LIGO: The issue of orientation vs amplitude


This is essentially a continuation from the previous post. Refer to the figure there. I realize that I have not explicitly addressed the issue of LIGO antenna orientation in my compact figure.

In the LIGO first discovery, they explained the observed different amplitudes at the two stations as a matter of different orientation of the two detectors with respect to the incoming wave. First the incoming angle was calculated from a time delay of ~ 7 ms between the two stations. Then the amplitude difference was calculated from the orientations.

In the second discovery the wave came in nearly vertically (a time delay of ~ 1.1 ms) and there is no observed difference in amplitude.

But all this is entirely irrelevant.

Actually these LIGO orientation effect calculations are not scientifically justified. The orientation effect depends entirely on what the angular pattern of the LIGO antenna is for gravitational wave. This is a concept similar to that in electromagnetics or acoustics.

LIGO has a directional pattern that depends on the instrument design. There are many reasons why this pattern is not an ideal cosine-type pattern assumed. Generally speaking, when an antenna is much smaller than the wavelength, its pattern tends towards being isotropic.

LIGO gravitational wave wavelength is ~ thousands of kms, and LIGO size is ~ kms.

So do not for a moment believe that the difference in amplitude between the two stations corresponds to LIGO theory.

The difference cannot be an attenuation either. But there is no problem. This is a bogus picture that should not even be discussed. There is nothing here about gravitational wave.

So all this phenomenal agreement between theory and observation covers a multitude of sins, layers upon layers of it.

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