When Newton discovered the law of universal gravitation, he did not know a single numerical value of the masses of celestial bodies, including the Earth. He also did not know the value of the constant G.
Meanwhile, the gravitational constant G has the same value for all bodies of the Universe and is one of the fundamental physical constants. How can you find its meaning?
It follows from the law of universal gravitation that G = Fr 2 /(m 1 m 2). So, in order to find G, it is necessary to measure the force of attraction F between bodies of known masses m 1 and m 2 and the distance r between them.
The first measurements of the gravitational constant were made in the middle of the 18th century. It was possible to estimate, though very roughly, the value of G at that time as a result of considering the attraction of a pendulum to a mountain, the mass of which was determined by geological methods.
Accurate measurements of the gravitational constant were first made in 1798 by the remarkable scientist Henry Cavendish, a wealthy English lord who was known as an eccentric and unsociable person. With the help of the so-called torsion balances (Fig. 101), Cavendish was able to measure the negligible force of attraction between small and large metal balls by the angle of twist of the thread A. To do this, he had to use such sensitive equipment that even weak air currents could distort the measurements. Therefore, in order to exclude extraneous influences, Cavendish placed his equipment in a box that he left in the room, and he himself carried out observations of the equipment using a telescope from another room.
Experiments have shown that
G ≈ 6.67 10 -11 N m 2 / kg 2.
The physical meaning of the gravitational constant is that it is numerically equal to the force with which two particles with a mass of 1 kg each, located at a distance of 1 m from each other, are attracted. This force, therefore, turns out to be extremely small - only 6.67 · 10 -11 N. Is this good or bad? Calculations show that if the gravitational constant in our Universe had a value, say, 100 times greater than the above, then this would lead to the fact that the lifetime of stars, including the Sun, would sharply decrease and intelligent life on Earth would not appear. In other words, we would not be with you now!
A small value of G leads to the fact that the gravitational interaction between ordinary bodies, not to mention atoms and molecules, is very weak. Two people weighing 60 kg at a distance of 1 m from each other are attracted with a force equal to only 0.24 microns.
However, as the masses of bodies increase, the role of gravitational interaction increases. So, for example, the force of mutual attraction of the Earth and the Moon reaches 10 20 N, and the attraction of the Earth by the Sun is 150 times stronger. Therefore, the motion of planets and stars is already completely determined by gravitational forces.
In the course of his experiments, Cavendish also proved for the first time that not only planets, but also ordinary bodies surrounding us in everyday life are attracted according to the same law of gravity, which was discovered by Newton as a result of the analysis of astronomical data. This law is indeed the law of universal gravitation.
“The law of gravity is universal. It extends over great distances. And Newton, who was interested in the solar system, could well have predicted what would come out of the Cavendish experiment, because the Cavendish scales, two attracting balls, are a small model of the solar system. If you increase it ten million million times, then we get the solar system. Let's increase it ten million million times more - and here you have galaxies that are attracted to each other according to the same law. Embroidering its pattern, Nature uses only the longest threads, and any, even the smallest, sample of it can open our eyes to the structure of the whole ”(R. Feynman).
1. What is the physical meaning of the gravitational constant? 2. Who was the first to make accurate measurements of this constant? 3. What does the small value of the gravitational constant lead to? 4. Why, sitting next to a friend at a desk, do you not feel attracted to him?
The section is very easy to use. In the proposed field, just enter the desired word, and we will give you a list of its meanings. I would like to note that our site provides data from various sources - encyclopedic, explanatory, word-building dictionaries. Here you can also get acquainted with examples of the use of the word you entered.
What does "gravitational constant" mean?
Encyclopedic Dictionary, 1998
gravitational constant
GRAVITATIONAL CONSTANT (denoted as G) proportionality factor in Newton's law of gravitation (see Universal gravitational law), G = (6.67259+0.00085) 10-11 N m2/kg2.
