I. MATERIAL REQUIREMENTS OF PERMANENT MAGNETS AND INSTRUMENT DESIGN
Design of permanent magnet representing the sun1,2,3. The permanent magnets representing the Sun all are NdFeB magnets(Nd2Fe14B)4,5,6,7,8; one cube magnet, triple cylindrical magnets, and one spherical magnet. Each permanent magnet was installed on the top of the shaft of a low-speed DC electric motor9. The centreline of the shaft passed through the centre of gravity of each permanent magnet. The electric motor base was round and made of non-magnetic materials. The round surface of the base was perpendicular to the rotation axis of the electric motor, making it stable when the base was placed on a horizontal surface. The electric motor speed controller was used to vary the electric motor speed (stop, slow, and fast) between1-25 r/S10. The permanent magnets were marked as "sun"m1, "sun"m2, "sun"m3, "sun"m4, and "sun"m5 depending on the characteristic of magnetic flux density and mass. The north and south poles of the permanent magnets were marked with “N” and “S” respectively. The "sun"m1 was a cube neodymium magnet of an edge length of 50 mm. Seven cylindrical NdFeB magnets of the same shape were used, the diameter and height of were 52 mm and 6.1 mm. Three "sun" magnets of different masses were are also designed; "sun"m2 was a cylindrical magnet, "sun"m3 comprised two cylindrical magnets, and "sun"m4 comprised four cylindrical magnets. Finally, "sun"m5 was a spherical neodymium magnet of a diameter of 63.2 mm. Since strong magnetic magnet will stick to each other at close distances, which could lead to unexpected outcomes during the experiment, the permanent magnets in the electric motor and the rotational shaft were placed in transparent spherical containers to prevent this outcome(See left side of Fig. 1).
Design of permanent magnets representing the planet1. The permanent magnets representing the planets were spherical11. Each spherical magnet was placed at the centre of a hollow spherical object floating on water to ensure free rotation. Alternatively, the spherical magnet could be directly placed in a round transparent container with a concave bottom or on the palm of the experimenter. For convenient observation and research, the north and south poles of each spherical permanent magnet were marked with dots in two different colours. A bisected circle perpendicular to the N-S pole axis (such as the equator of Earth) was then drawn on each spherical magnet. The two semi-circles of the bisected circle were marked with two different colours. The permanent magnets were marked as "planet"m①, "planet"m②, "planet"m③, and "planet"m④ depending on the characteristic of magnetic flux density and mass to distinguish them from each other and from the permanent magnets on the motor shaft. The diameters of the spheres of "planet"m① and "planet"m② are 12.5 mm, The diameter of "planet"m③ is 14 mm, The diameter of "planet"m④ is 9.6 mm, "planet"m①, "planet"m② and "planet"m④ are all NdFeB spherical magnet (Nd2Fe14B)12,13,14, "planet"m③ is ferrite spherical magnet(Fe2O3)15,16,17. During the experiment, each "planet" magnet is independent and cannot stick together(See right side of Fig. 1).
Method to measure magnetic flux density. When the Gauss meter was used to measure the magnetic flux density on the surface of the permanent magnet18, the maximum magnetic flux density of the spherical magnet was observed at small areas around the N and S poles. However, the magnetic pole areas were large on the bar, square, rectangular, and cylindrical permanent magnets. The magnetic flux density of the magnetic poles was often distributed unevenly in the polar area. There was a united specific position, determined by the positional characteristics of the maximum magnetic flux density of spherical magnets, which helped measure the maximum magnetic flux density of permanent magnets of different shapes. In this study, the probe of the Gauss meter was placed on the centre of the N pole on the surface of the permanent magnet18,19. Then, the positive value displayed on the Gauss counter was used as the value of the magnetic flux density. When measuring the magnetic flux density of combined magnets (i.e., stuck together) of the same shape, mass, and magnetic flux density, we first aligned the N and S poles of the magnet on the same straight line. Then, we placed the Gauss meter probe in the N-pole centre of the first magnet surface and measured the magnetic flux density of increase magnets mass18,19,20. The results are presented in Table I.
II. EXPERIMENTAL SETUPS AND PROCEDURES
First, a cubical permanent magnet with a mass of 950 g and magnetic flux density of 0.47 T ("sun"m1) was installed at the top of the rotational shaft of electric motor. The N and S poles of "sun"m1 were directed perpendicularly to the rotational shaft. The speed of rotation of "sun"m1 varied between 1-25 r/S using a motor speed controller10,21. Next, an 8-g spherical magnet with a magnetic flux density of 0.572 T18,19, labelled "planet"m①, was placed inside a hollow spherical object that floated on water. "planet"m① was then placed in a round transparent container filled with water with an opening of 1.5–2 times the diameter of "planet"m①. During the experiment, "sun"m1 and "planet"m① were kept away from ferromagnetic objects(See Fig. 1).
