THE SOLAR SYSTEM

Dominion, Volume 14, Issue 37, 8 November 1920, Page 3

THE SOLAR SYSTEM

NEW THEORY.ADVANCED.

Old theories.of the origin of the solar system have.a oommon feature in that tihey all suppose it to have been derived from a more or less symmetrical rotating nebula in a gaseous or half-gaseous state, notes Professor Harold Jeffreys, a careful student of the early' history of the sun._ By some process the details of which vary in • different theories, this mass is .supposed to havo condensed locally to form the sun planets . A recent study by the eminent astrophysicist, , ',: Jean 8, has indicated a way oF examining whether such condensation is possiblo; The factors of cosmic evolution involved are technical and abstruse but summing them up, Professor Jeffreys writing in London "Nature," thinks it necessary to abandon completelv those hypotheses whioh require the solar systo have been formed by the gradual condensation of a nebula. "We are led next to inquire whether planets could come into being by a moTeTapid or catastrophic process. ' .projection from the sun is not a possible origin, for a body started in this way must necessarily strike the sun attain onjtta retnrn, and be reabsorbed: further, there is no reason why all should revolve in .the same direction. Ihe tidal theory appears to (rive a better account of the present state of the system. According to this, a star much more massive than the sun approached it .Jj l7 k J°f el J'. »nd raised on opposite sides of it two projections, just as th"> Wo ? n 63 tide 9in tne eartn ' - tut the scale of the disturbance was in this case bo enormous that tho .sun's ■ pravifntion was unablft to prevent a 'rupture from oc; cvrnng. Thus either one or two streams of matter were shot out in a time comparable with a few months or venrs. Being longitudinally unstable,they broke up into a series of detached'masses, perhaps before the pnrts, nrojectwl later h*d iactnilly separated from the sun. That' such a Tupture could occnr has been proved by Jeans. Tho attraction of tlie disturbing body produced the direct revolution (in tho 6amo sense as tho motion of the star relative to the sun); some of the revolving matter returned Into thn sun, and gave it a direct rotation. The angular momentum thus acquired, was, of course.- derived from tho transverse motion .. of the disturbing body relative to the sun. '■•'.' >

_ "The me of tho deformed body has little influence on its chnnce of "being broken un. Thus tho detached maesfß might, well have produced systemß of eatellitcs ond developed direct rotations in the majority of cases, though: complete uniformity conld scarcely be expected nn arnounii of the number of complicating factors. The fission would cease when the star had receded a sufficient distance: thus .the outer nuclei, being the first ejected, would produce most .satellites. All tho bodies having recently formed part of sun, would naturally be very hot.

"This system. .after the passase of thn star, would therefore Include, n central sun surrounded hv a number of bcited planets, moving in direct, orbits, and attended by satellites; the m«wt Temoto planets would have most satellite. The rotation of the sun would he direct; tho rotation of each planet would he in the same «ens<» as the revolution of most of Ita satellites, and in most cases this also would he direct, though n few Moeptione misrht w»1I occur, especially in tblc outermost sub-system 9. In every point this airees existing solar system. The heated interior of tho early, tho building of mountains hy compression, and the present heated state of the greater planets are readily accounted for." '