Gravitational constant
coefficient of proportionality G in the formula expressing Newton's law of gravity F = G mM / r2, where F ≈ force of attraction, M and m ≈ masses of attracting bodies, r ≈ distance between bodies. Other designations of G. p .: g or f (less often k2). The numerical value of G. p. depends on the choice of the system of units of length, mass, and force. In the cgs system of units
G = (6.673 ╠ 0.003)×10-8days×cm2×g-2
or cm3×g
--1×sec-2, in the International system of units G = (6.673 ╠ 0.003)×10-11×n×m2×kg
--2
or m3×kg-1×sec-2. The most accurate value of G. p. is obtained from laboratory measurements of the force of attraction between two known masses using a torsion balance.
When calculating the orbits of celestial bodies (for example, satellites) relative to the Earth, the geocentric G. p. is used ≈ the product of G. p. by the mass of the Earth (including its atmosphere):
GE = (3.98603 ╠ 0.00003)×1014×m3×s-2.
When calculating the orbits of celestial bodies relative to the Sun, the heliocentric G. p. is used ≈ the product of G. p. by the mass of the Sun:
GSs = 1.32718×1020×m3×s-2.
These values of GE and GSs correspond to the system of fundamental astronomical constants adopted in 1964 at the congress of the International Astronomical Union.
Yu. A. Ryabov.
Wikipedia
Gravitational constant
Gravitational constant, Newton's constant(usually denoted , Sometimes or) - fundamental physical constant, gravitational interaction constant.
According to Newton's law of universal gravitation, the force of gravitational attraction between two material points with masses And , located at a distance , is equal to:
$F=G\frac(m_1 m_2)(r^2).$
Proportionality factor in this equation is called gravitational constant. Numerically, it is equal to the modulus of the gravitational force acting on a point body of unit mass from another similar body located at a unit distance from it.
6.67428(67) 10 m s kg, or N m² kg,
in 2010 the value was corrected to:
6.67384(80) 10 m s kg, or N m² kg.
In 2014, the value of the gravitational constant recommended by CODATA became:
6.67408(31) 10 m s kg, or N m² kg.
In October 2010, an article appeared in the journal Physical Review Letters suggesting an updated value of 6.67234(14), which is three standard deviations less than the value , recommended in 2008 by the Committee for Data for Science and Technology (CODATA), but corresponds to the earlier CODATA value presented in 1986. Revision of the value , which occurred between 1986 and 2008, was caused by studies of the inelasticity of suspension threads in torsion balances. The gravitational constant is the basis for converting other physical and astronomical quantities, such as the masses of the planets in the universe, including the Earth, as well as other cosmic bodies, into traditional units of measurement, such as kilograms. At the same time, due to the weakness of the gravitational interaction and the resulting low accuracy of measurements of the gravitational constant, the ratios of the masses of cosmic bodies are usually known much more accurately than individual masses in kilograms.
Being one of the fundamental quantities in physics, the gravitational constant was first mentioned in the 18th century. At the same time, the first attempts were made to measure its value, however, due to the imperfection of instruments and insufficient knowledge in this area, it was possible to do this only in the middle of the 19th century. Later, the result obtained was repeatedly corrected (the last time it was done in 2013). However, it should be noted that the fundamental difference between the first (G = 6.67428(67) 10 −11 m³ s −2 kg −1 or N m² kg −2) and the latter (G = 6.67384( 80) 10 −11 m³ s −2 kg −1 or N m² kg −2) values do not exist.
Applying this coefficient for practical calculations, it should be understood that the constant is such in global universal concepts (if you do not make reservations for elementary particle physics and other little-studied sciences). And this means that the gravitational constant of the Earth, the Moon or Mars will not differ from each other.
This quantity is a basic constant in classical mechanics. Therefore, the gravitational constant is involved in a variety of calculations. In particular, without information about the more or less exact value of this parameter, scientists would not be able to calculate such an important coefficient in the space industry as the acceleration of free fall (which will be different for each planet or other cosmic body).
