The Earth's surface masses are not uniformly distributed. There are powerful mountain ranges with a rock density of about three tons per cubic meter. There are oceans in which the density of water is only a ton per cubic meter - even at a depth of 11 kilometers. There are valleys lying below sea level - in which the density of matter is equal to the density of air. According to the logic of the law of universal gravitation, these mass distribution inhomogeneities should act on gravimetric instruments.
But some groups of people argue that this is not the case …
The simplest gravimetric instrument is a plumb line - when calmed down, it is oriented along the local vertical. For a long time, attempts have been made to detect the deviations of the plumb line due to the attraction, for example, of powerful mountain ranges. Only the role of a plumb line here was played, of course, by not a simple weight on a string - for how can you know where and how far it is deflected? And the method was used for comparing the geodetic coordinates of the measurement point (obtained, for example, using triangulation) and its coordinates obtained from astronomical observations. Only in the second of these methods is binding to the local vertical, which is realized, for example, using the mercury horizon at the telescope. Thus, by the difference in the coordinates of the point obtained by the above two methods, one can judge the deviation of the local vertical.
So, the resulting deviations in most cases turned out to be much less than those expected due to the action of the mountain ranges. Many textbooks on gravimetry refer to measurements made by the British south of the Himalayas in the mid-19th century. Record deviations were expected there, because from the north was the most powerful mountain range of the Earth, and from the south - the Indian Ocean. But the detected deviations turned out to be almost zero. Similar behavior of the plumb line is found near the sea coastline - contrary to expectations that land, denser than sea water, will pull the plumb line more.
To explain such miracles, scientists adopted the isostasy hypothesis. According to this hypothesis, the action of inhomogeneities of the surface masses is compensated by the action of inhomogeneities of the opposite sign located at a certain depth. That is, there should be loose rocks under the surface dense rocks, and vice versa. Moreover, these upper and lower heterogeneities should, by joint efforts, nullify the action on the plumb line everywhere - as if there are no heterogeneities at all.
Note that the deviations of the plumb line indicate the horizontal components of the local gravity vector. Its vertical component is determined using gravimeters. The same miracles happen with gravimeters as with plumb lines. But there are a lot of measurements with gravimeters. Therefore, in order not to make people laugh, experts have piled up terminological and methodological jungles through which it is difficult for the uninitiated to wade through.
If direct results of gravimetric measurements were published, it would be too obvious that they do not depend on surface mass inhomogeneities. Therefore, direct results are recalculated with special corrections. The first correction, "for free air" or "for height", reflects the location of the measurement point at an altitude that does not coincide with sea level (near the Earth's surface, this correction is about 0.3 mGal / m; 1 Gal = 1 cm / s2). The second correction reflects the effect of surface mass inhomogeneities. The sum of these amendments is called the Bouguer amendment. The difference between the measured and theoretical values of gravity is called an anomaly: without taking into account the second correction, this difference is called an anomaly in free air, and when both are taken into account, it is called a Bouguer anomaly.
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Thus, there is a clear pattern: if during gravimetric surveying, no corrections for the effect of surface masses are introduced, but only the correction “for free air” is used, then gravity anomalies everywhere become close to zero. But it is believed that the surface masses cannot but affect the gravimeter, therefore, corrections are calculated and introduced, which give anomalies equal in magnitude to these corrections. And then, to zero out the anomalies and bring the theoretical values in agreement with the measured ones, they use the same ingenious hypothesis of isostasy.
Do you think there cannot be such a deplorable state of affairs in science? Maybe, maybe. But what cannot be is isostatic compensation. And for a very simple reason. Now, let there be a local inclusion with a high density under the soil surface, and a compensating inclusion with a reduced density under it. Note that if the force of gravity above these inclusions is equal to the force of gravity above the section with normal density, then there is no compensation away from these inclusions: the isostatic dipole "attracts" differently than a similar section with normal density, which should cause a corresponding deviation of the plumb line …
With a given non-uniform distribution of surface masses, no distribution of compensating masses can achieve both zero plumb deviations and zero gravity anomalies at once: isostasy for plumb lines and isostasy for gravimeters are incompatible. In practice, everywhere zero deviations of the plumb line are observed together with zero gravity anomalies (if you do not introduce excessive corrections). Those. Practice clearly shows that gravimetric instruments do not respond to mass distribution. And why? Science has not yet come up with an answer to this question. And we answer: because the masses do not have an attractive effect.
