufficiently high temperature to kill all the germs present, the infusions would remain sterile, and no living organisms could develop in them.

To this fact we owe our ordinary methods of making preserves.

It is true that objections were raised against this demonstration.

The air, it was objected, is so changed by heating that subsequent development of minute organisms is rendered impossible.

But this last objection was refuted by the chemists Chevreul and Pasteur, as well as by the physicist Tyndall in the sixties and seventies of the past century.

These scientists demonstrated that no organisms are produced in air which is freed from the smallest germs by some other means than heating i.e., by nitration through cotton-wool.

The researches of Pasteur, in particular, and the methods of sterilization which are based upon them and which are applied every day in bacteriological laboratories, have more and more forced the conviction upon us that a germ is indispensable for the origination of life.

TO BE CONTINUED ...

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Re: ARRHENIUS, WORLDS IN THE MAKING

Post by thelivyjr » Sun Feb 16, 2020 1:40 p

VIII

THE SPREADING OF LIFE THROUGH THE UNIVERSE
, continued ...

And yet eminent scientists take up the pen again and again in order to demonstrate the possibility of the "Generatio spontanea."

In this they do not rely upon the safe methods of natural science, but they proceed on philosophical lines of argument.

Life, they suggest, must once have had a beginning, and we are hence forced to believe that spontaneous generation, even if not realizable under actual conditions, must have once occurred.


Considerable interest was excited when the great English physiologist Huxley believed he had discovered in the mud brought up from the very bottom of the sea an albuminoid substance which he called "Bathybius Haeckelii," in honor of the zealous German Darwinist Haeckel.

In this bathybius (deep-sea organism) one fancied for a time that the primordial ooze, which had originated from inorganic matter and from which all organisms might have been evolved, and of which Oken had been dreaming, had been discovered.

But the more exact researches of the chemist Buchanan demonstrated that the albuminoid substance in this primordial ooze consisted of flocks of gypsum precipitated by alcohol.

People then had recourse to the most fantastic speculations.

Life, it was argued, might possibly have had its origin in the incandescent mass of the interior of the earth.

At high temperatures organic compounds of cyanogen and its derivatives might be formed which would be the carriers of life (Pfliiger).

There is, however, little need of our entering into any of these speculations until they have been provided with an experimental basis.

Almost every year the statement is repeated in biological literature that we have at last succeeded in producing life from dead matter.

Among the most recent assertions of this kind, the discovery claimed by Butler-Burke has provoked much comment.

He asserted that he had succeeded, with the aid of the marvellous substance radium, in instilling life into lifeless matter namely, a solution of gelatine.

Criticism has, however, relegated this statement, like all similar ones, to the realm of fairy tales.

TO BE CONTINUED ...

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Re: ARRHENIUS, WORLDS IN THE MAKING

Post by thelivyjr » Mon Feb 17, 2020 1:40 p

VIII

THE SPREADING OF LIFE THROUGH THE UNIVERSE
, continued ...

We fully share the opinion which the great natural philosopher Lord Kelvin has expressed in the following words: "A very ancient speculation, still clung to by many naturalists (so much so that I have a choice of modern terms to quote in expressing it), supposes that, under meterological conditions very different from the present, dead matter may have run together or crystallized or fermented into 'germs of life,' or 'organic cells' or 'protoplasm.'"

"But science brings a vast mass of inductive evidence against this hypothesis of spontaneous generation."

"Dead matter cannot become living without coming under the influence of matter previously alive."

"This seems to me as sure a teaching of science as the law of gravitation."

Although the latter verdict may be a little dogmatic, it yet demonstrates how strongly many scientists feel the necessity of finding another way of solving the problem.

The so-called theory of panspermia really shows a way.

According to this theory life-giving seeds are drifting about in space.

They encounter the planets and fill their surfaces with life as soon as the necessary conditions for the existence of organic beings are established.

This view was probably foreshadowed long ago.

