Was the discovery truly the Holy Grail, of Science?
In 1916, the year after the final formulation of the field equations of general relativity, Albert Einstein predicted the existence of gravitational waves. He found that the linearised weak-field equations had wave solutions — transverse waves of spatial strain that travel at the speed of light, generated by time variations of the mass quadrupole moment of the source. Einstein understood that gravitational-wave amplitudes would be remarkably small; moreover, until the Chapel Hill conference in 1957 there was significant debate about the physical reality of gravitational waves.
While numerous black hole candidates have now been identified through electromagnetic observations, black hole mergers have not previously been observed — the discovery of the binary pulsar system by Hulse and Taylor and subsequent observations of its energy loss by Taylor and Weisberg demonstrated the existence of gravitational waves.
This discovery, along with emerging astrophysical understanding, led to the recognition that direct observations of the amplitude and phase of gravitational waves would enable studies of additional relativistic systems and provide new tests of general relativity, especially in the dynamic strong-field regime.
Experiments to detect gravitational waves began with Weber and his resonant mass detectors in the 1960s, followed by an international network of cryogenic resonant detectors.
Apart from other quandaries affecting LIGO, as noted by Xiaochun Mei and Ping Yu in the Journal of Modern Physics, 2016, 7, 1098-1104; it is improbable and highly unlikely, that the experiments were favourable since it cannot detect gravitational waves due to the existence of electromagnetic interaction. This is also the reason why Weber’s experiments of gravitational waves failed.
In fact, the formulas of general relativity that gravitational waves affect distances are only suitable for particles in vacuum.
The experiments to detect gravitational waves ought be conducted in space to avoid the influence of electromagnetic interaction since LIGO experiments are carried out on Earth — the laser interferometers are fixed on the steel pipes on the earth’s surface in the balanced state of electromagnetic force; electromagnetic force is 1040 times greater than gravity; and gravitational waves are too weak to overcome electromagnetic force and change the length of steel pipes.
Without considering these, the design principle of LIGO experiment has serious problem.
“Edwards, United States” featured image courtesy and copyright Jeremy Thomas