Science Line doesn’t care if you’re not supposed to be able to hear spaceship engines go “whooosh” – they say we’re actually being quietly bombarded with sounds from space:
“If there was a way to take the signal and hook it into speakers, we’d be able to hear it,” says Scott Hughes, a physicist at the Massachusetts Institute of Technology.
The trick is that the signal itself is really, really hard to detect — its effect, says Hughes, is a vibration smaller than the nucleus of a hydrogen atom. This is because the noise from distant galaxies isn’t coming to us through traditional sound waves, but through a different class of energy called gravitational waves.
Gravitational waves get made by big things in the universe, like supernovae and pairs of orbiting, colliding black holes. These events send out ripples of energy in all directions, like a pebble dropped into a lake. Instead of making waves in water, however, the energy emanating from these super-dense objects produces tiny undulations in space-time itself, vibrations in the fabric of the cosmos.
The frequencies are in the range of human hearing – just very, very quiet. We should be able to hear more in 2018, when a project named LISA takes off to listen to deep space.
[via Levitin]