Newton's System of the World and Comets

Isaac Newton’s cosmology apparently involved regular apocalypses caused by comets overstoking the furnace of the Sun and the repopulation of the Solar System by new intelligent species. He supports this speculation with an interestingly-incorrect anthropic argument.
history, philosophy, technology, insight-porn
2016-06-132019-01-11 finished certainty: highly likely importance: 2

Isaac New­ton pub­lished few of his works, and only those he con­sid­ered per­fect after long delays. This leaves his sys­tem the world, as described in the Prin­cipia and else­where, incom­plete, and many ques­tions sim­ply unad­dressed, like the fate of the Sun or role of comets. But in 2 con­ver­sa­tions with an admirer and his nephew, the elderly New­ton sketched out the rest of his cos­mogony.

Accord­ing to New­ton, the solar sys­tem is not sta­ble and must be adjusted by angels; the Sun does not burn per­pet­u­al­ly, but comets reg­u­larly fuel the Sun; and the final result is that human­ity will be extin­guished by a par­tic­u­larly large comet caus­ing the sun to flare up, and requir­ing intel­li­gent alien beings to arise on other plan­ets or their moons. He fur­ther gives an anthropic argu­ment: one rea­son we know that intel­li­gent races reg­u­larly go extinct is that human­ity itself arose only recent­ly, as demon­strated by the recent inno­va­tions in every field, incon­sis­tent with any belief that human beings have existed for hun­dreds of thou­sands or mil­lions of years.

This is all inter­est­ingly wrong, par­tic­u­larly the anthropic argu­ment. That New­ton found it so absurd to imag­ine human­ity exist­ing for mil­lions of years but only recently under­go­ing expo­nen­tial improve­ments in tech­nol­ogy demon­strates how coun­ter­in­tu­itive and extra­or­di­nary the Indus­trial & Sci­en­tific Rev­o­lu­tions were.

Isaac New­ton, in his , laid out the laws of celes­tial motion, but did­n’t solve many other ques­tions about the Solar sys­tem: how was the Solar Sys­tem cre­ated and how old was it, how did God keep it sta­ble rather than chaotic, how long would the Sun burn until its fire went out, what is the fate of human­i­ty, and what the role of comets?

What did he make of those prob­lems? New­ton declined to com­mit his beliefs to pub­li­ca­tion, but an inter­est­ing sum­mary sur­vives thanks to a rel­a­tive of his.


David Gre­gory sum­ma­rizes some 1694 com­ments by New­ton, then 52, about the sta­bil­ity of the solar sys­tem (from pg365–371 of The Cor­re­spon­dence of Isaac New­ton (Turn­bull 1961), Vol­ume III):

[New­ton says] that a con­tin­ual mir­a­cle is needed to pre­vent the Sun and the fixed stars from rush­ing together through grav­i­ty: that the great eccen­tric­ity in Comets in direc­tions both differ­ent from and con­trary to the plan­ets indi­cates a divine hand: and implies that the Comets are des­tined for a use other than that of the plan­ets. The Satel­lites of Jupiter and Sat­urn can take the places of the Earth, Venus, Mars if they are destroyed, and be held in reserve for a new Cre­ation.

In the later 1724 “Account of a con­ver­sa­tion between New­ton and Con­duitt”, the now-aged (83) reveals con­sid­er­ably more details of his spec­u­la­tions about the true sys­tem of the world to his nephew-in-law :

…there was a sort of rev­o­lu­tion in the heav­enly bod­ies that the vapours & light emit­ted by the sun which had their sed­i­ment as water & other mat­ter had gath­ered them­selves by degrees into a body & attracted more mat­ter from the plan­ets & at last made a sec­ondary planet (viz. one of those that go round another plan­et) & then by gath­er­ing to them & attract­ing more mat­ter became a pri­mary plan­et, & then by increas­ing still became a comet which after cer­tain rev­o­lu­tions by com­ing nearer & nearer the sun had all its volatile parts con­densed & became a mat­ter fit to recruit & replen­ish the sun…as a fagot would this fire if put into it…

…that would prob­a­bly be the effect of the sooner or lat­er…per­haps have 5 or 6 rev­o­lu­tions more first, but when­ever it did it would so much increase the heat of the sun that this earth would be burnt & no ani­mals in this earth could live.1

