引力波文章（英文版）------征求意见稿

Research Report on [LIGO scientists directly detect gravitational waves] event 
--- "gravitational waves" or "earthquake precursor wave" ---

Author: Dajiong Lu

Foreword

    Since the laser interferometer not only be able to record seismic waves, but also can record to a variety of earthquake precursors (Reference book "Impending Earthquake Prediction" by Dajiong Lu). The paper about detecting gravitational wave published as the name of "LIGO Scientific Collaboration and Virgo Collaboration"  only mentioned that they have been considered the exclusion of seismic waves, but at least did not see whether considering the exclusion of earthquake precursors or the other sources  from Earth's interior which is not entirely impossible ......

    Accordingly, we assume: whether the detected "gravitational waves" may be one kind of  "earthquake precursor waves"? Following this idea, we have made ​​some research!

A.   Is the “Gravitational wave” detected by America’s LIGO  the “earthquake precursor wave ” only ?

 If  the “gravitational wave” detected by America’s LIGO on Sept. 14, 2015 at 09:50:45 UTC was one kind of “earthquake precursor ”, it should occur before a large earthquake, again if  the “gravitational wave” was one kind of “impending earthquake precursor”, in that way  it should occur at a few days, for example 2 or 3 days,  before a large earthquake.

At first, let’s inquire large earthquakes over M7 in the world which occurred within half a year before Oct. 26 , 2015 :

1.    A magnitude 7.8 earthquake struck Nepal 34 km (21 mi) east southeast of Lamjung on April 25 at a depth of 8.2 km (5.1 mi).

2.     A magnitude 7.5 earthquake struck Papua New Guinea 130 km (81 mi) south southwest of Kokopo on May 5 at a depth of 55.0 km (34.2 mi).

3.    A magnitude 7.3 earthquake struck Nepal 19 km (12 mi) southeast of Kodari on May 12 at a depth of 15.0 km (9.3 mi).

4.    A magnitude 7.8 earthquake struck offshore of Japan 189 km (117 mi) west northwest of Chichi-jima in the Ogasawara Islands on May 30 at a depth of 664.0 km (412.6 mi).

5.    A magnitude 8.3 earthquake struck Chile 48 km (30 mi) west of Illapel on September 16 at a depth of 22.4 km (13.9 mi).

6.     A magnitude 7.1 earthquake struck Vanuatu 34 km (21 mi) northeast of Port Olry on October 20 at a depth of 135.0 km (83.9 mi).

7.    A magnitude 7.5 earthquake struck Afghanistan 45 km (28 mi) east of Farkhar, Farkhar district, Takhar province on October 26 at a depth of 231.0 km (143.5 mi).

Why so fortunately?  This is occasional coincidence or correct thinking? A large earthquake of M8.3 occurred in Chile which is 7000~8000 km far away from LIGO gravitational wave detectors and just within 2~3 days after so-called gravitational wave arrived. The “gravitational wave” event just fell into impending quake period of the large earthquake in Chile,  other large earthquakes in the world within same half a year were far away from LIGO gravitational wave detectors and were not within 2~3 days after that event.  It means that unique Chile earthquake which was closest from LIGO gravitational wave detectors and the “gravitational wave” was detected within 2~3 days before Chile earthquake. So that it may be a good idea that  the “gravitational wave” detected by America’s LIGO is one kind of earthquake precursor wave only!

According to our past experiments of earthquake prediction, it is not strange that the detectors which is far away from the epicenter of M8 earthquake can receive the earthquake precursor  wave   (electromagnetic wave) from  the emitter related with the M8 earthquake. On the other hand, it is very strange that the instruments with high sensitivity cannot receive   any impending earthquake precursor wave from M8 earthquake!

In conclusion, it is another possible  option that the earthquake precursor  wave  just are  the signals detected by America’s LIGO gravitational wave detectors.

B. About the signal spectrum:

    If someone detected a certain wave motion, then he (or she) would have described the detected signal spectrum  and the response curve of the detection equipment for the fluctuation frequency, thereby to determine whether the detected waveform has not been distorted ......         

    According to the introducing of the article "human directly detected the gravitational waves at first time” " (Tencent space Qiao Hui at 23:43 on February 11, 2016) , an initial frequency of the detected gravitational waves signal is 35 Hz, then quickly raised to 250 Hz, and finally becomes disorderly and disappear ...... (the whole process lasted only a quarter of a second. The signal catched by  detector in Livingston is 7 milliseconds earlier than the signal catched by detector in Hanford , the time difference indicates that gravitational waves was coming from the southern sky.)  