However, Newton, who voiced in a general way, the gravitational constant was known only in theory. That is, he was able to formulate one of the most important physical postulates, without having information about the value on which he, in fact, is based.
Unlike other fundamental constants, physics can only say with a certain degree of accuracy about what the gravitational constant is equal to. Its value is periodically obtained anew, and each time it differs from the previous one. Most scientists believe that this fact is not associated with its changes, but with more banal reasons. Firstly, these are measurement methods (various experiments are carried out to calculate this constant), and secondly, the accuracy of the instruments, which gradually increases, the data is refined, and a new result is obtained.
Taking into account the fact that the gravitational constant is a quantity measured by 10 to the -11 power (which is an ultra-small value for classical mechanics), there is nothing surprising in the constant refinement of the coefficient. Moreover, the symbol is subject to correction, starting from 14 after the decimal point.
However, there is another theory in modern wave physics, which was put forward by Fred Hoyle and J. Narlikar back in the 70s of the last century. According to their assumptions, the gravitational constant decreases with time, which affects many other indicators that are considered constants. Thus, the American astronomer van Flandern noted the phenomenon of slight acceleration of the Moon and other celestial bodies. Guided by this theory, it should be assumed that there were no global errors in the early calculations, and the difference in the results obtained is explained by changes in the value of the constant itself. The same theory speaks of the inconstancy of some other quantities, such as
All attempts by experimenters to reduce the measurement error of the Earth's gravitational constant have so far been reduced to zero. As noted earlier, since the time of Cavendish, the accuracy of measuring this constant has hardly increased. For more than two centuries, the accuracy of measurement has not budged. Such a situation can be called by analogy with the "ultraviolet catastrophe" as a "catastrophe of the gravitational constant." We got out of the ultraviolet catastrophe with the help of quanta, but how to get out of the catastrophe with the gravitational constant?
Nothing can be squeezed out of the Cavendish torsion balance, so the way out can be found using the average value of the acceleration of gravity and calculate G from the well-known formula:
Where, g is the free fall acceleration (g = 9.78 m / s 2 - at the equator; g = 9.832 m / s 2 - at the poles).
R is the radius of the Earth, m,
M is the mass of the Earth, kg.
The standard value of the gravitational acceleration, adopted in the construction of systems of units, is: g=9.80665. Hence the average value G will be equal to:
According to received G, specify the temperature from the proportion:
6.68 10 -11 ~x=1~4.392365689353438 10 12
This temperature corresponds on the Celsius scale to 20.4 o .
Such a compromise, I think, could well satisfy the two sides: experimental physics and the committee (CODATA), so as not to periodically revise and not change the value of the gravitational constant for the Earth.
It is possible to “legislatively” approve the current value of the gravitational constant for the Earth G=6.67408·10 -11 Nm 2 /kg 2, but correct the standard value g=9.80665, slightly reducing its value.
In addition, if we use the average temperature of the Earth, equal to 14 o C, then the gravitational constant will be equal to G=6.53748·10 -11 .
So, we have three values that claim to be the pedestal of the gravitational constant G for planet Earth: 1) 6.67408 10 -11 m³/(kg s²); 2) 6.68 10 -11 m³/(kg s²); 3) 6.53748 10 -11 m³/(kg s²).
It remains for the CODATA Committee to make a final verdict on which of them to approve as the gravitational constant of the Earth.
It may be objected to me that if the gravitational constant depends on the temperature of the interacting bodies, then the forces of attraction day and night, winter and summer should be different. Yes, that's exactly how it should be, with small bodies. But the Earth is a huge, rapidly rotating ball, has a huge supply of energy. Hence, the integral number of crafons in winter and summer, day and night, flying out of the Earth, is the same. Therefore, the acceleration due to gravity at one latitude remains always constant.
