History of Astronomy From The Roman Empire To The Present, part 11
The Transit of Venus and the Distance to the Sun
There are some things which every man or woman of ordinary intelligence knows are nonsensical; but when such things have been permitted to pose for generations as scientific knowledge it is not sufficient merely to say that they are absurd; they must be treated as seriously as though they really were the scientific concepts they are supposed to be, and it must be shown just how, and why, and where, they are absurd.
Not content with the work already done, all the world of astronomy set out to try to measure the distance to the sun again in the years 1874 and 1882, by observations of the Transit of Venus.
It was a most elaborate affair, ’tis said to be by far the greatest and most costly business ever undertaken for the purposes of astronomy. Men were trained specially for the work, equipped with all the most expensive things in the way of telescopes and instruments, and sent out by the British, French and German governments, all allied for the purpose, as expeditions of astronomers to all parts of the world in order to see Venus— like a small speck— pass across the face of the sun. We have it on the best authority that the 1874 transit was a failure; but, nothing daunted, the expeditions went out again in 1882, to the Indies, the Antipodes and the polar regions, but again the results are admitted to be unsatisfactory; though we may at least hope the astronomers found some entertainment by the way.
The Venus method has already been explained in an earlier chapter, and illustrated in diagram 10. It required that observations should be taken simultaneously by two observers placed as widely apart as possible in order to have the longest base-line obtainable; the ideal base-line being the entire diameter of the earth. From among a large number of observations taken in different parts of the world, two were selected as being better than the rest; they were the observations taken at Bermuda—those lovely little islands near the West Indies— and Sabrina Land, on the edge of the icy Antarctic regions; and from this pair the distance of the sun was computed, but the result obtained has never been considered good enough to take the place of the earlier figures of Gill. We will give it the coup-de-grace in short order ;— Bermuda is situated in 32° 15′ north latitude, and 64° 50′ west longitude; while Sabrina Land is 67° south, and 120° east of Greenwich. We must also mention the fact that both the sun and Venus were somewhere between these places, in the eastern hemisphere.
These common-place facts alone prove that the two observations were not taken at the same time, and consequently were useless for the purpose. I will explain how that is. In their endeavour to secure the longest possible base-line our astronomers separated themselves by 99 degrees in the north and south direction, and by 184° 50′ east and west, so it is perfectly plain that the sun had already set to the observer at Sabrina Land, before the observer at Bermuda could see it rise above his horizon at dawn.
N.B.— The sun rises and sets at a distance of 90 degrees from the observer, so that the Transit astronomers should not have been more than 180 degrees apart even if they had wished to see the sun on the horizon; but our observers had exceeded the limit by nearly five degrees. (See dia. 22.)
The two horizons diverge from each other, and for some part of the time the sun is between them, and not visible to either observer, while as it must be above each of these observer’s horizons in turn in order to be seen at all, it is ridiculous to imagine that any observations taken by B and S in a direction toward the top of this page and above their horizons could ever meet anywhere in the universe. The whole business was a fiasco.
Of all the various methods of estimating the distance of the sun, that by means of the measurement to Mars is by far the most important, while the second in order of merit is the one we have just dealt with; the computation by the transit of Venus, which, it will be remembered, was first used by Encke in 1824. But there are, no doubt, many adherents of astronomy who will still hope to save the time-honoured dogma which hangs upon the question of the distance to the sun; too egotistical to admit that they could have been mistaken, or too old-fashioned to accept new truths; and so— while they cannot any longer defend the Mars and Venus illusions— they will say that they know the sun is 93,000,000 miles away because it has been estimated and verified by quite a number of other methods, with always the same result, or thereabouts.
In these circumstances it becomes necessary for us to touch upon these also. The brief examination we shall give to them will be illuminating, and Astronomers will probably be surprised in one way while the layman will be surprised in another…There are some things which every man or woman of ordinary intelligence knows are nonsensical; but when such things have been permitted to pose for generations as scientific knowledge it is not sufficient merely to say that they are absurd; they must— for the moment-— be treated as seriously as though they really were the scientific concepts they are supposed to be, and it must be shown just how, and why, and where, they are absurd. Then, when that is done, they can masquerade no more, and will no longer obstruct the road to knowledge.
Any one of these means of estimating the sun’s distance might be made the subject of a lengthy argument, for they are like ” half-truths ” which, as we all know, are harder to deal with than down-right falsehood; but I do not wish to worry the reader with any more words than I am compelled to use, and so will deal with them as briefly as possible.
Every one of these things which are believed to be methods of computing the distance to the sun, or means of verifying the 93,000,000 mile estimate, presumes the distance of the sun to be already known; and in every case the method is the result of deductions from the figure “93,000,000 miles.”
I am not particularly concerned as to how or why this was done, nor is it my affair whether it seems incredible or not: but I do know that it is as I have stated, and that I am very well able to prove it. I am only interested in knowing the truth, and in proving it by reason and fact.