Definite suggestions in this direction we find in the writings of the Frenchman Sales-Guy on de Montlivault (1821), who assumed that seeds from the moon had awakened the first life on the surface of the earth.

The German physician H. E. Richter attempted to supplement the doctrine of Darwin by combining the conception of panspermia with it.

Flammarion's book on the plurality of inhabited worlds suggested to Richter the idea that seeds had come from some other inhabited world to our earth.

He emphasizes the fact that carbon has been found in meteorites which move in orbits similar to those of the comets which wander about in space; and in this carbon he sees the rest of organic life.

There is no proof at all for this latter opinion.

The carbon found in meteorites has never exhibited any trace of organic structure, and we may well imagine the carbon e.g., that which appears to occur in the sun to be of inorganic origin.

Still more fantastic is his idea that organisms floating high in our atmosphere are caught by the attraction of meteorites flying past our planet, and are in this way carried out into universal space and deposited upon other celestial bodies.

As the surface of meteorites becomes incandescent in their flight through the atmosphere, any germs which they might possibly have caught would be destroyed; and if, in spite of that, a meteorite should become the conveyor of live germs, those germs would be burned in the atmosphere of the planet on which they descended.

TO BE CONTINUED ...

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Re: ARRHENIUS, WORLDS IN THE MAKING

Post by thelivyjr » Tue Feb 18, 2020 1:40 p

VIII

THE SPREADING OF LIFE THROUGH THE UNIVERSE
, continued ...

In one point, however, we must agree with Richter.

There is logic in his statement that "The infinite space is filled with, or (more correctly) contains, growing, mature, and dying celestial bodies."

"By mature worlds we understand those which are capable of sustaining organic life."

"We regard the existence of organic life in the universe as eternal."

"Life has always been there; it has always propagated itself in the shape of living organisms, from cells and from individuals composed of cells."


Man used to speculate on the origin of matter, but gave that up when experience taught him that matter is indestructible and can only be transformed.

For similar reasons we never inquire into the origin of the energy of motion.

And we may become accustomed to the idea that life is eternal, and hence that it is useless to inquire into its origin.

The ideas of Richter were taken up again in a popular lecture delivered in 1872 by the famous botanist Ferdinand Cohn.

The best-known expression of opinion on the subject, however, is that of Sir William Thomson (later Lord Kelvin) in his presidential address to the British Association at Edinburgh in 1871:

"When two great masses come into collision in space, it is certain that a large part of each is melted; but it seems also quite certain that in many cases a large quantity of debris must be shot forth in all directions, much of which may have experienced no greater violence than individual pieces of rock experience in a landslip or in blasting by gunpowder."

"Should the time when this earth comes into collision with another body, comparable in dimensions to itself, be when it is still clothed as at present with vegetation, many great and small fragments carrying seed and living plants and animals would undoubtedly be scattered through space."

"Hence, and because we all confidently believe that there are at present, and have been from time immemorial, many worlds of life besides our own, we must regard it as probable in the highest degree that there are countless seed-bearing meteoric stones moving about through space."

"If at the present instant no life existed upon this earth, one such stone falling upon it might, by what we blindly call natural causes, lead to its becoming covered with vegetation."

"I am fully conscious of the many objections which may be urged against this hypothesis."

"I will not tax your patience further by discussing any of them on the present occasion."

"All I maintain is that I believe them to be all answerable."

TO BE CONTINUED ...

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Re: ARRHENIUS, WORLDS IN THE MAKING

Post by thelivyjr » Wed Feb 19, 2020 1:40 p

VIII

THE SPREADING OF LIFE THROUGH THE UNIVERSE
, continued ...

Unfortunately we cannot share Lord Kelvin's optimism regarding this point.

It is, in the first instance, questionable whether living beings would be able to survive the violent impact of the collision of two worlds.

We know, further, that the meteorite in its fall towards the earth becomes incandescent all over its surface, and any seeds on it would therefore be deprived of their germinating power.

Meteorites, moreover, show quite a different composition from that of the fragments from the surface of the earth or a similar planet.