In experiment A, "planet"m① was placed at approximately 15–65 cm from the centre of "sun"m1. Taking the horizontal plane in the round transparent container and the magnetic pole mark and the double-coloured circle on "planet"m① as reference system. Then, "sun"m1 rotated at a speed of 1–3 r/S10.
In experiment B, with "sun"m1 as the core, move "planet"m① back and forth within a distance of 15-65 cm, keeping "planet"m① away from or near the "sun"m1. Then, repeatedly adjust the speed of the "sun"m1 from 1 r/S to maximum speed 25 r/S10,21. For example, in the same horizontal plane, when the distance "planet"m① and "sun"m1 is 65cm, the initial speed of "sun"m1 cannot exceed 1 r/S, otherwise, "planet"m① cannot rotate, the fastest speed cannot exceed 7.5 r/S, otherwise, "planet"m① cannot rotate. When the distance "planet"m① and "sun"m1 is 30cm, the fastest speed of "sun"m1 cannot exceed 23 r/S, otherwise, "planet"m① cannot rotate.
In experiment C, With "sun"m1 the as core22, slowly move the "planet"m① from near to far in any direction. ⑴ When the "planet"m① is at every dot of the "sun"m1, first, stop the rotation of "sun"m1 and "planet"m①, secondly, let the "sun"m1 on the motor rotate at a speed of 1-3 r/S10, finally, find out and measure the maximum rotation distance between "sun"m1 and "planet"m①. ⑵ When the "planet"m① is at every dot of the "sun"m1, first, let "sun"m1 rotated at speed of 1-3 r/S10, Secondly, slowly move the rotating "planet"m① from near to far, finally, find out and measure the maximum rotation distance between "sun"m1 and "planet"m①. For example, when "sun"m1 and "planet"m① are in the same plane, the maximum rotation distance of "planet"m① and "sun"m1 from static to rotation is 65 cm. The maximum rotation distance of "planet"m① and "sun"m1 after rotation is 112cm(forbidden to use ferromagnetic ruler when measuring).
In experiment D, the rotation speed of "sun"m1 was between 1-3r/S. On any half-line with "sun"m1 as the core, we slowly moved "planet"m① and changed the distance between "planet"m① and "sun"m1, taking the horizontal plane in the round transparent container and the magnetic pole mark on "planet"m① as reference system. The direction of the magnetic pole of "planet"m① was measured as follows. The rotation of "sun"m1 was stopped when "planet"m① rotated at a certain point. The centre of the protractor was then aligned with the centre of "planet"m① to make the 0° line of the protractor parallel to the water surface. The magnetic pole above the horizontal plane was then rotated to one side of the 0° line. The angle corresponding to the magnetic pole of "planet"m① could be measured above the horizontal plane23.
In experiment E, with 1-3r/S rotated "sun"m1 as the core, under the behavior of the rotation torque of "sun"m1, the "planet"m① and "planet"m② was in a rotation state in the magnetic field. Be based on the mass and magnetic flux density of "planet"m① and "planet"m②, the minimum distance between "planet"m① and "planet"m② without affecting each other's rotation is adjusted and measure24. Then, based on the minimum distance between "planet"m① and "planet"m② that does not affect the rotation and maximum rotation distance from "planet"m① or "planet"m② to "sun"m1. Slowly move each "planet"m① or "planet"m② from near to far to the position of maximum rotation distance. According to the above method, many "planet"m① and "planet"m② Can placed in around "sun"m125. For example, the maximum rotation distance between "planet"m① or "planet"m② and "sun"m1 is 112 cm, and the minimum rotation distance between "planet"m① and "planet"m② is 10 cm. Therefore, 10 "planet"m① or "planet"m② can be arranged on any horizontal line segment with "sun"m1 as the core. By analogy, more "planet"m① and "planet"m② can be arranged around "sun"m1.
In experiment F, "planet"m① was placed at a distance of 15–65 cm from "sun"m1. (1) When "sun"m1 rotates at the speed of 1 r/S, the synchronous speed relation between "planet"m① and "sun"m1 can be observed26,27. (2) When the rotational speed of "sun"m1 exceeded 2 r/S, the synchronous speed relation between "sun"m1 and "planet"m① was measured using a laser Doppler velocimeter21.
In experiment G, "planet"m① was placed on the palm of the hand, and "sun"m1 was made to rotate at 1–25 r/S using the motor speed controller10. The motor to which "sun"m1 was attached and the sphere containing "planet"m① were held by the experimenter’s left and right hands, respectively. Then, the distance between "sun"m1 and "planet"m① was varied between 5 and 30 cm, the experimenter’s hands were used to feel the strength of the attractive force and rotation force between between "planet"m① and "sun"m128,29.
