Gravitational waves produce a background hum across the whole universe |
The fabric of the universe is constantly rippling, according to astronomers who have discovered a background buzz of #gravitational #waves. These waves may be produced by #supermassive #black #holes merging across the universe, but they might also have more exotic origins, such as leftover ripples in space-time created shortly after the #big #bang.
Pinning down their true nature could tell us about how supermassive black holes grow and affect their host galaxies, or even about how the universe evolved in its first moments.
To find this mysterious hum, astronomers have been tracking rapidly rotating neutron stars called #pulsars that blast out light with extreme regularity. By looking at different pulsars across the Milky Way, astronomers can effectively use them as a galaxy-sized gravitational-wave #detector called a pulsar #timing #array.
While individual gravitational waves, which are ripples in space-time created by massive objects colliding, have been seen regularly since the first detection in 2015, the object of this search is different. Those previous gravitational waves all have a #localised origin and rise and fall hundreds of times a second, but the newly-discovered signal is more like a gravitational wave #background that would permeate the entire universe at much #lower #frequencies, similar in concept to the cosmic microwave background, which is radiation left over by the big bang and seen all over the universe today.
https://www.newscientist.com/article/2380451-gravitational-waves-produce-a-background-hum-across-the-whole-universe/
