Home | Biography | An Attempt to Prove the Motion of the Earth |  Hooke's Law  | Resources

An Attempt to Prove the Motion of the Earth by Observations
(Continued)

The Controversie therefore notwithstanding all that hath been said either by the one or by the other Party, remains yet undetermined, Whether the Earth move about the Sun, or the Sun about the Earth; and all the Arguments alledged either on this or that side, are but probabilities at best, and admit not of a necessary and positive conclusion.

Nor is there indeed any other means left for humane industry to determine it, save this one which I have endeavoured to make; and the unquestionable certainty thereof is a most undenyable Argument of the truth of the Copernican Systeme; and the want thereof hath been the principal Argument that hath hitherto somewhat detained me from declaring absolutely for that Hypothesis, for though it doth in every particular almost seem to solve the appearances more naturally and easily, and to afford an exceeding harmonious constitution of the great bodies of the World compared one with another, as to their magnitudes, motions, and distances, yet this objection was alwayes very plausible to most men, that it is affirmed by such as have written more particularly of this subject, that there never was any sensible Parallax discovered by the best observations of this supposed annual motion of the Earth about the Sun as its center, though moved in an Orb whose Diameter is by the
greatest number of Astronomers reckoned between 11 and 12 hundred Diameters of the Earth: Though some others make it between 3 and 4 thousand; others between 7 and 8; and others between 14 and 15 thousands; and I am apt to believe it may be yet much more, each Diameter of the Earth being supposed to be between 7 and 8 thousand English miles, and consequently the whole being reduced into miles, if we reckon with the most, amounting to 120 millions of English miles.

It cannot, I confess, but seem very uncouth and strange to such as have been used to confine the World with less dimensions, that this annual Orb of the Earth of so vast a magnitude, should have no sensible Parallax amongst the fixt Stars, and therefore 'twas in vain to indeavour to answer that objection. For it is unreasonable to expect that the fancies of most men should be so far streined beyond their narrow dimensions, as to make them believe the extent of the Universe so immensly great as they must have granted it to be, supposing no Parallax could have been found.

The Inquisitive Jesuit Riccioli has taken great pains by 77 Arguments to overthrow the Copernican Hypothesis, and is therein so earnest and zealous, that though otherwise a very learned man and good Astronomer, he seems to believe his own Arguments; but all his other 76 Arguments might have been spared as to most men, if upon making observations as I have done, he could have proved there had been no sensible Parallax this way discoverable, as I believe this one Discovery will answer them, and 77 more, if so many can be thought of and produced against it. Though yet I confess had I fail'd in discovering a Parallax this way, as to my own thoughts and perswasion, the almost infinite extension of the Universe had not to me seem'd altogether so great an absurdity to be believed as the Generality do esteem it; for since 'tis confessedly granted on all hands the distance of the fixt Stars is meerly hypothetical, and not founded on any other ground or reason but fancy and supposition, and that there never was hitherto any Parallax observed, nor any other considerable Argument to prove the distances supposed by such as have been most curious and inquisitive in that particular, I see no Argument drawn from the nature of the thing that can have any necessary force in it to determine that the said distance cannot be more then this or that, whatever it be that is assigned.

For the same God that did make this World that we would thus limit and bound, could as easily make it millions of millions of times bigger, as of that quantity we imagine; and all the other appearances except this of Parallax would be the very same that now they are. To me indeed the Universe seems to be vastly bigger then 'tis hitherto asserted by any Writer, when I consider the many differing magnitudes of the fixt Stars, and the continual increase of their number according as they are looked after with better and longer Telescopes. And could we certainly determine and measure their Diameters, and distinguish what part of their appearing magnitude were to be attributed to their bulk, and what to their brightness, I am apt to believe we should make another distribution of their magnitudes, then what is already made by Ptolomy, Ticho, Kepler, Bayer, Clavius, Grienbergerus, Piff, Hevelius and others.

←Back  Next→

__________________________________________________

Send mail to webmaster@roberthooke.com with questions or comments about this web site.
Web site design and layout Copyright © 2002 www.roberthooke.com
Last modified: October 01, 2002