And this conclusion is valid not only for the surface masses of the Earth - gravimetry allows generalizing it to all matter of the Earth. This is possible using measurements under the surface of the geoid, carried out in mines or on board a submerged bathyscaphe. Look: according to the law of universal gravitation, the Earth's gravity in the approximation, when the Earth is considered a uniform non-rotating ball, is maximum on the surface of this ball. Indeed, when rising above the surface, the acceleration of gravity decreases according to the expression GMЗ / r2, where G is the gravitational constant, MЗ is the mass of the Earth, r is the distance to its center. And, when immersed under the surface, the acceleration of gravity decreases due to the fact that the "attracting" mass decreases, since the total effect of masses in the surface spherical layer with a thickness equal to the immersion depth is equal to zero.
In this case, the acceleration of gravity depends linearly on the distance to the center of the Earth: GMЗr / R3, where R is the radius of the Earth. Thus, in the named approximation, on the surface of the Earth there would be a break (as well as a change in sign!) In the dependence of the acceleration of gravity on the distance to the center of the Earth. If, as we argue, gravitation is not generated by masses, and the geometry of the frequency slopes (1.6) is specified independently of the mass distribution, then the dependence of the acceleration of gravity on the height does not have a kink on the Earth's surface - the function ~ 1 / r2 retains its form when deepening under the surface. This is what the raw, uncorrected measurement data shows.
In order not to advertise these fatal facts for the law of universal gravitation, the authors of publications on gravity in mines adhere to the following rules:
1) provide data only for levels below the surface, but not above - so that the absence of a "break" is not striking;
2) do not specify - the force of gravity increases or decreases when immersed under the surface;
3) do not provide "raw" data: provide only data that are corrected at least for the effect of surface masses (and these corrections are arbitrary: they depend on the adopted model of the distribution of surface masses).
With such cases, why are we sure that it is not the law of universal gravitation that is confirmed in the mines, but our model? Yes, lucky, you know. The authors of the article [R6], who carried out measurements in the mines of Queensland (Australia), published “raw” data (Table 1, column 3). Moreover, they clearly indicated that the values measured at depth are presented, minus the value measured on the surface - from which it is immediately clear that the acceleration of gravity increases with immersion, and does not decrease, as required by the law of universal gravitation.
Furthermore! Please note: according to this law, the modulus of the derivative of the altitude dependence of the gravitational acceleration when approaching the breakpoint from above, 2GMЗ / R3, is twice as large as when approaching the breakpoint from below, GMЗ / R3. h = 948.16 m [R6], the calculated value of the gravitational acceleration increment is 2GMЗh / R3, ie at above-surface -3 m / s2. Compare with it the measured value for the named difference in depths: 2.9274-3 m / s2 [R6]. It is quite obvious: when crossing the Earth's surface from top to bottom, not only a sign change does not take place, but also a twofold decrease in the modulus of the derivative of the altitude dependence of the gravitational acceleration.
This is possible if the entire substance of the Earth does not have an attractive effect! We find here, frankly speaking, a global puncture of the law of universal gravitation - our model is confirmed both qualitatively and quantitatively.
Eh, and yet different organizations still offer gravity survey services to simpletons. Reconnaissance on foot! Automotive! From the plane! From satellites!
"Any imaginations of clients - for their money!" Moreover, gravimetric maps are drawn - multi-colored! Well, what can you say. First, it's beautiful. And, secondly, who do these pictures interfere with?
Gravity map of the earth