The development of science and technology has continuously improved the ability of human beings to understand the world, and human beings have become more and more aware of the world they live in, and they know more and more things. Pen, fun, pavilion www. biquge。 info

In ancient times, when human beings came to draw a map of their own life, they often used mountains, rivers, etc. as references, and the maps drawn were at most only hundreds of miles within the range of their own lives, and they were often not clear and accurate.

With the further development of science and technology, human beings have entered the feudal society, and human beings in this period have had special personnel to study the world they live in, such as the astrological officials in ancient China, who would refer to the sun, moon, stars, etc. when drawing maps of their own countries, and the maps drawn were very vast and the relative accuracy was unsatisfactory.

In modern times, with the rise of modern scientific thought, the development of the Western Enlightenment, and the rise of the humanities, human beings for the first time have a more correct understanding of the time they live, knowing that they live on a huge ball, and with the rise of the Great Voyage, the world map is slowly becoming clear.

In the 20th century, with the development of aerospace science and technology, human beings began to view the world they live in from space, and they recognized the world they were in very intuitively and clearly, drew a map of the world with high accuracy, and even the galaxy where they were located had enough understanding to be able to draw a map of the galaxy.

Later, with the development of imperial science and technology, human beings officially entered the universe, galloping across the entire galaxy, in the river system, how to determine their position and distance, how to accurately draw the star map of the entire galaxy, scientists are very clever to use pulsars to accurately position, so that they will not be lost in the universe.

Now that the empire has reached level 6 cosmic civilization and has become a real cosmic civilization, how to map the Orentgo galaxy cluster, the local cluster where the Milky Way is located, how to accurately measure the distance between river systems, and many other problems have been plaguing the universe astronomical scientists of the empire!

A long time ago, astronomers in the universe mastered a method that could measure the distance between river systems - Cepheid variables!

Cepheids are a type of variable star whose photoperiod (i.e., the time it takes for brightness to change by one week) to be proportional to its luminosity, so it can be used to measure interstellar and intergalactic distances. Most of these variable stars are F-type (medium-temperature hot stars) at maximum luminosity; At the luminosity pole of light, it is a G-type star (a colder star like the Sun).

The typical star is the δ of the Immortal Constellation, whose luminosity was discovered by John Goodley in 1784, and by LeWitt at the Harvard Observatory in 1912, the period-luminosity relationship of the above-mentioned Cepheid variable star.

Cepheids are a type of high-luminosity periodic pulsating variable stars, that is, their brightness changes periodically with time. It is named after the typical δ of the constellation of the Star Immortals (Chinese name Father One). Because the distance of star clusters and galaxies can be determined according to the circumferential relationship of Cepheids, Cepheids are known as "measuring scales".

Cepheid variables are a method of measuring very long distances between river systems, which is why it has earned the title "Measuring Ruler", but in essence, this method is to study the spectrum of light that you can receive from distant river systems, and it takes millions of years for light to travel across the distance between river systems, which can often be millions of light years.

Therefore, the light we see in the Milky Way galaxy from the Andromeda galaxy and the triangular galaxy is all the light emitted by millions of years, and it is not particularly accurate to study these lights to measure and estimate the distance between river systems, and more importantly, there is no way to know the precise location of the river systems that are now far away.

You must know that the Andromeda Galaxy, the Milky Way, the Triangulum Galaxy and so on are all running along an unknown trajectory at high speed all the time, and the position of the time movement of millions of years will be very amazing, and the error will be very huge.

Now the empire wants to expand the galaxy outside the river, although the space teleportation technology is, but if you can't even do the accurate positioning, then the deviation of the space teleportation will be further expanded, and there will already be a deviation, you can't even get the current accurate positioning of the river system, the deviation will be very amazing, maybe a space teleportation will be teleported to the sea of death between the river system and the river system, then it will be miserable!

The Empire's cosmic astronomers continued to study and finally came up with two ways to cross long distances, calculate the distance between river systems in real time, and at the same time accurately locate the river system, and the deviation will be very small.

One is the spatial fluctuation method, in which the principle is to use the fluctuations generated by the ultra-large black hole in the core of the river system to measure the distance between the river systems, and the mass of the black hole in the core of the river system can be measured according to the size, frequency, intensity, etc. of this fluctuation, so that the size of the river system can be further inferred.