In experiment H, the distance between "planet"m① and "sun"m1 was set to 25–65 cm. Then, "sun"m1 was made to rotate at 1-3 r/S using the electric motor speed controller10. under the behavior of the rotation torque of "sun"m1, the "planet"m① was in a rotation state in the magnetic field. The "planet"m① move slowly at a 360° angle pass by the top and bottom of the electric motor with "sun"m1 as the core and the double-coloured circle on "planet"m① as the reference system30. The rotation direction of "planet"m① is observed from different angles and compared with that of "sun"m1.
In experiment I, the "sun" and "planet"magnet with different magnetic flux densities and the masses were used in the magnet rotation experiment. The observed phenomena are still the same, but the maximum rotation distance between the "sun" and "planet" magnet is different. Next, seven cylindrical magnets with the same material and shape were utilized, each with a mass of 100 g and a magnetic flux density of 0.117 T18,19, and three "sun" magnet with different masses were designed. "sun"m2 is a cylindrical magnet, "sun"m3 is composed of two attract together cylindrical magnets, and "sun"m4 is composed of four attract together cylindrical magnets. Each "sun" magnet installed on the electric motor shaft rotates at a speed of 1–3 r/S through the electric motor speed controller10. Then, the "planet"m①, m②, m③ and m④ are designed to float in each circular transparent container. Each "sun" magnet and each "planet" magnet are used for magnet rotation experiments. First, observe the change to magnetic flux density in case of any change to the mass of the "sun" magnet. Then observe the change to the maximum rotation distance from each "planet" magnet to the "sun" magnet (r) in case of any change to the mass and the magnetic flux density of the "sun" magnet. The results are shown in Table II.
In experiment J, the permanent magnet must be a spherical permanent magnet11. For example, a spherical magnet ("sun"m5) was affixed on the top of the rotational shaft of a low-speed electric motor1. An arbitrary circle passing through the N and S poles of "sun"m5 was drawn on the sphere. To divide these semicircles in half, two points, A and B, were selected on the NS and SN semicircles. Therefore, the central angles of the NA, NB, SA, and SB arcs were all 90°. Then, two arbitrary arcs were selected, such as NB and SA. The N and S points were denoted as 0°, while A and B were denoted as 90°. The subdivisions between 0° and 90° were then marked on the SA and NB arcs. The top of the motor’s rotational shaft was aligned with any point between 0°–90° of "sun"m5; therefore, the central axis of the electric motor rotational shaft also passed through the core of "sun"m5(See left side of Fig. 2).
In experiment K, a spherical magnet with a mass of 400 g and magnetic flux density of 0.3 T ("sun"m5) was installed at the top of the rotational shaft of the electric motor11. The "sun"m5 speed of rotation was adjusted to 1-25 r/S using a electric motor speed controller10. Next, an 8-g spherical magnet with a magnetic flux density of 0.572 T, la belled "planet"m①, was placed inside a hollow spherical object that floated on water. "planet"m① was then placed in a round transparent container filled with water with an opening of 1.5–2 times the diameter of "planet"m① (See Fig. 21).
(1) The distance between "planet"m① and "sun"m5 was set to 15–50 cm. The top of the motor’s rotational shaft was aligned to each point between 0°–14°, from S to A or N to B, while "sun"m5 was rotated at 1–25 r/S. The resulting rotation behavior of "planet"m① were then recorded. (2) The distance between "sun"m5 and "planet"m① was set to 15–50 cm, and "sun"m5 was rotated at 1 r/S. The top of the motor’s rotational shaft was aligned to the points between 15°–22° from S to A or from N to B. The resulting rotation behavior of "planet"m①, as well as the relationship between "sun"m5 and "planet"m① rotational speeds, were then observe. (3) The distance between "sun"m5 and "planet"m① was set to 15–50 cm, and "sun"m5 was rotated at 1–3 r/S. The top of the motor’s rotational shaft was aligned with points between 23°–90° from S to A or from N to B. The resulting rotation behavior of "planet"m① were then observed.
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Acknowledgments: I would like to thank Mr. Zhongping Jia and Mr. Guojun Wei from the Longnan Electric Power Bureau of Gansu Province, China, and Ms. Liping Liu and Mr. Qiang Liu from Cheng County, Gansu Province, China. Thank them for their financial support to this research work during the last decade.
Author Contributions Weiming Tong designed and made the instrument, and he wrote the paper according to its experimental procedure and methodology. He named the permanent magnet and distinguished it according to the characteristics of its quality and magnetic flux density. And he made measurement to the data using non-ferromagnetic centimeter ruler, laser Doppler velocimeter, gauss meter and microelectronic balance, and he also reviewed and commented on the paper.
Ethics declarations: This manuscript has not been published or presented elsewhere in part or in entirety and is not under consideration by another journal including the Internet. We have read and understood nature journal’s policies, and we believe that neither the manuscript nor the study violates any of these. There are no conflicts of interest to declare.
Author information: Affiliations, Suochi Schooling District, Cheng County, Gansu Province, China, 742509
Correspondence and requests for materials should be addressed to Weiming Tong at [email protected]