The verification of the sun’s distance by the measurements to the minor planets Victoria, Iris and Sappho, in 1888 and 1889, was done in the same manner as the measurement to Mars, and fails in precisely the same way, by the fallacy of Dr. Hailey’s Diurnal Method of Measurement by Parallax.
There is the calculation of the sun’s distance by the “Nodes of the Moon,” which it is not necessary for me to dilate upon, because it has already been discredited, and is not considered of any value by the authorities on astronomy themselves.
The computation of the distance to the sun by the “Aberration of Light” is based upon the theory that the earth travels along its orbit at the velocity of 18.64 miles per second. This velocity of the earth is the speed at which it is supposed to be travelling along an orbit round the sun, 18.64 miles a second, 66,000 miles an hour, 1,584,000 miles a day, or five hundred and eighty-four million miles in a year.
The last of these figures is the circumference of the orbit, half of whose diameter— the radius— is of course the distance of the sun itself, and it is from this (pardon the necessary repetition) distance of the sun, first calculated by Encke in 1824, and later by Gill in 1877, that the whole of the figures— including the alleged “ velocity of the earth 18.64 miles a second ”— were deduced. The 18.64 miles is wrong, because the 93,000,000 is wrong, because neither Encke nor Gill obtained any measurement of the sun’s distance whatever; and the whole affair is nothing more than a playful piece of arithmetic, where the distance of the sun is first presumed to be known; from that the Velocity of the earth per second is worked out by simple division, and then the result is worked up again by multiplication to the original figure, “93,000,000,” and the astronomer then says that is the distance to the sun. That is why it is absurd.
The estimation of the distance of the sun by the “Masses of the Planets” depends upon the size, weight, volume or masses of the planets, which depend upon their distance; and the distances of the planets were calculated by Kepler’s, Newton’s and Bode’s Laws from Sir David Gill’s attempt to measure the distance of Mars; wherefore, as we have discovered that he did not find the distance to Mars, all the calculations which are founded upon his entirely erroneous conception of the distance, size, and mass of that planet, go by the board.
It will not do for anyone to say to us that the distance to Mars is 35,000,000 miles (when in opposition) and therefore it must be 4,200 miles in diameter, therefore the distance of the sun must be 93,000,000 miles, therefore its diameter must be 875,000 miles and its mass 1,300,000 times greater than the mass of the earth, or three million times greater than Mars, &c., &c., &c., and therefore it must be 93,000,000 miles away. It is neither good logic, good mathematics, nor good sense. If anyone seeks to show that the distance from the earth to the sun can be measured by weighing the sun and the planets let him do his weighing first, and not assume anything; and he would do well to remember that “The sun’s distance is the indispensable link which connects terrestrial measures with all celestial ones.”
Finally the sun’s distance as 93,000,000 miles is said to be justified by the “Velocity of Light.” The Velocity of Light was measured by an arrangement of wheels and revolving mirrors in the year 1882 at the Washington Monument, U.S.A., and calculated to be 186,414 miles a second.
N.B.— Experiments had been made on several previous occasions, with somewhat similar results, but Professor Newcomb’s result obtained in 1882, is the accepted figure.
Taking up this figure, astronomers recalled that in the 17th century Ole Roemer had conceived the hypothesis that light took nearly 8 ¼ minutes to travel from the sun to the earth, and so they multiplied his 8 ¼ minutes by Newcomb’s 186,414, and said, in effect — “there you are again— the distance of the sun is 93,000,000 miles.” It is so simple; but we are not so simple as to believe it, for we have shown in diagram 4 how Ole Roemer deduced that 8 ¼ minute hypothesis from a mistaken idea of the cause of the difference in the times of the Eclipses of Jupiter’s Satellites; and we know that there is no evidence in the world to show that light takes 8 ¼ minutes to come from the sun to the earth, so the altogether erroneous and misconceived hypothesis of Ole Roemer can not be admitted as any kind of evidence and used in conjunction with the calculation of the Velocity of Light as an argument in favour of the ridiculous idea that the sun is ninety-three— or any other number of millions of miles from this world of ours.
All the extraordinary means used by astronomers have failed to discover the real distance of the sun, and the many attempts that have been made have achieved no more result than if they had never been done; that is to say— that it is not to be supposed that they may perhaps be somewhere near the mark; but it is to be understood, in the most literal sense of the word, that the astronomers of to-day have no more knowledge of the sun’s real distance than Adam. Indeed we have to forget all the romantic things that have been said since the time of Copernicus, and look at the universe, as frankly, and as fearlessly as he did : then we might acknowledge the debt we owe to such as he, for even though he was so greatly in error his originality stimulated the world of thought tremendously; and in that way furthered the world’s progress.
And then, tutored and encouraged by the shades of Hipparchus, Ptolemy, and Copernicus; Kepler, Newton and all their kind, we might, with the added experience and advantage of our times, rebuild the science of astronomy as they would do it now ; true to the facts of nature.