Because the size of a river system is inextricably linked to the core black hole, the core black hole has a large mass and strong gravitational attraction, the more interstellar dust and material it attracts, the wider the scope of gravitational influence, and the more prosperous the entire river system will be; On the other hand, if the mass of the black-hearted black hole in a river system is small, the gravitational attraction is weak, and the interstellar dust material attracted is less, and the whole river system is more barren and much smaller.

Another method is to measure the long distances between river systems and the situation of the river system itself according to the theory of cosmic space-time currents, according to the theory of cosmic space-time oceans, the entire universe is habitually transmitted by countless space-time currents, which are large and small, connecting every river system in the universe.

By connecting the magnitude of the space-time currents of the universe of this river system, the mass and range of the river system itself can be measured, and the current position of the river system can be measured according to the movement of the space-time currents!

Both of these methods were developed by astronomical scientists in the Imperial Universe, and are very accurate, measuring the distance of all the river systems around the Milky Way in real time, and estimating the prosperity of this river system.

Among the three river systems centered on the Andromeda Galaxy, the Milky Way and the Triangulum Galaxy, the mass of the Andromeda Galaxy is the first, and the mass of the black hole at its core is twice that of the black hole at its core, and the diameter of the entire Andromeda Galaxy is more than 220,000 light-years, and the diameter of the Milky Way is only 120,000 light-years!

As for the third-ranked Triangular Galaxy, it and the core black hole are only half the mass of the Milky Way, so the diameter of the Triangulum Galaxy scientists can accurately calculate that its diameter is only about 60,000 light-years!

In addition, in terms of prosperity, the most intuitive thing that can reflect the prosperity and barrenness of a river system is the number of stars that this river system has, the number of stars in the Andromeda galaxy in the first place is more than 1 trillion, which is a very terrifying and huge number, the number of stars in the galaxy The scientists of the empire can give an accurate number, the Milky Way has 500 billion stars, and the triangulum galaxy has only about 80 billion star systems, which is a very barren river system!

Only by mastering the real-time location of these river systems can the Empire's space scientists use space teleportation technology to teleport to distant river systems very accurately, otherwise there will be errors in space teleportation itself, plus there are errors in the distance measured by astronomical observations, even if they master the space teleportation technology, it is not a simple matter to reach other river systems.

It's like attacking with a long-range missile, the missile itself produces some errors, if you can't know exactly where you are and where the target is, then your missile wants to attack the target point very accurately, which is almost impossible!

The distances between river systems are so far, at least for now, that they are millions of light-years away, and the light has to travel millions of light-years, plus the movement of the rivers themselves, it is almost impossible to get a satisfactory result if you rely solely on the spectrum to calculate the distance between the river systems and the exact position in real time.

At least for empires that need spatial teleportation, such an outcome is unacceptable, and it is necessary to have a precise location in real time, and to have sufficient knowledge of the river system before it can be expanded.

What is the quality of this river system, how large is the scope, how many star systems are there, what is the structure of the river system itself, what is the level of the native civilization of the entire river system, etc., only on the basis of sufficient understanding, can the empire confidently and boldly invade the entire river system!

The mass of the black hole in the core of the triangular galaxy 2.64 million light-years away from the Milky Way is not large, and the mass of the black hole in the core of the triangular galaxy is only 0.56, while the mass of the black hole in the Andromeda galaxy reaches 2.12!

Because the mass of the core black hole is relatively small, gravity and many other aspects cannot be compared with the Milky Way and the Andromeda Galaxy, but the triangular galaxy is still a huge river system, not a satellite galaxy like the Big Magellanic Galaxy.

According to its structure, the river system can be roughly divided into four categories: vortex galaxies, spiral galaxies, barred spiral galaxies and irregular galaxies.

The Milky Way, the base of the empire, is the Barred Spiral Galaxy, and the middle of the river system resembles a rod, hence the name; The Andromeda Galaxy is a very typical vortex galaxy with a huge disk-like structure; And the triangular galaxy that the empire is about to expedition is a very typical spiral galaxy!