…He seemed to doubt whether there were not intel­li­gent beings supe­rior to us who super­in­tended these rev­o­lu­tions of the heav­enly bod­ies by the direc­tion of the supreme being—

He seemed to be very clearly of opin­ion that the inhab­i­tants of this earth were of a short date & alleged as one rea­son for that opin­ion that all arts as let­ters long ships print­ing—nee­dle &c2 were dis­cov­ered within the mem­ory of His­tory which could not have hap­pened if the world had been eter­nal

…when I asked him how this earth could have been repeo­pled if ever it had under­gone the same fate it was threat­ened with here­after by the Comet of 1680, he answered that required the power of a cre­ator—

…[I] told him I thought he owned there what wee had been talk­ing about—viz. that the Comet would drop into the sun, & that fixed stars were recruited & replen­ished by Comets when they Dropt into them, & con­se­quently the sun would be recruited too & asked him, why he would not own as freely what he thought of the sun as well as what he thought of the fixed stars—he said that con­cerned us more, & laugh­ing added he had said enough for peo­ple to know his mean­ing—

The System of the World

New­ton explains fully “what he had often hinted to me before” to Con­duitt: celes­tial bod­ies grow by accre­tion due to grav­i­ty, and as they grow big­ger, pass from moons to plan­ets to even larger (!) comets. Comets, in loop­ing past the Sun, slowly become cooked. The Sun would go out due to its con­stant con­fla­gra­tion, but for­tu­nate­ly, it is con­stantly renewed and pow­ered by the fresh fuel pro­vided it by comets pass­ing near­by. “Intel­li­gent beings” (an­gel­s?) over­see this whole process of reg­u­lar fuel­ing of the sun, but unfor­tu­nately the passed so close to the Sun that it seems likely that it will soon fall directly into the sun, rather than feed­ing it a small mea­sure of fuel.

With an enor­mous quan­tity of fuel abruptly dumped into the Sun instead of dis­pensed over eons, it will flare up like a bon­fire and quite likely roast the Earth (like a might, inci­den­tal­ly), killing every­thing on it. This pos­si­bly hap­pens reg­u­lar­ly, since human­ity seems to have been cre­ated only recent­ly, as evi­denced by how recently such major inno­va­tions like print­ing or nee­dles had been made (con­tra­dict­ing any sup­po­si­tion human­ity had existed for more than a few thou­sand years). After this, pos­si­bly God would renew cre­ation by repop­u­lat­ing instead the moons of Sat­urn or Jupiter3 which would have escaped the inferno rel­a­tively intact due to their dis­tance.

This is an inter­est­ing cos­mol­ogy and has a lot of sense to it (how does the Sun burn more than a long time with­out a mag­i­cal process like ‘fusion’ or else reg­u­lar resup­ply? pace Lord Kelv­in’s well-rea­soned & acute but wrong com­ments on the Sun’s age, comets as inad­e­quate fuel sources, & refut­ing Evo­lu­tion), but is still very alien. Angels in charge of comets! Things really were differ­ent then.

It would make for an excel­lent retro SF or nov­el, if noth­ing else. (Nat­u­ral­ly, the heroes would be recruited by the angels to help deal with the cri­sis of the return of New­ton’s comet… Per­haps would like to write a fol­lowup to “Exha­la­tion” or “Sev­enty Two Let­ters”, or Scott Alexan­der & ?)


It’s also inter­est­ing for why it’s wrong: New­ton needs comets to be at least plan­et-sized, because comets are too rare to be plau­si­bly fuel sources for the Sun if they’re small (they would­n’t dump enough fuel in to keep com­bus­tion going for another few decades/centuries until the next big comet, as astro­nom­i­cal records since the Baby­lo­ni­ans con­strained big comets to be highly infre­quen­t), but of course they’re very small; if they were plan­et-sized, you’d think they’d severely dis­turb plan­e­tary orbital cal­cu­la­tions, so was the exist­ing astro­nom­i­cal data insuffi­ciently pre­cise to prove the absence of such orbital dis­tur­bances or was there some other issue?

