How to Affect The Laser Pointer Shuttle Back And Forth in The Detection Arm

The extremely high sensitivity also implies that it can efficiently generate gravitational waves. To prove this conclusion, Pang and her colleagues specifically built a quantum mechanical model to explain how the bending of space affects the laser pointer that shuttles back and forth in the probe arm.

In order to make the measurement as accurate as possible, the physicists of LIGO must ensure that the peaks and troughs of the light wave—that is, the phase—are kept absolutely stable. Subject to the uncertainty principle of quantum mechanics, the amplitude of the light wave in this case must not be stable. This inevitable amplitude disturbance will generate a random impulse on the mirror, causing the mirror to move slightly and cause ripples in space and time, Pang said. Of course, compared with the gravitational wave generated by you throwing a bowling ball, the gravitational wave generated by LIGO can be really nothing, but the efficiency is the best.

“This conclusion is not unexpected,” said Fan Zhang, a physicist at Beijing Normal University. “The essence of this detector is its coupling with gravitational waves. Once the coupling occurs, the detection of gravitational waves and the emission of gravitational waves are the same. Something happened.”

Waterproof Laser Pointer 5 Meters Underwater

Although too weak to be directly observed, the gravitational waves generated by LIGO can still be used to detect quantum effects between macroscopic objects, Pang said. Microscopic particles (such as electrons) under quantum mechanics can appear in two places at the same time, and many physicists boldly speculate that maybe we can make macro objects (such as a mirror in LIGO) in a similar quantum state.

This microsecond state will not last long, and the system will be “decoherent” due to the influence of the outside world, and will collapse to a certain state. “However, we can obtain the speed of decoherence and compare it with the effect of gravitational waves,” Pang said. Some physicists believe that gravity plays a special role in the collapse of quantum states of macroscopic objects.

“This is an interesting green laser pointer idea, but it is very challenging to implement,” said Yiqui Ma, a collaborator of Pang and a physicist at the California Institute of Technology. “In order to see the quantum effects of gravitational waves, Researchers must eliminate all other sources of decoherence.” Pang agreed with this. “It’s really unbelievable.” She said, “but only LIGO has the conditions to achieve it.”