If you move to the Moon, where the temperature difference between the day and night hemispheres varies greatly, then gravimeters should record the difference in the force of attraction.
related posts
11 comments
Just one question for you:
Or do you have energy in space that does not spread in the sphere?
And if you have already decided to move on to temperature, then at the points of the centers of mass, which, of course, emit energy more correctly, it is also unknown (experimentally it cannot be confirmed in any way), respectively, it still needs to be calculated.
Well, you don’t even have the most meaningful description of the process of gravitational interaction of bodies, some kind of “red photons (krafons) flew into the body, brought energy, this is understandable, but does not answer the question: “why should it start moving at the same time ( move) exactly in the direction from which they arrived, and not in the opposite direction, that is, according to the applied force (given to the energy impulse from these crafons of yours)?
Just one question for you:
If you have already started talking about energy, then why did you completely forget about 4Pi before R^2?!
Or do you have energy in space that does not spread in the sphere?
And if you have already decided to move on to temperature, then at the points of the centers of mass, which, of course, emit energy more correctly, it is also unknown (experimentally it cannot be confirmed in any way), respectively, it still needs to be calculated.
Well, you don’t even have the most meaningful description of the process of gravitational interaction of bodies, some kind of “red photons (krafons) flew into the body, brought energy, this is understandable, but does not answer the question: “why should it start moving at the same time ( move) exactly in the direction from which they arrived, and not in the opposite direction, that is, according to the applied force (given to the energy impulse from these crafons of yours)?
________________________________________________________
Instead of one stated question, there were three, but that's not the point.
1. Regarding 4π. In formulas (9) and (10), R2 is the distance from the body (object) to the center of the Earth. Where 4π should appear here is not clear.
2. Regarding the maximum temperature of a substance in nature. You, obviously, were too lazy to open the link at the end of the article: "The gravitational constant is a variable."
3. Now regarding the "meaningful description of the process of gravitational interaction of bodies." Everything is thought out and described. Regarding which direction these same krafons fly, we read the articles: "". Solar photons start from the surface of the Luminary without recoil, with the acquisition of impulses of attachment. A photon, in contrast to the material world, has no inertia - its momentum occurs at the moment of separation from the source without recoil!
The phenomenon of recoil is observed only in bodies when, under the action of internal forces, it breaks up into parts, flying in opposite directions. A photon does not break up into parts, it does not part with its acquired momentum until it is absorbed, so expression (3) will be valid for it.
"", and part 2.
Quote from the 2nd part: “Craphons from an elementary ball fly out spontaneously, in different directions along the normal of its surface. Moreover, they are directed mainly to the atmosphere, i.e. into a more rarefied electromagnetic ether (EME) in comparison with the EME of the waters of the World Ocean. In principle, the same picture is observed on the continents.
Dear readers, on the topic: how gravity arises, and who is its carrier, read the entire chapter entitled: “Gravity”. Of course, you can also selectively, for this, click on the "Site Map" button in the top menu located above the site header.
Adding to previous comment.
Oct 12, 2016 On the pages of the electronic scientific and practical journal "Modern Scientific Research and Innovation" my article was published under the title: "Photon-quantum gravity". The article outlines the essence of gravity. Read on the link:
P.S. Alexey You are right, there is no such article in this journal. Read my comment below.
Something is missing from your article in the October issue of "Modern Scientific Research and Innovation" ((
“Something is missing your article in the October issue of “Modern Scientific Research and Innovation” ((”
Article: EARTH GRAVITY PHOTON-QUANTUM GRAVITY moved to another journal: Scientific-Researches No. 5(5), 2016, p. 79
http://tsh-journal.com/wp-content/uploads/2016/11/VOL-1-No-5-5-2016.pdf
01/05/2017. Would it make it difficult for you to show in more detail your calculations of the mass and radius of the Earth used in the verification formula G (9) for the Earth. Are you afraid of some physical tautology using these values CALCULATED with the same constants? Mikula
“Will it be more difficult for you to show in more detail your calculations of the mass and radius of the Earth used in the verification formula G (9) for the Earth. Are you afraid of some physical tautology using these values CALCULATED with the same constants? Mikula"
———————————
Yes, much more. In formula 9, two extreme values of G are calculated for the free fall acceleration (g=9.78 m/s2 - at the equator; g=9.832 m/s2 - at the poles). For the standard value of the acceleration of free fall, it is made in 10. As for the mass and radius of the Earth, they will practically not change. What is the tautology, I do not see.
