This article was published in the Bethune of the Israeli Astronomical Society, of which Yehuda Saberdarmish is one of the editors
Yehuda Sverdarmish
Direct link to this page: https://www.hayadan.org.il/sverdernishgravity.html
Unlike others who will start the history of gravitation with the story of Galileo Galilei, or Newton, I prefer to start with the story of Tycho Brahe.
Tycho Brahe (1546-1610), made very precise measurements on the planets known at the time (Mercury to Saturn). He made the measurements with the help of instruments he built himself and without the help of a telescope that had not yet been invented at the time. These data were transferred to his assistant Johannes Kepler (1630-1571) for a little over a year. Because of the great accuracy of the measurements, Kepler realized that the movement of the planets around the sun is not circular but elliptical, and hence the path to arrive at the three laws known by his name was short:
1. Ellipse - the planets move in an elliptical orbit in one
From its centers is the sun.
2. Equal areas at equal times-
The radius vector connecting a planet to the sun passes through
Equal areas at equal times.
3. The distance of the planet from the sun in the third, divided by the square of its cycle time, is constant.
Isaac Newton (1643-1727), who discovered the three laws of motion known by his name, also had Tycho Brahe's data and Kepler's laws. He understood that the gravitation in the planets is proportional to the centrifugal force and from all this information he deduced the law of universal gravitation:
F=(M*m*G)/(r squared)
Newton's initial conclusion was that gravitation works from the edge of the universe to the edge of every two pieces of matter at any distance. Is this too overwhelming a decision? It is clear that he did not test this at every point in the universe, but what, we must not forget that the known universe in Newton's time was relatively small. The known solar system in Zhemno was up to the planet Saturn, and apart from it, there was at most another count of Saturn stars. So Newton actually did not exaggerate too much when he said that his gravitation formula was proven for the entire universe known at the time. Also the movement of the planet Saturn, somewhere, close to the edge of the universe (known in his day) behaved according to its gravitation formula.
In the meantime, the discovery of the distant planets: Uranus - (1781), Neptune - (1846) and especially Pluto - (1930), moving at a distance between 30-50 YA from the Sun, contributed to the proof of the gravitation formula up to a distance of 50 YA, while Henry Cavendish In an experiment he conducted in 1798 with the help of scales invented by John Eichel, he proved the gravity formula for a distance of about one cm and determined the gravitational constant - G.
Conclusion: The gravitation formula is now proven to be correct from one cm to fifty eleven.
However, even though the formula is now proven for many times greater distances, this was also the known size of the universe at the time, so it was still not an exaggeration to state that Newton's gravitation formula is true for the entire universe.
However, from this moment on, the universe turns out to be a much larger body.
Measurements using the parallax method reveal that the distance to the stars closest to the sun is already measured in light years (a light year is a unit of length that is 63,240 astronomical units!)
Measurements using cupid variable stars show that the distance to the nearest galaxies is measured in millions of light years, and finally, measurements using the rate of expansion of the universe and the Hubble constant show that the size of the universe is actually billions of light years! To remind you, the proof of Newton's gravitation formula was done with certainty up to a distance of fifty astronomical units.
distances in the universe
50 YA - Limit of proof of the gravitation formula in the solar system.
250,000 Ya - the distance to the nearest star (Proxima Centauri).
10,000,000,000 YA - diameter of an average spiral galaxy.
1,000,000,000,000 XNUMX -
The distance to the nearest galaxies.
1,000,000,000,000,000 XNUMX -
The diameter of the visible universe.
There is no doubt now that the formula must be proven for greater distances as well. Attempting to ignore this contradicts the problem of induction already raised by the English philosopher David Yom, which simply says that one can draw conclusions from a certain statement only regarding the limits in which that statement was tested.
Attempts to prove Newton's gravitation formula were made with the help of the rotational motion of the spiral galaxies when the rotational speed of different regions of the galaxy measured with the help of an effect
Motion of a star in a spiral galaxy
(The attached figure at the top of the article)
Possible conclusions from the analysis of motion in spiral galaxies
A. Newton's gravitation formula is correct at large distances, therefore:
1. The mass of the galaxy is 10 times greater than the apparent mass.
2. Most of the mass is concentrated in the region of the gas clouds of the galaxy.
3. In galaxy clusters the mass must be 100 times greater than the apparent mass to maintain the cluster structure.
B. Newton's gravitation formula is incorrect at large distances and must be replaced.
third. Newton's acceleration formula: F=m*a
is not correct at small accelerations.
d. Gravitation does not explain the movement of the galaxy but something else.
The editor of the site comments: This something, meanwhile, is Einstein's theory of relativity, but the author of the article, Yehuda Sverdarmish, claims that even this is not enough and he has another theory, which was put forward in an article published in Bethune by the Astronomical Society. Due to technical difficulties - the article is full of formulas and graphs beyond the capacity of the tools of this site - it has not been uploaded yet.
