A Lunar Detector Will Hear What Dark Energy Sounds Like express
Until now, dark energy has been studied like a car engine — only by the acceleration the Universe's expansion gains. In the late 1990s, Adam Riess, Saul Perlmutter, and Brian Schmidt noticed that distant supernovae are receding ever faster, and discovered this acceleration. But what lies inside the engine itself remained a mystery.
A new study suggests not looking, but listening. A laser device on the Moon, akin to a giant stethoscope, will pick up spacetime vibrations on the scale of the observable Universe's horizon. This will allow measuring the 'speed of sound' of dark energy — how fast waves travel through it. If it turns out to be less than the speed of light, many theories will have to be reconsidered.
The method not only refines cosmic history but also tests whether fundamental principles like causality are violated. It can peer into an uncharted realm and, perhaps for the first time, show what dark energy is actually made of.
Dark energy makes up 68% of the Universe's total content, and its nature is one of science's greatest mysteries.
Sci-fi writers have long imagined the 'sound of space': in Dune, melange allowed sensing curvatures. The lunar detector might, for the first time, let us hear the real melody of the cosmos.