Yes, much more. In formula 9, two extreme values of G are calculated for the free fall acceleration (g=9.78 m/s2 - at the equator; g=9.832 m/s2 - at the poles). For the standard value of the acceleration of free fall, it is made in 10. As for the mass and radius of the Earth, they will practically not change. What is the tautology, I do not see.
“All bodies with mass excite gravitational fields in the surrounding space, just as electrically charged particles form an electrostatic field around themselves. It can be assumed that bodies carry a gravitational charge, similar to an electric one, or, in another way, have a gravitational mass. It was established with high accuracy that the inertial and gravitational masses coincide.
2
Let there be two point bodies with masses m1 and m2. They are separated from each other by a distance r. Then the force of gravitational attraction between them is equal to: F=C·m1·m2/r², where С is a coefficient that depends only on the chosen units of measurement.
3
If there is a small body on the surface of the Earth, its size and mass can be neglected, because the dimensions of the Earth far exceed them. When determining the distance between a planet and a surface body, only the radius of the Earth is considered, since the height of the body is negligible in comparison with it. It turns out that the Earth attracts the body with the force F=M/R², where M is the mass of the Earth, R is its radius.
4
According to the law of universal gravitation, the acceleration of bodies under the action of gravity on the surface of the Earth is: g=G M/R². Here G is the gravitational constant, numerically equal to approximately 6.6742 10^(−11).
5
The gravitational acceleration g and the radius of the earth R are found from direct measurements. The constant G was determined with great accuracy in the experiments of Cavendish and Yolli. So, the mass of the Earth is M=5.976 10^27 g ≈ 6 10^27 g.
PhTautology, in my opinion, of course erroneous, lies in the fact that when calculating the mass of the Earth, the same Cavendish Yolli coefficient G is used, called the gravitational constant, which is not even constant at all, in which I absolutely agree with you. Therefore, your message “You can’t squeeze anything out of the Cavendish torsion balance, so the way out can be found using the average value of the free fall acceleration and calculate G from the well-known formula:” is not entirely correct. Your calculation of the constant G has already been used in the calculation of the mass of the Earth. In no way do I want to reproach you, I just really want to deal with this gravitational constant, which was not even assigned by Newton in Robert Hooke's law. With deep respect, Mikula.
Dear Mikula, Your desire to understand and deal with the gravitational constant is commendable. Considering that many scientists wanted to understand this constant, but not many managed to do it.
"The constant G has been determined with great accuracy by the experiments of Cavendish and Yolli."
No! C is not big! Otherwise, why would science spend money and time for its regular rechecking and clarification, i.e. averaging the results, which is what CODATA does. And it is needed just in order to “weigh the Earth” and find out its density, which is what Cavendish became famous for. But as you can see, G walks from one experience to another. The same is true for free fall acceleration.
The gravitational constant is a coefficient for one temperature value, and the temperature is that of the drawbar.
What do I suggest? For the planet Earth, once and for all, establish one value of G and make it really constant, taking into account g.
Do not be lazy, read all the articles under the heading G (gravitational constant), I think a lot will become clear to you. Start over:
Our path is in darkness... And We bump our foreheads not only on the slimy walls of the dungeon in search of glimpses of the exit, but also on the foreheads of the same unfortunate ones, swearing and cursing... lame, armless, blind beggars... And we do not hear each other. We stretch out our hand and receive a spit in it ... and therefore Our path is endless ... And yet ... here is my hand. This is my version of understanding the nature of gravity... and the "strong force".