The anthropic/ argu­ment for the short dura­tion of the human race is also wrong, since we know anatom­i­cally mod­ern & pre­sum­ably equally intel­li­gent humans have been around for at least 50,000 years at this point, with human civ­i­liza­tion devel­op­ing only in the last small frac­tion. What’s par­tic­u­larly inter­est­ing about his argu­ment is that if he had made it at a truly ran­domly cho­sen point in human his­tory (picked at ran­dom from, say, 50,000 BC to 2019 AD), then he would have cor­rectly con­cluded the oppo­site, that the human race was ancient, due to the lack of any dis­cernible progress in the recent past (): in fact, he could only have made this argu­ment in a tiny win­dow between the start of the Scientific/Industrial Rev­o­lu­tion and the archaeological/geological/evolutionary proof of mankind’s antiq­uity start­ing around the 1800s, so maybe 400 years or 0.4 mil­len­nia; he had to have the bad luck to be born into that exact 0.8% his­tor­i­cal win­dow for the argu­ment from progress to be con­vinc­ing & wrong! Remark­able.

I won­der if New­ton’s belief that he was merely redis­cov­er­ing what the ancients like the Chaldeans or King Solomon knew, a con­vic­tion closely con­nected to his , is con­nected to this ‘recent progress’ argu­ment, as it could also be taken as evi­dence for human­ity exist­ing for a long time but in con­stant cycles of rise and fall, imply­ing the pos­si­bil­ity of many cycles of knowl­edge being eso­ter­i­cally encoded into the most ancient writ­ings & ide­olo­gies?

If I have seen fur­ther it is by stand­ing on the shold­ers [sic] of Giants.

Inter­est­ing­ly, it seems the ‘short human his­tory’ argu­ment is not orig­i­nal to New­ton, and has been used else­where to defend the (a posi­tion made tricky if indeed humans only came into exis­tence recent­ly) because I came across a ver­sion of it in Lucretius’s :

More­over, if heaven and earth never had a begin­ning or birth, but have existed from ever­last­ing, why have there not been other poets to sing of other events prior to the The­ban war and the tragedy of Troy? Why have so many heroic deeds so often been buried in obliv­ion, instead of flow­er­ing some­where, implanted in eter­nal memo­ri­als of fame? The true expla­na­tion, in my judg­ment, is that our world is in its youth: it was not cre­ated long ago, but is of com­par­a­tively recent ori­gin. That is why at the present time some arts are still being refined, still being devel­oped. This age has seen many improve­ments in ship­build­ing; it is not long since musi­cians first molded melo­di­ous tunes; our sys­tem of phi­los­o­phy too is a recent inven­tion, and I myself am found to be the very first with the abil­ity to expound it in the lan­guage of my coun­try [Lat­in].

If by chance you believe that all these same things hap­pened before, but that the races of human beings per­ished in a great con­fla­gra­tion, or that their cities were razed by a mighty con­vul­sion of the world, or that rivers, rapa­cious after unremit­ting rains, inun­dated the earth and sub­merged towns, there is all the more neces­sity for you to admit defeat and acknowl­edge that heaven and earth are des­tined to be destroyed.

Lucretius’s argu­ment is not quite the same, as he equiv­o­cates a lit­tle on whether intel­li­gent species/humans go in cycles of cre­ation & destruc­tion (which appears to be New­ton’s take) or if the uni­verse is sim­ply of recent date (which would, inci­den­tal­ly, be con­sis­tent with a lit­er­al­ist Bib­li­cal take in which recent progress is because the world & human­ity were cre­ated only recent­ly, per Gen­e­sis), but it’s the same idea: given the fact of recent progress in appar­ently easy low-hang­ing fruit like com­pos­ing epics or invent­ing needles, this implies either that human­ity is itself of recent ori­gin (in some sense) or that progress only began recently for no good rea­son. But and the lat­ter is absurd, so they reject it and accept the other pos­si­bil­i­ty.

Another argu­ment, defend­ing Lucretius on differ­ent grounds, is pro­vided by in his II.5 (“The Changes Of Reli­gion And Of Lan­guages, Together With The Occur­rence Of Del­uges And Pesti­lences, Destroy The Record Of Things”) in which he defends eter­nal­ism by argu­ing that we should not expect any trust­wor­thy records because political/religious move­ments reg­u­larly destroy all ancient things (eg the ) every few thou­sand years, and then par­tic­u­larly extreme dis­as­ters wipe out humans every few tens to hun­dreds of thou­sands of years:

To those philoso­phers who main­tain that the world has existed from eter­ni­ty, we might reply, that, if it were really of such antiq­ui­ty, there would rea­son­ably be some record beyond 5000 years, were it not that we see how the records of time are destroyed by var­i­ous caus­es, some being the acts of men and some of Heav­en. Those that are the acts of men are the changes of reli­gion and of lan­guage; for when a new sect springs up, that is to say a new reli­gion, the first effort is (by way of assert­ing itself and gain­ing influ­ence) to destroy the old or exist­ing one; and when it hap­pens that the founders of the new reli­gion speak a differ­ent lan­guage, then the destruc­tion of the old reli­gion is eas­ily effect­ed. This we know from observ­ing the pro­ceed­ings of the Chris­tians against the hea­then reli­gion; for they destroyed all its insti­tu­tions and all its cer­e­monies, and effaced all record of the ancient the­ol­o­gy. It is true that they did not suc­ceed in destroy­ing entirely the record of the glo­ri­ous deeds of the illus­tri­ous men of the ancient creed, for they were forced to keep up the Latin lan­guage by the neces­sity of writ­ing their new laws in that tongue; but if they could have writ­ten them in a new lan­guage (bear­ing in mind their other per­se­cu­tion­s), there would have been no record what­ever left of pre­ced­ing events. Who­ever reads the pro­ceed­ings of , and of the other heads of the Chris­t­ian reli­gion, will see with what obsti­nacy they per­se­cuted all ancient memo­ri­als, burn­ing the works of the his­to­ri­ans and of the poets, destroy­ing the stat­ues and images and despoil­ing every­thing else that gave but an indi­ca­tion of antiq­ui­ty. So that, if they had added a new lan­guage to this per­se­cu­tion, every­thing relat­ing to pre­vi­ous events would in a very short time have been sunk in obliv­ion.

It is rea­son­able to sup­pose that what the Chris­tians prac­tised towards the Pagans, these prac­tised in like man­ner upon their pre­de­ces­sors. And as the reli­gions changed 2 or 3 times in 6000 years, all mem­ory of the things done before that time was lost; and if nev­er­the­less some ves­tiges of it remain, they are regarded as fab­u­lous, and are believed by no one; as is the case with the his­tory of , who gives of some 40 or 50,000 years, yet is gen­er­ally looked upon as being men­da­cious, and I believe with jus­tice.

As to causes pro­duced by Heav­en, they are such as destroy the human race, and reduce the inhab­i­tants of some parts of the world to a very few in num­ber; such as pesti­lence, famine, or inun­da­tions.4 Of this the lat­ter are the most impor­tant, partly because they are most uni­ver­sal, and partly because the few that escape are chiefly igno­rant moun­taineers, who, hav­ing no knowl­edge of antiq­uity them­selves, can­not trans­mit any to pos­ter­i­ty. And should there be amongst those who escape any that have such knowl­edge, they con­ceal or per­vert it in their own fash­ion, for the pur­pose of gain­ing influ­ence and rep­u­ta­tion; so that there remains to their suc­ces­sors only just so much as they were dis­posed to write, and no more. And that such inun­da­tions, pesti­lences, and famines occur can­not be doubt­ed, both because all his­tory is full of accounts of them, and because we see the effects of them in the obliv­ion of things, and also because it seems rea­son­able that they should occur.

This is a rea­son­able argu­ment by Machi­avel­li: it is true that reli­gions attempt to erase and recy­cle their pre­de­ces­sors and if only through neglect, assure their dis­ap­pear­ance5, and it is also true that occa­sional cat­a­stro­phes like pan­demics can depop­u­late regions & end civ­i­liza­tions (eg the New World, or the Black Plague). Yet, he is still wrong. There were no civ­i­liza­tions 50,000 years ago, and more than enough sur­vives of pre-Chris­t­ian or pre-Is­lamic civ­i­liza­tions for us to under­stand them.

