Voyage of the Stars

At that time, many countries had such laser interference space antennas, among which the Chinese had two sets, one was called Tai Chi and the other was called Tian Qin.

The third type is the pulsar timing array.

As the name suggests, it is a method of measuring gravitational waves using a pulsar array.

The so-called pulsar is actually a type of neutron star, that is, a rotating neutron star. The characteristic of a pulsar is that it continuously emits electromagnetic pulse signals from the two poles, forming two radiation cones.

The powerful electromagnetic pulse signal of the radiation cone sweeps across the starry sky like a flashlight. If its two-pole radiation cone does not coincide with the axis of rotation, then it will sway in the starry sky like a regularly shaking flashlight. If the radiation cone happens to sweep across On Earth, people will observe that this neutron star exists in the form of a pulsar.

Another characteristic of pulsars is that their periods are very stable, especially pulsars with rotation periods in the millisecond range.

Therefore, people came up with this gravitational wave detection method based on the characteristics of pulsars.

That is to form an array based on the observed millisecond-level pulsars at different locations, and then use an astronomical telescope to very accurately measure the time when each pulse reaches the earth.

After this, if a gravitational wave signal reaches the earth, it will have different effects on pulsars at different positions and distances in the pulsar array.

Gravitational waves are ripples in space-time. Changes in space-time ripples will affect the arrival time of the pulsar pulse, causing different changes in the pulse period and arrival time.

By analyzing changes in pulse arrival, changes in the position of the pulsar, and other information, people can discover the arrival of gravitational waves.

The range of gravitational waves detected by this method is nanohertz gravitational waves, that is, the range of 10-9 Hertz.

At that time, the Chinese company's pulsar timing array was FAST - Sky Eye.

Well, there is actually another method called polarization measurement of microwave background radiation. The principle is to use the two special polarization modes of gravitational waves themselves. One of these two special polarization modes is called E-brane and the other is It's called B membrane.

However, this method is used to detect primordial gravitational waves. If primordial gravitational waves exist, they will leave imprints in the cosmic microwave background radiation. People can use the imprints they leave to determine whether it is an E-mode or a B-brane. Know whether primordial gravitational waves exist.

Of course, now that the new humanity has become a starship civilization and is still sailing at a constant speed of 30% of the speed of light, it is naturally impossible to use the pulsar timing array to detect gravitational waves.

The Laser Interferometer Gravitational Wave Observatory cannot be used, after all, it is placed on the ground.

So only the laser interference space antenna is left.

According to this principle, when the new human warships are sailing, they will deliberately arrange warships equipped with detectors in groups of three to keep them moving in the same direction and at synchronized speeds, so that their spatial positions are fixed.

In this way, every three warships equipped with such detectors during the constant-speed sailing stage can form a set of laser interference space antennas.

The gravitational waves now detected by new humans were obtained through this array.

Precisely because the fleet had just entered the uniform speed stage, scientists at first thought that the warship carrying the detector had not yet adjusted its synchronization.

But after discovering that almost all arrays detected the same gravitational wave signal, they realized that it was indeed a gravitational wave signal.

The space-time deformation caused by gravitational waves is actually very weak, that is, stretching or squeezing. Generally, its deformation amplitude is only 10-21 levels.

And its signal sources can also be divided into many types.

The first thing people think of is the merger of stellar-level dense objects, such as the merger of two neutron stars and the merger of two black holes. The gravitational waves generated by this type of gravitational wave source have a high frequency, generally in the range of a few hertz or tens of tens of seconds. Hertz or even hundreds of Hertz.

The second is the merger of two white dwarfs. The mass of the white dwarf is not as large as that of the neutron star and the black hole, and its merger rate is not that fast, so this gravitational wave source also has a relatively low frequency.

The source of gravitational waves with smaller frequencies is the merger of supermassive black holes in the centers of distant galaxies. For example, the Milky Way and the Andromeda Galaxy will collide in about 3.7 billion years. If there is a civilization outside the local galaxy group, they will detect this type of gravitational wave source in a few years.

The gravitational waves in the lower frequency band are primordial gravitational waves.

With this accumulation of knowledge, new human scientists can determine the type of source by analyzing the frequency of gravitational waves.

New Humanity scientists quickly obtained gravitational wave source data from the laser interference space antenna array, and then drew corresponding conclusions based on these data.

"General, if the data is correct, then this gravitational wave source must be produced by the merger of massive stars. As for its orientation."

The speaker was Gan De. The moment he confirmed that he had received the gravitational wave signal, he notified Yue Yuan. He was also talking to Yue Yuan at this moment.

Speaking of directions, Gander stopped talking and pointed to the star map on the big screen.

"This is Sirius?!" Yue Yuan quickly recognized the marked location from the star map,

Because Sirius is very close to the sun, only 8.6 light years away, and the sun can be seen on a large-scale star map. On the human star map, the sun, which had been destroyed to the point of being completely destroyed, was naturally specially marked.

But when Yue Yuan looked at the star map, a question arose in his mind, that is, there is no natural merger event of massive stars in Sirius.

In other words, something big must have happened there.

When Yue Yuan was about to ask a question, a member of the astronomy team hurriedly floated towards Gan De and shouted at the same time: "Professor Gan, the data has changed. You see there are more than one sources of gravitational waves, and their frequency is extremely short." The internal frequency increases dramatically!"

Gander quickly took over the latest detection results, and after just a few glances, a solemn look appeared on his face.

He looked at Yue Yuan and said: "Chief Commander, it seems that the gravitational waves detected before were not caused by the merger of massive stars, but were caused by some kind of man, or aliens. If so, then I dare to conclude that that There will be new changes in the gravitational wave signal coming from the direction!”

Sure enough, as soon as he finished speaking, another news came from the observation center, saying that the frequency of gravitational waves had changed again. In just one minute, the frequency of the gravitational wave signal source soared to extremely high levels and then again. Falling sharply.

It is completely outside the scope of normal natural phenomena.

"It seems that some advanced civilizations are fighting somewhere. I don't know what kind of weapons can cause such a large disturbance in space and time." Seeing the detection results, Yue Yuan also made a judgment in his heart, but for a while, he didn't know what to do. What to do.

Human beings haven't run very far before something like this happens. It's really terrible.