Plants develop almost exclusively in loose soil, and a lump of earth falling through our atmosphere would, no doubt, be disintegrated into a shower of small particles by the resistance of the atmosphere.

Each of these particles would by itself flash up like a shooting-star, and could not reach the earth in any other shape than that of burned dust.

Another difficulty is that such collisions, which, as we presume, are responsible for the flashing-up of so-called new stars, are rather rare phenomena, so that little likelihood remains of small seeds being transported to our earth in this manner.

The question has, however, entered into a far more favorable stage since the effects of radiation have become understood.

Bodies which, according to the deductions of Schwarzschild, would undergo the strongest influence of solar radiation must have a diameter of 0.00016 mm., supposing them to be spherical.

The first question is, therefore: are there any living seeds of such extraordinary minuteness?

The reply of the botanist is that the so-called permanent spores of many bacteria have a size of 0.0003 or 0.0002 mm., and there are, no doubt, much smaller germs which our microscopes fail to disclose.

Thus, yellow-fever in man, rabies in dogs, the foot-and-mouth disease in cattle, and the so-called mosaic disease common to the tobacco plant in Netherlandish India, and also observed in other countries are, no doubt, parasitical diseases; but the respective parasites have not yet been discovered, presumably because they are too minute to be visible under the microscope.

It is, therefore, very probable that there are organisms so small that the radiation pressure of a sun would push them out into space, where they might give rise to life on planets, provided they met with favorable conditions for their development.

NOTE: Meanwhile a large number of organisms which are invisible under
the ordinary microscope have been rendered visible by the aid of the
ultra-microscope, among others the presumable microbe of the foot-
and-mouth disease.

TO BE CONTINUED ...

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Re: ARRHENIUS, WORLDS IN THE MAKING

Post by thelivyjr » Thu Feb 20, 2020 1:40 p

VIII

THE SPREADING OF LIFE THROUGH THE UNIVERSE
, continued ...

We will, in the first instance, make a rough calculation of what would happen if such an organism were detached from the earth and pushed out into space by the radiation pressure of our sun.

The organism would, first of all, have to cross the orbit of Mars; then the orbits of the smaller and of the outer planets; and, having passed the last station of our solar system, the orbit of Neptune, it would drift farther into infinite space towards other solar systems.

It is not so difficult to estimate the time which the smallest particles would require for this journey.

Let their specific gravity be that of water, which will very fairly correspond to the facts.

The organisms would cross the orbit of Mars after twenty days, the Jupiter orbit after eighty days, and the orbit of Neptune after fourteen months.

Our nearest solar system, Alpha Centauri, would be reached in nine thousand years.

These calculations have been made under the supposition that the radiation pressure is four times as strong as gravitation, which would be nearly correct according to the figures of Schwarzschild.

These time intervals required for the organisms to reach the different planets of our solar system are not too long for the germs in question to preserve their germinating power.

The estimate is more unfavorable in the case of their transference from one planetary system to another, which will require thousands of years.

But we shall see further on that the very low temperature of those parts of space (about 220 C.) would suspend the extinction of the germinating power, as it arrests all chemical reactions.

As regards the period during which the germinating power can be preserved at ordinary temperature, we have been told that the so-called "mummy wheat" which had been found in ancient Egyptian tombs was still capable of germination.

Critics, however, have established that the respective statements of the Arabs concerning the sources of that wheat are very doubtful.

The French scientist Baudoin asserts that bacteria capable of germination were found in a Roman tomb which had certainly remained untouched for eighteen hundred years; but this statement is to be received with caution.

It is certain, however, that both seeds of some higher plants and spores of certain bacteria e.g., anthrax do maintain their germinating power for several years (say, twenty), and thus for periods which are much longer than those we have estimated as necessary for their transference to our planet.

NOTE: The radiation pressure has here been assumed to be somewhat
greater than on page 103, because the spores are here regarded as opaque, while the drops of hydrocarbons have been regarded as partially translucid to luminous rays.

TO BE CONTINUED ...

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