Three bodies

[1] See "Ball Lightning" published by the author in 2004

[2] This refers to Asimov's science fiction novel "Billards".

[3] One of the most outstanding contemporary physicists, has made great achievements in experimental physics research.She proved for the first time in the laboratory the theoretical conjectures of Li Zhengdao and Yang Zhenning on parity non-conservation in weak interactions, overturning the law of parity conservation.

[4] At that time, in most colleges and universities, these two majors were integrated.

[5] The first generation of computer high-level language.

[6] The problem of how three objects with the same or similar mass move under the action of mutual gravitation is a classic problem in classical physics, which is of great significance to the study of celestial body motion and has been concerned since the sixteenth century.Swiss mathematician Euler, French mathematician Lagrange, and some scholars with the help of computer research in recent years have found some special solutions to the three-body problem.

[7] French mathematicians in the [-]th century once proved that the three-body problem is unsolvable in mathematics, and started from the three-body problem to create a new mathematical method on the differential equation problem.

[8] The founder of modern computer technology.

[9] Founder of cybernetics.

[10] French astronomer Roche proved that any solid celestial body, when approaching another celestial body much larger than it, will be subjected to strong tidal forces and will eventually be torn to pieces.The distance at which this smaller object will be shredded is known as the Roche limit, and is usually 2.44 times the equatorial radius of the large object.

[11] In order to pass through the 32-meter-wide lock of the Panama Canal, a considerable number of large ocean-going ships are designed to be 31 meters wide, known as the Panama-scale type.

[12] The main artificially excavated part of the Ma Canal, the channel is narrow.

[13] The engineer who designed and built the Panama Canal, Gaillard Waterway is named after him.

[14] Shorthand for Trisolaris.

[15] Short for Planetary Defense Council.

[16] That is, "The Romance of the Three Kingdoms".

[17] The connection between the space elevator and the ground.

[18] Amendments to the Charter of the United Nations due to the needs of Earth's defense.

[19] Short for Planetary Defense Council, formerly known as the United Nations Security Council.

[20] The urgently deployed defense system consisting of existing intercontinental missiles and NMD systems is mainly used to prevent the low-dimensional deployment of sophons in near-earth space.

[21] A plan to establish an Earth space fleet, in which each country independently forms a space force and then integrates it into an Earth fleet.

[22] When the fighter plane enters the air combat state, it needs to discard the auxiliary fuel tank to reduce the weight.

[23] A guessed brain information storage method that can restore all the information stored in any part of the brain.

[24] A disk-shaped region containing many small ice crystals at the edge of the solar system, 30 to 100 astronomical units from the sun.

[25] The spherical cloud surrounding the solar system, filled with a large number of inactive comets.

[26] The fuel-type nuclear fusion engine is similar to the chemical rocket. It uses the energy of nuclear fusion to propel the working medium with mass, and generates reverse thrust to propel the spacecraft; the non-propellant nuclear fusion engine uses the radiation energy of nuclear fusion to propel directly. spaceship.The former requires the spacecraft to carry the propellant. When the long-distance voyage is accelerated and decelerated for a long time, the demand for the propellant will be very large, so the propellant engine cannot carry out interstellar voyage.

[27] The protagonist in the masterpiece "Foundation" by American science fiction writer Isaac Asimov.

[28] Refers to the number of circuits integrated on an integrated circuit chip, doubling every 18 months.

[29] This is the Fermi paradox about extraterrestrial civilization: In theory, human beings can fly to various planets in the Milky Way in one million years. Should come to earth.The paradox is convincing because it is based on two facts about the Milky Way: first, the Milky Way is very old, about 100 billion years old; second, the diameter of the Milky Way is only about 100 light-years.So even if aliens traveled in space at only one-thousandth the speed of light, they would only need about 100 million years to traverse the Milky Way—a time far shorter than the age of the Milky Way.If aliens really exist, they should have reached the solar system by this reason.

[30] The genetic weapon in the concept is only recessively transmitted among non-target populations and does not produce any symptoms.

[31] Vouchers used in the domestic purchase of large electrical appliances and other commodities in the 70s and [-]s.

[32] Robert Haig, a professor at the University of California, Los Angeles, is the most authoritative collector of meteorites in the world.He started collecting meteorites at the age of 23, and his own meteorites have become the largest private collection of meteorites in the world.

