A New Tool for Finding Dark Matter Digs Up Nothing

Each mile of Earth's surface is compressed by one-thousandth the diameter of an atom by the strongest waves created by black holes. It is hard to imagine how small the ripples are in spacetime. Physicists spent decades building and fine- tuning an instrument called the Laser Interferometer Gravitational-Wave Observatory (LIGO), which they got in 2016

The landscape of invisible black holes is being unfurled. That is only part of the story.

Some wave detectors are getting some work.

Rana Adhikari is a physicist at the California.

Researchers are looking for ways to use the detectors to search for dark matter, the nonluminous stuff that holds galaxies together.

In December, a team led by Hartmut Grote of Cardiff University reported in Nature that they had used a gravitational wave detector to look for dark matter, a lesser-known candidate for the missing mass in and around galaxies. A large class of dark matter models were ruled out by the team. If it affects normal matter weakly, it can only exist.

The result is a very nice one, according to a University of Michigan astronomer who wasn't involved in the research.

The leading candidate for dark matter used to be a weakly interacting particle similar to other elementary particles. Experiments for the so-called WIMPs keep coming up empty-handed, making room for other alternatives.

We have reached the stage in dark matter searches where we are looking everywhere, according to a theoretical physicist at Caltech.

Three physicists proposed in 1999 that dark matter might be made of particles that are so light and numerous that they are best thought of as a field of energy. The scalar field has a value at each point in space, and the value varies with a characteristic Frequency.

The properties of other particles and fundamental forces would be subtly altered by scur-field dark matter. The electron's mass and strength would change with the field.

Physicists have wondered if the detectors could spot a wobble. Interferometry is the approach used by these detectors. The beams reflect off mirrors at the ends of both arms after the laser light enters a beam splitter. If the returning laser beams have been pushed out of sync by a passing wave, a pattern of dark and light fringes forms.

The common thought was that if the beams were pushed out of sync, they would cancel out. The idea of the beam splitter came to him one morning.