      If we say that the detected signal is one kind of earthquake precursors wave , then let's take a look at the general earthquake precursor wave which  Meets spectrum of the signal detected by LIGO detector or not
    For the earthquakes over M6.5 to M7, if using the frequency counter to measure the frequency of earthquakes, their spectrum should be between 40Hz to 1575Hz. We can treat the earthquake precursor as the analog of initial motion of large earthquake (no shock after being triggered), its low-end frequency of the initial motion should be the same as the low-end frequencies of earthquake, but it should be less than the high-end frequency 1575Hz of earthquake, to be estimated as several hundred Hz . Thus the bands of earthquake precursor  are  in accordance with the bands of so-called "gravitational waves signal”.

 Secondly, assuming that the electromagnetic radiation precursor is caused by certain kind of piezoelectric effect, then the bands of electromagnetic radiation precursors  should be consistent with bands of stress precursor.Therefore  it  cannot be excluded that the signal detected by LIGO detector is one kind of earthquake precursors waves as one kind of possibility.

C.  About the duration of the signal:

   why is the duration of the precursor only 0.4 seconds?  Namely why only 0.4 seconds if their signals are one kind of earthquake precursor ?

   In the past years, major study of the author was  impending earthquake precursor, namely, the precursors occurred in few days before large earthquake.

   Before the earthquake, crustal stress is being modulated by solid tide, so the precursor would occur only while crustal stress reaches or exceeds the precursor threshold. In other word, impending earthquake precursor as sudden change form occur in the peaks or valleys of solid tide, generally speaking, they are short-lived. ( The earthquake would occur while crustal stress reaches or exceeds the threshold of earthquake.) Due to their gravitational wave detectors is shielded certainly very good, so only the strongest electromagnetic radiation emitted  in the short duration (for example 0.4 second ) in which there are largest peak or valley value of tidal  is able to penetrate the shield and to be detected. The electromagnetic radiation outside the duration ( 0.4 second ) is shielded by their  instrument.

D. About arriving time of the signal:             
          
    Typically impending earthquake precursor occur in 2 to 3 days before the earthquake. Most will be the case! we have said  In the previous section that the so-called "gravitational waves" detected by  LIGO did occur in 2-3 days  before    M 8.3 earthquake in Chile!   

E. About the angle of incidence and the signal strength:

   The problem of the incident angle of "gravitational waves"  seems not to be mentioned detail in the paper from LIGO . How about the angle between the incident angle of "gravitational waves" and the plane of detection equipment? It is directly related to the signal strength. Because two arms, which is perpendicular to each other, of their each interferometer are in free status, so two signals may be offset at a certain angle of incident. Also, because the interferometer arms of two interferometers are not in same direction (refer to paper screenshot), so the signal strength detected by two interferometers may be differences: or large or small......

Let's look a passage in LIGO English paper: “Only the LIGO detectors were observing at the time of GW150914. The Virgo detector was being upgraded, and GEO 600, though not sufficiently sensitive to detect this event, was operating but not in observational mode”.   “With only two detectors the source position is primarily determined by the relative arrival time and ……” 
    That is, they are anti-deducted, not measured out. 

 Also an introductory article said: “The positioning accuracy of gravitational wave sources can be improved only after Australian interferometer is networked. In other words, the sources position has difficulties before Australian interferometer is networked. It shows Indirectly that our suspect is a grain of truth!

F.  Discussion on the time difference of signals detected by two 

     detectors:

1. The time difference of signals detected by two LIGO detectors is about 7 milliseconds. Some people think that this can only be a error value of signal which is made by human. We think: If the signal is emitted from the epicenter of the Chile earthquake, then this 7 ms may be human error and in fact the time difference should be 10 milliseconds!
  2. The second possibility is: It is not necessary that the epicenter is a cradleland of specific precursor ( of course the precursor also can be emitted from epicenter), the area of rupture plate of M8 earthquake may have an extension up to thousands of kilometers, it is entirely possible that a stress point of precursor is far away from L1, H1 and locate in another direction! It is expected that  this stress point is likely located in a fault of the eastern Pacific. It is required to find this stress point which meets the condition with 7 ms time difference between two detectors.  To test and verify this argument, three detectors are necessary at least! This echoes with the content discussed in Section E!

G. Using GRB ( gamma-ray bursts) could not explain the signal 

detected by LIGO to be gravitational wave     

(Wish discuss with Professor Cai Yifu, University of Science and 

Technology of China )

At first Mr Choi affirmed the question for gravitational wave detection, but he defended for the result of LIGO detection: While Merging of black holes, was emitted not only gravitational wave but also electromagnetic signal, that is, gamma-ray bursts, the relevant signals are captured and examined each other by other telescopes independently . This shows that the probability of non- gravitational wave is very low.