The claims of and evo­lu­tion—that the observed geog­ra­phy and biol­ogy arose only incre­men­tally over hypoth­e­sized peri­ods of mil­lions or even bil­lions of years, such lengths being nec­es­sary to account for the human-ob­served short­-term sta­sis of species or geog­ra­phy—­would have doubt­less struck them as even more absurd. Who could accept a the­ory like “after bil­lions of years, humans evolved, but then noth­ing of any impor­tance hap­pened for hun­dreds of thou­sands or mil­lions of years, until then every­thing started hap­pen­ing in the past 10,000 years at an ever-ac­cel­er­at­ing pace”? Nev­er­the­less… (Here we have a sit­u­a­tion sim­i­lar to that of , of being wrong for the right rea­sons. notes the irony: par­tic­u­larly in the Renais­sance, these the­o­ries of an eter­nal world emerged as part of the awak­en­ing of crit­i­cal thought about the­o­log­i­cal dog­mas like Cre­ation­is­m—but it was the dog­mas which were right about the uni­verse being of a finite age.)

From our per­spec­tive, the pace of progress in New­ton’s day—n­ever mind Lucretius 1700 years pri­or—was ago­niz­ingly slow and near-in­vis­i­ble, but to New­ton and his con­tem­po­raries, it must have appeared rapid, even more rapid than for Lucretius.

This offers a lit­tle twist on the “Sin­gu­lar­ity” idea: appar­ently peo­ple have always been able to see progress as rapid in the right time peri­ods, and they are not wrong to! We would not be too impressed at sev­eral cen­turies with merely some ship­build­ing improve­ments or a long phi­los­o­phy poem writ­ten in Lat­in, and we are only mod­estly impressed by nee­dles or print­ing press­es. Human his­to­ry, start­ing some­time in the Neolithic, is a giant expo­nen­tial, which just keeps going up. What seemed star­tlingly rapid at one point may seem ago­niz­ingly slow viewed from a later stand­point.

  1. How this can be rec­on­ciled with his beliefs in a Sec­ond Com­ing of Jesus or the var­i­ous or even the occur­rence of an Apoc­a­lypse & Sec­ond Com­ing of Jesus, I do not know.↩︎

  2. This is a con­fus­ing sen­tence and the scan is not avail­able to check, but I inter­pret Con­duitt as mean­ing “that all arts, such as [al­pha­bet­ic] let­ters, long [ocean-go­ing] ships, print­ing [press­es], nee­dles [and thread], etc”.↩︎

  3. New­ton was not the only astronomer to sus­pect intel­li­gent life on the Jov­ian moons. In April 1610, wrote to Galileo of his :

    …Mean­while I can­not refrain from con­tribut­ing this addi­tional fea­ture to the unortho­dox aspects of your find­ings. It is not improb­a­ble, I must point out,344 that there are inhab­i­tants not only on the moon but on Jupiter too or (as was delight­fully remarked at a recent gath­er­ing of cer­tain philoso­phers345) that those areas are now being unveiled for the first time. But as soon as some­body demon­strates the art of fly­ing, set­tlers from our species of man will not be lack­ing. Who would once have thought that the cross­ing of the wide ocean was calmer and safer346 than of the nar­row Adri­atic Sea, Baltic Sea, or Eng­lish Chan­nel? Given ships or sails adapted to the breezes of heav­en, there will be those who will not shrink from even that vast expanse. There­fore, for the sake of those who, as it were, will presently be on hand to attempt this voy­age, let us estab­lish the astron­o­my, Galileo, you of Jupiter, and me of the moon.

    1. This state­ment was mis­tak­enly trans­ferred from Kepler to Galileo by Bryk (p. 347). Galileo did not attribute inhab­i­tants to the moon and to Jupiter, despite Bryk.
    2. In the let­ter of April 19 (NE X, 336:606) Kepler said instead: “at Wack­her’s din­ner table” (in mensa nos­tri Vack­herii).
    3. In “Four Voy­ages” the first two cross­ings were calm and safe. Per­haps Kepler did not read as far as the third voy­age (“On those days [of the Atlantic cross­ing] we expe­ri­enced worse weather than any­one had ever suffered at sea before”) and the fourth voy­age (“A fierce and bit­ter storm arose, and a con­trary wind and adverse weather pre­vailed”); in , fol. e2v, Bv.
  4. Note Machi­avel­li’s here.↩︎

  5. As almost hap­pened to Lucretius (2 or 3 sur­viv­ing copies) and (only a quar­ter sur­vives); and as Machi­avelli notes later on, the Romans were unkind to their pre­de­ces­sors, who remain mys­te­ri­ous. (We could also note that mod­ern pop­u­la­tion genet­ics has shown that near-to­tal pop­u­la­tion replace­ment is quite com­mon through­out deep his­to­ry.)↩︎