War Suspicions

In those days, many countries possessed such Laser Interferometer Space Antenna, including China, which had two sets: one called Taiji and the other called Lyra.

The third type is the Pulsar timing array.

As the name suggests, it is a method of measuring Gravitational Wave using Pulsar arrays.

Pulsar is actually a type of Neutron Star, specifically a rotating Neutron Star. A key characteristic of Pulsar is that they continuously emit electromagnetic pulses, which emanate from their poles, forming two radiation cones.

The powerful electromagnetic pulse signal of the radiation cone sweeps across the sky like a flashlight. If the two poles of the radiation cone do not coincide with the Rotating Shaft, it will swing across the sky like a regularly shaking flashlight. If the radiation cone happens to sweep across the Earth, people will observe that this Neutron Star exists in the form of Pulsar.

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

Therefore, based on the characteristics of Pulsar, people came up with this method of Gravitational Wave detection.

That is, based on the observation of millisecond-level Pulsar at different locations, they are arranged into an array, and then the arrival time of each pulse is measured very precisely using Astronomical Telescope.

If a Gravitational Wave signal then reaches Earth, it will have different effects on Pulsar at different locations and distances in the Pulsar array.

Gravitational Wave are ripples in spacetime. Changes in these ripples can affect the arrival time of Pulsar pulses, causing variations in the pulse period and arrival time.

By analyzing information such as the changes in the arrival of the pulse and the location of the changing Pulsar, people can detect the arrival of Gravitational Wave.

The range of Gravitational Wave detected using this method is the nanohertz Gravitational Wave, which is the range of 10 to the power of -9 hertz.

In that era, China's Pulsar timing array was FAST— the Sky Eye.

Well, there is another method called polarization measurement of Cosmic Microwave Background Radiation. Its principle is based on the two special polarization modes of Gravitational Wave. One of these special polarization modes is called the E-mode, and the other is called the B-mode.

However, this method is used to detect Primordial Gravitational Wave. If Primordial Gravitational Wave exist, they will leave a mark in the cosmic Cosmic Microwave Background Radiation. By observing the mark left behind, people can determine whether it is the E mode or the B-mode, and thus know whether Primordial Gravitational Wave exist.

Of course, now that the New Humans have become a starship civilization and are traveling at a constant speed of 30% of the speed of light, they naturally cannot use Pulsar timing arrays to detect Gravitational Wave.

The Laser Interferometer Gravitational-Wave Observatory is also unusable, since it's placed on the ground.

So all that's left is the Laser Interferometer Space Antenna.

Following this principle, when the New Humans warships are sailing, they will deliberately arrange the warships carrying probes in groups of three to keep them moving in the same direction and at the same speed, so that their spatial positions are fixed.

In this way, every three warships carrying such detectors during the constant speed navigation phase can form a Laser Interferometer Space Antenna.

The Gravitational Wave detected by the New Humans today were obtained through this array.

Because the fleet had only recently entered a period of steady speed, scientists initially thought that the warships carrying the probes had not yet adjusted their synchronization.

But after discovering that almost all the arrays detected the same Gravitational Wave signal, they realized that it was indeed Gravitational Wave signal.

The spacetime deformation caused by Gravitational Wave is actually very weak, that is, stretching or compression, and its deformation amplitude is generally only on the order of 10 to 21.

Its signal source can also be divided into many types.

The first thing that comes to mind is the merger of Star-Class- mass compact objects, such as the merger of two Neutron Star or two black holes. This type of Gravitational Wave produces Gravitational Wave with a relatively high frequency, generally in the range of a few hertz, tens of hertz, or even hundreds of hertz.

Secondly, there is the merger of two White Dwarf Star. White Dwarf Star are not as massive as Neutron Star and black holes, so their merger rate is not as fast, resulting in relatively low frequencies for Gravitational Wave.

Even lower frequency Gravitational Wave are the mergers of Supermassive Black Hole at the centers of distant galaxies. For example, if the Milky Way Galaxy and the Andromeda Galaxy collide in about 3.7 billion years, then a civilization located outside the Local Group would detect this type of Gravitational Wave some time from now.

Gravitational Wave at even lower frequencies are Primordial Gravitational Wave.

With this accumulated knowledge, scientists of the New Humans can determine the type of origin of Gravitational Wave by analyzing their frequencies.

Scientists from the New Humans quickly obtained Gravitational Wave data from the Laser Interferometer Space Antenna array, and then drew corresponding conclusions based on this data.

"Chief, if the data is correct, then this Gravitational Wave must have been produced by the merger of massive stars. As for its location..."

It was Gan De was speaking. The moment he confirmed that he had received the Gravitational Wave signal, he notified Yue Yuan, and he was talking to Yue Yuan at this moment.

When the topic of location came up, Gan De paused and pointed to the star map on the large screen.

"This is... Sirius?!" Yue Yuan quickly recognized the marked location on the star map. Sirius is very close to the sun, only 8.6 light-years away, and the sun is visible on a large-scale star map. On human star maps, the sun, which has been destroyed beyond recognition, is naturally marked out.

But as Yue Yuan looked at the star map, a question popped into his mind: there was absolutely no way that a natural, massive stellar merger could occur on Sirius.

In other words, something big must have happened there.

Just as Yue Yuan was about to ask a question, a member of the astronomy team hurriedly floated towards Gan De and shouted, "Professor Gan, the data has changed! You see, there is more than one source of Gravitational Wave, and moreover, its frequency has increased dramatically in a very short time!"

Gan De quickly took the latest detection results, and after only glancing at them a few times, a solemn expression appeared on his face.

He looked at Yue Yuan and said, "Chief, it seems that the Gravitational Wave detected earlier were not produced by the merger of massive stars, but by some kind of human... extraterrestrial activity. If so, then I dare say that the Gravitational Wave signal coming from that direction will undergo new changes!"

Sure enough, no sooner had he finished speaking than another message came from the observation center, saying that the frequency of the Gravitational Wave had changed again. In just one minute, the frequency of the Gravitational Wave signal source spiked to extremely high levels and then plummeted.

This is completely outside the scope of normal natural phenomena.

"It seems that some advanced civilizations are fighting somewhere. I wonder what kind of weapon could cause such a large spacetime disturbance." After seeing the detection results, Yue Yuan had a judgment in his mind, but for a moment, he didn't know what to do.

Humans haven't gone very far, and this has already happened; it's absolutely terrible.