Mezentsev Nikolai Fyodorovich
Your hand, unfortunately, did not help me in any way, but why.
This site uses Akismet to fight spam. .
Your comment is under moderation.
Experiments on the measurement of the gravitational constant G, carried out in recent years by several groups, show a striking discrepancy with each other. The recently published new measurement, made at the International Bureau of Weights and Measures, is different from all of them and only exacerbates the problem. The gravitational constant remains an extremely unyielding quantity for precise measurement.
Gravitational constant measurements
The gravitational constant G, also known as Newton's constant, is one of the most important fundamental constants of nature. This is the constant that enters Newton's law of universal gravitation; it does not depend on the properties of attracting bodies or on the surrounding conditions, but characterizes the intensity of the gravitational force itself. Naturally, such a fundamental characteristic of our world is important for physics, and it must be accurately measured.
However, the situation with the measurement of G is still very unusual. Unlike many other fundamental constants, the gravitational constant is very difficult to measure. The fact is that an accurate result can only be obtained in laboratory experiments, by measuring the force of attraction of two bodies of known mass. For example, in the classical experiment of Henry Cavendish (Fig. 2), a dumbbell of two heavy balls is suspended on a thin thread, and when another massive body is pushed to these balls from the side, the gravitational force tends to rotate this dumbbell by some angle, while the rotational moment of the forces is slightly twisted filament will not compensate for gravity. By measuring the angle of rotation of the dumbbell and knowing the elastic properties of the thread, one can calculate the force of gravity, and hence the gravitational constant.
This device (it is called "torsion balance") in various modifications is used in modern experiments. Such a measurement is very simple in essence, but difficult in execution, since it requires accurate knowledge of not only all masses and all distances, but also the elastic properties of the thread, and also obliges to minimize all side effects, both mechanical and thermal. Recently, however, the first measurements of the gravitational constant have appeared by other, atomic interferometric methods, which use the quantum nature of matter. However, the accuracy of these measurements is still much inferior to mechanical installations, although, perhaps, the future lies with them (for details, see the news The gravitational constant is measured by new methods, "Elements", 01/22/2007).
One way or another, but, despite more than two hundred years of history, the accuracy of measurements remains very modest. The current "official" value recommended by the American National Institute of Standards (NIST) is (6.67384 ± 0.00080)·10 -11 m 3 kg -1 s -2. The relative error here is 0.012%, or 1.2 10 -4, or, in even more familiar notation for physicists, 120 ppm (millionths), and this is several orders of magnitude worse than the measurement accuracy of other equally important quantities. Moreover, for several decades now, the measurement of the gravitational constant has not ceased to be a source of headache for experimental physicists. Despite dozens of experiments carried out and the improvement of the measuring technique itself, the measurement accuracy remained low. A relative error of 10–4 was reached 30 years ago, and there has been no improvement since then.
Situation as of 2010
In the past few years, the situation has become even more dramatic. Between 2008 and 2010, three groups published new G measurements. A team of experimenters worked on each of them for years, not only directly measuring G, but also carefully looking for and rechecking all possible sources of error. Each of these three measurements was highly accurate: the errors were 20–30 ppm. In theory, these three measurements should have significantly improved our knowledge of the numerical value of G. The only trouble is that they all differed from each other by as much as 200–400 ppm, that is, by a dozen declared errors! This situation as of 2010 is shown in Fig. 3 and briefly described in the note An awkward situation with the gravitational constant.
It is quite clear that the gravitational constant itself is not to blame; it really must be the same always and everywhere. For example, there are satellite data that, although they do not allow a good measurement of the numerical value of the constant G, they make it possible to verify its invariance - if G changed in a year by at least one trillionth (that is, by 10 -12), this would already be noticeable . Therefore, the only conclusion that follows from this is that in some (or some) of these three experiments there are unaccounted sources of errors. But in what?