[33] The space elevator is actually an artificial satellite running in a geosynchronous orbit. In order to achieve balance during operation, it is necessary to add the same weight as the elevator to the outside of the orbit.

[34] The poem by Emma Lazarus on the pedestal of the Statue of Liberty reads: Give me all you weary ones, you poor ones/You huddled ones longing for the air of freedom/Take The homeless and the weather-beaten are sent / By this golden gate, for them I will lift the lamp.

[35] From Milton's poem "My Blindness": God ordered people to work / Didn't they give light / I asked stupidly / But "Patience" wanted to stop this murmur / and answered immediately / God needs no man's hand or man's own endowment / Who best bears his gentle yoke / Serves him best.

[36] Due to the gravitational force of the planet it carries, the star produces a slight swing when the planet revolves around it. Under the condition that the observation ability of the telescope cannot directly observe the planet outside the solar system, it is often observed indirectly by observing this periodic swing of the star. The existence of planets is speculated.

[37] When the planet passes between the star and the observer, the periodic small change in the brightness of the star.

[38] No matter how large the equivalent of the hydrogen bomb is, its radiation effect has little deceleration effect on Mercury. The real effective deceleration is to blow up a huge amount of formation material to the second cosmic speed of Mercury to generate recoil force. According to the conservation of momentum According to the principle, even if the stratum material reaches the first cosmic speed of Mercury and becomes its satellite, it will not have any deceleration effect.So the rocks that make the most sense for Rey Diaz's plan are the rocks that exploded off Mercury to become solar asteroids.

[39] Due to the limitation of the speed of light in signal transmission, the monitoring accuracy of microsecond level cannot be achieved no matter how far the distance is.

[40] Population of New York City.

[41] American psychologists advocate the use of LSD hallucinogens to control human minds, and then achieve the salvation of souls. In the middle of the last century, there were a large number of followers in the field of psychology and culture.

[42] Refers to the period from the emergence of the three-body crisis to the end of the Great Trough.

[43] The English meaning of the legendary Marlboro.

[44] The atomic nuclei of a neutron star are all pressed together and arranged neatly.

[45] The specific gravity of neutron star matter is equivalent to 10^14 times that of water.

[46] The temperature of an object is caused by molecular vibrations.

[47] The strong interaction force is the strongest among all the forces in nature, and its strength is a hundred times that of the electromagnetic force, but it can only work in a very short distance inside the nucleus, and the scale of the nucleus is very different from that of the atom. If the atom is the size of a theater, the nucleus is only as big as a walnut. Therefore, the scale of the atom is far beyond the scope of the strong interaction force, and the main force between atoms and molecules is the electromagnetic force.

[48] ​​The last time humans successfully used the tactic of directly hitting a warship in a naval battle was the Rissa naval battle in 1811. After the tragedy of the Zhiyuan in the Sino-Japanese War of [-], this tactic was completely eliminated.

[49] Mathematical problem of connecting multiple points with non-repeating paths.

[50] A nuclear weapon in space, used to strike spaceship targets that are well shielded from conventional radiation. Multiple nuclear explosions can occur continuously at the frequency of infrasonic waves in the air. Each nuclear explosion produces strong electromagnetic radiation. Electromagnetic radiation and The metal shells of the target spacecraft interact to convert the electromagnetic energy into the acoustic energy of the air inside the spacecraft, generating super-strong infrasound waves, killing all macroscopic life inside the spacecraft, but basically not damaging the facilities of the spacecraft.

[51] Since the infrasonic hydrogen bomb produces damage through electromagnetic pulses, it does not need to hit the target directly, and the personnel inside the target can be killed by detonating at a considerable distance from the target.For missiles that are invisible to radar, they can only be detected by other detection methods including visible light observation when they are close to the target.

[52] The gravitational equilibrium point of the Earth and the Moon.

[53] Civilizations with different life properties need to occupy different resources, so the resource allocation of civilizations in the universe may be divided into many parallel levels. From carbon-based life, silicon-based life to star life and electromagnetic life, the resources required are basically Including all material forms in the universe, most of the resources involved in each layer do not interfere with each other, but there are overlaps.

[54] In biology, biological classification is divided into kingdom, phylum, class, order, family, genus, and species. The lower the level is, the more similar the characteristics are to each other.The biological differences between human races on Earth are limited to the level of species. If the existence of non-carbon-based organisms is considered, the differences of alien races may exceed the level of the world.

[55] The plane in which the Earth orbits the Sun.