The only way to try to figure it out is to repeat the measurements on other setups, preferably with different methods. Unfortunately, it has not yet been possible to achieve a particular variety of methods here, since one or another mechanical device is used in all experiments. But still, different implementations may have different instrumental errors, and comparing their results will make it possible to understand the situation.
new dimension
The other day in a magazine Physical Review Letters one such measurement has been published. A small group of researchers working at the International Bureau of Weights and Measures in Paris built an apparatus from scratch that measured the gravitational constant in two different ways. It is the same torsion balance, but not with two, but with four identical cylinders mounted on a disk suspended on a metal thread (internal part of the installation in Fig. 1). These four weights gravitationally interact with four other, larger cylinders mounted on a carousel that can be rotated to an arbitrary angle. The scheme with four bodies instead of two makes it possible to minimize the gravitational interaction with asymmetrically located objects (for example, the walls of a laboratory room) and focus specifically on the gravitational forces inside the installation. The thread itself has not a round, but a rectangular section; it is rather not a thread, but a thin and narrow metal strip. This choice makes it possible to more evenly transfer the load along it and minimize the dependence on the elastic properties of the substance. The entire apparatus is in a vacuum and at a certain temperature regime, which is maintained with an accuracy of a hundredth of a degree.
This device allows you to perform three types of measurements of the gravitational constant (see details in the article itself and on the page of the research group). Firstly, this is a literal reproduction of the Cavendish experiment: a load was brought up, the scales turned through a certain angle, and this angle is measured by the optical system. Secondly, it can be launched in the mode of a torsion pendulum, when the internal installation periodically rotates back and forth, and the presence of additional massive bodies changes the oscillation period (however, the researchers did not use this method). Finally, their installation allows you to measure the gravitational force no turn weights. This is achieved with the help of electrostatic servo control: electric charges are applied to the interacting bodies so that the electrostatic repulsion fully compensates for the gravitational attraction. This approach allows us to get rid of instrumental errors associated specifically with the mechanics of rotation. Measurements have shown that the two methods, classical and electrostatic, give consistent results.
The result of the new measurement is shown as a red dot in fig. 4. It can be seen that this measurement not only did not resolve the sore point, but also exacerbated the problem even more: it is very different from all other recent measurements. So, by now we already have four (or five, if you count the unpublished data from the California group) different and, at the same time, fairly accurate measurements, and they all drastically diverge from each other! The difference between the two most extreme (and chronologically the most recent) values already exceeds 20(!) declared errors.
As for the new experiment, here is what needs to be added. This group of researchers had already performed a similar experiment in 2001. And then they also got a value close to the current one, but only slightly less accurate (see Fig. 4). They could be suspected of simply repeating measurements on the same hardware, if not for one "but" - then it was another installation. From that old plant they have now taken only the 11 kg outer cylinders, but the entire central apparatus has now been rebuilt. If they really had some kind of unaccounted for effect associated specifically with the materials or manufacture of the device, then it could well change and “drag along” a new result. But the result remained about the same place as in 2001. The authors of the work see this as an extra proof of the purity and reliability of their measurements.
The situation when four or five results obtained by different groups at once All differ by a dozen or two of the declared errors, apparently unprecedented for physics. No matter how high the accuracy of each measurement and no matter how proud the authors may be, it is now of no importance for establishing the truth. And for now, trying to find out on their basis the true value of the gravitational constant can only be done in one way: put the value somewhere in the middle and attribute an error that will cover this entire interval (that is, one and a half to two times worsen current recommended error). One can only hope that the next measurements will fall into this interval and will gradually give preference to some one value.
One way or another, but the gravitational constant continues to be a puzzle of measurement physics. In how many years (or decades) this situation will actually begin to improve, it is now difficult to predict.