[56] Luo Ji once suspected that after the formation of dust clouds, sophons could spread two-dimensionally in the gaps between the clouds and also block the sun, thus interfering with the transmission of information. Without any space maneuvering and positioning capabilities, it can only maintain its shape with the gravity of the planet as the skeleton. If it is unfolded in space, it will soon lose its planar shape under the action of solar wind and other factors. The reason why sophons can only maintain their shape for circuit etching when enveloping a trisolaran planet.

[57] In 1204, the Crusaders occupied and sacked Constantinople during the Fourth Eastern Crusade.

[58] Nickname of Ottoman Turkish Sultan Mehmed II, meaning conqueror.

[59] Urban, a Hungarian engineer, went to Constantinople to build a cannon, but the financially empty Byzantine authorities could not even pay his meager salary, so he defected to Mehmed II and built a giant cannon for the Ottomans. The cannon, more than eight meters long and about 75 centimeters in diameter, can fire half a ton of shells to a distance of one mile. It is known as the Urban Cannon in history and played a huge role in the siege of Constantinople. , is the only weapon capable of destroying the city's fortified walls.

[60] NASA.

[61] is the ratio of engine thrust to engine mass.Cheng Xin imagined that if the spaceship carried a large number of nuclear bombs, it would have a large mass and a very low thrust-to-weight ratio, so it would be impossible to reach a high speed.

[62] According to the laws established by the "Bronze Age" when it left the solar system, newborns can only be born when someone on board dies.

[63] Due to the limitation of the speed of light, it is difficult to explain the current high uniformity of the universe, that is, all directions of the universe have the same galaxy density and microwave background temperature, because after the big bang, all parts of the universe during the normal expansion process It is impossible to balance the interaction, so the theory of inflation appeared, which believed that the universe suddenly expanded from a small diameter to the current scale in a very short period of time.

[64] A high-density state of matter.Since the Pauli Exclusion Principle prohibits different constituent particles from occupying the same quantum state, reducing the volume forces the particles into high-energy states, creating enormous degeneracy pressures.Degenerate matter includes electron degenerate state, neutron degenerate state and so on.

[65] Transit interference means that when the observer, the observation target and the sun are in the same straight line, the observation target is the sun as the background, and the sun is a huge source of electromagnetic emission, then the observer will be subjected to the sun’s emission. strong interference.

[66] See "Three-Body II·Dark Forest", a super-strength material whose atoms are linked by strong interactions among elementary particles.

[67] In the system formed by the planet and the sun, there are five Lagrangian points of gravitational balance, and two are stable, and the second Lagrangian point is located outside the planet on the line connecting the planet and the sun.

[68] The effect of this test is related to the hardness and cleanliness of the water. It is best to add a rudder to the rear of the boat, otherwise the boat may not go straight.

[69] When the speed of light in vacuum is lower than the escape velocity of the solar system, the radius of the solar system is smaller than its Schwarzschild radius.The Schwarzschild radius is the critical radius of any gravitational mass. When the radius of a celestial body is smaller than the Schwarzschild radius, light cannot escape from the gravitational field within the radius, and it will become a black hole.The formula for the Schwarzschild radius is actually derived from the formula for the escape velocity of an object. It sets the escape velocity of an object as the speed of light, and with the gravitational constant and the mass of a celestial body, the Schwarzschild radius can be obtained.

[70] The boundary of a black hole is called the event horizon.Matter and radiation outside the black hole can enter the interior of the black hole through the event horizon, and any matter and radiation inside the black hole cannot pass through the event horizon, so the event horizon is also called a one-way membrane.The event horizon is not a material plane. It means that external observers, in a physical sense, know nothing except the basic parameters such as the total mass and total charge contained in it (referring to the event horizon).The event horizon radius of a spherical black hole is the Schwarzschild radius.

[71] A liquid that allows people to breathe in it, can be filled with human organs and tissues, and can protect the human body when the spacecraft accelerates at high power, see "Three-Body II·Dark Forest".

[72] Astronomical Unit.

[73] When the gravitational source exerts a force on the object, due to the different distances from the points on the object to the gravitational source, the magnitude of the gravitational force is different, resulting in a gravitational difference and a tearing effect on the object. This gravitational difference is the tidal force.

[74] For the above content, see "Three-Body Problem" and "Three-Body Problem II·Dark Forest".

[75] This brings to mind dark matter.